阅读说明：本技术 密封组合物和半导体装置 (Sealing composition and semiconductor device ) 是由 山浦格 姜东哲 石桥健太 儿玉拓也 田中实佳 堀慧地 于 2018-12-18 设计创作，主要内容包括：密封组合物含有环氧树脂、固化剂、以及包含莫氏硬度为8以上的无机材料的粒子和莫氏硬度为5以下的无机材料的粒子的无机填充材料。(The sealing composition contains an epoxy resin, a curing agent, and an inorganic filler containing particles of an inorganic material having a Mohs hardness of 8 or more and particles of an inorganic material having a Mohs hardness of 5 or less.)

1. A sealing composition contains an epoxy resin, a curing agent, and an inorganic filler containing inorganic material particles having a Mohs hardness of 8 or more and inorganic material particles having a Mohs hardness of 5 or less.

2. The sealing composition according to claim 1, wherein the inorganic material particles having a mohs hardness of 5 or less have an average circularity of 0.6 or more.

3. The sealing composition according to claim 1 or 2, wherein the inorganic material particles having a mohs hardness of 5 or less account for less than 30 mass% of the inorganic filler.

4. The sealing composition according to any one of claims 1 to 3, wherein the content of the inorganic filler is 88 vol% or less.

5. A semiconductor device comprising a semiconductor element and a cured product of the sealing composition according to any one of claims 1 to 4 sealing the semiconductor element.

Technical Field

The invention relates to a sealing composition and a semiconductor device.

Background

In recent years, with miniaturization and high integration of semiconductor packages, heat generation inside the semiconductor packages is concerned. There is a fear that the heat generation may cause a decrease in the performance of an electric component or an electronic component having a semiconductor package. Therefore, a member used for the semiconductor package is required to have high thermal conductivity. For example, it is required to improve the heat conduction of the sealing material of the semiconductor package.

As one of the methods for improving the heat conductivity of the sealing material, there are: a method of using silica and alumina as a highly thermally conductive filler as an inorganic filler contained in a sealing material (for example, see patent document 1).

In addition, when the semiconductor package is sealed with the sealing material, warpage after sealing may be a problem. In the case of compression molding which is large and forms an integral seal, this problem tends to become conspicuous. When the semiconductor package after sealing is subjected to various thermal histories, the warpage behavior of the semiconductor package may change. As a result, the semiconductor package may be difficult to handle in another step.

Disclosure of Invention

Problems to be solved by the invention

In the method described in patent document 1, since silica having a lower thermal conductivity than alumina is used as a part of the inorganic filler, sufficient thermal conductivity may not be obtained.

In addition, since both silica and alumina are hard fillers, the elastic modulus of a cured product tends to be high. When the modulus of elasticity of the cured product is increased, the semiconductor package after sealing may be warped to such an extent that handling in another step becomes difficult.

An aspect of the present invention has been made in view of the above conventional circumstances, and an object thereof is to provide a sealing composition having high thermal conductivity and capable of suppressing the occurrence of warpage, and a semiconductor device using the sealing composition.

Means for solving the problems

Specific means for solving the above problems are as follows.

< 1 > a sealing composition comprising an epoxy resin, a curing agent, and an inorganic filler comprising inorganic material particles having a Mohs hardness of 8 or more and inorganic material particles having a Mohs hardness of 5 or less.

< 2 > the sealing composition according to < 1 >, wherein the inorganic material particles having a Mohs hardness of 5 or less have an average circularity of 0.6 or more.

< 3 > the sealing composition according to < 1 > or < 2 >, wherein the inorganic material particles having a Mohs hardness of 5 or less account for less than 30% by mass of the inorganic filler.

< 4 > the sealing composition according to any one of < 1 > to < 3 >, wherein the content of the inorganic filler is 88% by volume or less.

< 5 > a semiconductor device comprising a semiconductor element and a cured product of the sealing composition described in any one of < 1 > -4 > sealing the semiconductor element.

Effects of the invention

According to one embodiment of the present invention, a sealing composition having high thermal conductivity and capable of suppressing the occurrence of warpage, and a semiconductor device using the sealing composition can be provided.

Detailed Description

The sealing composition of the present invention and an embodiment for implementing a semiconductor device will be described in detail below. However, the present invention is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps) are not necessarily required unless otherwise explicitly stated. The present invention is not limited to the numerical values and ranges thereof.

In the present disclosure, the numerical range shown by the term "to" includes the numerical values before and after the term "to" as the minimum value and the maximum value, respectively.

In the present disclosure, in the numerical ranges described in stages, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value described in another numerical range described in stages. In the numerical ranges disclosed in the present disclosure, the upper limit or the lower limit of the numerical range may be replaced with the values shown in the examples.

In the present disclosure, each component may contain a plurality of the same substances. When a plurality of substances corresponding to each component are present in the composition, the content or content of each component represents the total content or content of the plurality of substances present in the composition unless otherwise specified.

In the present disclosure, a plurality of particles corresponding to each component may be contained. When a plurality of particles corresponding to each component are present in the composition, the particle diameter of each component refers to the value of a mixture of the plurality of particles present in the composition unless otherwise specified.

Sealing composition

The sealing composition of the present disclosure contains: an epoxy resin, a curing agent, and an inorganic filler containing particles of an inorganic material having a mohs hardness of 8 or more (hereinafter sometimes referred to as "hard particles") and particles of an inorganic material having a mohs hardness of 5 or less (hereinafter sometimes referred to as "soft material") (hereinafter sometimes referred to as "soft particles").

The sealing composition of the present disclosure has high thermal conductivity, and can suppress the occurrence of warpage. The reason is not clear, but is presumed as follows.

The sealing composition contains hard particles and soft particles as inorganic fillers. In the cured product of the sealing composition, when the hard particles are in contact with each other, the hard particles are hard, and therefore the contact between the hard particles is a point contact on the particle surface. On the other hand, in the cured product of the sealing composition, when the hard particles and the soft particles are in contact with each other, the soft particles in contact with the hard particles are deformed at the positions in contact with the hard particles, and the hard particles and the soft particles are likely to be brought into surface contact with each other. In the case where the particles are in surface contact with each other, the heat conduction path formed between the inorganic fillers is more easily widened than in the case where the particles are in point contact with each other. Therefore, the sealing composition of the present disclosure containing hard particles and soft particles as inorganic fillers is presumed to have high thermal conductivity.

In addition, the sealing composition of the present disclosure, which further contains soft particles as an inorganic filler together with hard particles, has a lower elastic modulus of a cured product than the case of containing only hard particles as an inorganic filler. Therefore, it is presumed that the strain generated in the cured product is easily relaxed and the occurrence of warpage can be suppressed.

The components constituting the sealing composition will be described below. The sealing composition of the present disclosure contains an epoxy resin, a curing agent, and an inorganic filler, and may contain other components as necessary.

-epoxy resins-

The sealing composition contains an epoxy resin. The type of the epoxy resin is not particularly limited, and a known epoxy resin can be used.

Specific examples thereof include: epoxy resins (for example, phenol novolac type epoxy resins and o-cresol novolac type epoxy resins) obtained by condensing or co-condensing at least 1 selected from phenol compounds (for example, phenol, cresol, xylenol, resorcinol, catechol, bisphenol a, and bisphenol F) and naphthol compounds (for example, α -naphthol, β -naphthol, and dihydroxynaphthalene) with aldehyde compounds (for example, formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicylaldehyde) in the presence of an acidic catalyst to obtain a phenol resin and epoxidizing the phenol resin; diglycidyl ethers of at least 1 member selected from bisphenols (e.g., bisphenol a, bisphenol AD, bisphenol F, and bisphenol S) and biphenols (e.g., alkyl-substituted or unsubstituted biphenols); epoxides of phenol aralkyl resins; an epoxide of an adduct or addition polymer of a phenol compound and at least 1 selected from dicyclopentadiene and a terpene compound; glycidyl ester type epoxy resins obtained by the reaction of polybasic acids (such as phthalic acid and dimer acid) with epichlorohydrin; glycidylamine-type epoxy resins obtained by the reaction of polyamines (such as diaminodiphenylmethane and isocyanuric acid) with epichlorohydrin; linear aliphatic epoxy resins obtained by oxidizing olefinic bonds with a peracid (e.g., peracetic acid); and cycloaliphatic epoxy resins. The epoxy resin may be used alone or in combination of two or more.

From the viewpoint of preventing corrosion of aluminum wiring or copper wiring on an element such as an Integrated Circuit (IC), the purity of the epoxy resin is preferably high, and the amount of hydrolyzable chlorine is preferably small. The amount of hydrolyzable chlorine is preferably 500ppm or less by mass from the viewpoint of improving the moisture resistance of the sealing composition.

The amount of hydrolyzable chlorine is a value obtained by dissolving 1g of an epoxy resin as a sample in 30mL of dioxane, adding 5mL of a 1N-KOH methanol solution, refluxing for 30 minutes, and then titrating by potential difference.

The content of the epoxy resin in the sealing composition is preferably 1.5 to 20% by mass, more preferably 2.0 to 15% by mass, and still more preferably 3.0 to 10% by mass.

The content of the epoxy resin in the sealing composition excluding the inorganic filler is preferably 30 to 65 mass%, more preferably 35 to 60 mass%, and still more preferably 40 to 55 mass%.

Curing agents

The sealing composition contains a curing agent. The type of the curing agent is not particularly limited, and a known curing agent can be used.

Specific examples thereof include: phenol resins obtained by condensing or co-condensing at least 1 selected from the group consisting of phenol compounds (e.g., phenol, cresol, resorcinol, catechol, bisphenol a, and bisphenol F) and naphthol compounds (e.g., α -naphthol, β -naphthol, and dihydroxynaphthalene) with aldehyde compounds (e.g., formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicylaldehyde) in the presence of an acidic catalyst; phenol aralkyl resin; biphenyl aralkyl resin; triphenylmethane type phenol resins; and naphthol aralkyl resins. One curing agent may be used alone, or two or more curing agents may be used in combination.

The curing agent is preferably blended so that the equivalent of the functional group of the curing agent (for example, phenolic hydroxyl group in the case of a phenol resin) is 0.5 to 1.5 equivalents relative to 1 equivalent of the epoxy group of the epoxy resin, and particularly preferably 0.7 to 1.2 equivalents.

Inorganic filler materials

The sealing composition contains an inorganic filler material containing particles of an inorganic material having a Mohs hardness of 8 or more and particles of an inorganic material having a Mohs hardness of 5 or less. When the sealing composition contains the inorganic filler, the moisture absorption of the sealing composition tends to be reduced, and the strength in a cured state tends to be improved.

The content of the inorganic filler is preferably 60% by volume or more, more preferably 65% by volume or more, and still more preferably 70% by volume or more of the entire sealing composition, from the viewpoints of moisture absorption, reduction in linear expansion coefficient, improvement in strength, and improvement in solder heat resistance. The content of the inorganic filler is preferably 88 vol% or less, and more preferably 85 vol% or less.

As the hard material, alumina (Mohs hardness: 9), aluminum nitride, silicon carbide, diamond, and the like can be cited. Among these, alumina is preferable from the viewpoint of thermal conductivity, fluidity and reliability. The hard material has a Mohs hardness of 8 or more, preferably 9 or more. The hard material may have a mohs hardness of 10 or less.

The hard particles preferably have an average particle diameter of 0.1 to 80 μm, more preferably 0.3 to 50 μm, and still more preferably 1 to 40 μm.

The average particle diameter of the inorganic filler can be measured by the following method.

The inorganic filler to be measured is added to the solvent (pure water) in a range of 0.01 to 0.05 mass%, and the mixture is vibrated for 1 to 5 minutes by an ultrasonic cleaner of 110W to disperse the inorganic filler. About 10mL of the dispersion was poured into a measuring cell and measured at 25 ℃. The measurement apparatus measures the volume-based particle size distribution using a laser diffraction/scattering particle size distribution measurement apparatus (for example, LA920 (trade name) manufactured by horiba ltd.). The average particle size was determined as the particle size (D50%) at which the cumulative particle size from the smaller diameter side reached 50% in the volume-based particle size distribution.

The proportion of the hard particles in the inorganic filler is preferably 50 mass% or more, more preferably 60 mass% or more, and still more preferably 70 mass% or more. The proportion of the hard particles in the inorganic filler may be 95 mass% or less.

The average circularity of the hard particles is preferably 0.80 or more, more preferably 0.85 or more, and still more preferably 0.90 or more.

The circularity of the inorganic filler material means: the value obtained by dividing the circumference of the circle calculated from the circle equivalent diameter, which is the diameter of the circle having the same area as the projected area of the inorganic filler, by the circumference (the length of the contour line) measured from the projected image of the inorganic filler can be obtained by the following equation. In the case of a perfect circle, the circularity is 1.00.

Circularity (circumference of equivalent circle)/(circumference of particle section image)

Specifically, the average circularity is the following value: the image magnified 1000 times was observed with a scanning electron microscope, 10 inorganic fillers were arbitrarily selected, the circularity of each inorganic filler was measured by the above method, and the arithmetic average value was calculated. The circularity, the perimeter of the equivalent circle, and the perimeter of the projected image of the particle can be obtained by commercially available image analysis software.

Examples of the soft material include boehmite (Mohs hardness: 3.5 to 4), dolomite, mica, and hexagonal boron nitride. Among these, boehmite and dolomite are preferable from the viewpoint of fluidity.

The soft material has a mohs hardness of 5 or less, preferably 4 or less. The soft material may have a mohs hardness of 2 or more.

The soft particles preferably have an average particle diameter of 0.1 to 20 μm, more preferably 0.3 to 10 μm, and still more preferably 0.5 to 5 μm.

The proportion of the soft particles in the inorganic filler is preferably less than 30% by mass, more preferably 20% by mass or less, and still more preferably 10% by mass or less. The proportion of the soft particles in the inorganic filler may be 5% by mass or more.

The soft particles preferably have an average circularity of 0.6 or more, more preferably 0.7 or more, and still more preferably 0.8 or more.

The inorganic filler may contain particles of other inorganic materials having a mohs hardness of more than 5 and less than 8, in addition to the hard particles and the soft particles. Examples of the other inorganic materials include silica (Mohs hardness: 7), magnesium oxide, and zinc oxide.

The proportion of the particles of the other inorganic material in the inorganic filler may be 10 mass% or less, and may be 1 mass% or less.

(curing accelerators)

The sealing composition may further contain a curing accelerator. The kind of the curing accelerator is not particularly limited, and a known curing accelerator can be used.

Specifically, there may be mentioned: cyclic amidine compounds such as 1, 8-diaza-bicyclo [5.4.0] undecene-7, 1, 5-diaza-bicyclo [4.3.0] nonene, 5, 6-dibutylamino-1, 8-diaza-bicyclo [5.4.0] undecene-7 and the like; compounds having intramolecular polarization, which are obtained by adding a quinone compound such as maleic anhydride, 1, 4-benzoquinone, 2, 5-toluenequinone, 1, 4-naphthoquinone, 2, 3-dimethylbenzoquinone, 2, 6-dimethylbenzoquinone, 2, 3-dimethoxy-5-methyl-1, 4-benzoquinone, 2, 3-dimethoxy-1, 4-benzoquinone, or phenyl-1, 4-benzoquinone, or a compound having a pi bond such as diazophenylmethane or phenol resin to a cyclic amidine compound; tertiary amine compounds and derivatives of tertiary amine compounds such as benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol, and the like; imidazole compounds such as 2-methylimidazole, 2-phenylimidazole and 2-phenyl-4-methylimidazole, and derivatives of imidazole compounds; organic phosphine compounds such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, tris (4-methylphenyl) phosphine, diphenylphosphine, and phenylphosphine; a phosphorus compound having intramolecular polarization, which is obtained by adding a compound having a pi bond such as maleic anhydride, the quinone compound, diazophenylmethane, or a phenol resin to an organic phosphorus compound; tetraphenylboron salts such as tetraphenylphosphonium tetraphenylboron ate, triphenylphosphine tetraphenylboron ate, 2-ethyl-4-methylimidazolium tetraphenylboron ate and N-methylmorpholine tetraphenylboron ate, and derivatives of tetraphenylboron salts; and adducts of phosphine compounds such as triphenylphosphonium-triphenylborane and N-methylmorpholintetraphenylphosphonium-tetraphenylborate with tetraphenylborate. The curing accelerator may be used singly or in combination of two or more.

The content of the curing accelerator is preferably 0.1 to 8% by mass based on the total amount of the epoxy resin and the curing agent.

(ion scavenger)

The sealing composition may further comprise an ion trap.

The ion scavenger that can be used in the present disclosure is not particularly limited as long as it is an ion scavenger that is generally used for a sealing material used in the production of a semiconductor device, and examples thereof include hydrotalcite. As the ion scavenger, for example, a compound represented by the following general formula (II-1) or the following general formula (II-2) can be used.

Mg_1－aAl_a(OH)₂(CO₃)_a/2·uH₂O (II－1)

(in the general formula (II-1), a is 0 < a.ltoreq.0.5, and u is a positive number.)

BiO_b(OH)_c(NO₃)_d(II－2)

(in the general formula (II-2), b is 0.9. ltoreq. b.ltoreq.1.1, c is 0.6. ltoreq. c.ltoreq.0.8, and d is 0.2. ltoreq. d.ltoreq.0.4.)

The ion scavenger is available in the form of a commercially available product. As the compound represented by the general formula (II-1), "DHT-4A" (product name, Kyowa Kagaku K.K.) is available as a commercial product. Further, as the compound represented by the general formula (II-2), "IXE 500" (trade name, manufactured by Toyo Seisaku-sho Co., Ltd.) is available in the form of a commercially available product.

Examples of the ion scavenger other than the above include hydrous oxides of elements selected from magnesium, aluminum, titanium, zirconium, antimony, and the like.

One kind of ion scavenger may be used alone, or two or more kinds may be used in combination.

When the sealing composition contains an ion scavenger, the content of the ion scavenger is preferably 1 part by mass or more per 100 parts by mass of the epoxy resin in the sealing composition from the viewpoint of achieving sufficient moisture resistance reliability. The content of the ion scavenger is preferably 15 parts by mass or less with respect to 100 parts by mass of the epoxy resin in the sealing composition from the viewpoint of sufficiently exerting the effects of other components.

The average particle diameter of the ion scavenger is preferably 0.1 to 3.0 μm, and the maximum particle diameter is preferably 10 μm or less. The average particle diameter of the ion scavenger can be measured in the same manner as in the case of the inorganic filler.

(coupling agent)

The sealing composition may further comprise a coupling agent. The kind of the coupling agent is not particularly limited, and a known coupling agent can be used. Examples of the coupling agent include a silane coupling agent and a titanium coupling agent. One kind of coupling agent may be used alone, or two or more kinds may be used in combination.

Examples of the silane coupling agent include: vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (beta-methoxyethoxy) silane, gamma-methacryloxypropyltrimethoxysilane, beta- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, gamma-mercaptopropyltrimethoxysilane, gamma-aminopropyltriethoxysilane, gamma- [ bis (beta-hydroxyethyl) ] aminopropyltriethoxysilane, N-beta- (aminoethyl) -gamma-aminopropyltrimethoxysilane, gamma- (beta-aminoethyl) aminopropyldimethoxymethylsilane, N- (trimethoxysilylpropyl) ethylenediamine, N- (dimethoxymethylsilylisopropyl) ethylenediamine, methyltrimethoxysilane, methyltriethoxysilane, N-beta- (N-vinylbenzylaminoethyl) -gamma-aminopropyltrimethoxysilane, gamma-methacryloxypropyltrimethoxysilane, gamma-glycidyloxypropyltrimethoxysilane, gamma-glycidyloxypropyltriethoxysilane, gamma-beta-glycidyloxypropyltrimethoxysilane, gamma-glycidyloxypropyltrimethoxysilane, gamma-chloropropyltrimethoxysilane, hexamethyldisilane, gamma-anilinopropyltrimethoxysilane (N-phenyl-3-aminopropyltrimethoxysilane), vinyltrimethoxysilane and gamma-mercaptopropylmethyldimethoxysilane.

Examples of the titanium coupling agent include: triisostearoyltitanate isopropyl ester, trioctylphosphatoxy titanium isopropyl ester, isopropyltris (N-aminoethyl) titanate, tetraoctylbis (ditridecylphosphonoxy) titanate, tetrakis (2, 2-diallyloxymethyl-1-butyl) bis (ditridecylphosphonoxy) phosphonoxy titanate, bis (dioctylphosphatoxy) oxyacetate titanate (Japanese: ビス (ジオクチルパイロホスフェート) オキシアセテートチタネート), bis (dioctylphosphatoxy) ethylene titanate, isopropyltrioctyl titanate, isopropyldimethylacryloylstearoyl titanate, isopropyltris (dodecylbenzenesulfonyl) titanate, isopropylisostearoldiglyldigalloyl titanate, isopropyltris (dioctylphosphoxy) titanate, isopropyltris (dioctylphosphonoxy) titanate, isopropyltris (di-octylphosphonoxy) titanate, isopropyltris (di-decylphosphatoxy) titanate, isopropyltris (di-octylphosphonoxy) titanate, and mixtures thereof, Isopropyl tricumylphenyl titanate and tetraisopropyl bis (dioctylphosphatidyloxy) titanate.

When the sealing composition contains a coupling agent, the content of the coupling agent is preferably 3% by mass or less with respect to the entire sealing composition, and from the viewpoint of exerting the effect thereof, is preferably 0.1% by mass or more.

(mold releasing agent)

The sealing composition may further contain a release agent. The kind of the release agent is not particularly limited, and a known release agent can be used. Specific examples thereof include higher fatty acids, higher fatty acid esters, carnauba wax, and polyethylene waxes. The release agent may be used alone or in combination of two or more.

When the sealing composition contains a release agent, the content of the release agent is preferably 10% by mass or less with respect to the total amount of the epoxy resin and the curing agent, and is preferably 0.5% by mass or more from the viewpoint of exerting the effect thereof.

(coloring agent and modifying agent)

The sealing composition may contain a colorant (e.g., carbon black). In addition, the sealing composition may contain a modifier (e.g., silicone and silicone rubber). The colorant and the modifier may be used singly or in combination of two or more.

When conductive particles such as carbon black are used as the colorant, the content of particles having a particle diameter of 10 μm or more in the conductive particles is preferably 1% by mass or less.

When the sealing composition contains conductive particles, the content of the conductive particles is preferably 3% by mass or less with respect to the total amount of the epoxy resin and the curing agent.

< method for producing sealing composition >

The method for producing the sealing composition is not particularly limited, and can be carried out by a known method. For example, a mixture of raw materials in a predetermined blending amount may be prepared by thoroughly mixing the raw materials in a mixer or the like, and then subjecting the mixture to kneading, cooling, pulverization or the like by a hot roll, an extruder or the like. The state of the sealing composition is not particularly limited, and may be in the form of powder, solid, liquid, or the like.

< semiconductor device >

The semiconductor device of the present disclosure includes a semiconductor element, and a cured product of the sealing composition of the present disclosure sealing the semiconductor element.

The method for sealing the semiconductor element with the sealing composition is not particularly limited, and a known method can be applied. For example, transfer molding is generally used, and compression molding, injection molding, and the like may also be used.

The semiconductor device of the present disclosure is preferably an IC, an LSI (Large-Scale Integration), or the like.