JPH07316266A - Epoxy resin molding material for sealing and semiconductor device - Google Patents

Abstract

PURPOSE:To obtain an epoxy resin molding material excellent in the resistance to soldering crack after moisture absorption and moldability. CONSTITUTION:This material comprises an epoxy resin having a biphenyl skeleton represented by formula I and a bisphenol A novolac epoxy resin represented by formula II (wherein n is 0-10).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing epoxy resin molding material used for sealing electric / electronic parts and semiconductors, and a semiconductor device sealed using the sealing epoxy resin molding material. Is.

[0002]

2. Description of the Related Art Conventionally, diodes, transistors,
As a sealing method for electric / electronic components such as integrated circuits and semiconductor devices, a resin sealing method using epoxy resin or silicon resin, or a hermetic seal method using glass, metal, ceramics, etc. is adopted. However, in recent years, a resin encapsulation method by low-pressure transfer molding using an epoxy resin, which has advantages in mass production and cost as well as improved reliability, has become mainstream.

In the sealing method using this epoxy resin, for example, JP-A-2-102217 and JP-A-3
-220228, JP-A-3-220229, JP-A-3-285910, etc., a composition containing an o-cresol novolac type epoxy resin as a resin component and a phenol novolac resin as a curing agent component. Most commonly used encapsulation materials are used.

[0004]

However, the IC,
Along with the higher density and higher integration of electronic components such as LSI and VLSI and semiconductor devices, conventional epoxy resin compositions have not always been able to sufficiently satisfy the demand for thinner mold resins. . For example, in a surface mounting device, the device itself is directly immersed in solder during mounting, and is rapidly exposed to a high temperature and harsh environment, so that the occurrence of package cracks is inevitable. That is, when the moisture absorbed by the encapsulating resin during storage after molding is rapidly vaporized and expanded, the encapsulating resin cannot withstand this and cracks occur in the package.

With respect to the encapsulating resin composition, improvements in heat resistance and adhesion have been studied, and these characteristics have been actually improved. However, improvement in moisture absorption solder crack resistance is still satisfactory. Not in a situation. In addition, when the resin composition for encapsulation is used for encapsulation, internal voids may occur in the resin composition, resulting in low moldability. The present invention has been made in view of the above points, and can improve the resistance to moisture absorption solder cracking, and has high moldability, and a sealing epoxy resin molding material, and this sealing epoxy resin molding material. It is an object of the present invention to provide a semiconductor device using the.

[0006]

The epoxy resin molding material for encapsulation according to the present invention comprises an epoxy resin having a biphenyl skeleton represented by the following formula (1) and a bisphenol A novolak type represented by the following formula (2). It is characterized by containing an epoxy resin.

[0007]

[Chemical 6]

[0008]

[Chemical 7]

In the present invention, the epoxy resin represented by the following formula (3) can be used as the epoxy resin having the biphenyl skeleton represented by the formula (1).

[0010]

[Chemical 8]

Further, in the present invention, as the resin having the biphenyl skeleton represented by the formula (1), the average number of hydroxyl groups in one molecule is 2.3 per epoxy group of the epoxy resin of the formula (3). It is possible to use an epoxy resin prepared by reacting the phenolic hydroxyl groups of polyhydric phenols of 10 to 0.05 at a ratio of 0.05 to 0.6. In the present invention, the epoxy resin having the biphenyl skeleton represented by the formula (1) can be contained in an amount of 30 to 70% by weight based on the whole epoxy resin.

Further, in the present invention, the epoxy resin represented by the formula (2) can be contained in an amount of 30 to 70% by weight based on the whole epoxy resin. In the present invention, the following formula (4)
It is possible to contain the hardening material of 3 to 50% by weight in the whole hardening material.

[0013]

[Chemical 9]

Further, in the present invention, the hardened material represented by the following formula (5) may be contained in an amount of 3 to 50% by weight based on the entire hardened material.

[0015]

[Chemical 10]

A semiconductor device according to the present invention is characterized by being sealed with the above-mentioned sealing epoxy resin molding material. Hereinafter, the present invention will be described in detail. In the present invention, as the epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, naphthalene skeleton-containing epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin,
A bisphenol S type epoxy resin, a triphenol methane type epoxy resin, a tetrahydroindene derivative epoxy resin, a dicyclo skeleton-containing epoxy resin, and any other epoxy resin for semiconductor encapsulation may be used alone or in combination. In the present invention, the epoxy resin having a biphenyl skeleton represented by the formula (1) and the bisphenol A novolac type epoxy resin represented by the formula (2) are contained as a part of these epoxy resins.

The epoxy resin of the formula (1) has the formula (3)
In the epoxy resin of the formula (3), R _{1 to} R ₄ are CH ₃ and the epoxy equivalent is 192 can be used. It is also possible to react the epoxy resin of the formula (3) with polyhydric phenols to prepare epoxy resins having different epoxy equivalents and use it as the epoxy resin having the skeleton of the formula (1). The polyhydric phenols are novolak type phenol resins obtained by reacting phenols such as phenol and alkylphenol with formaldehyde or paraformaldehyde, and modified resins thereof, and the number of hydroxyl groups is 2.
3-10, by reacting both at a ratio such that the epoxy group of the epoxy resin of the formula (3) becomes 0.05-0.6 phenolic hydroxyl groups of polyhydric phenol per epoxy group Epoxy resins can be prepared.

The epoxy resin having the skeleton of the formula (1) is preferably contained in the total epoxy resin in an amount of 30 to 70% by weight. If it is less than 30% by weight, the effect of improving the soldering resistance cannot be sufficiently obtained, and if it exceeds 70% by weight, the internal voids increase. The epoxy resin of the formula (2) is preferably contained in the total epoxy resin in an amount of 30 to 70% by weight. If it is less than 30% by weight, the problem that the number of internal voids is increased occurs, and if it exceeds 70% by weight, the solder resistance is deteriorated.

In the present invention, as the curing material, cresol novolac, phenol novolac, polyfunctional phenol, dicyclo skeleton-containing resin, and any other resin may be used alone or in combination. In the present invention, these curing agents are used. As a part of the material, the hardened material represented by the formula (4) or the formula (5) is contained. It is preferable that the hardened material represented by the formula (4) or (5) is contained in an amount of 3 to 50% by weight based on the entire hardened material. If it is less than 3% by weight, the effect of improving the soldering resistance cannot be sufficiently obtained, and if it exceeds 50% by weight, the problem that the moldability (release property) is lowered occurs.

Further, in the present invention, as the inorganic filler, fused silica, crystalline silica, alumina, silicon nitride and the like can be used, and among them, fused silica is preferably used. Further, in the present invention, as the curing accelerator,
Diazabicycloundecene, triphenylphosphine,
Tetraphenylphosphonium / tetraphenylborate, imidazole, tertiary amine and the like can be used.

Then, the above-mentioned epoxy resin, curing agent, inorganic filler, curing accelerator and, if necessary, low-stress component, colorant, coupling agent, etc. are blended and uniformly mixed with a mixer or a blender. The epoxy resin molding material for sealing of the present invention can be obtained by heating and kneading with a kneader or roll. Further, after kneading, it may be cooled and solidified if necessary, and may be pulverized to be formed into particles.

A semiconductor device such as a QFP can be manufactured by using the thus obtained sealing epoxy resin molding material for sealing a semiconductor by performing transfer molding or the like.

[0023]

EXAMPLES Next, the present invention will be described in more detail by way of examples. (Examples 1 to 6 and Comparative Examples 1 and 2) The compositions shown in Tables 1 and 2 were uniformly mixed with a mixer, a blender, or the like, and then heated and kneaded with a kneader or a roll, thereby sealing the present example. An epoxy resin molding material for fixing is obtained. Further, after kneading, it may be cooled and solidified if necessary, and may be pulverized to be formed into particles.

In Tables 1 and 2, "N865" (epoxy equivalent 207) manufactured by Dainippon Ink and Chemicals, Inc. was used as the bisphenol A novolac type epoxy resin of the formula (2) (epoxy resin A in Tables 1 and 2). Shown). Also, equation (3)
Examples of the epoxy resin include R _{1 to} R ₄ = CH ₃ , 4,
4'-dihydroxy-tetramethylbiphenyl epoxy ("YX4000H" manufactured by Yuka Shell Co., epoxy equivalent 1
92) was used (shown as epoxy resin B in Tables 1 and 2).

Further, a biphenyl epoxy of R _{1 to} R ₄ = CH ₃ (epoxy equivalent 315) obtained by reacting the epoxy resin of the formula (3) with a polyhydric phenol was used (epoxy in Tables 1 and 2). Resin C). This epoxy resin comprises an epoxy resin of the formula (3) having R _{1 to} R ₄ of CH ₃ and an epoxy equivalent of 192, and a phenol novolac having a hydroxyl group of 6.0, which is a phenol novolac per epoxy group of the epoxy resin. Phenolic hydroxyl group is 0.25
It can be obtained by reacting at a ratio such that it becomes individual.

As a brominated epoxy resin, Sumitomo Chemical
"ESB400" (epoxy equivalent 400) manufactured by the company was used.
(Shown as epoxy resin D in Tables 1 and 2). Table 1 and Table 2
In the above, as the curing material of the formula (4), naphthalene novo
Rack (“Kayahard NHN” manufactured by Nippon Kayaku Co., OH equivalent
140) was used. There are two types of curing agents of formula (5).
The formula (5) -1 is manufactured by Mitsui Toatsu Co., Ltd. where R = H.
"Milex XL-225" (OH equivalent 172), formula
For (5) -2, R = CH ₃Made by Dainippon Ink and Co.
Use "EXB-6095" (OH equivalent 212) respectively.
I used it. The blending amounts in Tables 1 and 2 are shown in parts by weight.
It

[0027]

[Table 1]

[0028]

[Table 2]

Using the epoxy resin molding material for sealing prepared as described above, the injection time is 14 seconds and the injection pressure is 80 kgf.
/ Cm ² , cure time 90 seconds, mold temperature was 175 ° C., and transfer molding was performed to prepare a 60-pin QFP model element (TEG). With respect to this QFP model element, moisture absorption solder crack resistance, moisture resistance reliability, and internal voids were measured.

Moisture absorption solder crack resistance is 85 ° C, 85%
After absorbing moisture for 24 hours in a high humidity atmosphere of RH, 250 ° C
Was dipped in the solder bath for 10 seconds, and the presence or absence of cracks in the appearance was observed with a stereoscopic microscope. Moisture resistance is measured by absorbing moisture in a high humidity atmosphere of 85 ° C and 85% RH for 24 hours, and then immersing it in a solder bath at 250 ° C for 10 seconds, at a temperature of 133 ° C, 100% RH and 2 atm.
A pressure cooker test (PCT) was performed for 0 hours, and the number of subsequent open defects (breakage defects due to corrosion of the aluminum pattern) was measured.

Regarding the internal voids, those which can be confirmed by observing the presence or absence of the internal voids on the chip are regarded as defective. The results are shown in Table 3. The number of measurements is shown in the denominator, and the number of defects is shown in the numerator.

[0032]

[Table 3]

As shown in Table 3, in each of the examples containing both the epoxy resin having the skeleton of the formula (1) and the epoxy resin of the formula (2), moisture absorption crack resistance, moisture resistance reliability, internal resistance While the number of defects was small in any of the void tests, in Comparative Example 1 composed only of the epoxy resin of the formula (3), the number of defects increased in the moisture resistance reliability test and the internal void test. In Comparative Example 2 composed only of the epoxy resin of the formula (2), the number of defects in the moisture absorption crack resistance and moisture resistance reliability tests is large.

[0034]

As described above, according to the present invention, the epoxy resin having the biphenyl skeleton represented by the formula (1) and the formula (2)
Since it contains the bisphenol A novolac type epoxy resin shown in Fig. 3, the epoxy resin of the formula (1) and the epoxy resin of the formula (2) can improve the resistance to moisture absorption solder cracking, and further the internal voids. Can be reduced and moldability can be improved.

Since the epoxy resin represented by the formula (3) is used as the epoxy resin having the biphenyl skeleton represented by the formula (1), the epoxy resin represented by the formula (3) improves the moisture absorption solder crack resistance. In addition, the internal voids can be reduced and the moldability can be improved. As the epoxy resin having the biphenyl skeleton represented by the formula (1), the average number of hydroxyl groups in one molecule is 2. per epoxy group of the epoxy resin of the formula (3).
Since the epoxy resin prepared by reacting the phenolic hydroxyl groups of the polyhydric phenols of 3 to 10 at a ratio of 0.05 to 0.6 is used, the epoxy resin is used to improve the resistance to moisture absorption solder cracking. In addition, the internal voids can be reduced and the moldability can be improved.

Further, an epoxy resin having a biphenyl skeleton represented by the formula (1) is contained in an amount of 30 to 70 in all epoxy resins.
Since it is contained by weight%, the effect of improving the soldering resistance can be sufficiently obtained, and the problem of increasing the number of internal voids does not occur. Furthermore, since the epoxy resin represented by the formula (2) is contained in an amount of 30 to 70% by weight in the total epoxy resin, the problem of increasing internal voids does not occur, and the solder resistance may decrease. It will disappear.

In addition, the curing agent of the formula (4) is added to the total curing agent in an amount of 3
Since it is contained in an amount of ˜50% by weight, the effect of improving the solder resistance can be sufficiently obtained, and the problem that the moldability (release property) is reduced does not occur. In addition, since the curing material of the formula (5) is contained in the total curing material in an amount of 3 to 50% by weight, the effect of improving the solder resistance is sufficiently obtained, and the moldability (release property) is reduced. The problem does not occur.

Further, since the semiconductor device of the present invention is encapsulated with the above-mentioned encapsulating epoxy resin molding material, it is possible to reduce damages and failures due to defects such as package cracks of the encapsulating resin.

Claims (8)

[Claims] 1. An encapsulating epoxy comprising an epoxy resin having a biphenyl skeleton represented by the following formula (1) and a bisphenol A novolac type epoxy resin represented by the following formula (2). Resin molding material. [Chemical 1] [Chemical 2] 2. The epoxy resin for encapsulation according to claim 1, wherein the epoxy resin having the biphenyl skeleton represented by the formula (1) is an epoxy resin represented by the following formula (3). Molding material. [Chemical 3] 3. The epoxy resin having a biphenyl skeleton represented by the formula (1) has an average number of hydroxyl groups in one molecule of 2.3 per epoxy group of the epoxy resin of the formula (3).
The epoxy resin prepared by reacting the phenolic hydroxyl groups of polyhydric phenols of 10 to 0.05 at a ratio of 0.05 to 0.6 is used, and the encapsulation according to claim 1 or 2. Epoxy resin molding material. 4. The seal according to claim 1, wherein the epoxy resin having a biphenyl skeleton represented by the formula (1) is contained in an amount of 30 to 70% by weight based on the total epoxy resin. Epoxy resin molding compound for stop. 5. The epoxy resin for encapsulation according to claim 1, wherein the epoxy resin represented by the formula (2) is contained in an amount of 30 to 70% by weight based on the whole epoxy resin. Molding material. 6. A curable material represented by the following formula (4) in 3 parts of the total curable material.
% Of 50% by weight.
6. The epoxy resin molding material for sealing according to any one of 1 to 5. [Chemical 4] 7. A cured material of the following formula (5) is added to the total cured material in an amount of 3
% Of 50% by weight.
7. The epoxy resin molding material for encapsulation according to any one of 1 to 6. [Chemical 5] 8. A semiconductor device, which is encapsulated with the epoxy resin molding material for encapsulation according to any one of claims 1 to 7.