JP2006063119A - Resin composition and semiconductor device made by using the resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition which has sufficiently low stress properties even when used for large-area bonding and shows good adhesiveness and to provide a high-reliability semiconductor device by using the resin composition as a die attachment or heatsink material therefor. <P>SOLUTION: The resin composition essentially consists of a compound (A) obtained by reacting a diisocyanate with a dicarboxylic acid and a compound having one hydroxyl group and one radically polymerizable functional group and a filler (B). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a resin composition and a semiconductor device manufactured using the resin composition.

  The problem of heat generated during the operation of semiconductor products has become more prominent with the increase in capacity, high-speed processing and fine wiring of semiconductor products. So-called thermal management, which releases heat from semiconductor products, is an increasingly important issue. It has become to. For this reason, a method of attaching a heat sink (heat radiating plate) to a semiconductor product is generally adopted, but a material having a higher thermal conductivity of the material to which the heat sink is bonded has been desired. On the other hand, depending on the form of the semiconductor product, the semiconductor element itself may be bonded to a metal heat sink, or may be bonded to an organic substrate having a heat dissipation mechanism such as a thermal via. In this case as well, a high thermal conductivity is required for the material to which the semiconductor element is bonded. In this way, high thermal conductivity is required for die attach materials or heat sink attachment materials, but at the same time, it is necessary to withstand reflow processing when mounting semiconductor substrates on substrates, and there are many cases where large area bonding is required. In order to suppress the occurrence of warping or the like due to the difference in the thermal expansion coefficient between the structural members, it is necessary to have low stress.

Here, metal fillers such as silver powder and copper powder and ceramic fillers such as aluminum nitride and boron nitride are usually added to organic binders at a high content, but the amount that can be contained is limited. When high thermal conductivity cannot be obtained, a large amount of solvent is contained and the cured product itself has good thermal conductivity, but in semiconductor products, after the solvent remains or volatilizes in the cured product, it becomes voids and the thermal conductivity is low. When it is not stable, there is no satisfactory case such as a case where the low stress property is insufficient based on the high filler content (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-43587

  INDUSTRIAL APPLICABILITY The present invention has a resin composition that has sufficient low stress even when used for large-area bonding applications and exhibits good adhesion, and uses the resin composition as a die attach material for semiconductors or a heat sink attachment material This is to provide a semiconductor device with excellent reliability.

Such an object is achieved by the present invention described in the following [1] to [9].
[1] A compound obtained by reacting (A) diisocyanate, dicarboxylic acid, and a compound each having one hydroxyl group and one radical polymerizable functional group, and (B) a filler as an essential component. A resin composition.
[2] The resin composition according to item [1], wherein the diisocyanate is a cyclic diisocyanate having no aromatic ring.
[3] The resin composition according to item [1] or [2], wherein the cyclic diisocyanate having no aromatic ring is at least one selected from isophorone diisocyanate or norbornene diisocyanate.
[4] The resin composition according to item [1], [2] or [3], wherein the dicarboxylic acid does not contain an aromatic ring.
[5] The resin composition according to items [1] to [4], wherein the dicarboxylic acid contains a structure of the general formula (1).

[6] The resin composition according to items [1] to [5], wherein the radical polymerizable functional group is a (meth) acryloyl group.
[7] The resin composition according to items [1] to [6], wherein the filler (B) is silver powder.
[8] The resin composition according to any one of [1] to [7], wherein the filler (B) is contained in the resin composition in an amount of 80% by weight or more.
[9] A semiconductor device manufactured using the resin composition according to any one of items [1] to [8] as a die attach material or a heat sink attach material.

  According to the present invention, it is possible to provide a resin composition excellent in low-stress property and adhesiveness and a semiconductor device excellent in reliability using the resin composition as a die attach material for a semiconductor or a heat sink attach material.

  In the present invention, the compound (A) obtained by reacting the following raw materials is used. Compound (A) can react with diisocyanate under the condition of excess dicarboxylic acid to obtain a terminal carboxylic acid product, and then react with a compound having one hydroxyl group and one radically polymerizable functional group. It is. A compound having one hydroxyl group and one radically polymerizable functional group is used to introduce a radically polymerizable functional group into the compound (A) to impart thermosetting properties to the resin composition. Although it will not specifically limit if it is a functional group which can be radically polymerized, For example, a (meth) acryloyl group, a vinyl group, a maleimide group etc. are mentioned. A (meth) acryloyl group can be suitably used. The reaction between diisocyanate and dicarboxylic acid may be due to the lack of moisture resistance of the urethane bond produced by the reaction product of diisocyanate and diol, which is generally used. The amide bond obtained by the reaction of isocyanate group and hydrocarbonyl group This is because the amide bond formed is more stable and the adhesion to the adherend is as good as the urethane bond. As the diisocyanate, those having no aromatic ring are preferable, and at least one selected from isophorone diisocyanate or norbornene diisocyanate is more preferably used.

As the dicarboxylic acid, an aliphatic compound is preferred from the viewpoint of flexibility after curing of the resin composition. In particular, when stressing low stress, a diol having the structure represented by the general formula (1) and a dicarboxylic acid such as succinic acid, maleic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, or a phthalic acid derivative It is preferred to use a reactant. In the structure of the general formula (1), R ¹ is a hydrocarbon group having 3 to 6 carbon atoms. If the number of carbon atoms is less than this, it is preferable because the hydrophilicity becomes too strong and the moisture resistance of the cured product is deteriorated. If the amount is larger than this, the hydrophobicity becomes too strong, which leads to a decrease in adhesive strength. X is at least one selected from —O—, —COO—, and —OCOO—, and is preferably used for imparting flexibility to the cured product. The number of repetitions n is 2 to 50, but if it is less than this, even if it is introduced, the effect of reducing the stress does not appear, and if it is more than this, the molecular weight becomes too large, leading to an increase in the viscosity of the resin composition. . Usually, the molecular weight of the compound (A) is preferably smaller than 5000. This is because the viscosity of the resin composition becomes too high when it is larger than this.
More preferably, the molecular weight of the compound (A) is 1000 to 2000.
As the filler (B) used in the present invention, silver powder is usually used, but gold powder, copper powder, aluminum nitride, boron nitride, silica, alumina and the like can also be used. In particular, when high thermal conductivity needs to be imparted to the cured product, silver powder is preferably contained in the resin composition in an amount of 80% by weight or more.

In the present invention, it is also possible to use a radical polymerizable monomer if necessary. Although what can be used is not specifically limited, It is a compound as illustrated below. Methyl (meth) acrylate, ethyl (meth) acrylate. n-butyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) Acrylate, isoamyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, other alkyl (meth) acrylates, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, tertiary butyl cyclohexyl (meth) Acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, Lysidyl (meth) acrylate, glycerol mono (meth) acrylate, glycerol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, zinc mono (meth) acrylate, zinc di (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, dimethylylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, neopentyl glycol (meth) acrylate, trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 2,2,3,3,4,4-hexafluorobutyl (meth) acrylate, perfluorooctyl (meth) acrylate Perfluorooctylethyl (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-brandiol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate 1,9-nonanediol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, polyethylene Glycol di (meth) acrylate, polypropylene glycol mono (meth) acrylate, polypropylene glycol di (meth) acrylate, tetramethylene glycol mono (meth) acrylate, tetramethylene glycol di (meth) a Acrylate, polytetramethylene glycol mono (meth) acrylate, polytetramethylene glycol di (meth) acrylate, methoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxypolyalkylene glycol mono (meta ) Acrylate, octoxy polyalkylene glycol mono (meth) acrylate, lauroxy polyalkylene glycol mono (meth) acrylate, stearoxy polyalkylene glycol mono (meth) acrylate, allyloxy polyalkylene glycol mono (meth) acrylate, nonylphenoxy poly Alkylene glycol mono (meth) acrylate, polyalkylene oxide modified bisphenol A di (meth) acrylate 2-hydroxy-3-phenoxypropyl (meth) acrylate, N, N′-methylenebis (meth) acrylamide, N, N′-ethylenebis (meth) acrylamide, 1,2-di (meth) acrylamide ethylene glycol Di (meth) acryloyloxymethyl tricyclodecane, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl, 2 -Hydroxypropyl phthalate, 2-hydroxy-3-acryloyloxypropyl methacrylate, N- (meth) acryloyloxyethyl maleimide, N- (meth) acryloyloxyethyl hexahydrophthalimide, N- (meth) acryloyloxyethyl Phthalimide, n-vinyl-2-pyrrolide , Styrene derivatives, alpha-methylstyrene derivatives.

In the present invention, a radical polymerization initiator can be used. Although it is not particularly limited as long as it is normally used as a thermal radical polymerization initiator, it is desirable that a rapid heating test (decomposition start temperature when a sample is placed on an electric heating plate and heated at 4 ° C./min. In which the decomposition temperature is 40 to 140 ° C. When the decomposition temperature is less than 40 ° C., the storage stability of the resin composition at normal temperature is deteriorated.

Specific examples of the radical polymerization initiator satisfying this include methyl ethyl ketone peroxide, methylcyclohexanone peroxide, methyl acetoacetate peroxide, acetylacetone peroxide, 1,1-bis (t-butylperoxy) 3,3,5- Trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-hexylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) Cyclohexane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) cyclododecane, n-butyl 4,4-bis (t-butyl) Peroxyvalerate, 2,2-bis (t-butylperoxy) pig 1,1-bis (t-butylperoxy) -2-methylcyclohexane, t-butyl hydroperoxide, P-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t- Hexyl hydroperoxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, α, α'-bis (t-butylperoxy) diisopropylbenzene, t-butylcum Ruperoxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, Octanoyl peroxide, lauroyl peroxide, cinnamic acid peroxide, m- Toluoyl peroxide, benzoyl peroxide, diisopropyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, Di-sec-butyl peroxydicarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, α, α′-bis (neodecanoyl) Peroxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-Hexylperoxy Odecanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate , T-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxymaleic acid, t-butylperoxylaurate, t-butylperoxy-3,5, 5-trimethylhexanoate, t-butylperoxyisopropyl monocarbonate, t-butyl Luperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxy-m-toluoyl Benzoate, t-butylperoxybenzoate, bis (t-butylperoxy) isophthalate, t-butylperoxyallyl monocarbonate, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, etc. These may be used alone or in combination of two or more in order to control curability. Although not specifically limited, it is preferable to mix | blend 0.5-5 weight with respect to a compound (A). Since the present invention is usually used under illumination such as a fluorescent lamp, if a photoinitiator is contained, an increase in viscosity is observed due to reaction during use, and therefore a photoinitiator cannot be blended. Further, various polymerization inhibitors and antioxidants may be added in advance in order to improve the storage stability of the resin composition.

If necessary, additives such as a reactive diluent, a coupling agent, an antifoaming agent, and a surfactant can be used in the resin composition of the present invention.
The resin composition of the present invention can be produced, for example, by premixing the components, kneading using three rolls, and degassing under vacuum.
As a method of manufacturing a semiconductor device using the resin composition of the present invention, a known method can be used.

[Examples 1, 2, and 3]
Preparation of Compound (A) Polytetramethylene glycol diol (manufactured by Mitsubishi Chemical Corporation, PTMG650, about 9 repeating units determined by NMR measurement) and 24 g of succinic anhydride (reagent) were added to acetonitrile / toluene (weight ratio 1: 3) After stirring for 4 hours under reflux in a mixed solvent, liquid separation washing was performed 5 times using ion-exchanged water. The acetonitrile / toluene layer was recovered, 10 g of norbornene diisocyanate (manufactured by Mitsui Chemicals, NBDI) and dimethylaminopyridine were added, and the mixture was stirred at room temperature for 2 hours in a nitrogen atmosphere and reacted for 4 hours under reflux. After cooling, 20 g of 2-hydroxyethyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light ester HO) and dicyclohexylcarbodiimide / dimethylaminopyridine were added and reacted at room temperature for 4 hours and further under reflux for 4 hours. After cooling, it was separated and washed 5 times with ion-exchanged water, and the organic solvent layer was filtered to remove the solid content. The solvent was removed with an evaporator and a vacuum dryer, and used for the following tests. (Hereinafter component A, yield of about 82%. Formation of amide bond and ester bond was confirmed by NMR and IR. The molecular weight in terms of styrene by GPC was about 1700.)
As a starting material, polypropylene glycol diol (manufactured by NOF Corporation, D-700,
A reaction product was obtained in the same manner except that the number of repeating units of about 12) determined by NMR measurement was used. (Hereinafter, component B, yield: about 85%. Formation of amide bond and ester bond was confirmed by NMR and IR. The molecular weight in terms of styrene by GPC was about 1900.)
Dicumyl peroxide (manufactured by NOF Corporation, Park Mill D, decomposition temperature in rapid heating test: 126 ° C., hereinafter initiator) was used as the radical polymerization initiator.
Lauryl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., light ester LA, hereinafter LA), diacrylate whose repeating unit is tetramethylene oxide (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester A-PTMG65, hereinafter A-PTMG65), average Table 1 contains flaky silver powder (hereinafter referred to as silver powder) having a particle size of 5 μm and a maximum particle size of 30 μm, and a silane coupling agent having a methacrylic group (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-503, hereinafter referred to as methacrylsilane). A resin composition was obtained by kneading and defoaming using three rolls. The blending ratio is parts by weight.

[Comparative Examples 1 and 2]
The resin composition was obtained in the same manner as in Example 1 by blending at the ratio shown in Table 1.
[Comparative Example 3]
Polytetramethylene glycol diol (Mitsubishi Chemical Corporation, PTMG650) 133
g, 21 g of norbornene diisocyanate (manufactured by Mitsui Chemicals, NBDI) and dimethylaminopyridine were stirred in toluene at room temperature for 2 hours in a nitrogen atmosphere and then reacted for 4 hours under reflux. After cooling, 69 g of 2-methacryloyloxyethyl succinic acid (manufactured by Kyoeisha Chemical Co., Ltd., light ester HO-MS) and dicyclohexylcarbodiimide / dimethylaminopyridine were added, and the reaction was carried out at room temperature for 4 hours and further under reflux for 4 hours. After cooling, the solution was separated and washed five times with ion-exchanged water, and the organic solvent layer was filtered to remove solids, and the solvent was removed with an evaporator and a vacuum dryer. (Hereinafter, component C, yield: about 87%. Formation of an ester bond was confirmed by NMR and IR. The molecular weight in terms of styrene by GPC was about 1900.)
A resin composition was obtained in the same manner as in Example 1 except that Component C was used.
The obtained resin composition (die attach paste) was evaluated by the following methods. The evaluation results are shown in Table 1.

Evaluation Method / Viscosity: Using an E-type viscometer (3 ° cone), the values at 25 ° C. and 2.5 rpm were measured immediately after preparing the resin composition and after leaving at 25 ° C. for 48 hours. The case where the viscosity immediately after the production was in the range of 15 to 25 Pa · s and the increase in viscosity after 48 hours was less than 20% was regarded as acceptable. The unit of viscosity is Pa · s, and the unit of increase in viscosity is%.

Adhesive strength: A 6 × 6 mm silicon chip was mounted on a silver-plated copper frame and cured in an oven at 150 ° C. for 15 minutes. After curing and after moisture absorption treatment (85 ° C., 85%, 72 hours), the hot die shear strength at 260 ° C. was measured using an automatic adhesive force measuring apparatus. The case where the die shear strength when heated at 260 ° C. was 40 N / chip or more was regarded as acceptable. The unit of adhesive strength is N / chip.

-Warpage amount and reflow resistance: Using the resin composition shown in Table 1, the following substrate and silicon chip were cured and bonded at 150 ° C for 15 minutes. The amount of warpage of the chip surface after curing was measured with a surface roughness meter. The unit of warpage was μm and 20 μm or less was accepted. Similarly, the die-bonded lead frame was sealed with a sealing material (Sumicon EME-7026, manufactured by Sumitomo Bakelite Co., Ltd.), subjected to a moisture absorption treatment at 30 ° C. and a relative humidity of 60% for 192 hours, and then subjected to an IR reflow treatment ( 260 ° C., 10 seconds, 3 reflows). The degree of peeling of the treated package was measured with an ultrasonic flaw detector (transmission type). The case where the peeling area of the die attach part was less than 10% was regarded as acceptable. The unit of the peeled area is%.
Package: QFP (14x20x2.0mm)
Lead frame: Silver plated copper frame Chip size: 9 x 9 mm
Resin composition curing conditions: 150 ° C. for 15 minutes in oven

  Since the resin composition of the present invention exhibits good low stress properties and good adhesiveness, it can be suitably used for adhering semiconductor chips or heat sinks that are required simultaneously.

Claims (9)

(A) A compound obtained by reacting diisocyanate, dicarboxylic acid, and a compound each having one hydroxyl group and one radically polymerizable functional group, and (B) a resin comprising a filler as an essential component Composition. The resin composition according to claim 1, wherein the diisocyanate is a cyclic diisocyanate having no aromatic ring. The resin composition according to claim 1 or 2, wherein the cyclic diisocyanate having no aromatic ring is at least one selected from isophorone diisocyanate or norbornene diisocyanate. The resin composition according to claim 1, 2 or 3, wherein the dicarboxylic acid does not contain an aromatic ring. The resin composition of Claims 1-4 in which dicarboxylic acid contains the structure of General formula (1).

The resin composition according to claim 1, wherein the radical polymerizable functional group is a (meth) acryloyl group. The resin composition according to claim 1, wherein the filler (B) is silver powder. The resin composition according to any one of claims 1 to 7, wherein the filler (B) is contained in an amount of 80% by weight or more in the resin composition. A semiconductor device manufactured using the resin composition according to claim 1 as a die attach material or a heat sink attach material.