阅读说明：本技术 背面研磨带 (Back grinding belt ) 是由 金殷英 金色拉 李光珠 金相还 朴成灿 尹美善 于 2019-03-07 设计创作，主要内容包括：根据本发明的背面研磨带具有优异的耐水性,因此容易地保护图案,并且具有优异的各层之间的粘合性,因此在移除带的过程中各层不分离,使得其适用于背面研磨过程。(The back grinding tape according to the present invention has excellent water resistance, thus easily protecting patterns, and excellent adhesiveness between layers, thus the layers are not separated during the removal of the tape, making it suitable for a back grinding process.)

1. A back side grinding tape comprising: a hard coating layer; an intermediate layer comprising a polyurethane resin; and an adhesive layer, wherein the adhesive layer,

wherein the sum of the polar energy values of the hard coat layer and the intermediate layer according to the following mathematical equation 1 is 13 to 17 dynes/cm, and

the intermediate layer has a polar energy value of 3.5 dynes/cm or less according to the following mathematical equation 1:

[ mathematical equation 1]

Polar properties (dyne/cm) ═ surface free energy (dyne/cm) -dispersion (dyne/cm)

Wherein, in the equation, the surface free energy and the dispersion degree use water and diiodomethane (CH) according to Wu harmonization method₂I₂) The solution.

2. The backgrinding tape according to claim 1, wherein the sum of the polar energy values of the hard coat layer and the intermediate layer comprising a polyurethane-based resin is from 13.3 dyne/cm to 16 dyne/cm, and the polar energy value of the intermediate layer comprising a polyurethane-based resin is 3.0 dyne/cm or less.

3. The backgrinding tape of claim 1, wherein the hard coating has a thickness of 0.1 to 10 μ ι η.

4. The back-grinding tape according to claim 1, wherein the thickness of the intermediate layer comprising a polyurethane-based resin is 50 μm to 500 μm.

5. The back grinding tape according to claim 1, wherein the bonding layer has a thickness of 0.5 μm to 60 μm.

6. The backgrinding tape of claim 1, wherein the hard coating comprises one or more selected from the group consisting of: a polyester compound, an acryl compound, a modified polyurethane compound, a cellulose acetate compound, and a polycaprolactone compound.

7. The back-grinding tape according to claim 1, wherein the intermediate layer comprising a polyurethane-based resin is formed of a composition for forming an intermediate layer comprising a polyurethane-based resin, an acrylate-based monomer, a curing agent, and a photoinitiator.

8. The backgrinding tape of claim 7, wherein the acrylate-based monomer comprises a hydroxyl-containing acrylate-based monomer.

9. The backgrinding tape of claim 9, wherein the hydroxyl-containing acrylate-based monomer is included at a content of 1 to 25 wt% based on the total content of the composition.

10. The back-grinding tape according to claim 1, wherein the adhesive layer is formed of a composition for forming an adhesive layer comprising an acrylate-based thermosetting resin, a curing agent, a photoinitiator, and a solvent.

11. The backgrinding tape of claim 1, wherein the backgrinding tape is used in a backgrinding process.

Technical Field

Cross Reference to Related Applications

This application claims the benefit of korean patent application No. 10-2018-0033909, filed on 23.3.2018 from the korean intellectual property office, the disclosure of which is incorporated herein by reference in its entirety.

The present invention relates to a back-grinding tape, and particularly to an adhesive tape attached on a surface of a semiconductor wafer and used for protecting the surface in a back-grinding process during a manufacturing process of a semiconductor.

Background

Recently, as the trend of electronic devices toward miniaturization, high functionality, and large capacity is increasing, the demand for high density and high integration of semiconductor packages is rapidly increasing. Reflecting this, the size of semiconductor chips is becoming larger and larger, and at the same time, the thickness of chips is becoming thinner and the degree of integration of circuits is increasing. However, the modulus of the semiconductor chip itself is lowered, thereby causing a problem in terms of the reliability of the manufacturing process or the final product.

According to such a demand for a large and thin semiconductor, a back grinding process is basically performed in which the back of a wafer is ground with a grinding wheel composed of fine diamond particles to form a thin chip thickness, thereby facilitating assembly, but during the back grinding process, damage of the wafer such as contamination caused by a large amount of silicon powder and particles and crack generation are frequently generated. Therefore, the function of the back grinding tape for protecting the surface of the semiconductor wafer becomes more important.

In order to smoothly perform the back grinding process, the back grinding tape should effectively protect the pattern side of the wafer, and should be easily removed without residue after the grinding process is completed, and thus various studies on the improvement of the adhesive force and other characteristics of the back grinding tape are underway.

Meanwhile, in the case where the back-grinding tape is composed of multiple layers, the layers may be separated during the removal of the back-grinding tape, and therefore it is necessary to develop a technique capable of simultaneously achieving improvement in the characteristics for protecting the pattern side and easy removal.

[ Prior art documents ]

[ patent document ]

(patent document 0001) Korean patent laid-open publication No. 10-2007- -

Disclosure of Invention

Technical problem

An object of the present invention is to provide a back grinding tape attached on a surface of a wafer to protect the surface during a back grinding process during a manufacturing process of a semiconductor.

Technical scheme

According to the present invention, there is provided a back-grinding tape comprising: a hard coating layer; an intermediate layer comprising a polyurethane resin; and an adhesive layer, wherein the sum of the polar energy values according to mathematical equation 1 of the hard coating layer and the intermediate layer is 13 dyne/cm to 17 dyne/cm, and the polar energy value according to mathematical equation 1 of the intermediate layer is 3.5 dyne/cm or less.

The back grinding tape is an adhesive tape for protecting the surface of the wafer pattern during back grinding.

Hereinafter, a back-grinding tape according to an embodiment of the present invention will be described in detail.

First, technical terms used in the present specification are used only to refer to specific embodiments, and are not intended to limit the present invention unless specifically mentioned.

The singular forms "a", "an" and "the" include plural referents unless the content clearly dictates otherwise or is clear from the context.

As used herein, the terms "comprises," "comprising," "includes" and the like, are intended to specify the presence of stated features, quantities, steps, elements, or combinations thereof, and they are not intended to preclude the presence or addition of one or more other features, quantities, steps, elements, or combinations thereof.

In addition, terms including ordinal numbers such as "first", "second", and the like are used to distinguish one constituent element from other constituent elements, and the present invention is not limited thereto. For example, within the scope of the claims of the present invention, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

Further, in the case where it is stated that any constituent element is formed "on the upper portion (or lower portion) of the base" or "on the base (or lower portion)", this means that any constituent element is formed in contact with the upper side (or lower side) of the base, or other constituent elements may be additionally included between the base and any configuration formed on (or under) the base.

As used herein, (meth) acrylate refers to both acrylate and methacrylate.

Fig. 1 shows a sectional structure of a back-grinding tape 10 according to an embodiment.

According to fig. 1, the back-grinding tape 10 may include a hard coating layer 100, an intermediate layer 200 including a polyurethane-based resin, and an adhesive layer 300. The hard coat layer 100, the intermediate layer 200 including the polyurethane-based resin, and the adhesive layer 300 may be sequentially stacked, and a predetermined functional layer may be additionally formed on either side of or between the hard coat layer 100, the intermediate layer 200 including the polyurethane-based resin, and the adhesive layer 300.

Further, in the case where the back grinding tape 10 is used for the back grinding process, the adhesive layer 300 may be attached adjacent to the wafer pattern.

In the present invention, the hard coating layer 100 may be located on the lower side, and the intermediate layer 200 and the adhesive layer 300 may be stacked thereon.

The back grinding tape 10 according to one embodiment of the present invention may be used to protect the surface of a wafer pattern in a back grinding process during a manufacturing process of a semiconductor.

The tape used in the back grinding process may be composed of multiple layers, but in this case, the layers may be separated in the step of removing the tape, and thus sufficient adhesion between the layers is required. The tape may absorb water or solvent or the like used in the back grinding process, thereby causing a defective pattern. However, since the water resistance and the adhesiveness of such an adhesive tape are in a trade-off relationship with each other, it is difficult to simultaneously secure the characteristics.

Accordingly, the present inventors simultaneously achieved excellent water resistance of the tape and excellent adhesion between the respective layers by extracting specific parameters from contact angles measured at the hard coating layer 100 and the intermediate layer 200 including the polyurethane-based resin, respectively.

The back-grinding tape 10 according to the present invention satisfies the following requirements: the sum of the polar energy values of the hard coat layer 100 and the intermediate layer 200 comprising a polyurethane-based resin is 13 dyne/cm to 17 dyne/cm, and the polar energy value of the intermediate layer 200 comprising a polyurethane-based resin is 3.5 dyne/cm or less, thereby ensuring excellent water resistance and interlayer adhesiveness. Therefore, the back grinding process can be smoothly performed, and the film can be easily removed after the process is completed, thereby improving the reliability of the semiconductor chip.

In the back-grinding tape 10 according to the present invention, if the sum of the polar energy values of the hard coating layer 100 and the intermediate layer 200 including the urethane-based resin is less than 13 dyne/cm, the interlayer adhesion may be deteriorated, and thus it may be difficult to smoothly perform the back-grinding process, and the layers may be separated in the step of removing the film after the back-grinding process is completed. Further, if the sum of the polar energy values of the two layers is more than 17 dynes/cm, the hygroscopicity may increase to affect the pattern, and it may be difficult to uniformly perform the process due to the variation of the film thickness.

In the back-grinding tape 10 according to the present invention, if the polarity energy value of the intermediate layer 200 including the urethane-based resin is greater than 3.5 dynes/cm, the water resistance may be significantly deteriorated, thereby causing a defective pattern during back-grinding.

Further, preferably, the requirement that the sum of the polar energy values is 13.3 to 16 dynes/cm and the polar energy value of the intermediate layer 200 comprising the polyurethane-based resin is 3.0 dynes/cm or less can be simultaneously achieved, in which case the above-described effect can be maximized.

In the present invention, the polarity energy is respectively applied to the surfaces of the hard coating layer 100 and the intermediate layer 200 including the polyurethane-based resin according to the following mathematical formula 1The above measured value. Since the polymer material has viscosity and elasticity, the surface energy of the polymer material cannot be directly measured, and thus the surface energy is indirectly calculated through the measurement of the contact angle. In the present invention, two measurement solutions (water and diiodomethane (CH) were used according to the Wu-Harmonic method₂I₂) Solution) the contact angle on each measurement object side was measured, and Wu harmonic equations were introduced to calculate the surface energy and dispersion degree, from which the polar properties were derived.

[ mathematical equation 1]

Polar properties (dyne/cm) ═ surface free energy (dyne/cm) -dispersion (dyne/cm)

In the equation, surface free energy and dispersity are achieved using water and diiodomethane (CH) according to Wu's harmonization method₂I₂) The solution.

In the present invention, Wu harmonic equation is an equation commonly used in the art, and a contact angle using polar solvent water and non-polar solvent diiodomethane and its unique surface tension are introduced into Wu harmonic equation to design two equations separately, from which the surface free energy value and the dispersion value of the present invention can be calculated by arithmetic mean thereof.

For such measurement of surface free energy and dispersion according to Wu's harmony equation, the disclosures of reference 1(S.Wu, culture of Interfacial tests in Polymer systems. in: J.Polym.Sci.43(1971), pp.19 to 30) and reference 2(S.Wu, Polar and Nonpolarinteraction in addition. in: J.addition 5(1973), pp.39 to 55) can be applied. In addition, it can be calculated by the ADVANCE software commercially available from KRUSS Company.

For example, in the mathematical equation 1 of the present invention, the surface free energy and the dispersion degree can be derived by the following simultaneous equations of the mathematical equations 1-1 and 1-2.

The surface free energy of mathematical equation 1 corresponds to σ in the following mathematical equations 1-1 and 1-2_sThe polarity energy corresponds to σ_s ^D(polar part of surface energy of solid) and the degree of dispersion corresponds to σ_s ^ND(nonpolar portion of the surface energy of the solid). Namely, satisfyσ_s＝σ_s ^D+σ_s ^ND(or σ)_s ^D＝σ_s-σ_s ^ND)。

The following mathematical Equation 1-1 is Young's Equation.

[ mathematical equation 1-1]

σ_s＝σ_sl+σ_l·cosθ

In the mathematical equation 1-1,

σ_sis the surface free energy of a solid, theta is the contact angle measurement on the surface of the object, sigma_lIs the surface tension, σ, of the liquid_slIs the interfacial tension between a liquid and a solid. Herein, the contact angle is a value obtained through experiments, and the surface tension of the liquid is a unique value of water or methyl iodide.

Furthermore, the interfacial tension σ between liquid and solid_slCan be derived from the Fowkes method of the following mathematical equation 2.

[ mathematical equations 1-2]

In mathematical equation 1-2, σ_sIs the surface free energy of a solid, σ_lIs the surface tension, σ, of the liquid_s ^DIs the polar part of the surface energy of the solid, σ_s ^NDIs the non-polar part of the surface energy of the solid, σ_l ^DIs the polar part of the surface tension of the liquid, σ_l ^NDIs the non-polar part of the surface tension of the liquid.

The surface free energy value and the dispersion value of the polymer layer for each solvent can be derived by the simultaneous equations of the above mathematical equation 1 and mathematical equation 2, and the surface free energy value and the dispersion value of the present invention can be derived by the arithmetic mean thereof.

Hard coating 100

In the back-grinding tape 10 according to one embodiment of the present invention, the hard coating layer 100 is an outermost layer for protecting the pattern from external foreign substances (abrasives, solvents, etc. used in the grinding process) and physical impact, etc. during the back-grinding process, and for this reason, a material that achieves optimal strength may be selected.

In the present invention, the hard coating layer 100 satisfies the specific polar energy parameter value as described above, thus exhibiting excellent water resistance, and has excellent adhesion to an underlying layer, thus being suitable for use as a film for a back grinding process.

The hard coating layer 100 may have a thickness of 0.1 μm to 10 μm, preferably 1 μm to 5 μm, and if the above thickness range is satisfied, it may be easily handled while achieving optimal strength, and may prevent unnecessary steps from being generated in the back grinding process.

If the thickness of the hard coating layer is less than 0.1 μm, the anti-blocking effect may be insignificant, and if the thickness of the hard coating layer is greater than 10 μm, bubble generation may increase when attaching to a wafer, and stress relaxation of the film may deteriorate.

As the hard coat layer 100, a material capable of satisfying the above-described polarity parameter may be appropriately selected, and specifically, the hard coat layer 100 may contain one or more selected from the group consisting of: a polyester compound, an acryl compound, a modified urethane compound, a cellulose acetate compound, and a polycaprolactone compound.

The hard coat layer 100 may be prepared by an extrusion process, a casting process, a calendering process, a heat curing process, or a photo-curing process, and in the case where the hard coat layer is formed by the photo-curing process, it may be formed by applying a composition for forming a hard coat layer, which includes a curable monomer, a photo-curing initiator, and additional additives in addition to the above components, on a base film and performing photo-curing.

The base film may be formed of a peelable material, and it may be removed after forming the intermediate layer 200 including the polyurethane-based resin, and the adhesive layer 300 thereon.

Intermediate layer 200 comprising polyurethane resin

In the back-grinding tape 10 according to one embodiment of the present invention, the intermediate layer 200 including the urethane-based resin is formed on the hard coat layer 100, and the intermediate layer 200 is a layer for protecting a pattern from external foreign substances (abrasives, solvents, etc. used in a grinding process), physical impact, and the like, and for this reason, a material having excellent stress relaxation can be selected.

In the present invention, the intermediate layer 200 including the polyurethane-based resin satisfies the specific polar energy parameter value as described above, thus exhibiting excellent water resistance, and has excellent adhesion to the lower hard coat layer 100, thus being suitable for use as a film for the back grinding process.

The thickness of the intermediate layer 200 including the polyurethane-based resin may be 50 μm to 500 μm, preferably, 100 μm to 300 μm, and in the case where it satisfies the above thickness range, it may achieve optimal stress relaxation, and thus it is suitable for protecting the pattern from external physical impact, and in particular, even if it absorbs external moisture, it may minimize the influence on the pattern side. If the thickness of the intermediate layer is less than 50 μm, the durability thereof may be slightly insufficient, and thus it may be difficult to perform the function as a support.

The intermediate layer 200 including the urethane-based resin may be formed of a composition for forming the intermediate layer including the urethane-based resin, an acrylate-based monomer, a curing agent, and a photoinitiator.

The polyurethane-based resin is a polymer resin having a urethane bond (-NHCOO-) in a repeating unit of a main chain, and it can be formed by condensation polymerization of a diol-based compound and a diisocyanate compound.

As specific examples of the diol-based compound used for synthesizing the polyurethane-based resin, there may be mentioned ethylene glycol, 1, 4-butanediol, diethylene glycol, polycarbonate diol, and the like, but not limited thereto, and these compounds may be used alone or in combination of two or more.

As specific examples of the isocyanate used for synthesizing the polyurethane-based resin, there may be mentioned isocyanates having 4 to 20 carbon atoms, such as tetramethylene 1, 4-diisocyanate, pentamethylene 1, 5-diisocyanate, hexamethylene 1, 6-diisocyanate, 2-methyl-1, 5-diisocyanatopentane, octamethylene 1, 8-diisocyanate, decamethylene 1, 10-diisocyanate, dodecamethylene 1, 12-diisocyanate, tetradecamethylene 1, 14-diisocyanate, 2, 4-trimethylhexane isocyanate and 2,4, 4-trimethylhexane isocyanate, 1, 3-bis (1-isocyanato-1-methylethyl) benzene (m-TMXDI), lysine diisocyanate derivatives and the like, and mixtures of the above isocyanates may be used. Further, there may be mentioned isoborodiisocyanate, diphenylmethane-4, 4' -diisocyanate, isophorone diisocyanate, toluene diisocyanate and the like. These compounds may be used alone or in a combination of two or more.

For the synthesis of the polyurethane-based resin, a (meth) acrylate-based monomer as a diluent monomer and a hydroxyl group-containing (meth) acrylate as a terminal capping agent may be further included. However, the diluent monomer does not participate in the reaction and thus may remain. The components of the (meth) acrylate-based monomers described below can be used for this purpose.

The content of the polyurethane-based resin may be 10 to 40% by weight, preferably 15 to 35% by weight, or 20 to 30% by weight, based on the total weight of the composition, and if used in the above content range, the water resistance and interlayer adhesion of the final multilayer film may be improved at the same time.

As specific examples of the acrylate-based monomer, aliphatic (meth) acrylates, alicyclic (meth) acrylates, aromatic (meth) acrylates, hydroxyl group-containing (meth) acrylates, carboxyl group-containing (meth) acrylates, and the like can be mentioned. These compounds may be used alone or in a combination of two or more. Among them, the hydroxyl group-containing (meth) acrylate is preferably used because it is suitable for satisfying the polar energy parameter defined in the present invention.

As the aliphatic alkyl (meth) acrylate, there may be mentioned alkyl (meth) acrylates having an alkyl group having a carbon number of 1 to 20, and specifically, there may be mentioned methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, sec-butyl (meth) acrylate, pentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, and the like. These compounds may be used alone or in a combination of two or more.

As the alicyclic alkyl (meth) acrylate, there may be mentioned cycloalkyl (meth) acrylates having a cycloalkyl group having a carbon number of 3 to 30, and specifically, isobornyl acrylate (IBOA), trimethylcyclohexyl acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentyl methacrylate, dicyclopentenyl oxy (meth) acrylate, and the like. These compounds may be used alone or in a combination of two or more.

As the aromatic hydrocarbon-based (meth) acrylate, hydrocarbon-based (meth) acrylates having an aromatic group with a carbon number of 6 to 30 may be mentioned, and specifically, phenylhydroxypropyl (meth) acrylate, o-phenylphenol EO (meth) acrylate, 2-hydroxy-3-phenylphenoxypropyl (meth) acrylate, phenol EO (meth) acrylate, and the like may be mentioned. These compounds may be used alone or in a combination of two or more.

As the hydroxyl group-containing (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and the like may be mentioned, and as the carboxyl group-containing (meth) acrylate, (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid and the like may be mentioned. These compounds may be used alone or in a combination of two or more.

The content of the acrylate-based monomer may be 50 to 85 wt%, preferably 65 to 80 wt%, based on the total weight of the composition, and if used in the above content range, economic efficiency may be excellent while achieving optimal curing efficiency. Among the acrylate-based monomers, a diluent monomer used during the synthesis of the polyurethane-based resin may be included.

In the case where the hydroxyl group-containing (meth) acrylate is contained in the acrylate-based monomer, the hydroxyl group-containing (meth) acrylate does not participate in the photocuring reaction for forming the intermediate layer, and therefore, after the intermediate layer is formed, the hydroxyl group-containing (meth) acrylate affects the polar energy parameter desired in the present invention. Therefore, the hydroxyl group-containing (meth) acrylate may be included in a content of 1 to 25% by weight, preferably 5 to 15% by weight, based on the total content of the composition, and if included in the above content range, it may be suitable to satisfy the polar energy parameter defined in the present invention, thereby simultaneously improving the water resistance and interlayer adhesiveness of the final multilayer film. Meanwhile, the acrylate-based monomer other than the hydroxyl group-containing (meth) acrylate may be included in a remaining content to satisfy the above range (40 to 90 wt%).

As specific examples of the curing agent, polar monomers such as polyfunctional acrylates may be mentioned, and specifically, 1, 4-butanediol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1, 2-ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1, 12-dodecanediol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, neopentyl glycol hydroxypivalate di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone-modified dicyclopentenyl di (meth) acrylate, ethylene oxide-modified di (meth) acrylate, di (meth) acryloyloxyethyl isocyanurate, allylated cyclohexyl di (meth) acrylate, cyclohexyl acrylate, and the like may be mentioned, Tricyclodecanedimethanol (meth) acrylate, dimethyloldicyclopentane di (meth) acrylate, ethylene oxide-modified hexahydrophthalate di (meth) acrylate, tricyclodecanedimethanol (meth) acrylate, neopentyl glycol-modified trimethylpropane di (meth) acrylate, adamantane di (meth) acrylate, 9-bis [4- (2-acryloyloxyethoxy) phenyl ] fluorene, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid-modified dipentaerythritol tri (meth) acrylate, propylene oxide-modified trimethylolpropane tri (meth) acrylate, tris (meth) acryloyloxyethyl isocyanurate, diglycerol tetra (meth) acrylate, propylene oxide-modified trimethylolpropane tri (meth) acrylate, trimethylolpropane tetra (meth) acrylate, propylene oxide di (meth) acrylate, dipentaerythritol tetra (meth) acrylate, propionic acid-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, urethane (meth) acrylate, a reaction product of an isocyanate monomer and trimethylolpropane tri (meth) acrylate, and the like. These compounds may be used alone or in a combination of two or more.

The content of the curing agent may be 0.1 to 5% by weight, preferably 0.5 to 2% by weight, based on the total weight of the composition for forming the intermediate layer, and if used in the above content range, economic efficiency may be excellent while achieving optimal curing efficiency.

The photoinitiator is not particularly limited as long as it initiates a photocuring reaction by light irradiation, and as specific examples thereof, benzoin methyl ether, 2,4, 6-trimethylbenzoyl diphenylphosphine oxide, bis (2,4, 6-trimethylbenzoyl) phenylphosphine oxide, α -methoxy- α -hydroxyacetophenone, 2-benzoyl-2- (dimethylamino) -1- [4- (4-morpholino) phenyl ] -1-butanone, 2-dimethoxy-2-phenylacetophenone, 2-dimethoxy-1, 2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenylketone, 2-benzyl-2- (dimethylamino) -1- [4- (4-morpholino) phenyl ] -1-butanone and the like. These compounds may be used alone or in a combination of two or more.

The photoinitiator may be used in a content of 0.1 to 5 wt%, preferably 0.3 to 1.5 wt%, based on the total weight of the composition for forming the intermediate layer, and if used in the above content range, excellent economic efficiency may be obtained while achieving optimal photocuring efficiency.

The intermediate layer 200 including the polyurethane-based resin may be prepared by a photo-curing process, and it may be formed by applying a composition for forming the intermediate layer including the polyurethane-based resin and performing photo-curing as described above for the hard coating layer 100.

Adhesive layer 300

In the back-grinding tape 10 according to one embodiment of the present invention, the adhesive layer 300 is formed on the intermediate layer 200 including the polyurethane-based resin, and the adhesive layer 300 is a layer attached to be adjacent to the wafer pattern, for which a photo-curable pressure-sensitive adhesive material may be selected.

In the present invention, the adhesive layer 300 should have appropriate adhesive force when processing a product such as a semiconductor wafer, and thus should be attached to the semiconductor wafer exactly during processing, and it should be easily peeled off after processing without applying a load to the product. Therefore, it is preferable to use a material containing a certain amount of a thermal curing agent and a photoinitiator for this purpose.

Preferably, the following materials are applied to the adhesive layer 300: a film is formed on the intermediate layer 200 including the polyurethane-based resin by heat curing to prepare an adhesive film for protecting the surface of the semiconductor wafer, and after the back grinding process is completed, the material peeled off from the surface of the wafer may be irradiated with additional light.

The thickness of the adhesive layer 300 may be 0.5 μm to 60 μm, preferably 1 μm to 50 μm, or 5 μm to 40 μm, and if the thickness of the adhesive layer satisfies the above thickness range, it may be easily adhered to and peeled from the surface of the wafer, and if the thickness of the adhesive layer does not fall within the above range, it may be difficult to obtain a uniform adhesive layer, and the characteristics of the film may become uneven. If the thickness is less than 0.5 μm, the thickness of the layer may be too thin to deteriorate the adhesive force, and conversely, if the thickness is more than 60 μm, residues may remain on the surface of the wafer when the adhesive film is removed due to an excessive thickness.

The adhesive layer 300 may include an acrylate-based thermosetting resin, and it may further include a solvent, a thermal curing agent, and a photoinitiator. The acrylate-based thermosetting resin may be prepared by mixing an acrylate-based monomer, a polymerization initiator, and a solvent to perform a polymerization reaction and reacting the polymerized acrylate-based polymer with a curing agent.

The adhesive layer 300 may be formed by: applying a composition for forming an adhesive layer comprising the above components, additional additives and a solvent on the intermediate layer 200 comprising a polyurethane-based resin and performing heat curing; or the adhesive layer 300 is formed on a separate releasable base film and then the adhesive layer 300 is bonded to the polyurethane-based film layer 200.

The back-grinding tape 10 according to one embodiment of the present invention includes: a hard coating layer; an intermediate layer comprising a polyurethane resin; and an adhesive layer, and satisfies specific polarity energy parameters as described above, thereby easily preventing damage to a circuit pattern and the like present on the surface during precision processing of the semiconductor wafer, or preventing contamination of the semiconductor wafer due to foreign substances, moisture, or chemicals generated during processing. Further, since the back-grinding tape 10 satisfies the above-described characteristics, it can be removed without peeling residue after the precision processing of the semiconductor wafer is completed.

Advantageous effects

The back grinding tape according to the present invention has excellent water resistance, thus easily protecting a pattern, and excellent interlayer adhesiveness, thus the layers are not separated during a process of removing a film, thereby providing a tape suitable for a back grinding process.

Drawings

Fig. 1 shows a sectional structure of a back-grinding tape 10 according to an embodiment of the present invention.

Detailed Description

Hereinafter, preferred embodiments are presented to better understand the present invention. However, the following examples are presented only as illustrations of the present invention, and the scope of the present invention is not limited thereto.

Preparation example 1: composition for forming hard coat layer

Preparation examples 1 to 1: composition for forming hard coat layer

A composition for forming a hard coat layer (1-1) was prepared by mixing 40g of PS1000 (containing a polycaprolactone-based compound) from Cho Kwang Paint, 8g of PS1000 blue, and 7g of Methyl Ethyl Ketone (MEK) as a diluent solvent.

Preparation examples 1 to 2: composition for forming hard coat layer

50g of Sam Young Ink's CAP varnish (containing a cellulose acetate-based compound) and 50g of a dilution solvent of Methyl Ethyl Ketone (MEK) were mixed to prepare a composition (1-2) for forming a hard coat layer.

Preparation examples 1 to 3: composition for forming hard coat layer

30g of Sam Young Ink A-PET 328 varnish (containing a polyester-based compound), 10g of acrylic blue (T-6), 20g of Methyl Ethyl Ketone (MEK) and 0.15g of Sam Young Ink LP.SUPER curing agent were mixed to prepare compositions (1-3) for forming a hard coat layer.

Preparation examples 1 to 4: composition for forming hard coat layer

6g of polymer silicone resin KS-3650 of Shin-Etsu silicone, 0.1g of platinum catalyst PL-50T, 50g of a toluene solvent and 50g of Methyl Ethyl Ketone (MEK) were mixed to prepare compositions (1-4) for forming a hard coat layer.

Preparation example 2: composition for forming intermediate layer comprising polyurethane-based resin

Preparation example 2-1: composition for forming intermediate layer comprising polyurethane-based resin

A diluted monomer of 21g of polycarbonate diol, 3g of isophorone diisocyanate (IPDI) and 21g of cyclohexyl methacrylate (CHMA) was mixed to perform polymerization, and then the terminals were capped with 1g of 1-hydroxyethyl methacrylate (1-HEMA) to synthesize a polyurethane oligomer having a weight average molecular weight of 30,000 g/mol.

Next, 25g of the urethane oligomer prepared above, 21g of the remaining diluted monomer cyclohexyl methacrylate (CHMA), 22g of o-phenylphenol EO acrylate (OPPEA), 32g of hydroxyethyl acrylate (HEA), 2g of a curing agent 1, 6-hexanediol diacrylate (HDDA), and 0.5g of a photoinitiator Irgacure 651 were mixed to prepare a composition (2-1) for forming an intermediate layer.

Preparation examples 2 to 2: composition for forming intermediate layer comprising polyurethane-based resin

A diluted monomer of 21g of polycarbonate diol, 3g of isophorone diisocyanate (IPDI), and 21g of Trimethylcyclohexyl Methacrylate (TMCHA) was mixed to perform polymerization, and then the terminals were capped with 1g of 1-hydroxyethyl methacrylate (1-HEMA) to synthesize a urethane oligomer having a weight average molecular weight of 30,000 g/mol.

Next, 25g of the urethane oligomer prepared above, 21g of the remaining diluent monomer Trimethylcyclohexyl Methacrylate (TMCHA), 29g of o-phenylphenol EO acrylate (OPPEA), 10g of isobornyl acrylate (IBOA), 10g of hydroxyethyl acrylate (HEA), 5g of 2-hydroxy-3-phenylphenoxypropyl acrylate, 2g of curing agent 1, 6-hexanediol diacrylate (HDDA), and 0.5g of photoinitiator Irgacure 651 were mixed to prepare a composition (2-2) for forming an intermediate layer.

Preparation examples 2 to 3: composition for forming intermediate layer comprising polyurethane-based resin

21g of polycarbonate diol, 3g of isophorone diisocyanate (IPDI) and 33g of diluted monomers of isobornyl acrylate (IBOA) were mixed to perform polymerization, and then the terminals were capped with 1g of 1-hydroxyethyl methacrylate (1-HEMA) to synthesize a polyurethane oligomer having a weight average molecular weight of 30,000 g/mol.

Next, 25g of the urethane oligomer prepared above, 33g of the remaining diluent monomer Trimethylcyclohexyl Methacrylate (TMCHA), 22g of o-phenylphenol EO acrylate (OPPEA), 15g of hydroxyethyl acrylate (HEA), 5g of hydroxyethyl acrylate (HEA), 2g of curing agent 1, 6-hexanediol diacrylate (HDDA), and 0.5g of photoinitiator Irgacure 651 were mixed to prepare a composition for forming an interlayer (2-3).

Preparation example 3: composition for forming adhesive layer

185g of an acryl-based polymer was prepared using 72g of 2-ethylhexyl acrylate (2-EHA), 13g of 2-hydroxyethyl acrylate (2-HEA), 0.1g of benzoyl peroxide as a polymerization initiator, and 100g of Methyl Ethyl Ketone (MEK).

100g of the acryl-based polymer prepared above was reacted with 15g of methacryloyloxyethyl isocyanate (MOI) to prepare an acryl-based thermosetting resin.

30g of the prepared thermosetting resin and 70g of Methyl Ethyl Ketone (MEK) were mixed to prepare a thermosetting composition for forming an adhesive layer.