阅读说明：本技术 半导体加工用带 (Semiconductor processing belt ) 是由 桥本浩介 仙台晃 佐野透 于 2018-07-18 设计创作，主要内容包括：本发明提供能够在短时间充分加热收缩且能够保持切口(kerf)宽度的半导体加工用带。本发明的半导体加工用带(10)的特征为具有粘合带(15),该粘合带(15)具有基材膜(11)及形成于所述基材膜(11)的至少一面侧的粘合剂层(12),所述粘合带(15)以于任意第一方向的利用热机械特性试验机于升温时测定的40℃～80℃之间的每1℃的热变形率的总和算出的积分值与以于与所述第一方向成直角的第二方向的利用热机械特性试验机于升温时测定的40℃～80℃之间的每1℃的热变形率的总和算出的积分值之和为负值。(The invention provides a semiconductor processing belt which can be heated and contracted fully in a short time and can keep the width of a notch (kerf). The tape (10) for semiconductor processing is characterized by comprising an adhesive tape (15), wherein the adhesive tape (15) comprises a base material film (11) and an adhesive layer (12) formed on at least one surface side of the base material film (11), and the adhesive tape (15) has a negative value of the sum of an integrated value calculated from the sum of thermal deformation rates per 1 ℃ at a temperature of 40 to 80 ℃ measured by a thermomechanical property tester at a temperature rise in any first direction and an integrated value calculated from the sum of thermal deformation rates per 1 ℃ at a temperature of 40 to 80 ℃ measured by the thermomechanical property tester at a temperature rise in a second direction perpendicular to the first direction.)

1. A tape for semiconductor processing, comprising an adhesive tape having a base film and an adhesive layer formed on at least one surface side of the base film,

The adhesive tape has a negative value for the sum of an integrated value calculated as the sum of thermal deformation rates per 1 ℃ at 40 to 80 ℃ measured by a thermomechanical property tester at a temperature rise in the MD direction and an integrated value calculated as the sum of thermal deformation rates per 1 ℃ at 40 to 80 ℃ measured by a thermomechanical property tester at a temperature rise in the TD direction.

2. the tape for semiconductor processing according to claim 1, wherein an adhesive layer is laminated on the adhesive layer side.

3. The semiconductor processing tape according to claim 1 or 2, wherein the blade dicing for full-cut and half-cut, the laser dicing, or the stealth dicing by laser.

Technical Field

The present invention relates to a stretchable semiconductor processing tape which can be used for fixing a wafer in a dicing step for cutting the wafer into chip-like members, can be used in a die bonding step or a mounting step for bonding chips to each other or bonding chips to a substrate after dicing, and can be used in a step for cutting an adhesive layer along the chips by stretching.

Background

Conventionally, in a process of manufacturing a semiconductor device such as an Integrated Circuit (IC), the following steps are performed: a back grinding step of grinding the back surface of the wafer to make the wafer thin after the circuit pattern is formed, a dicing step of attaching a semiconductor processing tape having adhesiveness and stretchability to the back surface of the wafer, and then cutting the wafer by a chip unit, an expanding step of expanding (expanding) the semiconductor processing tape, a picking up step of picking up the cut chips, and a die bonding (mounting) step of bonding the picked chips to a lead frame, a package substrate, or the like (or stacking and bonding the chips in a stack package).

In the back grinding step, a surface protective tape is used to protect the circuit pattern formation surface (wafer surface) of the wafer from contamination. After the back surface of the wafer is ground, in order to peel the surface protective tape from the front surface of the wafer, a semiconductor processing tape (dicing die bonding tape) described below is bonded to the back surface of the wafer, the semiconductor processing tape side is fixed to a suction table, and the surface protective tape is subjected to a treatment for reducing the adhesion to the wafer, and then the surface protective tape is peeled. The wafer from which the surface protective tape was peeled off was then picked up from the suction table with the wafer bonded to the back surface, and subjected to a subsequent dicing step. The treatment for reducing the adhesive strength is an energy ray irradiation treatment when the surface-protective tape is formed of an energy ray-curable component such as ultraviolet rays, and a heating treatment when the surface-protective tape is formed of a thermosetting component.

In the dicing step to the mounting step after the back grinding step, a semiconductor processing tape in which a pressure-sensitive adhesive layer and an adhesive layer are sequentially laminated on a base film is used. In general, when such a semiconductor processing tape is used, first, an adhesive layer of the semiconductor processing tape is bonded to the back surface of a wafer, the wafer is fixed, and the wafer and the adhesive layer are diced in a chip unit by using a dicing blade. Subsequently, an expanding process of expanding the interval between the chips is performed by expanding the tape in the radial direction of the wafer. The expanding process is performed to improve the recognition of the chip by a CCD camera or the like in the subsequent picking-up process and to prevent the chip from being broken due to the contact between the adjacent chips when the chips are picked up. Subsequently, the chip is peeled from the adhesive layer and picked up in a pickup step together with the adhesive layer, and is directly bonded to a lead frame, a package substrate, or the like in a mounting step. In this manner, the die with the adhesive layer can be directly bonded to the lead frame, the package substrate, or the like by using the semiconductor processing tape, and therefore, the step of applying the adhesive and the step of bonding the die bonding film to each die can be omitted.

However, in the dicing step, since the wafer is diced together with the adhesive layer using the dicing blade as described above, not only chips of the wafer but also chips of the adhesive layer are generated. Therefore, when the chips of the adhesive layer are clogged in the dicing grooves of the wafer, the chips are stuck together, which causes pickup failure and the like, and thus lowers the manufacturing yield of the semiconductor device.

in order to solve such a problem, a method has been proposed in which only the wafer is diced by a blade in the dicing step, and the adhesive layer is cut into individual chips by spreading a tape for semiconductor processing in the spreading step (for example, patent document 1). Thus, according to the method of cutting the adhesive layer by the tension during spreading, no cutting debris of the adhesive is generated, and no adverse effect is exerted on the pickup process.

in recent years, as a method for cutting a wafer, a so-called stealth dicing (stealth dicing) method has been proposed, which can cut a wafer without contact by using a laser processing apparatus. For example, patent document 2 discloses a method for cutting a semiconductor substrate, which includes a step of aligning focused light inside a semiconductor substrate to which a sheet is attached with a modified region formed by multiphoton absorption inside the semiconductor substrate by irradiating the semiconductor substrate with laser light through an adhesive layer (die bonding resin layer) interposed therebetween to form the modified region as a portion to be cut, and a step of cutting the semiconductor substrate and the adhesive layer along the portion to be cut by expanding the sheet.

As another wafer dividing method using a laser processing apparatus, for example, patent document 3 discloses a wafer dividing method including the steps of: the method for manufacturing the semiconductor device includes a step of mounting an adhesive layer (adhesive film) for die bonding on the back surface of a wafer, a step of bonding an extensible protective adhesive tape to the adhesive layer side of the wafer to which the adhesive layer is bonded, a step of irradiating the wafer surface to which the protective adhesive tape is bonded with a laser beam along streets to divide the wafer into individual chips, a step of expanding the protective adhesive tape to apply a tensile force to the adhesive layer and break the adhesive layer for each chip, and a step of separating the broken chip to which the adhesive layer is bonded from the protective adhesive tape.

According to the wafer dicing methods described in patent documents 2 and 3, since the wafer is diced without contact by irradiation of the laser light and spreading of the tape, the physical load on the wafer is small, and the wafer dicing can be performed without generating the wafer cutting chips (chips) at the time of performing the blade dicing which is currently the mainstream. Further, since the adhesive layer is cut by spreading, no cutting chips of the adhesive layer occur. Therefore, attention is being paid to the cutting technique as an alternative to the blade cutting.

However, as described in patent documents 1 to 3, the methods of expanding and spreading and cutting the adhesive layer have the following problems when using the conventional semiconductor processing tape: as the expansion amount increases, the portion of the expansion ring that is pushed up expands, and after the expansion is released, the portion relaxes, and the space between chips (hereinafter referred to as "notch width") cannot be maintained.

Therefore, a method has been proposed in which an adhesive layer is cut by expansion, and after the expansion is released, the slack portion of the semiconductor processing tape is contracted by heating to maintain the width of the cut (for example, patent documents 4 and 5).

disclosure of Invention

Problems to be solved by the invention

As a method of shrinking the slack of the semiconductor processing tape caused by the expansion by heating, a method of shrinking an annular portion that is pushed up by the expansion ring and is relaxed by surrounding a pair of warm air nozzles with the annular portion, and causing warm air to collide with the annular portion, is generally used.

The semiconductor processing tape described in patent document 4 has a thermal shrinkage rate of 0% to 20% in both the longitudinal direction and the width direction of the tape when heated at 100 ℃ for 10 seconds. However, when the semiconductor processing tape is heated by surrounding the warm air nozzle, the temperature in the vicinity of the surface of the semiconductor processing tape gradually rises, and therefore, it takes time to remove all the slack in the annular portion. Further, the holding property of the slit width is insufficient, and the adhesive layers come into contact with each other and adhere again, which causes a problem that the yield in the semiconductor component manufacturing process is deteriorated.

The semiconductor processing tape described in patent document 5 has a shrinkage rate of 0.1% or more at 130 to 160 ℃ (see claim 1 in the specification of patent document 5), and the temperature at which shrinkage occurs is high. Therefore, when the thermal contraction is performed by warm air, a high temperature and a long heating time are required, and the influence of the warm air may be exerted on the adhesive layer in the vicinity of the outer periphery of the wafer, and the divided adhesive layer may be melted and re-melted.

accordingly, an object of the present invention is to provide a semiconductor processing tape which can be sufficiently shrunk by heating in a short time and can sufficiently maintain a notch width to such an extent that adhesive layers can be prevented from coming into contact with each other and being reattached.

Means for solving the problems

In order to solve the above problems, the tape for semiconductor processing according to the present invention includes an adhesive tape having a substrate film and an adhesive layer formed on at least one surface side of the substrate film, wherein a sum of an integrated value calculated from a sum of thermal deformation rates per 1 ℃ at 40 to 80 ℃ measured by a thermomechanical property tester at a time of temperature rise in an MD direction and an integrated value calculated from a sum of thermal deformation rates per 1 ℃ at 40 to 80 ℃ measured by a thermomechanical property tester at a time of temperature rise in a TD direction is a negative value.

in the semiconductor processing tape, it is preferable that an adhesive layer and a release film are laminated in this order on the adhesive layer side.

The above-described semiconductor processing tape is preferably used for full-cut and half-cut blade dicing, full-cut laser dicing, or stealth dicing (stealth dicing) using a laser.

effects of the invention

According to the semiconductor processing tape of the present invention, it is possible to sufficiently shrink by heating in a short time and sufficiently maintain the slit width to such an extent that the adhesive layers can be prevented from coming into contact with each other and re-adhering.

Drawings

Fig. 1 is a cross-sectional view schematically showing the structure of a semiconductor processing tape according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view showing a state of the wafer bonding surface protection tape.

Fig. 3 is a sectional view for explaining a process of bonding a wafer and a ring frame to a semiconductor processing tape according to an embodiment of the present invention.

FIG. 4 is a sectional view showing a step of separating the surface protective tape from the wafer surface.

Fig. 5 is a cross-sectional view showing how a modified region is formed in a wafer by laser processing.

Fig. 6(a) is a cross-sectional view showing a state in which the semiconductor processing tape according to the embodiment of the present invention is mounted on the expanding device. (b) A cross-sectional view showing a process of cutting a wafer into chips by expanding a semiconductor processing tape is shown. (c) A cross-sectional view of the stretched semiconductor processing tape, adhesive layer and chip is shown.

Fig. 7 is a sectional view for explaining a heat shrinking process.

Fig. 8 is an explanatory view showing a notch width measurement point in the evaluation of the examples and comparative examples.

fig. 9 shows an example of the measurement result of the thermal deformation rate.

Detailed Description

The following describes embodiments of the present invention in detail.

fig. 1 is a cross-sectional view showing a semiconductor processing tape 10 according to an embodiment of the present invention. The semiconductor processing tape 10 of the present invention cuts the adhesive layer 13 along the chip when the wafer is cut into chips by expansion. The semiconductor processing tape 10 includes a pressure-sensitive adhesive tape 15 including a base film 11 and a pressure-sensitive adhesive layer 12 provided on the base film 11, and an adhesive layer 13 provided on the pressure-sensitive adhesive layer 12, and the back surface of the wafer is bonded to the adhesive layer 13. Further, each layer may be cut into a predetermined shape (precut) in advance in accordance with the use process or the apparatus. The semiconductor processing tape 10 of the present invention may be cut into pieces for every 1 wafer, or may be wound into a roll from a long sheet on which a plurality of tapes cut into pieces for every 1 wafer are formed. The structure of each layer will be described below.

< substrate film >

The base film 11 is preferable in that it has uniform and isotropic stretchability and the wafer can be cut in all directions without being biased in the stretching step, and the material thereof is not particularly limited. In general, a crosslinked resin has a larger restoring force to stretching than a non-crosslinked resin, and a larger shrinkage stress when heat is applied in a stretched state after an expansion step. Therefore, it is excellent in that slack generated in the tape is removed by thermal shrinkage after the expanding step, and the tape is stretched to stably maintain the pitch (the slit width) of each chip. Among the crosslinked resins, a thermoplastic crosslinked resin is more preferably used. On the other hand, the non-crosslinked resin has a smaller restoring force to stretching than the crosslinked resin. Therefore, the tape is not likely to shrink when the tape is returned to normal temperature after being once loosened after the expanding step at a low temperature range of-15 ℃ to 0 ℃ and then is subjected to the picking-up step and the mounting step, and therefore, the tape is excellent in that the adhesive layers adhering to the chips can be prevented from coming into contact with each other. Among the non-crosslinked resins, an olefin-based non-crosslinked resin is more preferably used.

Examples of such a thermoplastic crosslinked resin include ionomer resins obtained by crosslinking an ethylene- (meth) acrylic acid binary copolymer or a terpolymer containing an ethylene- (meth) acrylic acid alkyl (meth) acrylate as a main polymer constituent component with a metal ion. These are suitable for the expansion step in terms of uniform expandability, and are particularly suitable in terms of exerting a strong restoring force upon heating by crosslinking. The metal ions contained in the ionomer resin are not particularly limited, but examples thereof include zinc, sodium, and the like, and zinc ions are preferably low in elution property and low in contamination property. Among the alkyl (meth) acrylates of the terpolymer, an alkyl group having 1 to 4 carbon atoms is preferable because it has a high elastic modulus and can transmit a strong force to a wafer. Examples of such alkyl (meth) acrylates include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate.

The thermoplastic crosslinked resin is preferably a resin obtained by irradiating a resin selected from low-density polyethylene having a specific gravity of 0.910 or more and less than 0.930, ultra-low-density polyethylene having a specific gravity of less than 0.910, and an ethylene-vinyl acetate copolymer with an energy ray such as an electron beam to crosslink the resin, in addition to the ionomer resin. Such a thermoplastic crosslinked resin has a certain uniform expansibility because a crosslinked portion and a non-crosslinked portion coexist in the resin. Further, since the tape exerts a strong restoring force during heating, it is also suitable for removing slack of the tape generated in the expanding step, and since the molecular chain structure contains almost no chlorine, chlorinated aromatic hydrocarbons such as dioxin and the like do not occur even if the tape is incinerated, which is unnecessary after use, and thus the load on the environment is small. By appropriately adjusting the amount of energy rays to be irradiated to the polyethylene or ethylene-vinyl acetate copolymer, a resin having sufficiently uniform expansibility can be obtained.

Further, as the non-crosslinked resin, for example, a mixed resin composition of polypropylene and a styrene-butadiene copolymer is exemplified.

As the polypropylene, for example, a homopolymer or a block-type or random-type propylene-ethylene copolymer of propylene can be used. The random type propylene-ethylene copolymer is less rigid and is preferred. When the content of the ethylene constituent unit in the propylene-ethylene copolymer is 0.1% by weight or more, the adhesive tape is excellent in rigidity and compatibility between resins in the mixed resin composition is high. When the rigidity of the tape is appropriate, the cuttability of the wafer is improved, and when the compatibility between resins is high, the extrusion amount is easily stabilized. More preferably 1% by weight or more. When the content of the ethylene constituent unit in the propylene-ethylene copolymer is 7% by weight or less, the propylene-ethylene copolymer is excellent in that stable polymerization of polypropylene is facilitated. More preferably 5% by weight or less.

As the styrene-butadiene copolymer, a copolymer obtained by hydrogenation may be used. The styrene-butadiene copolymer, when hydrogenated, has good compatibility with propylene and can prevent embrittlement and discoloration due to oxidative deterioration of the double bond in butadiene. When the content of the styrene constituent unit in the styrene-butadiene copolymer is 5% by weight or more, the styrene-butadiene copolymer is preferable in that stable polymerization of the styrene-butadiene copolymer is facilitated. And 40% by weight or less is excellent in flexibility and spreadability. More preferably 25% by weight or less, and still more preferably 15% by weight or less. As the styrene-butadiene copolymer, any of a block type copolymer and a random type copolymer can be used. The random copolymer is preferable because the styrene phase is uniformly dispersed, and the expandability can be improved by suppressing an excessively large rigidity.

When the content of polypropylene in the mixed resin composition is 30% by weight or more, it is excellent in that the thickness unevenness of the base film can be suppressed. When the thickness is uniform, the stretchability becomes easy to be isotropic, and it is easy to prevent the stress relaxation property of the base film from becoming too large, the distance between chips from becoming small with time, and the adhesive layers from being brought into contact with each other and being re-welded. More preferably 50% by weight or more. When the content of polypropylene is 90% by weight or less, the rigidity of the base film can be easily adjusted appropriately. If the rigidity of the base film is too high, the force required to spread the base film increases, which may increase the load on the apparatus and may not spread sufficiently to cut the wafer or adhesive layer 13. The lower limit of the content of the styrene-butadiene copolymer in the mixed resin composition is preferably 10% by weight or more, and can be easily adjusted to the rigidity of the base film suitable for the apparatus. An upper limit of 70 wt% or less is excellent in terms of suppressing thickness unevenness, and more preferably 50 wt% or less.

In the example shown in fig. 1, the base film 11 is a single layer, but is not limited thereto, and may have a multilayer structure in which 2 or more kinds of resins are laminated, or may have 1 kind of resin in which 2 or more layers are laminated. When the crosslinking property or the non-crosslinking property of 2 or more kinds of resins is uniform, the resin is preferable from the viewpoint that the respective properties can be more strongly exhibited, and when the crosslinking property or the non-crosslinking property is combined, the resin is preferable from the viewpoint that the respective disadvantages are complemented. The thickness of the base film 11 is not particularly limited as long as it has sufficient strength to be easily stretched and not to be broken in the expanding step of the semiconductor processing tape 10. For example, it is preferably about 50 to 300. mu.m, more preferably 70 to 200. mu.m.

As a method for producing the multilayer substrate film 11, a conventionally known extrusion method, lamination method, or the like can be used. When the lamination method is used, an adhesive may be interposed between the layers. As the adhesive, a conventionally known adhesive can be used.

< adhesive layer >

The adhesive layer 12 may be formed by applying an adhesive composition to the base film 11. The pressure-sensitive adhesive layer 12 constituting the tape 10 for semiconductor processing of the present invention may have such a property that it does not peel off from the pressure-sensitive adhesive layer 13 at the time of dicing, has such a holding property that defects such as chip scattering do not occur, and is easily peeled off from the pressure-sensitive adhesive layer 13 at the time of picking up.

In the semiconductor processing tape 10 of the present invention, the structure of the adhesive composition constituting the adhesive layer 12 is not particularly limited, but in order to improve the pickup property after dicing, an energy ray-curable structure is preferable, and a material which is easily peeled from the adhesive layer 13 after curing is preferable. One embodiment is exemplified by a pressure-sensitive adhesive composition containing a polymer (a) as a base resin, the polymer (a) containing 60 mol% or more of a (meth) acrylate having an alkyl chain with 6 to 12 carbon atoms and having an energy ray-curable carbon-carbon double bond with an iodine value of 5 to 30. The energy ray here means an ultraviolet ray or an ionizing radiation such as an electron beam.

In the polymer (a), when the amount of introduction of the energy ray-curable carbon-carbon double bond is 5 or more in terms of iodine value, the effect of reducing the adhesive force after irradiation with an energy ray is excellent. More preferably 10 or more. Further, when the iodine value is 30 or less, the excellent results are obtained in that the holding force of the chip after the irradiation with the energy ray until the pickup is performed is high and the chip gap is easily enlarged when the pickup process is expanded. If the chip gap is sufficiently increased before the pickup step, the image of each chip at the time of pickup is easily recognized or the pickup is easily performed, which is preferable. Further, it is preferable that the amount of carbon-carbon double bonds introduced is 5 to 30 in terms of iodine value because the polymer (a) itself has stability and can be easily produced.

When the glass transition temperature of the polymer (A) is-70 ℃ or higher, the polymer (A) is excellent in heat resistance against heat accompanying energy ray irradiation, and more preferably-66 ℃ or higher. Further, when the temperature is 15 ℃ or lower, the wafer having a rough surface state is excellent in the effect of preventing chips from scattering after dicing, and is more preferably 0 ℃ or lower, and still more preferably-28 ℃ or lower.

The polymer (a) can be produced in any manner, and for example, an acrylic copolymer and a compound having an energy ray-curable carbon-carbon double bond are mixed, or an acrylic copolymer having a functional group or a methacrylic copolymer having a functional group (a1) and a compound having a functional group reactive with the functional group and an energy ray-curable carbon-carbon double bond (a2) are reacted.

Among them, examples of the functional group-containing methacrylic copolymer (A1) include those obtained by copolymerizing a monomer (A1-1) having a carbon-carbon double bond such as an alkyl acrylate or an alkyl methacrylate with a monomer (A1-2) having a carbon-carbon double bond and a functional group. Examples of the monomer (a1-1) include hexyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, decyl acrylate, lauryl acrylate having an alkyl chain of 6 to 12 carbon atoms, pentyl acrylate, n-butyl acrylate, isobutyl acrylate, ethyl acrylate, methyl acrylate, and the like methacrylic acid esters having the same structure as those of the above monomers, as well as those having an alkyl chain of 5 or less carbon atoms.

The component having an alkyl chain of 6 or more carbon atoms in the monomer (a1-1) is excellent in terms of pickup properties because it can reduce the peel strength between the pressure-sensitive adhesive layer and the adhesive layer. The component having 12 or less carbon atoms has a low elastic modulus at room temperature, and is excellent in terms of adhesion at the interface between the pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer. When the adhesive force at the interface between the adhesive layer and the pressure-sensitive adhesive layer is high, it is preferable to suppress the interfacial deviation (ズ レ) between the adhesive layer and the pressure-sensitive adhesive layer and improve the cuttability when the tape is spread and the wafer is cut.

Further, as the monomer (a1-1), the glass transition temperature becomes lower as the monomer having a larger carbon number in the alkyl chain is used, and therefore, a pressure-sensitive adhesive composition having a desired glass transition temperature can be prepared by appropriately selecting the monomer. In addition, a low molecular weight compound having a carbon-carbon double bond such as vinyl acetate, styrene, or acrylonitrile may be blended for the purpose of improving various properties such as compatibility, in addition to the glass transition temperature. In this case, these low molecular weight compounds are blended in a range of 5 mass% or less of the total mass of the monomer (A1-1).

on the other hand, examples of the functional group of the monomer (A1-2) include a carboxyl group, a hydroxyl group, an amino group, a cyclic acid anhydride group, an epoxy group, an isocyanate group and the like, and examples of the monomer (A1-2) include acrylic acid, methacrylic acid, lauric acid, itaconic acid, fumaric acid, phthalic acid, 2-hydroxyalkyl acrylates, 2-hydroxyalkyl methacrylates, glycol monoacrylates, glycol monomethacrylates, N-methylolacrylamide, N-methylolmethacrylamide, allyl alcohol, N-alkylaminoethyl acrylates, N-alkylaminoethyl methacrylates, acrylamides, methacrylamides, maleic anhydride, itaconic anhydride, fumaric anhydride, phthalic anhydride, glycidyl acrylate, glycidyl methacrylate, and the like, Glycidyl methacrylate, allyl glycidyl ether, and the like.

in addition, in the compound (a2), examples of the functional group used include a hydroxyl group, an epoxy group, an isocyanate group and the like when the functional group of the compound (a1) is a carboxyl group or a cyclic acid anhydride group, an epoxy group, an isocyanate group and the like when the functional group is a hydroxyl group, an epoxy group, an isocyanate group and the like when the functional group is an amino group, an epoxy group, an isocyanate group and the like when the functional group is an epoxy group, a carboxyl group, a cyclic acid anhydride group, an amino group and the like, and the same as those exemplified as the specific examples of the monomer (a1-2) are exemplified as specific examples. Further, as the compound (a2), one obtained by urethanizing a part of the isocyanate groups of the polyisocyanate compound with a monomer having a hydroxyl group or a carboxyl group and an energy ray-curable carbon-carbon double bond can also be used.

In addition, in the reaction of the compound (a1) and the compound (a2), a desired substance having a desired property such as an acid value or a hydroxyl value can be produced by leaving an unreacted functional group. When the OH group remains so that the hydroxyl valence of the polymer (A) is 5 to 100, the adhesive force after irradiation with energy rays is reduced, thereby further reducing the risk of pickup errors. In addition, when the COOH group remains so that the acid value of the polymer (a) is 0.5 to 30, the effect of improving the recovery of the adhesive layer after the expansion of the tape for semiconductor processing of the present invention is preferably obtained. When the hydroxyl value of the polymer (a) is 5 or more, it is excellent in terms of the effect of reducing the adhesive force after irradiation with an energy ray, and when it is 100 or less, it is excellent in terms of the fluidity of the adhesive after irradiation with an energy ray. And an acid value of 0.5 or more is excellent in terms of the restorability of the tape, and 30 or less is excellent in terms of the fluidity of the adhesive.

In the synthesis of the polymer (a), ketone, ester, alcohol and aromatic solvents are used as the organic solvent in the reaction by solution polymerization, but among them, toluene, ethyl acetate, isopropyl alcohol, benzyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone and other good solvents of general acrylic polymers and solvents having a boiling point of 60 to 120 ℃ are preferable, and as the polymerization initiator, azo-bis such as α, α' -azobisisobutyronitrile and the like, and radical generators such as benzoyl peroxide and the like are used. In this case, a catalyst and a polymerization inhibitor may be used in combination as necessary, and the polymerization temperature and the polymerization time may be adjusted to obtain the polymer (A) having a desired molecular weight. In addition, for the adjustment of the molecular weight, a thiol or carbon tetrachloride solvent is preferably used. The reaction is not limited to solution polymerization, and may be carried out by other methods such as bulk polymerization and suspension polymerization.

The polymer (a) can be obtained as described above, but in the present invention, when the molecular weight of the polymer (a) is 30 ten thousand or more, the polymer (a) is excellent in terms of improvement of cohesive force. When the cohesive force is high, it is preferable in terms of improving the separability of the adhesive layer because it has an effect of suppressing interfacial misalignment with the adhesive layer during expansion and easily transmits a tensile force to the adhesive layer. When the molecular weight of the polymer (a) is 200 ten thousand or less, the polymer (a) is excellent in terms of suppression of gelation during synthesis and coating. The molecular weight in the present invention is a mass average molecular weight in terms of polystyrene.

In the semiconductor processing tape 10 of the present invention, the resin composition constituting the pressure-sensitive adhesive layer 12 may further include a compound (B) that functions as a crosslinking agent in addition to the polymer (a). For example, polyisocyanates, melamine-formaldehyde resins, and epoxy resins are exemplified, and these may be used alone or in combination of 2 or more. The compound (B) reacts with the polymer (a) or the base film, and the resultant crosslinked structure can improve the cohesive force of the adhesive containing the polymers (a) and (B) as main components after the adhesive composition is applied.

The polyisocyanate is not particularly limited, and examples thereof include aromatic isocyanates such as 4,4' -diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, 4' -diphenyl ether diisocyanate and 4,4' - [2, 2-bis (4-phenoxyphenyl) propane ] diisocyanate, hexamethylene diisocyanate, 2, 4-trimethyl-hexamethylene diisocyanate, isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, 2, 4' -dicyclohexylmethane diisocyanate, lysine diisocyanate and lysine triisocyanate, and specifically CORONATE L (trade name, manufactured by japan polyurethane limited) can be used. Specific examples of the melamine-formaldehyde resin include NIKALAC MX-45 (trade name, manufactured by Sanko chemical industries, Ltd.), MELAN (trade name, manufactured by Hitachi chemical industries, Ltd.), and the like. As the epoxy resin, TETRAD-X (trade name, manufactured by Mitsubishi chemical Co., Ltd.) or the like can be used. In the present invention, polyisocyanates are particularly preferably used.

The pressure-sensitive adhesive layer in which the amount of the compound (B) added is 0.1 part by mass or more per 100 parts by mass of the polymer (a) is excellent in terms of cohesive force. More preferably 0.5 parts by mass or more. Further, the adhesive layer of 10 parts by mass or less is excellent in terms of suppressing the drastic gelation at the time of coating, and the workability such as mixing and coating of the adhesive is good. More preferably 5 parts by mass or less.

In the present specification, the pressure-sensitive adhesive layer 12 may contain a photopolymerization initiator (C). The photopolymerization initiator (C) contained in the pressure-sensitive adhesive layer 12 is not particularly limited, and conventionally known ones can be used. Examples thereof include benzophenones such as benzophenone, 4' -dimethylaminobenzophenone, 4' -diethylaminobenzophenone and 4,4' -dichlorobenzophenone, acetophenones such as acetophenone and diethoxyacetophenone, anthraquinones such as 2-ethylanthraquinone and tert-butylanthraquinone, 2-chlorothioxanthone, benzoin ethyl ether, benzoin isopropyl ether, benzil, 2,4, 5-triarylimidazole dimer (Lophine dimer), acridine compounds, and these compounds may be used alone or in combination of 2 or more. The amount of the photopolymerization initiator (C) added is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, per 100 parts by mass of the polymer (a). The upper limit is preferably 10 parts by mass or less, and more preferably 5 parts by mass or less.

The energy ray-curable adhesive used in the present invention may contain a tackifier, an adhesive preparation agent, a surfactant, and the like, or other modifiers, if necessary. Further, an inorganic compound filler may be added as appropriate.

the pressure-sensitive adhesive layer 12 can be formed by a conventional pressure-sensitive adhesive layer forming method. For example, the pressure-sensitive adhesive layer 12 can be formed on the base film 11 by a method in which the pressure-sensitive adhesive composition is applied to a predetermined surface of the base film 11, or a method in which the pressure-sensitive adhesive composition is applied to a spacer (for example, a plastic film or sheet coated with a release agent) to form the pressure-sensitive adhesive layer 12, and then the pressure-sensitive adhesive layer 12 is transferred to a predetermined surface of the base. The pressure-sensitive adhesive layer 12 may have a single-layer form or a laminated form.

The thickness of the pressure-sensitive adhesive layer 12 is not particularly limited, and when the thickness is 2 μm or more, the adhesive layer is excellent in terms of the contact adhesion, and more preferably 5 μm or more. When the particle diameter is 15 μm or less, the pick-up property is excellent, and more preferably 10 μm or less.

The adhesive tape 15 has a negative value, that is, a value smaller than 0, which is the sum of an integrated value calculated as the sum of thermal deformation rates per 1 ℃ at 40 to 80 ℃ measured by a thermomechanical property tester at the time of temperature rise in the MD (Machine Direction) Direction and an integrated value calculated as the sum of thermal deformation rates per 1 ℃ at 40 to 80 ℃ measured by a thermomechanical property tester at the time of temperature rise in the TD (Transverse Direction). The MD direction is the direction of travel when a film is formed, and the TD direction is a direction perpendicular to the MD direction.

The semiconductor processing tape 10 can be contracted by heating at a low temperature for a short time by making a negative sum of an integrated value calculated from a sum of thermal deformation rates per 1 ℃ at 40 to 80 ℃ measured by a thermomechanical property tester at a temperature rise in the MD direction and an integrated value calculated from a sum of thermal deformation rates per 1 ℃ at 40 to 80 ℃ measured by a thermomechanical property tester at a temperature rise in the TD direction. Therefore, even when a method is used in which the portion of the semiconductor processing tape 10 where slack is generated is heated and contracted around the pair of warm air nozzles, the slack generated by the expansion can be removed in a short time without performing the heating and contraction several times while reducing the amount of expansion, and an appropriate notch width can be maintained.

The thermal deformation rate was measured by measuring the amount of deformation due to temperature in accordance with JIS K7197:2012 and calculated from the following formula (1).

Thermal deformation rate TMA (%) (amount of deformation in sample length/sample length before measurement) × 100(1)

In addition, the expansion direction of the sample is represented as positive and the contraction direction is represented as negative with respect to the deformation amount.

The integrated value of the thermal deformation rate corresponds to an area enclosed by the MD direction curve or the TD direction curve and the x-axis in fig. 9, and the sum of the MD direction integrated value and the TD direction integrated value is the sum of areas including symbols. Therefore, a negative value of sum means that the adhesive tape as a whole exhibits a behavior of shrinkage between 40 ℃ and 80 ℃.

in order to make the sum of the integrated value in the MD direction and the integrated value in the TD direction negative, a stretching step may be added after the resin film is formed, and the thickness of the adhesive tape 15, and the stretching amount in the MD direction or the TD direction may be adjusted according to the type of resin constituting the adhesive tape 15. As a method of stretching the adhesive tape in the TD direction, a method using a tenter, a method of blow molding (inflation), a method using an expanding roll, and the like are exemplified, and as a method of stretching in the MD direction, a method of stretching at the time of die ejection, a method of stretching in a transfer roll, and the like are exemplified. As a method for obtaining the adhesive tape 15 of the present invention, any method can be used.

< adhesive layer >

in the semiconductor processing tape 10 of the present invention, the adhesive layer 13 is formed by peeling the adhesive layer 12 and adhering to the chip when the chip is picked up after the wafer is bonded and diced. The adhesive is used for fixing a chip to a substrate or a lead frame.

The adhesive layer 13 is not particularly limited as long as it is a film-like adhesive generally used for wafers, and examples thereof include those containing a thermoplastic resin and a thermally polymerizable component. The thermoplastic resin used for the adhesive layer 13 of the present invention is preferably a resin having thermoplasticity or a resin having thermoplasticity in an uncured state and forming a crosslinked structure after heating, and is not particularly limited, but one embodiment thereof is a thermoplastic resin having a weight average molecular weight of 5000 to 200,000 and a glass transition temperature of 0 to 150 ℃. In another embodiment, the thermoplastic resin has a weight average molecular weight of 100,000 to 1,000,000 and a glass transition temperature of-50 to 20 ℃.

Examples of the former thermoplastic resin include polyimide resin, polyamide resin, polyetherimide resin, polyamideimide resin, polyester resin, polyesterimide resin, phenoxy resin, polysulfone resin, polyethersulfone resin, polyphenylene sulfide resin, and polyetherketone resin, among which polyimide resin and phenoxy resin are preferably used, and a polymer containing a functional group is preferably used as the latter thermoplastic resin.

The polyimide resin can be obtained by condensation reaction of tetracarboxylic dianhydride and diamine by a known method. That is, an addition reaction is carried out at a reaction temperature of 80 ℃ or less, preferably 0 to 60 ℃ using equimolar or approximately equimolar tetracarboxylic dianhydride and diamine (the order of addition of the components is arbitrary) in an organic solvent. As the reaction proceeds, the viscosity of the reaction solution gradually increases, and polyamic acid as a polyimide precursor is produced. The polyamic acid can be depolymerized by heating at 50 to 80 ℃ to adjust its molecular weight. The polyimide resin can be obtained by subjecting the above reactant (polyamic acid) to dehydration ring-closure. The dehydration ring closure can be carried out by a thermal ring closure method in which heat treatment is carried out, and a chemical ring closure method using a dehydrating agent.

The tetracarboxylic acid dianhydride used as a raw material of the polyimide resin is not particularly limited, and examples thereof include 1,2- (ethylene) bis (trimellitic acid anhydride), 1,3- (trimethylene) bis (trimellitic acid anhydride), 1,4- (tetramethylene) bis (trimellitic acid anhydride), 1,5- (pentamethylene) bis (trimellitic acid anhydride), 1,6- (hexamethylene) bis (trimellitic acid anhydride), 1,7- (heptamethylene) bis (trimellitic acid anhydride), 1,8- (octamethylene) bis (trimellitic acid anhydride), 1,9- (nonamethylene) bis (trimellitic acid anhydride), 1,10- (decamethylene) bis (trimellitic acid anhydride), 1,12- (dodecamethylene) bis (trimellitic acid anhydride), 1,16- (hexadecamethylene) bis (trimellitic acid anhydride), 1,18- (octadecylidene) bis (trimellitic anhydride), pyromellitic dianhydride, 3,3', 4,4' -biphenyltetracarboxylic dianhydride, 2', 3,3' -biphenyltetracarboxylic dianhydride, 2-bis (3, 4-dicarboxyphenyl) propane dianhydride, 2-bis (2, 3-dicarboxyphenyl) propane dianhydride, 1-bis (2, 3-dicarboxyphenyl) ethane dianhydride, 1-bis (3, 4-dicarboxyphenyl) ethane dianhydride, bis (2, 3-dicarboxyphenyl) methane dianhydride, bis (3, 4-dicarboxyphenyl) sulfone dianhydride, 3,4,9, 10-perylene tetracarboxylic dianhydride, bis (3, 4-dicarboxyphenyl) ether dianhydride, Benzene-1, 2,3, 4-tetracarboxylic dianhydride, 3,4, 3', 4' -benzophenonetetracarboxylic dianhydride, 2,3, 2', 3' -benzophenonetetracarboxylic dianhydride, 3,3, 3', 4' -benzophenonetetracarboxylic dianhydride, 1,2,5, 6-naphthalenetetracarboxylic dianhydride, 1,4,5, 8-naphthalenetetracarboxylic dianhydride, 2,3,6, 7-naphthalenetetracarboxylic dianhydride, 1,2,4, 5-naphthalenetetracarboxylic dianhydride, 2, 6-dichloronaphthalene-1, 4,5, 8-tetracarboxylic dianhydride, 2, 7-dichloronaphthalene-1, 4,5, 8-tetracarboxylic dianhydride, 2,3,6, 7-tetrachloronaphthalene-1, 4,5, 8-tetracarboxylic dianhydride, phenanthrene-1, 8,9, 10-tetracarboxylic dianhydride, Pyrazine-2, 3,5, 6-tetracarboxylic dianhydride, thiophene-2, 3,5, 6-tetracarboxylic dianhydride, 2,3, 3', 4' -biphenyltetracarboxylic dianhydride, 3,4, 3', 4' -biphenyltetracarboxylic dianhydride, 2,3, 2', 3' -biphenyltetracarboxylic dianhydride, bis (3, 4-dicarboxyphenyl) dimethylsilane dianhydride, bis (3, 4-dicarboxyphenyl) methylphenylsilane dianhydride, bis (3, 4-dicarboxyphenyl) diphenylsilane dianhydride, 1, 4-bis (3, 4-dicarboxyphenyldimethylsilyl) benzene dianhydride, 1, 3-bis (3, 4-dicarboxyphenyl) -1,1,3, 3-tetramethylbicyclohexane dianhydride, p-phenylenebis (trimellitic anhydride), ethylenetetracarboxylic dianhydride, 1,2,3, 4-butanetetracarboxylic dianhydride, decahydronaphthalene-1, 4,5, 8-tetracarboxylic dianhydride, 4, 8-dimethyl-1, 2,3,5,6, 7-hexahydronaphthalene-1, 2,5, 6-tetracarboxylic dianhydride, cyclopentane-1, 2,3, 4-tetracarboxylic dianhydride, pyrrolidine-2, 3,4, 5-tetracarboxylic dianhydride, 1,2,3, 4-cyclobutanetetracarboxylic dianhydride, bis (exo-bicyclo [2,2,1] heptane-2, 3-dicarboxylic dianhydride, bicyclo- [2,2,2] -oct-7-ene-2, 3,5, 6-tetracarboxylic dianhydride, 2, 2-bis (3, 4-dicarboxyphenyl) hexafluoropropane dianhydride, 2, 2-bis [4- (3, 4-dicarboxyphenyl) phenyl ] hexafluoropropane dianhydride, 4' -bis (3, 4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 1, 4-bis (2-hydroxyhexafluoroisopropyl) benzene bis (trimellitic anhydride), 1, 3-bis (2-hydroxyhexafluoroisopropyl) benzene bis (trimellitic anhydride), 5- (2, 5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1, 2-dicarboxylic dianhydride, tetrahydrofuran-2, 3,4, 5-tetracarboxylic dianhydride, and the like, and 1 or 2 or more of these can be used in combination.

The diamine used as a raw material of the polyimide is not particularly limited, and examples thereof include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 3 '-diaminodiphenyl ether, 3,4' -diaminodiphenyl ether, 4 '-diaminodiphenyl ether, 3' -diaminodiphenylmethane, 3,4 '-diaminodiphenylmethane, 4' -diaminodiphenyl ether methane, bis (4-amino-3, 5-dimethylphenyl) methane, bis (4-amino-3, 5-diisopropylphenyl) methane, 3 '-diaminodiphenyldifluoromethane, 3,4' -diaminodiphenyldifluoromethane, 4 '-diaminodiphenyldifluoromethane, 3' -diaminodiphenylsulfone, and the like, 3,4' -diaminodiphenyl sulfone, 4' -diaminodiphenyl sulfone, 3' -diaminodiphenyl sulfide, 3,4' -diaminodiphenyl sulfide, 4' -diaminodiphenyl sulfide, 3' -diaminodiphenyl ketone, 3,4' -diaminodiphenyl ketone, 4' -diaminodiphenyl ketone, 2-bis (3-aminophenyl) propane, 2' - (3,4' -diaminodiphenyl) propane, 2-bis (4-aminophenyl) propane, 2-bis (3-aminophenyl) hexafluoropropane, 2- (3,4' -diaminodiphenyl) hexafluoropropane, 2-bis (4-aminophenyl) hexafluoropropane, 1, 3-bis (3-aminophenoxy) benzene, 1, 4-bis (4-aminophenoxy) benzene, 3' - (1,4 phenylenebis (1-methylethylidene)) dianiline, 3,4' - (1,4 phenylenebis (1-methylethylidene)) dianiline, 4' - (1,4 phenylenebis (1-methylethylidene)) dianiline, 2-bis (4- (3-aminophenoxy) phenyl) propane, 2-bis (4- (4-aminophenoxy) phenyl) propane, 2-bis (4- (3-aminophenoxy) phenyl) hexafluoropropane, 2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, Bis (4- (3-aminophenoxy) phenyl) sulfide, bis (4- (4-aminophenoxy) phenyl) sulfide, bis (4- (3-aminophenoxy) phenyl) sulfone, bis (4- (4-aminophenoxy) phenyl) sulfone, an aromatic diamine such as 3, 5-diaminobenzoic acid, 1, 2-diaminoethane, 1, 3-diaminopropane, 1, 4-diaminobutane, 1, 5-diaminopentane, 1, 6-diaminohexane, 1, 7-diaminoheptane, 1, 8-diaminooctane, 1, 9-diaminononane, 1, 10-diaminodecane, 1, 11-diaminoundecane, 1, 12-diaminododecane, 1, 2-diaminocyclohexane, a diaminopolysiloxane represented by the following general formula (1), a salt thereof, a water-soluble organic solvent, and the like, 1, 3-bis (aminomethyl) cyclohexane, and aliphatic diamines such as JEFFAMINE D-230, D-400, D-2000, D-4000, ED-600, ED-900, ED-2001, EDR-148 and the like available from SAN TECHNO Chemicals Ltd, and 1 or 2 or more of these may be used in combination. The polyimide resin preferably has a glass transition temperature of 0 to 200 ℃ and a weight average molecular weight of 1 to 20 ten thousand.

[ CHEMICAL ] A novel process for the preparation of a compound

(wherein R1 and R2 represent a divalent hydrocarbon group having 1 to 30 carbon atoms and may be the same or different, R3 and R4 represent a monovalent hydrocarbon group and may be the same or different, and m is an integer of 1 or more).

The phenoxy resin, which is one of the preferable thermoplastic resins other than those described above, is preferably a resin obtained by a method of reacting various bisphenols with epichlorohydrin or a method of reacting a liquid epoxy resin with a bisphenol, and examples of the bisphenol include bisphenol a, bisphenol AF, bisphenol AD, bisphenol F, and bisphenol S. The phenoxy resin has a structure similar to that of an epoxy resin, and therefore has good compatibility with the epoxy resin, and can suitably impart good adhesion to an adhesive film.

Examples of the phenoxy resin used in the present invention include resins having a repeating unit represented by the following general formula (2).

[ CHEM 2]

In the general formula (2), X represents a single bond or a 2-valent linking group. Examples of a 2-valent linking group are an alkylene group, a phenylene group, -O-, -S-, -SO-or-SO 2-. Here, the alkylene group is preferably an alkylene group having 1 to 10 carbon atoms, and more preferably-C (R1) (R2) -. R1 and R2 each represents a hydrogen atom or an alkyl group, and the alkyl group is preferably a linear or branched alkyl group having 1 to 8 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an isooctyl group, a 2-ethylhexyl group, and a1, 3, 3-trimethylbutyl group. In addition, the alkyl group may be substituted with a halogen atom, such as trifluoromethyl. X is preferably alkylene, -O-, -S-, fluorenylidene (フ ル オ レ ン group) or-SO 2-, more preferably alkylene, -SO 2-. Among them, preferred are-C (CH3)2-, -CH (CH3) -, -CH2-, -SO2-, more preferred are-C (CH3)2-, -CH (CH3) -, -CH2-, and particularly preferred is-C (CH3) 2-.

The phenoxy resin represented by the above general formula (2), if having a repeating unit, may be a resin having a plurality of kinds of repeating units different in X of the above general formula (2), or may be composed of only the same repeating unit in X. In the present invention, a resin composed of only repeating units in which X is the same is preferable.

When the phenoxy resin represented by the above general formula (2) contains a polar substituent such as a hydroxyl group or a carboxyl group, the compatibility with the thermally polymerizable component can be improved, and uniform appearance and properties can be provided.

When the mass average molecular weight of the phenoxy resin is 5000 or more, the phenoxy resin is excellent in terms of film formability. More preferably 10,000 or more, and still more preferably 30,000 or more. When the mass average molecular weight is 150,000 or less, the resin composition is preferably used in view of fluidity during thermocompression bonding and compatibility with other resins. More preferably 100,000 or less. When the glass transition temperature is-50 ℃ or higher, the glass transition temperature is excellent in terms of film formability, and is more preferably 0 ℃ or higher, and still more preferably 50 ℃ or higher. When the glass transition temperature is 150 ℃, the adhesive force of adhesive layer 13 at the time of die bonding is excellent, and more preferably 120 ℃ or lower, and still more preferably 110 ℃ or lower.

On the other hand, examples of the functional group in the functional group-containing polymer include a glycidyl group, an acryloyl group, a methacryloyl group, a hydroxyl group, a carboxyl group, an isocyanurate group, an amino group, and an amide group, and among them, a glycidyl group is preferable.

Examples of the high molecular weight component having a functional group include (meth) acrylic copolymers having a functional group such as a glycidyl group, a hydroxyl group, and a carboxyl group.

examples of the (meth) acrylic copolymer include a (meth) acrylate copolymer and an acrylic rubber, and an acrylic rubber is preferable. The acrylic rubber is a rubber mainly composed of an acrylic ester and mainly composed of a copolymer of butyl acrylate and acrylonitrile or a copolymer of ethyl acrylate and acrylonitrile.

When a glycidyl group is contained as the functional group, the amount of the glycidyl group-containing repeating unit is preferably 0.5 to 6.0% by weight, more preferably 0.5 to 5.0% by weight, and particularly preferably 0.8 to 5.0% by weight. The repeating unit containing a glycidyl group is a constituent monomer of a (meth) acrylic copolymer containing a glycidyl group, and specifically, glycidyl acrylate or glycidyl methacrylate. When the amount of the repeating unit containing a glycidyl group is within this range, the adhesive strength can be secured and gelation can be prevented.

examples of the constituent monomers of the above-mentioned (meth) acrylic copolymer other than glycidyl acrylate and glycidyl methacrylate include, for example, ethyl (meth) acrylate and butyl (meth) acrylate, and these may be used alone or in combination of 2 or more. In the present invention, ethyl (meth) acrylate means ethyl acrylate and/or ethyl methacrylate. The mixing ratio when the functional monomers are used in combination may be determined in consideration of the glass transition temperature of the (meth) acrylic copolymer. When the glass transition temperature is-50 ℃ or higher, the film-forming property is excellent, and it is preferable that excessive contact adhesion at ordinary temperature can be suppressed. When the tack-free force at room temperature is excessive, handling of the adhesive layer becomes difficult. More preferably-20 ℃ or higher, and still more preferably 0 ℃ or higher. When the glass transition temperature is 30 ℃ or lower, the adhesive strength of the adhesive layer at the time of die bonding is excellent, and more preferably 20 ℃ or lower.

when the monomer is polymerized to produce a high molecular weight component containing a functional monomer, the polymerization method is not particularly limited, and for example, bead polymerization (solution polymerization) and the like can be used, and bead polymerization is preferable.

In the present invention, when the weight average molecular weight of the high molecular weight component containing the functional monomer is 100,000 or more, the high molecular weight component is excellent in terms of film-forming properties, more preferably 200,000 or more, and still more preferably 500,000 or more. When the weight average molecular weight is adjusted to 2,000,000 or less, the adhesive layer is excellent in that the heat fluidity at the time of die bonding is improved. When the fluidity of the adhesive layer under heating is improved during die bonding, the adhesive layer can be made to adhere well to the adherend to improve the adhesive strength, and the unevenness of the adherend can be easily embedded to suppress voids. More preferably 1,000,000 or less, still more preferably 800,000 or less, and even more preferably 500,000 or less, the effect can be further increased.

The thermally polymerizable component is not particularly limited as long as it is polymerizable by heat, and examples thereof include compounds having a functional group such as a glycidyl group, an acryloyl group, a methacryloyl group, a hydroxyl group, a carboxyl group, an isocyanurate group, an amino group, an amide group and the like, and a trigger material, and these may be used alone or in combination of 2 or more, but when the heat resistance of the adhesive layer is considered, it is preferable to contain a thermosetting resin which is cured by heat and brings about an adhesive action together with a curing agent and an accelerator. Examples of the thermosetting resin include epoxy resin, acrylic resin, silicone resin, phenol resin, thermosetting polyimide resin, polyurethane resin, melamine resin, and urea resin, and epoxy resin is most preferably used particularly in order to obtain an adhesive layer having excellent heat resistance, workability, and reliability.

The epoxy resin is not particularly limited as long as it has an adhesive action by curing, and a bifunctional epoxy resin such as a bisphenol a type epoxy resin, a phenol novolac type epoxy resin such as a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, or the like can be used. In addition, generally known epoxy resins such as polyfunctional epoxy resins, glycidyl amine type epoxy resins, heterocyclic ring-containing epoxy resins, and alicyclic epoxy resins can be used.

Examples of the bisphenol A type epoxy resin include EPICOTE series (EPICOTE 807, EPICOTE 815, EPICOTE 825, EPICOTE827, EPICOTE 828, EPICOTE 834, EPICOTE 1001, EPICOTE 1004, EPICOTE 1007, EPICOTE 1009), DER-330, DER-301, DER-361, and YD8125 and YDF8170, which are available from Mitsubishi chemical corporation. Examples of the phenol novolac-type epoxy resin include EPICOTE 152 and EPICOTE 154 manufactured by Mitsubishi chemical corporation, EPPN-201 manufactured by Nippon chemical corporation, DEN-438 manufactured by Dow chemical corporation, and the o-cresol novolac-type epoxy resin includes EOCN-102S, EOCN-103S, EOCN-104S, EOCN-1012, EOCN-1025 and EOCN-1027 manufactured by Nippon chemical corporation, and YDCN701, YDCN702, YDCN703 and YDCN704 manufactured by Nippon chemical corporation. Examples of the above-mentioned polyfunctional epoxy resin include Epon 1031S manufactured by Mitsubishi chemical corporation, Araldite 0163 manufactured by Ciba specialty Chemicals corporation, DENACOL EX-611 manufactured by NAGASE CHEMTEX corporation, EX-614B, EX-622, EX-512, EX-521, EX-421, EX-411, and EX-321. Examples of the amine-type epoxy resin include EPICOTE 604 manufactured by Mitsubishi chemical corporation, YH-434 manufactured by Tokyo chemical corporation, TETRAD-X and TETRAD-C manufactured by Mitsubishi gas chemical corporation, and ELM-120 manufactured by Sumitomo chemical industry Co. Examples of the heterocyclic ring-containing epoxy resin include ARALDITE PT810 manufactured by Ciba specialty Chemicals, ERL4234, ERL4299, ERL4221, and ERL4206 manufactured by UCC. These epoxy resins may be used alone or in combination of 2 or more.

In order to cure the thermosetting resin, an appropriate additive may be added. Examples of such additives include a curing agent, a curing accelerator, and a catalyst, and when a catalyst is added, a co-catalyst may be used as needed.

When an epoxy resin is used as the thermosetting resin, an epoxy resin curing agent or a curing accelerator is preferably used, and more preferably used in combination. Examples of the curing agent include phenol resins, dicyandiamide, boron trifluoride complexes, organic hydrazide compounds, amines, polyamide resins, imidazole compounds, urea or thiourea compounds, polythiol compounds, polythioether resins having a mercapto group at the terminal, acid anhydrides, and light/ultraviolet curing agents. These may be used alone or in combination of 2 or more.

Among them, boron trifluoride-amine complexes with various amine compounds (preferably primary amine compounds) are exemplified as boron trifluoride complexes, and isophthalic dihydrazide is exemplified as an organic hydrazide compound.

Examples of the phenol resin include phenol novolac resins, phenol aralkyl resins, cresol novolac resins, t-butylphenol novolac resins, nonylphenol novolac resins and other phenol novolac resins, resol novolac resins, polyhydroxystyrenes such as polyparahydroxystyrene, and the like. Among them, a phenol compound having at least 2 phenolic hydroxyl groups in the molecule is preferable.

as the phenol-based compound having at least 2 phenolic hydroxyl groups in the molecule, for example, phenol novolac resin, cresol novolac resin, tert-butylphenol novolac resin, dicyclopentadiene cresol novolac resin, dicyclopentadiene phenol novolac resin, xylene-modified phenol novolac resin, naphthol novolac resin, triphenol novolac resin, tetraphenol novolac resin, bisphenol a novolac resin, poly-p-vinylphenol novolac resin, phenol aralkyl resin and the like are illustrated. Among these phenol resins, phenol novolac resins and phenol aralkyl resins are particularly preferable, and connection reliability can be improved.

Examples of the amines include chain aliphatic amines (diethylenetriamine, triethylenetetramine, hexamethylenediamine, N-dimethylpropylamine, benzyldimethylamine, 2- (dimethylamino) phenol, 2,4, 6-tris (dimethylaminomethyl) phenol, m-xylylenediamine, etc.), cyclic aliphatic amines (N-aminoethylpiperazine, bis (3-methyl-4-aminocyclohexyl) methane, bis (4-aminocyclohexyl) methane, menthenediamine (メ ン セ ン ジ ア ミ ン), isophoronediamine, 1, 3-bis (aminomethyl) cyclohexane, etc.), heterocyclic amines (piperazine, N-dimethylpiperazine, triethylenediamine, melamine, guanamine, etc.), aromatic amines (m-phenylenediamine, 4' -diaminodiphenylmethane, diamino compound (ジ ア ミ ノ), etc.), 4,4' -diaminodiphenyl sulfone, etc.), polyamide resins (preferably polyamidoamine, condensate of dimer acid and polyamine), imidazole compounds (2-phenyl-4, 5-dihydroxymethylimidazole, 2-methylimidazole, 2, 4-dimethylimidazole, 2-N-heptadecylimidazole, 1-cyanoethyl-2-undecylimidazolium-trimellitate, epoxy-imidazole adduct, etc.), urea or thiourea compounds (N, N-dialkylurea compounds, N-dialkylthiourea compounds, etc.), polythiol compounds, polythioether resins having a mercapto group at the terminal, acid anhydrides (e.g., tetrahydrophthalic anhydride), and light/ultraviolet curing agents (e.g., diphenyliodonium hexafluorophosphate, triphenylsulfonium hexafluorophosphate).

the curing accelerator is not particularly limited as long as it can cure a thermosetting resin, and examples thereof include imidazoles, dicyandiamide derivatives, dicarboxylic acid dihydrazide, triphenylphosphine, tetraphenylphosphonium tetraphenylborate, 2-ethyl-4-methylimidazole-tetraphenylborate, and 1, 8-diazabicyclo [5.4.0] undecene-7-tetraphenylborate.

examples of the imidazoles include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-ethylimidazole, 1-benzyl-2-ethyl-5-methylimidazole, 2-phenyl-4-methyl-5-hydroxydimethylimidazole, 2-phenyl-4, 5-dihydroxymethylimidazole, and the like.

The content of the curing agent or curing accelerator for epoxy resin in the adhesive layer is not particularly limited, and the optimum content varies depending on the kind of the curing agent or curing accelerator.

The mixing ratio of the epoxy resin and the phenol resin is preferably 0.5 to 2.0 equivalents of hydroxyl group in the phenol resin to 1 equivalent of epoxy group in the epoxy resin component. More preferably 0.8 to 1.2 equivalents. That is, if the mixing ratio of the two components is out of the above range, the curing reaction cannot be sufficiently performed, and the properties of the adhesive layer are likely to be deteriorated. The other thermosetting resin and the curing agent are contained in an amount of 0.5 to 20 parts by mass in one embodiment and 1 to 10 parts by mass in another embodiment, based on 100 parts by mass of the thermosetting resin. The content of the curing accelerator is preferably less than the content of the curing agent, and the curing accelerator is preferably 0.001 to 1.5 parts by mass, more preferably 0.01 to 0.95 parts by mass, per 100 parts by mass of the thermosetting resin. By adjusting within the range, sufficient progress of the curing reaction can be assisted. The content of the catalyst is preferably 0.001 to 1.5 parts by mass, and more preferably 0.01 to 1.0 part by mass, based on 100 parts by mass of the thermosetting resin.

The adhesive layer 13 of the present invention may contain a filler as appropriate depending on the application. This can improve the cuttability of the adhesive layer in an uncured state, improve the handleability, adjust the melt viscosity, provide thixotropy, further provide thermal conductivity to the adhesive layer in a cured state, and improve the adhesive strength.

as the filler used in the present invention, an inorganic filler is preferable. The inorganic filler is not particularly limited, and examples thereof include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum nitride, aluminum borate whisker, boron nitride, crystalline silicon oxide, amorphous silicon oxide, and antimony oxide. These may be used alone or in combination of 2 or more.

Among the inorganic fillers, alumina, aluminum nitride, boron nitride, crystalline silica, amorphous silica, and the like are preferably used from the viewpoint of improving the thermal conductivity. From the viewpoint of adjusting melt viscosity or imparting thixotropy, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, crystalline silicon oxide, and amorphous silicon oxide are preferable. In addition, alumina and silica are preferably used from the viewpoint of improving the cuttability.

When the content of the filler is 30% by mass or more, the wire bondability is excellent. In the wire bonding, it is preferable that the storage elastic modulus after curing of the adhesive layer for bonding the chip by wire bonding is adjusted to a range of 20 to 1000MPa at 170 ℃, and when the content ratio of the filler is 30 mass% or more, the storage elastic modulus after curing of the adhesive layer is easily adjusted to the range. When the content of the filler is 75% by mass or less, film formability and heat fluidity of the adhesive layer at the time of die bonding are excellent. When the fluidity of the adhesive layer under heating during die bonding is improved, the adhesive layer adheres well to the adherend to improve the adhesive strength, and the unevenness of the adherend is easily embedded to suppress voids. More preferably 70% by mass or less, and still more preferably 60% by mass or less.

The adhesive layer of the present invention may contain 2 or more types of fillers having different average particle diameters as the filler. In this case, compared to the case of using a single filler, in the raw material mixture before forming a film, an increase in viscosity at a high filler content or a decrease in viscosity at a low filler content is easily prevented, good film formability is easily obtained, fluidity of the uncured adhesive layer can be optimally controlled, and excellent adhesive strength is easily obtained after curing the adhesive layer.

In the adhesive layer of the present invention, the average particle size of the filler is preferably 2.0 μm or less, more preferably 1.0 μm or less. When the average particle size of the filler is 2.0 μm or less, the film becomes easily thin. Here, the thin film means a thickness of 20 μm or less. Further, when the average particle size is 0.01 μm or more, the dispersibility is good.

In addition, from the viewpoint of preventing an increase or decrease in the viscosity of the raw material mixture before forming a film, optimally controlling the fluidity of the uncured adhesive layer, and improving the adhesion after curing of the adhesive layer, it is preferable to include the 1 st filler having an average particle diameter in the range of 0.1 to 1.0 μm and the 2 nd filler having an average particle diameter of the primary particle diameter in the range of 0.005 to 0.03 μm. Preferably, the composition comprises a1 st filler having an average particle diameter of 0.1 to 1.0 μm and 99% or more of particles distributed in a particle diameter range of 0.1 to 1.0 μm, and a2 nd filler having an average particle diameter of 0.005 to 0.03 μm and 99% or more of particles distributed in a particle diameter range of 0.005 to 0.1 μm.

The average particle diameter in the present invention means a D50 value of a cumulative volume distribution curve in which 50% by volume of particles have a diameter smaller than that value. In the present invention, the average particle diameter or the D50 value is measured by a laser diffraction method using, for example, a Malvern Mastersizer 2000 manufactured by Malvern Instruments. In this technique, the particle size in the dispersion is determined using diffraction of laser light, based on any application of the Fraunhofer or Mie theory. The present invention relates to a method for measuring an average particle diameter or a D50 value by scattering an incident laser beam at 0.02 to 135 DEG using Mie theory or Mie theory corrected for non-spherical particles.

In one embodiment of the present invention, the adhesive composition constituting the adhesive layer 13 may contain 10 to 40 mass% of a thermoplastic resin having a weight average molecular weight of 5000 to 200,000, 10 to 40 mass% of a thermopolymerizable component, and 30 to 75 mass% of a filler. In this embodiment, the filler content may be 30 to 60 mass%, or 40 to 60 mass%. The thermoplastic resin may have a mass average molecular weight of 5000 to 150,000, or 10,000 to 100,000.

in another embodiment, the adhesive composition constituting the adhesive layer 13 may contain 10 to 20 mass% of a thermoplastic resin having a weight average molecular weight of 200,000 to 2,000,000, 20 to 50 mass% of a thermopolymerizable component, and 30 to 75 mass% of a filler. In this embodiment, the filler content may be 30 to 60 mass%, or 30 to 50 mass%. The thermoplastic resin may have a mass average molecular weight of 200,000 to 1,000,000, or 200,000 to 800,000.

By adjusting the mixing ratio, the storage elastic modulus and the fluidity of the adhesive layer 13 after curing can be optimized, and the heat resistance at high temperature can be sufficiently obtained.

In the semiconductor processing tape 10 of the present invention, the adhesive layer 13 may be formed by directly or indirectly laminating a film formed in advance (hereinafter referred to as an adhesive film) on the base film 11. The temperature during lamination is preferably in the range of 10 to 100 ℃ and a linear pressure of 0.01 to 10N/m is applied. In this case, the release film may be peeled off after lamination, or may be used as it is as a cover film for the semiconductor processing tape 10 and peeled off when bonding a wafer.

The adhesive film may be laminated on the entire surface of the adhesive layer 12, or an adhesive film cut in advance to have a shape (precut) corresponding to the bonded wafer may be laminated on the adhesive layer 12. When the adhesive films corresponding to the wafers are laminated in this manner, as shown in fig. 3, the adhesive layer 13 is present in the portion where the wafer W is bonded, and the adhesive layer 13 is absent in the portion where the ring frame 20 is bonded, and only the adhesive layer 12 is present. In general, since the adhesive layer 13 is not easily peeled from an adherend, the ring frame 20 and the adhesive layer 12 can be bonded by using a precut adhesive film, and an effect that paste residue on the ring frame 20 is not easily generated when a tape is peeled after use is obtained.

< use >

The semiconductor processing tape 10 of the present invention can be used in a method for manufacturing a semiconductor device including a step of expanding the adhesive layer 13 by at least expanding the adhesive layer. Therefore, the other steps, the order of the steps, and the like are not particularly limited. For example, the present invention can be suitably used in the following methods (a) to (E) for manufacturing a semiconductor device.

Method (A) for manufacturing semiconductor device

A method for manufacturing a semiconductor device, comprising the steps of:

(a) A step of bonding a surface protective tape to the surface of the wafer on which the circuit pattern is formed,

(b) A back grinding step of grinding the back surface of the wafer,

(c) a step of bonding an adhesive film bonded to the adhesive layer of the semiconductor processing tape to the back surface of the wafer in a state where the wafer is heated at 70 to 80 ℃,

(d) a step of peeling the surface protective tape from the wafer surface,

(e) Irradiating the planned dividing portions of the wafer with laser light to form modified regions by multiphoton absorption in the wafer,

(f) A step of obtaining a plurality of adhesive film-attached chips by expanding the semiconductor processing tape and cutting the wafer and the adhesive film along a cutting line,

(g) A step of heating and shrinking a portion of the semiconductor processing tape not overlapping the chips to remove slack generated in the expanding step and maintain the spacing between the chips, and

(h) And picking up the chip with the adhesive layer from the adhesive layer of the tape for semiconductor processing.

The method for manufacturing a semiconductor device uses stealth dicing.

Method for manufacturing semiconductor device (B)

A method for manufacturing a semiconductor device, comprising the steps of:

(a) A step of bonding a surface protective tape to the surface of the wafer on which the circuit pattern is formed,

(b) A back grinding step of grinding the back surface of the wafer,

(c) A step of bonding an adhesive film bonded to the adhesive layer of the semiconductor processing tape to the back surface of the wafer in a state where the wafer is heated at 70 to 80 ℃,

(d) A step of peeling the surface protective tape from the wafer surface,

(e) Irradiating the wafer surface with laser light along the dividing lines to cut the wafer into individual chips,

(f) A step of obtaining a plurality of adhesive film-attached chips by expanding the semiconductor processing tape to cut the adhesive film so as to correspond to the chips,

(g) A step of heating and shrinking a portion of the semiconductor processing tape not overlapping the chips to remove slack generated in the expanding step and maintain the spacing between the chips, and

(h) and picking up the chip with the adhesive layer from the adhesive layer of the tape for semiconductor processing.

The method for manufacturing a semiconductor device is a method using full-cut laser dicing.

Method for manufacturing semiconductor device (C)

A method for manufacturing a semiconductor device, comprising the steps of:

(a) A step of bonding a surface protective tape to the surface of the wafer on which the circuit pattern is formed,

(b) A back grinding step of grinding the back surface of the wafer,

(c) A step of bonding an adhesive film bonded to the adhesive layer of the semiconductor processing tape to the back surface of the wafer in a state where the wafer is heated at 70 to 80 ℃,

(d) A step of peeling the surface protective tape from the wafer surface,

(e) Cutting the wafer along the dividing lines by using a dicing blade to cut the wafer into individual chips,

(f) A step of obtaining a plurality of adhesive film-attached chips by expanding the semiconductor processing tape to cut the adhesive film so as to correspond to the chips,

(g) A step of heating and shrinking a portion of the semiconductor processing tape not overlapping the chips to remove slack generated in the expanding step and maintain the spacing between the chips, and

(h) And picking up the chip with the adhesive layer from the adhesive layer of the tape for semiconductor processing.

The method for manufacturing a semiconductor device is a method for dicing using a full-cut blade.

Method for manufacturing semiconductor device (D)

a method for manufacturing a semiconductor device, comprising the steps of:

(a) A step of cutting the wafer formed with the circuit pattern along the predetermined cutting lines by using a dicing blade to a depth smaller than the thickness of the wafer,

(b) A step of bonding a surface protection tape to the surface of the wafer,

(c) A back grinding step of grinding the back surface of the wafer,

(d) a step of bonding an adhesive film bonded to the adhesive layer of the semiconductor processing tape to the back surface of the chip in a state where the wafer is heated at 70 to 80 ℃,

(e) A step of peeling the surface protective tape from the wafer surface,

(f) A step of obtaining a plurality of adhesive film-attached chips by expanding the semiconductor processing tape to cut the adhesive film corresponding to the chips,

(g) A step of heating and shrinking a portion of the semiconductor processing tape not overlapping the chips to remove slack generated in the expanding step and maintain the spacing between the chips, and

(h) And picking up the chip with the adhesive layer from the adhesive layer of the tape for semiconductor processing.

The method for manufacturing a semiconductor device is a method for dicing using a half-cut blade.

Method for manufacturing semiconductor device (E)

A method for manufacturing a semiconductor device, comprising the steps of:

(a) A step of bonding a surface protective tape to the surface of the wafer on which the circuit pattern is formed,

(b) Irradiating the planned dividing portions of the wafer with laser light to form modified regions based on multiphoton absorption in the wafer,

(c) a back grinding step of grinding the back surface of the wafer,

(d) A step of bonding the adhesive layer of the semiconductor processing tape to the back surface of the wafer in a state where the wafer is heated at 70 to 80 ℃,

(e) A step of peeling the surface-protective tape from the wafer surface,

(f) A step of obtaining a plurality of adhesive film-attached chips by expanding the semiconductor processing tape and cutting the wafer and the adhesive layer along a cutting line,

(g) A step of heating and shrinking a portion of the semiconductor processing tape not overlapping the chips to remove slack generated in the expanding step and maintain the spacing between the chips, and

(h) And picking up the chip with the adhesive layer from the adhesive layer of the semiconductor processing tape.

The method for manufacturing a semiconductor device uses stealth dicing.

< method of use >

A method of using the tape when the semiconductor processing tape 10 of the present invention is applied to the method (a) for manufacturing a semiconductor device will be described with reference to fig. 2 to 5. First, as shown in fig. 2, a surface protective tape 14 for protecting a circuit pattern, which contains an ultraviolet curable component in an adhesive, is bonded to the front surface of the wafer W having the circuit pattern formed thereon, and a back surface polishing step of grinding the back surface of the wafer W is performed.

After the back grinding step is completed, as shown in fig. 3, the wafer W is placed on the heating stage 25 of the wafer mounter with the front surface side facing downward, and then the semiconductor processing tape 10 is bonded to the back surface of the wafer W. The semiconductor processing tape 10 used here is one in which an adhesive film cut in advance (precut) in a shape corresponding to the shape of the wafer W to be bonded is laminated, and the adhesive layer 12 is exposed around the region where the adhesive layer 13 is exposed on the surface bonded to the wafer W. The portion of the semiconductor processing tape 10 exposed out of the adhesive layer 13 is bonded to the back surface of the wafer W, and the portion of the adhesive layer 12 around the adhesive layer 13 exposed is bonded to the ring frame 20. At this time, the heating stage 25 is set to 70 to 80 ℃ in advance, and thus the heating and bonding are performed. In the present embodiment, the tape 10 for semiconductor processing having the pressure-sensitive adhesive tape 15 including the base film 11 and the pressure-sensitive adhesive layer 12 provided on the base film 11 and the pressure-sensitive adhesive layer 13 provided on the pressure-sensitive adhesive layer 12 is used, but a pressure-sensitive adhesive tape and a film-like adhesive may be used separately. In this case, first, a film-like adhesive is bonded to the back surface of the wafer to form an adhesive layer, and the adhesive layer of the adhesive tape is bonded to the adhesive layer. In this case, the adhesive tape 15 of the present invention is used as the adhesive tape.

Next, the wafer W to which the semiconductor processing tape 10 is bonded is carried out of the heating stage 25, and is placed on the suction stage 26 with the semiconductor processing tape 10 side facing downward, as shown in fig. 4. Then, the surface protective tape 14 is peeled from the surface of the wafer W by irradiating the substrate surface side of the surface protective tape 14 with ultraviolet rays of, for example, 1000mJ/cm2 from above the wafer W which is suction-fixed to the suction table 26 using the energy ray light source 27 to reduce the adhesion of the surface protective tape 14 to the wafer W.

Next, as shown in fig. 5, the portions to be divided of the wafer W are irradiated with laser light, and modified regions 32 based on multiphoton absorption are formed in the wafer W.

next, as shown in fig. 6(a), the semiconductor processing tape 10 with the wafer W and the ring frame 20 bonded thereto is placed on the step 21 of the expanding device with the base film 11 side facing downward.

Next, as shown in fig. 6(b), the hollow cylindrical jacking member 22 of the expanding device is raised in a state where the ring frame 20 is fixed, and the semiconductor processing tape 10 is expanded (expanded). The expansion rate is, for example, 5 to 500mm/sec, and the expansion amount (lift amount) is, for example, 5 to 25 mm. As described above, the semiconductor processing tape 10 is stretched in the radial direction of the wafer W, whereby the wafer W is cut into the chip 34 units starting from the reformed region 32. At this time, in the adhesive layer 13, elongation (deformation) due to expansion is suppressed in a portion bonded to the back surface of the wafer W without causing breakage, but at a position between the chips 34, tension concentration due to expansion of the tape causes breakage. Therefore, as shown in fig. 6(c), the adhesive layer 13 is cut together with the wafer W. Thereby, a plurality of chips 34 with adhesive layers 13 can be obtained.

Next, as shown in fig. 7, the lift member 22 is returned to the original position, and a step for removing the slack of the semiconductor processing tape 10 generated in the previous expanding step and stably maintaining the pitch of the chips 34 is performed. In this step, for example, warm air of 40 to 120 ℃ is blown to an annular heat shrinking region 28 between a region of the semiconductor processing tape 10 where the chip 34 is present and the ring frame 20 by using a warm air nozzle 29 to shrink the base film 11 by heating, and the semiconductor processing tape 10 is brought into an open state with the pins (ピ ン). Subsequently, the adhesive layer 12 is subjected to energy ray curing treatment, thermosetting treatment, or the like to weaken the adhesive force of the adhesive layer 12 to the adhesive layer 13, and then the chip 34 is picked up.

The semiconductor processing tape 10 of the present embodiment has the adhesive layer 13 on the pressure-sensitive adhesive layer 12, but may be configured without providing the adhesive layer 13. In this case, the wafer may be simply cut after the wafer is bonded to the adhesive layer 12, or when the tape for semiconductor processing is used, an adhesive film prepared in the same manner as the adhesive layer 13 may be bonded to the adhesive layer 12 together with the wafer, and the wafer and the adhesive film may be cut.

< example >

Next, in order to further clarify the effects of the present invention, examples and comparative examples are described in detail, but the present invention is not limited to these examples.

[ production of semiconductor processing tape ]

(1) Production of substrate film

< substrate film A >

Resin beads of a zinc ionomer (15% methacrylic acid, 5% ethyl methacrylate, 72 ℃ softening point, 90 ℃ melting point, 0.96g/cm3 density, 5% zinc ion content) of an ethylene-methacrylic acid-ethyl methacrylate copolymer synthesized by a radical polymerization method were melted at 230 ℃ and formed into a long film having a thickness of 150 μm using an extruder. Subsequently, the long film was stretched in the TD direction so as to have a thickness of 90 μm, thereby producing a base film a.

< substrate film B >

A base film B was produced in the same manner as the base film a except that the thickness of the long film was set to 180 μm and the long film was stretched in the TD direction so as to have a thickness of 90 μm.

< substrate film C >

A base film C was produced in the same manner as the base film a except that the thickness of the long film was 215 μm and the long film was stretched in the TD direction so as to have a thickness of 90 μm.

< substrate film D >

Resin beads of a zinc ionomer (11% methacrylic acid content, 9% isobutyl methacrylate content, 64 ℃ softening point, 83 ℃ melting point, 0.95g/cm3 density, 4% zinc ion content) of an ethylene-methacrylic acid-isobutyl methacrylate copolymer synthesized by a radical polymerization method were melted at 230 ℃ and formed into a long film having a thickness of 150 μm using an extruder. Subsequently, the long film was stretched in the TD direction so as to have a thickness of 90 μm, thereby producing a base film D.

< substrate film E >

Mixing a hydrogenated styrene thermoplastic elastomer and homopolypropylene (PP) in a ratio of 52: the resin beads mixed at the compounding ratio of 48 were melted at 200 ℃ and formed into a long film having a thickness of 150 μm by using an extruder. Subsequently, the long film was stretched in the TD direction so as to have a thickness of 90 μm, thereby producing a base film E.

< substrate film F >

Mixing a hydrogenated styrene thermoplastic elastomer and homopolypropylene (PP) in a ratio of 64: the resin beads mixed at the compounding ratio of 36 were melted at 200 ℃ and molded into a long film having a thickness of 150 μm by using an extruder. Subsequently, the long film was stretched in the TD direction so as to have a thickness of 90 μm, thereby producing a base film F.

< substrate film G >

A base film G was produced in the same manner as the base film a except that the long film was stretched in the MD so as to have a thickness of 90 μm, taking the thickness of the long film as 150 μm.

< substrate film H >

A base film H was produced in the same manner as the base film D except that the long film was stretched in the MD so as to have a thickness of 90 μm, taking the thickness of the long film as 150 μm.

< substrate film I >

a base film I was produced in the same manner as the base film a except that the thickness of the long film was 90 μm and the long film was not subjected to the stretching treatment.

< substrate film J >

A base film J was produced in the same manner as the base film D, except that the thickness of the long film was 90 μm, and the long film was not subjected to the stretching treatment.

< substrate film K >

A base film K was produced in the same manner as the base film E, except that the thickness of the long film was 90 μm and the long film was not subjected to the stretching treatment.

< substrate film L >

A base film K was produced in the same manner as the base film F except that the thickness of the long film was 90 μm and the long film was not subjected to the stretching treatment.

< substrate film M >

A base film M was produced in the same manner as the base film a except that the long film was stretched in the TD direction so as to have a thickness of 90 μ M, assuming that the long film had a thickness of 110 μ M.

< substrate film N >

A base film N was produced in the same manner as the base film a except that the long film was stretched in the TD direction so as to have a thickness of 90 μm, taking the thickness of the long film as 120 μm.

(2) Preparation of acrylic copolymer

As the acrylic copolymer having a functional group (a1), a copolymer was prepared which contained 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate and methacrylic acid and had a mass average molecular weight of 70 ten thousand and a ratio of 2-ethylhexyl acrylate of 60 mol%. Then, 2-isocyanatoethyl methacrylate was added so that the iodine value became 25, and an acrylic copolymer having a glass transition temperature of-50 ℃, a hydroxyl value of 10mgKOH/g and an acid value of 5mgKOH/g was prepared.

(3) Preparation of adhesive composition

MEK was added to a composition comprising 40 parts by mass of an epoxy resin "1002" (product name, bisphenol A type epoxy resin, epoxy equivalent 600, manufactured by Mitsubishi chemical corporation), 100 parts by mass of an epoxy resin "806" (product name, bisphenol F type epoxy resin, epoxy equivalent 160, specific gravity 1.20, manufactured by Mitsubishi chemical corporation), 5 parts by mass of a curing agent "Dyhard 100 SF" (product name, dicyandiamide, manufactured by DEGUSSA), 200 parts by mass of a silica filler "SO-C2" (product name, manufactured by ADMAFINE corporation, average particle size 0.5 μm) and 3 parts by mass of a silica filler "AEROSIL 972" (product name, manufactured by Japan AEROSIL corporation, average particle size of primary particle size 0.016 μm) and mixed by stirring to prepare a uniform composition.

To this, 100 parts by mass of a phenoxy resin "PKHH" (trade name: 52,000 mass average molecular weight, glass transition temperature 92 ℃ C. manufactured by INCHEM), 0.6 part by mass of "KBM-802" (trade name: mercaptopropyltrimethoxysilane, manufactured by shin-Etsu Silicone Co., Ltd.) as a coupling agent, and 0.5 part by mass of "CUREZOL 2 PHZ-PW" (trade name: 2-phenyl-4, 5-dihydroxymethylimidazole, decomposition temperature 230 ℃ C. manufactured by Sikko Co., Ltd.) as a curing accelerator were added, and they were stirred and mixed until uniform. The mixture was filtered through a 100-mesh filter and vacuum defoamed to obtain a varnish of the adhesive composition.

< example 1>

To 100 parts by mass of the acrylic copolymer, 5 parts by mass of CORONATE L (manufactured by japan polyurethane) as a polyisocyanate was added, and 3 parts by mass of Esacure KIP150 (manufactured by Lamberti) as a photopolymerization initiator was added, and the obtained mixture was dissolved in ethyl acetate and stirred to prepare an adhesive composition.

Next, the pressure-sensitive adhesive composition was applied to a release liner formed of a polyethylene terephthalate film subjected to release treatment so that the thickness after drying became 10 μm, and after drying at 110 ℃ for 3 minutes, the pressure-sensitive adhesive composition was bonded to a base film to prepare a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed on the base film.

Next, the adhesive composition was applied onto a release liner formed of a polyethylene terephthalate film subjected to release treatment so that the thickness after drying became 20 μm, and the film was dried at 110 ℃ for 5 minutes to prepare an adhesive film having an adhesive layer formed on the release liner.

the adhesive sheet is cut into a shape shown in fig. 3 or the like so as to be attached to the ring frame so as to cover the opening. The adhesive film is cut into a shape shown in fig. 3 or the like so as to cover the back surface of the wafer. Then, the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive sheet and the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive film are bonded to each other so as to form a portion exposing the pressure-sensitive adhesive layer 12 around the pressure-sensitive adhesive film as shown in fig. 3 and the like, thereby producing a tape for semiconductor processing.

< examples 2 to 8 and comparative examples 1 to 6>

Semiconductor processing tapes of examples 2 to 8 and comparative examples 1 to 6 were produced in the same manner as in example 1, except that the base films described in table 1 were used.

The adhesive tape of the semiconductor processing tape of examples and comparative examples was cut into a length of 24mm (direction in which the amount of deformation was measured) and a width of 5mm (direction orthogonal to the direction in which the amount of deformation was measured), and sample pieces were prepared. The deformation of the obtained sample piece due to temperature in 2 directions of MD and TD was measured by a tensile load method under the following measurement conditions using a thermo-mechanical property tester (product name: TMA8310 manufactured by RIGAKU corporation).

(measurement conditions)

measuring temperature: -60 to 100 DEG C

Temperature rise rate: 5 ℃/min

And (3) measuring the load: 19.6mN

ambient gas: nitrogen environment (100ml/min)

Sampling: 0.5s

The distance between the clamps: 20mm

Then, the thermal deformation rate is calculated from the following formula (1), an integrated value calculated as the sum of the thermal deformation rates at 1 ℃ between 40 ℃ and 80 ℃ in each of the MD direction and the TD direction is obtained, and the sum thereof is calculated. The results are shown in tables 1 and 2.

Thermal deformation rate TMA (%) (displacement of sample length/sample length before measurement) × 100(1)

[ evaluation of the holding Property of the slit Width ]

The wafers were cut into chips by the following method using the semiconductor processing tapes of the examples and comparative examples, and the notch width retention was evaluated.

The following steps are carried out:

(a) A step of bonding a surface protective tape to the surface of the wafer on which the circuit pattern is formed,

(b) Irradiating the planned dividing portions of the wafer with laser light to form modified regions based on multiphoton absorption in the wafer,

(c) A back grinding step of grinding the back surface of the wafer,

(d) A step of bonding the adhesive layer of the semiconductor processing tape to the back surface of the wafer in a state where the wafer is heated at 70 to 80 ℃,

(e) A step of peeling the surface-protective tape from the wafer surface,

(f) A step of obtaining a plurality of adhesive film-attached chips by expanding the semiconductor processing tape and cutting the wafer and the adhesive layer along a cutting line,

(g) Heating and shrinking a portion of the semiconductor processing tape not overlapping the chip (an annular region between a region where the chip is present and an annular frame) to remove (f) slack generated in the expanding step and maintain the spacing between the chips, and

(h) And picking up the chip with the adhesive layer from the adhesive layer of the tape for semiconductor processing.

In the step (d), the wafer is bonded to the semiconductor processing tape so that the cut line of the wafer is along the MD direction and the TD direction of the base film.

(f) In the process, a cutting ring frame attached to a semiconductor processing tape was pressed down by an expanding ring of the DDS2300 manufactured by DISCO corporation, and a portion of the outer periphery of the wafer attachment portion of the semiconductor processing tape, which portion does not overlap the wafer, was pressed against a circular push-up member to expand the semiconductor processing tape. As the conditions in the step (f), the expansion amount was adjusted so that the expansion speed was 300mm/sec and the expansion height was 10 mm. Here, the expansion amount is an amount of change in relative positions of the ring frame and the jack member before and after the pushing. The chip size is 1X 1mm square.

(g) the process comprises the steps of expanding the film again at an expansion rate of 1mm/sec and an expansion height of 10mm at normal temperature, and then performing heat shrinkage treatment under the following conditions.

[ Condition 1]

Setting temperature of a heater: 220 deg.C

Hot air quantity: 40L/min

Spacing between heater and semiconductor processing tape: 20mm

heater rotation speed: 7 DEG/sec

[ Condition 2]

Setting temperature of a heater: 220 deg.C

Hot air quantity: 40L/min

Spacing between heater and semiconductor processing tape: 20mm

Heater rotation speed: 5 deg./sec

Immediately after the step (g), as shown in fig. 8, the semiconductor processing tapes of examples 1 to 8 and comparative examples 1 to 6 were measured for the notch width X (MD notch width) between the chip 50a at the rightmost end of the adhesive tape in the MD direction and the chip adjacent to the MD direction center, and for the notch width Y (TD notch width) between the chip 50a and the chip adjacent to the TD direction center, which were free from defects in the MD direction. Similarly, the MD slit width and the TD slit width were measured for the chip 50b at the leftmost end of the adhesive tape in fig. 8, which had no defect in the MD direction. The MD slit width and the TD slit width were also measured for the endmost chip 51 and the chip 52 located at the center of the adhesive tape, which had no defect in the TD direction. The average value of the 5-point MD-direction slit width and the average value of the 5-point TD-direction slit width are calculated. Then, the smaller of the 5-point average value of the MD-direction slit width and the 5-point average value of the TD-direction slit width is set as the minimum slit width. In the above-described (g) step, the samples with the minimum notch widths of 7 μm or more were evaluated as "excellent" for good products, the samples with the minimum notch widths of 7 μm or more were evaluated as "good products" for condition 2, the samples with the minimum notch widths of 5 μm or more were evaluated as "Δ" for acceptable products, and the samples with the minimum notch widths of less than 5 μm were evaluated as "poor" for defective products for condition 1 and condition 2. The results are shown in tables 1 and 2.

[ Table 1]