JPH0379623A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition for sealing semiconductors having high freeze resistance, thermal shock resistance and molding and processing properties by using a curing agent of epoxy resin containing a reaction resin of a specific polyfunctional phenol resin and organopolysiloxane. CONSTITUTION:The objective composition comprising (A) an epoxy resin, (B) a curing agent of epoxy resin containing 50-100wt.% based on total amounts of phenol resin of a random copolymer silicone modified polyfunctional phenol resin prepared by reacting a polyfunctional phenol resin shown by formula l (n is 0-10; R1 to R5 are H, halogen or alkyl) with an organopolysiloxane shown by formula II [R6 is (ethyl)phenyl; R7 is methyl or (ethyl)phenyl; A is group shown by formula III or formula IV; 10<=(k+l+m+2)<=200, 0<=1/(k+l+m+2)<=0.1 and 5<=(k+l+m+2)/m<=50] and (C) an inorganic filler as essential components.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an epoxy resin ff1 composition for semiconductor encapsulation that has excellent soldering heat resistance, thermal shock resistance, and moldability.

(Prior Art) Semiconductor-related technology has progressed in the direction of improving packaging density due to the recent trend toward lighter, thinner, and smaller devices.

For this reason, the degree of integration of memory is increasing, and the mounting method is shifting from through-hole mounting to surface mounting.

Therefore, the package can be changed from the conventional DIP type to a surface-mounted small, thin flat package, such as 5OP.
1SOJ% PLCC, which has problems such as cracks occurring due to internal stress and a decrease in moisture resistance due to these cracks.

In particular, when soldering leads in the surface mounting process, the package is subject to rapid temperature changes, and the problem of cracks occurring in the package due to this is attracting a lot of attention.

In order to solve these problems, thermoplastic oligomers are added to alleviate the thermal shock during soldering (Japanese Unexamined Patent Application Publication No. 62-119).
115849) and various silicone compound additives I
(Unexamined Japanese Patent Publication No. 115850/1983
6654, JP 62-128162),
Furthermore, methods such as silicone modification (Japanese Unexamined Patent Publication No. 136800/1983) have been used to deal with the problem, but in both cases cracks occur in the package during soldering, resulting in an epoxy resin composition for semiconductor encapsulation with excellent reliability. It didn't reach that point.

On the other hand, in order to obtain a heat-resistant epoxy resin composition with excellent soldering heat resistance, the use of a polyfunctional epoxy resin as the resin system (Japanese Patent Application Laid-Open No. 168620/1983) has been considered; The use of resin increases the crosslinking density and improves heat resistance, but the soldering heat resistance is insufficient especially when exposed to high temperatures such as 200 to 300°C, and the resin becomes hard and brittle, resulting in poor thermal shock resistance. It was extremely unsatisfactory.

Therefore, in order to solve these problems, the present inventors
We have already proposed an epoxy resin composition containing a random copolymerized silicone-modified multifunctional epoxy resin, and have found that this can significantly improve soldering heat resistance and thermal shock resistance.

However, as packages are becoming thinner and chips are becoming larger, the required characteristics for epoxy resin compositions for semiconductor encapsulation are becoming increasingly strict.
Furthermore, there is a demand for resin compositions that have excellent soldering heat resistance and thermal shock resistance.

(Problems to be Solved by the Invention) The present invention has been made in view of the above circumstances, and its purpose is to provide a semiconductor encapsulation material with good soldering heat resistance, thermal shock resistance, and moldability. An object of the present invention is to provide an epoxy resin composition.

(Means for Solving the Problems) The present inventors have carried out intensive studies in an attempt to obtain a well-balanced and excellent epoxy resin composition for semiconductor encapsulation, which could not be overcome using conventional techniques. The polyfunctional phenol resin having the structure shown by the following formula (1) has good properties and has the effect of improving soldering heat resistance, and the following formula has the effect of imparting remarkable toughness and low elasticity without impairing moldability. 〇・and/or (I[[
) A curing agent and inorganic filler obtained by blending 50 to 10% by weight of a random copolymerized silicone-modified polyfunctional phenolic resin with respect to the total phenolic resin by reacting with an organopolysiloxane having a specific structure shown in The present inventors have completed the present invention by discovering that a resin composite parallax made of the following material significantly improves moldability, solder heat resistance, and Mij impact resistance even in thin and large chip packages.

(Function) The epoxy resin used in the present invention has two
Any type of epoxy resin may be used as long as it has at least two epoxy groups, such as bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, Talesol novolak epoxy resin, alicyclic epoxy resin, and these. Examples include modified resins, and these epoxy resins can be used alone or in combination of two or more.

Among these epoxy resins, the epoxy equivalent is 150~
250, a softening point of 60 to 130°C, and Na'',
It is preferable that the amount of ionic impurities such as CQ- is as small as possible.

The random copolymerized silicone-modified polyfunctional phenolic resin curing agent used in the present invention is an extremely important component that has the effect of improving both soldering heat resistance and thermal shock resistance.

The polyfunctional phenolic resin having the structure represented by formula (I) used as a raw material for these random copolymerized silicone-modified polyfunctional phenolic resin curing agents is a polyfunctional phenolic resin having three or more hydroxyl groups in one molecule.

R9-R1 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. When the number of carbon atoms exceeds 4, the reactivity with the epoxy resin tends to decrease and the curability tends to decrease.

The value of n needs to be in the range of 0 to IO.

If the value of n is greater than lO, the fluidity decreases,
Formability deteriorates.

However, with epoxy resins having less than two functional groups, the crosslinking density is not increased, the heat resistance is poor, and the effect of solder stress resistance cannot be obtained.

The organopolysiloxane used as the other raw material has a structure represented by the formula (II) or (m), (R,: phenyl group or ethylphenyl group).

R7: methyl group, phenyl group or ethylphenyl group 10≦(k+12+m+2)≦200 and O≦Q/(
k+4+m+2)≦0. l.

5≦(k-H2+m+2)/m≦50 Rs: phenyl group or ethylphenyl group.

R: methyl group, phenyl group or ethylphenyl group 10≦(o+p1q+2)≦200 and O≦p/(o
+p+q+2)≦0.1゜5≦(o+p+q+2)/q
≦50) It has the effect of improving soldering heat resistance and thermal shock resistance without impairing molding processability, and has a specific ratio of epoxy group-containing organic groups that can react with phenolic hydroxyl groups. and O+1)+Q
+2) is in the range of 10 to 200, and the structure of the organopolysiloxane may be either linear or branched.

In addition, the mole fraction of the phenyl group or ethylphenyl group-modified moiety (12/(k+α+m+2) and p/(.

+p+q+2)) is o, l or less, siloxane polymerization degree/number of functional groups ((k+α+m+2)/m and (O+p10q+
2) It is necessary to use a material with /p) of 5 or more and 50 or less.

Degree of siloxane polymerization (k + α + m + 2 and o + p + q +
If 2) is less than 1O, the molecular weight of the silicone reaction part becomes too small, resulting in a decrease in the properties of the composition.If it exceeds 200, the compatibility with other components of the composition decreases, resulting in a decrease in the composition's The viscosity increases, wire deformation, etc. are more likely to occur, and the imprintability decreases, making it easier for mold stains to occur.
It is necessary to use a siloxane having a degree of polymerization of 10 or more and 200 or less.

Molar fraction CQ of phenyl group or ethylphenyl group modified moiety
/ (k + c + m + 2) and p / (o + p + q + 2
)) is 0. l or less, preferably around 0.05,
Silicone-modified polyfunctional phenolic resin curing agent for synthetic leather,
Organopolysiloxane has moderate compatibility with a polyfunctional phenolic resin curing agent or an organic solvent, and ifc using a silicone-modified polyfunctional phenolic resin curing agent
The silicone-modified polyfunctional phenolic resin curing agent is suitably used in products because it has moderate compatibility with other components.

The mole fraction of the phenyl group or ethylphenyl group modified moiety is 0
．． If it exceeds 1, in a composition using a silicone-modified polyfunctional phenolic resin curing agent, the compatibility between the silicone-modified polyfunctional phenolic resin curing agent and other components becomes too good, and the glass transition point and soldering heat resistance decrease. .

Siloxane polymerization degree/number of functional groups ((k+L+m+2)7m
and (o+p+q+2)/p) are extremely important parameters, and the degree of siloxane polymerization/number of functional groups is 5 or more,
50 or less has strength, without impairing moldability.
It becomes possible to improve thermal shock resistance and soldering heat resistance.

If this parameter is less than 5, in a composition using a silicone-modified polyfunctional phenolic resin curing agent, the compatibility with other components will be too good, the glass transition point and soldering heat resistance will decrease, and the silicone reaction area The molecular weight of the composition becomes too large, and the viscosity of the composition increases, making it easy for the gold wire to deform.

On the other hand, if it exceeds 50, the resin becomes opaque and tends to cause phase separation in the silicone reaction area, resulting in decreased strength, fluidity, and imprintability, and mold stains.

These organopolysiloxanes having an epoxy group-containing organic group are produced by an addition reaction between an organohydrodiene polysiloxane and an unsaturated double bond group-containing epoxy, such as allyl glycidyl ether, in an organic solvent using chloroplatinic acid as a catalyst. can get.

In addition, the random copolymerized silicone-modified polyfunctional phenol resin is produced by combining an epoxy group-containing organopolysiloxane and a polyfunctional phenol resin in an organic solvent with one or two selected from imidazoles, organic phosphines, and tertiary amines.
Examples include a method of carrying out a ring-opening addition reaction using more than one type of catalyst.

The obtained random copolymerized silicone-modified polyfunctional phenolic resin may be mixed with a conventional phenolic resin and used as a curing agent for epoxy resin, but in these mixed systems, the silicone-modified polyfunctional phenolic resin is It is necessary to mix it in an amount of 50% by weight or more based on the amount of resin.

If the blending amount is less than 50% by weight, both solder heat resistance and thermal shock resistance will decrease, making it insufficient.

The conventional phenolic resins mentioned here include phenol novolak, cresol novolac, and modified resins thereof, and these may be used alone or in combination of two or more.

The phenolic resin used has a hydroxyl equivalent of 80 to 150.
It is preferable that the softening point is 60-120°C and that the content of ionic impurities such as Na'' and C1- is as small as possible.

Examples of inorganic fillers used in the present invention include crystalline silica, fused silica, alumina, calcium carbonate, talc, mica, and glass fiber.

These i types or a mixture of two or more types are used.

Among these, crystalline silica or fused silica is particularly preferably used.

In addition, as a component other than these, a curing accelerator etc. may be used as necessary, but the curing accelerator may be one that promotes the reaction between the epoxy group and the phenolic hydroxyl group, and is generally used in sealing materials. For example, tertiary amines such as BDMA, imidazoles, l,8-diazabicyclo[5,4,01 undecene-7 (DBU), triphenylphosphine (TP),
Organic phosphorus compounds such as P) may be used alone or in combination of two or more.

In addition, if necessary, a silane coupling agent,
Brominated epoxy resins, flame retardants such as antimony dioxide and hexabromobenzene, colorants such as carbon black and red iron, mold release agents such as natural wax and synthetic wax, and low stress additives such as silicone oil and rubber. Additives may be added as appropriate.

In order to produce the epoxy resin composition for sealing of the present invention as a molding material, the epoxy resin, curing agent, inorganic filler, curing accelerator, and other additives are thoroughly and uniformly mixed using a mixer or the like, and then It can be obtained by melt-kneading with a heated roll or kneader, cooling, and then pulverizing. These molding materials can be used for sealing, covering, insulating, etc. electronic or electrical components.

(Example) Next, examples will be described together with comparative examples.

First, 20 parts by weight of organopolysiloxane and 100 parts by weight of polyfunctional phenol resin were mixed in 200!1 parts of butanol solvent.
The reaction was carried out in the presence of a catalyst in the ffi section to obtain silicone-modified polyfunctional phenol resins (1 to 1) shown in Table 1.

*Li It is a polyfunctional phenol resin having a structure represented by the following formula (IV), with n-0, 1, 2, 3, and a mixing ratio of n-0 of 4. n-1 is 3. n=2 is 1.5. It is made by mixing n-3 at a ratio of 1.5, has a hydroxyl equivalent of 98 g/eq, and a softening point of 113°C.

*Li A polyfunctional phenol resin having a structure represented by formula (V), where n = 0.1.2. and the mixing ratio n-〇 is 7. n-1 is 2. n-2 is mixed at a ratio of 1, the hydroxyl equivalent is 1t2g/eq, and the softening point is 100.
℃ ones.

*Organopolysiloxane represented by the formula (VT) *Organopolysiloxane represented by the formula (■)* Organopolysiloxane represented by the formula (■) *7) Organopolysiloxane represented by formula (X) *Organopolysiloxane represented by formula (n) *9) Organopolysiloxane represented by formula (n) *10) Organopolysiloxane represented by formula (!it) Polysiloxane Example 1 The following composition Talesol novolac type epoxy resin (epoxy weight: 1200. Softening point: 65°C) 90
Part by weight Brominated phenol novolak type epoxy resin (Evo) ft272. Softening point 75℃, bromine content 32%
) tons (parts) Corn-modified polyfunctional phenolic novolak resin curing agent (a) 60 parts by weight fused silica
450 parts by weight antimony dioxide
25 parts by weight silane coupling agent
2ffiffi part triphenylphosphine
2f [1 part carbon black 3
Parts by weight 3 parts by weight of carnauba wax are thoroughly mixed at room temperature, then kneaded at 95 to 100°C with twin-screw rolls, cooled and crushed to form tabs to obtain the epoxy resin composition for semiconductor encapsulation of the present invention. I got it.

This material was molded using a transfer molding machine (molding conditions: mold temperature 175°C, curing time 2 minutes), and the mold staining property and resin breakage of this material were determined, and the resulting molded amount was measured at 175°C, 8 After curing for a period of time, the marking properties, thermal shock resistance, soldering moisture resistance, and soldering heat resistance were evaluated. The results are shown in Table 2.

Examples 2 to 3 Epoxy resin compositions for semiconductor encapsulation were obtained in the same manner as in Example 1 by blending according to Table 2.

The evaluation results of this epoxy resin product for semiconductor encapsulation are also shown in Table 2.

Comparative Examples 1 to 7 Epoxy resin compositions for semiconductor encapsulation were obtained in the same manner as in Example 1 by blending according to Table 12.

The evaluation results of this epoxy resin product for semiconductor encapsulation are also shown in Table 2.

Wood grain) Tris(hydroxyalkylphenyl)methane triglycidyl ether represented by the following formula (II) (nO, 1,2, with a mixing ratio of n-0 of 8 and n-
1 is L and n-2 is mixed at a ratio of 1.

Epoxy equivalent: 210 g/eq, softening point: 84°C) When m=
A mixture of 1 and 4 parts of the compound.

Epoxy equivalent: 210g/eq, softening point: 84°C) *1 Li
Judgment is based on the number of molding shots until mold fogging occurs.

*14) Measure the length of the resin at the vent part of the molded product obtained.

*") Using a molded product made by IO & Yotsuto Hyaku, after stamping, sellotape is applied, and when the sellotape is removed, the number of stamps removed is determined.

The table shows the number of peeled seals out of 50.

*11) 20 molded products (chip size 36mm', package thickness 2.05mm, post-curing 175°C, 8Hrs) were subjected to a temperature cycle test (150°C to -196°C),
Judging by the number of molded products with cracks after 500 cycles of testing. The number of molded products with cracks is shown in the table.

*1) The sealed test device was heated at 85℃ and 85%R)
After processing for 72 hours under water vapor of
After immersion for seconds, pressure couture test (125℃, 1
00%RH) to measure open defects in the circuit.

*18) After processing 20 molded products (chip size 36 mm, package thickness 2.05 mm) under steam at 85°C and 85% RH for 72 hours, solder bath at 260°C 1:00
Judgment is made by the number of molded products that develop cracks after being immersed for seconds.

The number of molded products with cracks is shown in the table.

(Effects of the Invention) According to the present invention, it is possible to obtain an epoxy resin composition that has a high degree of heat resistance, thermal shock resistance, and moldability that could not be obtained using conventional techniques. It has excellent crack resistance and thermal shock resistance when subjected to thermal stress due to temperature changes, so when used for sealing, covering, and insulating electronic and electrical components, it is especially suitable for surface mount packages. It is suitable for applications that require a high level of reliability, such as mounted thin, highly integrated large-chip ICs.

Claims (1)

[Claims] (1) (A) Epoxy resin (B) Random copolymerized silicone modified by reacting a polyfunctional phenol resin with the structure shown by the following formula (I) and an organopolysiloxane with the structure shown by the following formula (II) Epoxy resin curing agent containing 50 to 100% by weight of polyfunctional phenolic resin based on the total amount of phenolic resin▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(I) (n is an integer from 0 to 10) , R_1 to R_5 are hydrogen,
Atoms or groups selected from halogens and alkyl groups) ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼... (II) (R_6: phenyl group or ethylphenyl group, R_7:
Methyl group, phenyl group or ethylphenyl group A: ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ 10≦(k+l+m+2)≦200 and 0≦l/(k+l+m+2)≦0 .1, 5≦(k+l+m+2)/m≦50) (C) A resin composition for semiconductor encapsulation which contains an inorganic filler as an essential component. (A) Epoxy resin (B) Random copolymerized silicone-modified polyfunctional phenol obtained by reacting a polyfunctional phenol resin with a structure represented by the following formula (I) and an organopolysiloxane with a structure represented by the following formula (III) Epoxy resin curing agent containing 50 to 100% by weight of resin based on the total amount of phenolic resin▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(I) (n is an integer from 0 to 10, and R_1 to R_6 is hydrogen,
(Atoms or groups selected from halogens, alkyl groups) ▲Mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(III) (R_8: phenyl group or ethylphenyl group, R_9;
Methyl group, phenyl group or ethylphenyl group B: ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ 10≦(o+p+q+2)≦200 and 0≦p/(o+p+q+2)≦0 .1, 5≦(o+p+q+2)/q≦50) (C) A resin composition for semiconductor encapsulation which contains an inorganic filler as an essential component. (A) Epoxy resin (B) Random copolymerized silicone obtained by reacting a multifunctional phenol resin with a structure represented by the following formula (I) and an organopolysiloxane with a structure represented by the following formulas (II) and (III). Epoxy resin curing agent containing modified polyfunctional phenolic resin in an amount of 50 to 100% by weight based on the total amount of phenolic resin▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・(I) (n is an integer from 0 to 10) Yes, R_1 to R_5 are hydrogen,
Atoms or groups selected from halogens and alkyl groups) ▲Mathematical formulas, chemical formulas, tables, etc. are available▼・・・・・・(II) ▲Mathematical formulas, chemical formulas, tables, etc. are available▼・・・・・・(III) (R_6: phenyl group or ethylphenyl group, R_7:
Methyl group, phenyl group or ethylphenyl group A: ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ 10≦(k+l+m+2)≦200 and 0≦R/(k+l+m+2)≦0 .1, 5≦(k+l+m+2)/m≦50 R_8: Phenyl group or ethylphenyl group, R_9: Methyl Go, phenyl group or ethylphenyl group B: ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Numerical formulas, chemical formulas, There are tables etc. ▼ 10≦(o+p+q+2)≦200, 0≦p/(o+p+q+2)≦0.1, 5≦(o+p+q+2)/q≦50) (C) Semiconductor encapsulation with inorganic filler as an essential component Resin composition for.