JPS636017A - epoxy resin composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an epoxy resin composition particularly suitable for use in encapsulating semiconductor devices.

In recent years, there has been a demand for high-volume, low-cost production of semiconductor devices, etc.
For this reason, in recent years, resin encapsulation of semiconductor devices has become mainstream using transfer molding, which allows for mass production, and in particular, with advances in chip passivation technology and related technologies, low-pressure transfer molding has become the mainstream. ,
The number of cavities in the molds for these molding methods is increasing, and the size of the molds is becoming larger, and in addition, unmanned production is progressing. On the other hand, the materials for the frames of semiconductor devices have also been moving toward lower prices, and have changed from 4,270 I to silver-plated copper plates, and then to nickel-plated copper plates.

In response to these trends, resin compositions used for resin encapsulation of semiconductor devices are currently required to have various characteristics improved. In other words, in response to the above-mentioned increase in the size of molds, resin compositions are required to have even better fluidity and filling properties than conventional ones, and similarly, in response to the above-mentioned unmanned production, resin compositions Better storage stability and wider workability are required so that production can be carried out without changing production conditions such as the composition of the composition and molding conditions. In addition, as a recent trend, resin compositions with a high content of inorganic fillers aimed at improving heat dissipation properties are being unfilled, without creating defects such as voids, and without causing disconnection of semiconductor devices. There is a growing demand for resin compositions that can produce expensive semiconductor devices without rejecting them and have sufficient fluidity at low pressure. It reflects the requirements. On the other hand, in response to changes in the material of the frame of semiconductor devices, resin compositions of 4.2
Excellent adhesion to alloys, silver, nickel, etc. is required.

In this regard, epoxy resin molding materials generally have superior electrical properties, mechanical properties, adhesive properties, moisture resistance, etc. compared to other thermosetting resins, and also have sufficient fluidity even at particularly low molding pressures. It has properties such as not deforming or damaging inserts, and epoxy resin compositions using this resin are more suitable for encapsulating semiconductor devices than other resin compositions. In particular, those using novolak type phenolic resin as a curing agent are superior in terms of moisture resistance, reliability, moldability, etc., and are less toxic than epoxy resin compositions using other curing agents. Because it has the characteristic of being relatively inexpensive, it is widely used as a resin encapsulation material for semiconductor devices such as ICs, LSIs, diodes, and transistors.

However, although epoxy resin compositions using such phenolic curing agents have excellent adhesion to 4.270I and silver, they have poor adhesion to nickel.
When a semiconductor device is encapsulated with an epoxy resin composition using a phenolic curing agent, moisture resistance may be poor or
Flat packs with thin resin have disadvantages such as blistering due to poor adhesion between the frame and the resin.

In addition, conventional epoxy resin compositions have a high modulus of elasticity and poor flexibility, so they tend to crack when molded and processed into devices or during heat cycle tests.
The device had defects such as deterioration of the device's function and easy damage due to deformation of the device due to excessive stress.

The present invention was made in view of the above circumstances, and it is an object of the present invention to provide an epoxy resin composition that has excellent adhesion to nickel, moisture resistance, and crack resistance.

In order to achieve the above object, the present inventors conducted various studies and found that an epoxy resin containing a curable epoxy resin and a curing agent for curing the same was developed. In the composition, the following formula (A
) When a specific carboxyl group-containing silicone compound shown in It was discovered that the durability and crack resistance were significantly improved, and the present invention was completed.

Therefore, the present invention provides an epoxy resin composition containing a curable epoxy resin and a curing agent for curing the same, in which the following formula (A) ... (A) (wherein R' and R3 are Both represent monovalent organic groups, and R1 and R3 may be the same or different,
R2 represents a divalent organic group, a.

b is a positive number satisfying 1≦a゛+b≦4.1≦b≦4. ) The present invention provides an epoxy resin composition containing a carboxyl group-containing silicone compound represented by the following formula.

The present invention will be explained in more detail below.

First, the curable epoxy resin constituting the epoxy resin composition of the present invention is an epoxy resin having two or more epoxy groups in one molecule, and this epoxy resin can be cured with various curing agents described below. There are no restrictions on molecular structure, molecular weight, etc., and various conventionally known ones can be used. Specifically, for example, novolac type synthesized from various novolac resins including epichlorohydrin and bisphenol A. Examples include epoxy resins, bisphenol A type epoxy resins, alicyclic epoxy resins, and substituted epoxy resins into which halogen atoms such as chlorine and bromine atoms are introduced.Among them, cresol novolac epoxy resins, especially cresol novolac epoxy resins represented by the average structural formula Resins are preferred.

In terms of moisture resistance, the above epoxy resin has a hydrolyzable chlorine content of 500 ppm or less, free Na and Cl content of 2 ppm or less, and an epoxy equivalent of 180 to 180 ppm.
The range is preferably 210.

In addition, when using the above-mentioned epoxy resin, there is no problem in using a monoepoxy compound as appropriate, and examples of this monoepoxy compound include styrene oxide, cyclohexene oxide, propylene oxide, methyl glycidyl ether, ethyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl. Examples include ether, octylene oxide, and dodecene oxide. The above-mentioned epoxy resins are not necessarily limited to the use of only one type, but may be used in combination of two or more types.

In addition, curing agents include amine-based curing agents such as diaminodiphenylmethane, diaminodiphenylsulfone, and metaphenylenediamine, and acid anhydride-based curing agents such as phthalic anhydride, romellitic anhydride, and benzophenonetetracarboxylic anhydride. Examples include phenol novolac curing agents having two or more hydroxyl groups in one molecule, such as phenol novolak and Talezol novolak, among which novolac-type phenolic resins, especially phenols with the average structural formula (% formula %) A novolac type phenol resin obtained by reacting formalin with an acid catalyst is suitable.

These curing agents, like the above-mentioned curable epoxy resin, contain free Na from the viewpoint of moisture resistance of semiconductors.

It is preferable that the CI is 2 ppm or less, and when a novolak type phenolic resin is used among these curing agents, if the amount of 7-mer phenol, that is, free phenol contained therein exceeds 1%, The amount of the above-mentioned free phenol should be 1% or less because it may adversely affect moisture resistance or cause defects such as voids, unfilling, and whiskers in the molded product when molded products are made with this composition. It is preferable to Furthermore, when the softening point of the novolac type phenolic resin becomes less than 50°C, the Tg becomes low,
As a result, heat resistance deteriorates, and if the softening point exceeds 120°C, the melt viscosity of the epoxy resin composition tends to increase, resulting in poor workability, and in either case, moisture resistance may decrease. The softening point of the novolac type phenolic resin is preferably 50 to 120°C.

Furthermore, in the present invention, various curing accelerators such as imidazole or its derivatives, tertiary amine derivatives,
There is no problem in using phosphine derivatives, cycloamidine derivatives, etc. in combination.

In addition, the amount of the curing agent blended is the amount usually used,
The amount of the curing accelerator can also be within a normal range, but the amount of the curing accelerator that undergoes a curing reaction with the epoxy group (al) of the epoxy resin and the epoxy group, such as the phenolic hydroxyl group of a novolac type phenol resin, is Reactive group (bl
The molar ratio (alb) with is 0.8 to 1.5, especially 1.0 to
It is preferable to adjust the amount of the curing agent used so that the molar ratio is less than 0.8. If the molar ratio is less than 0.8, the epoxy resin composition may not be sufficiently cured or the glass of the molded product may deteriorate after curing. If the transition point (Tg) decreases and the heat resistance worsens, and if the above molar ratio exceeds 1.5, the Tg of the molded product will also decrease.
There may be cases where g decreases and electrical characteristics deteriorate.

The carboxyl group-containing silicone compound blended into the epoxy resin composition of the present invention has the following formula (A
) ...(A) (However, in the formula, R1 and R3 both represent a monovalent organic group, and R1 and R3 may be the same or different, and R2 represents a divalent organic group. Expression, a, b are 1≦a+
It is a positive number satisfying b≦4.1≦b≦4. ) with a small number of silicon atoms in one molecule (
The structure thereof may be either a monomer or a polymer, and may be linear, branched, or cyclic.

Here, monovalent organic groups constituting R1 in the formula include methyl group, ethyl group, propyl group, phenyl group, vinyl group,
3.3.3-Trifluoropropyl group, methoxy group, ethoxy group etc. are exemplified, and divalent organic groups constituting R2 include alkylene groups such as methylene group, ethylene group and propylene group, phenylene group, -CH2CH20CH2C )
Examples include a group consisting of 12- or a combination of these groups, and examples of the monovalent organic group constituting R3 include a methyl group,
Examples include ethyl group, propyl group, phenyl group, and vinyl group.

Further, as the carboxyl group-containing silicone compound to be blended into the epoxy resin composition of the present invention, it is preferable to use one having a melting point below the heating temperature when molding this epoxy resin composition; When an epoxy resin composition containing a carboxyl group-containing silicone compound is molded, the carboxyl group-containing silicone compound does not melt, resulting in poor dispersibility, and when sealing a semiconductor device, the adhesion to the frame of the semiconductor device is poor. This results in large variations in the quality of the product, and also, the releasability from molds etc. becomes poor, which may impair moldability. On the other hand, from the viewpoint of compound preparation, it is preferable to use a compound having a temperature of 180° C. or lower. This is because when creating a compound by kneading an epoxy resin composition containing a carboxyl group-containing silicone compound with a temperature exceeding 180°C using an extruder, sufficient mixing may not be carried out and white spots may appear. It is.

Therefore, from the above, it is preferable that the carboxyl group-containing silicone compound has a melting point of 180° C. or lower, which is lower than the heating temperature at which the epoxy resin composition is molded.

The method for producing the carboxyl group-containing silicone compound according to the present invention described above is not particularly limited, but for example, when producing a carboxyl group-containing silicone compound represented by the following formula (B)...(B). If necessary, gradually add an acetone solution of an organosiloxane represented by the following formula % (%) to an acetone solution of trimellitic anhydride until the trimellitic anhydride and the organosiloxane reach equimolar amounts. (White salt precipitates), after the completion of the dropwise addition, stirring is continued for 1 hour, after which unreacted substances are washed three times with acetone and dried at low temperature. A carboxyl group-containing silicone compound represented by is obtained.

The amount of the carboxyl group-containing silicone compound of formula (A) mentioned above is 0.2 to 10 parts by weight, particularly 0.3 to 5 parts by weight, per 100 parts by weight of the total amount of the curable epoxy resin and the curing agent for curing it. Preferably in parts by weight, 0.2
If the amount is less than 10 parts by weight, the effect of the above compound may be insufficient and the adhesion to the frame of a semiconductor device may become insufficient. If it exceeds 10 parts by weight, the adhesion may be abnormally strong. This may result in poor releasability from the mold, etc.

The epoxy resin composition of the present invention may further contain an inorganic filler.

Examples of the inorganic filler include quartz powder, alumina powder, talc, glass fiber, and antimony trioxide. The epoxy resin composition may be a mixture, and may be either natural or synthetic. However, when using the epoxy resin composition to take measures against alpha rays for semiconductor devices for VLSI memory, the epoxy resin composition may contain uranium, thorium, etc. It is preferable to use a small amount of powdered or spherical synthetic quartz, and in addition to the above cases, it is preferable to use synthetic quartz with high thermal conductivity and good heat dissipation.
% or more of crystallinity or fused silica obtained by once melting 5i02 is preferably used with a cavity filling rate, and crystalline silica is particularly preferable.

Furthermore, in order to increase the thermal conductivity of the epoxy resin composition,
In addition to the above-mentioned inorganic fillers, boron hydride such as (BH), aluminum nitride, alumina, magnesium oxide,
An inorganic filler with high thermal conductivity such as silicon carbide can be used in combination as appropriate.

The preferred average particle diameter range of the inorganic filler is 5 to 50 μm.
The compounding amount is 200 to 8 parts per 100 parts by weight of the total amount of the curable epoxy resin and the curing agent for curing it.
It is preferable to set it as 00 parts by weight. The above blending amount is 200
If the amount is less than 800 parts by weight, the fluidity of the composition will be too good, resulting in voids, blisters, etc., resulting in poor molded appearance. When molding with a mold, problems such as non-filling may occur.

Moreover, in order to achieve the purpose of the present invention more effectively,
The following formula (C) (wherein R4 is H or -CH2CHCHz, RS.

R6 represents a divalent organic group, R7 to R'' represent a monovalent organic group or a hydroxyl group, and n is 1 to 500. ) is preferably used in combination with the carboxyl group-containing silicone compound of formula (A). In this case, the amount of the silicone flexibility imparting agent of the above formula (C) is 4 to 60 parts by weight, particularly 6 to 60 parts by weight, based on 100 parts of the total amount of the curable epoxy resin and the curing agent for curing it. The amount is desirably 30 parts by weight, and by incorporating the amount within this range, the adhesion to the frame of the semiconductor device and the crank resistance of the epoxy resin composition are further improved.

However, if the above-mentioned amount exceeds 60 parts by weight, the mechanical strength of the epoxy resin composition may decrease and it may become brittle.

The epoxy resin composition of the present invention may further contain various additives depending on its purpose, use, etc., if necessary. e.g. carbon-functional silanes for improved adhesion;
Waxes, mold release agents such as fatty acids such as stearic acid and their metal salts, pigments such as carbon black, dyes, antioxidants, flame retardants, surface treatment agents such as γ-glycidoxypropyltrimethoxysilane, There is no problem in blending other additives. In addition, it is preferable to use carnauba wax as the mold release agent from the viewpoint of adhesive properties.

When producing the epoxy resin composition of the present invention, predetermined amounts of the above-mentioned components are uniformly stirred and mixed, and the epoxy resin composition is prepared in advance at 70-90%
It can be obtained by heating to 5°C, kneading with a roll, extruder, etc., cooling, and pulverizing. Note that there is no particular restriction on the order of blending the components.

The epoxy resin composition of the present invention can be suitably used as a molding material and a powder coating material, and can also be used for sealing semiconductor devices such as ICLSI, LANRISK, SIRISK, and diodes, and for manufacturing printed circuit boards. can also be used effectively.

Note that when sealing the semiconductor device, conventionally employed molding methods such as transfer molding, injection molding, and casting can be used. In this case, the molding temperature of the epoxy resin composition is 1
50~180℃, post cure 150~180'
It is preferable to carry out the reaction at C for 2 to 16 hours.

As explained above, the epoxy resin composition of the present invention contains a curable epoxy resin and a curing agent for curing the epoxy resin composition. By blending the carboxyl group-containing silicone compound shown, an epoxy resin composition can be obtained that has excellent adhesion to nickel, moisture resistance, and crack resistance, and is therefore suitable for use in semiconductor device encapsulation. be.

EXAMPLES Hereinafter, the present invention will be specifically explained by showing examples and comparative examples, but the present invention is not limited to the following examples.

In addition, in the descriptions in Examples and Comparative Examples, "parts" simply refer to parts by weight.

[Examples 1 to 4. Comparative Example 1] 60 parts of creso'-crucible epoxy resin (EOCN-102 manufactured by Nippon Kayaku Co., Ltd.) with an epoxy equivalent of 215, 60 parts of a novolac type phenol resin (TD-2 manufactured by Dainippon Ink Co., Ltd.)
093) 30 parts, 10 parts of brominated epoxy resin (BREN manufactured by Nippon Kayaku Co., Ltd.), 475 parts of crystalline silica (Crystallite 5K manufactured by Taramori Co., Ltd.), 1.5 parts of carbana wax
Part, γ-glycidoxypropyltrimethoxysilane 1.
5 parts, carbon black 1 part, antimony trioxide 5 parts,
1 part of 2-phenylimidazole was blended with a carboxyl group-containing silicone compound represented by the following formula (1) in the amount shown in Table 1 and thoroughly mixed, and then rolled on an 8-inch roll heated to 100°C. The mixture was kneaded for 3 minutes, then cooled and pulverized to obtain epoxy resin compositions (Examples 1 to 4 and Comparative Example 1).

Using these epoxy resin compositions, the following measurements A to D were performed.

A. Adhesiveness 611 width x 11 crane length x 2 made of the material listed in Table 1
Using two metal pieces having a thickness of 00 μm, these metal pieces m and m were sealed in an epoxy resin composition n, as shown in FIG. 1.2. In this case, both metal pieces m.

M was sealed in an epoxy resin composition n so that its six ends faced each other. Epoxy resin composition n was molded at a molding temperature of 180° C. for 2 minutes, sealed with resin, and post-cured at 180° C. for 16 hours to obtain a measurement sample.

The left and right metal pieces of the obtained measurement sample were fixed to a tensile tester and pulled to measure the adhesive strength.

B. A sample was prepared by molding a 14-pin DIP IC using a moisture-resistant epoxy resin composition.

The obtained sample was placed in a high pressure cooker and heated to 121°C.

After processing for 1000 hours under the condition of 2.0 kg/Cl11, the number of samples with open wiring defects was measured.
Next, the open defect rate of the wiring was calculated.

The moisture resistance of the resulting wiring was evaluated based on the open defect rate.

Using C5 crank resistant epoxy resin composition, 0 is used in the center of the frame.
．． A sample was prepared by molding a 14-pin DIP IC on which a 5 tm x 5 tm x 4 ta silicon chip was mounted.

The resulting sample was incubated at -50°C for 5 minutes, then for 1
10 heat cycles with 5 minutes at 80°C.
The test was repeated 0 times, and the number of samples in which resin cracks had occurred up to this time was measured, and then the resin crack occurrence rate was calculated.

The crack resistance was evaluated based on the resin crack occurrence rate.

The above results are shown in Table 1.

Table 1 [Examples 5 to 7] As a carboxyl group-containing silicone compound, Example 5
In Example 6, a carboxyl group-containing silicone compound represented by the following formula (n); in Example 6, a carboxyl group-containing silicone compound represented by the following formula (1) % formula % ([); in Example 7, the carboxyl group-containing silicone compound Same as Example 1, except that in addition to silicone compound I, a silicone-based flexibility imparting agent (formula ■ below) consisting of a silicone-modified phenolic resin was used, and the amount of crystalline silica was 500 parts. Epoxy resin compositions (Examples 5 to 7) were produced using similar materials and in similar amounts.

Measurements A to C above were performed using these epoxy resin compositions.

The results are also listed in Table 2.

From the results shown in Table 2, it is confirmed that the cured product of the epoxy resin composition according to the present invention has excellent adhesion to copper, 4.270I, and nickel, and has good moisture resistance and crank resistance. .

[Brief explanation of the drawing]

Fig. 1.2 shows an epoxy resin composition sample in which a metal piece is sealed for evaluating the adhesive force of the epoxy resin composition, Fig. 1 is a plan view, and Fig. 2 is a front view. m...Metal piece, n...Epoxy resin composition.

Claims (1)

[Claims] 1. The epoxy resin composition containing a curable epoxy resin and a curing agent for curing the same contains the following formula (A) ▲ mathematical formula, chemical formula, table, etc. ▼... (A) (However, in the formula, R^1 and R^3 both represent a monovalent organic group, R^1 and R^3 may be the same or different, and R^2 is a divalent organic group. represents a valent organic group, a and b are 1≦
It is a positive number satisfying a+b≦4 and 1≦b≦4. ) An epoxy resin composition comprising a carboxyl group-containing silicone compound represented by: 2. The epoxy resin composition according to claim 1, wherein the curable epoxy resin is a cresol novolak epoxy resin. 3. The curable epoxy resin has a hydrolyzable chlorine content of 500 ppm or less and a free Na and Cl content of 2.
The epoxy resin composition according to claim 1 or 2, which has an epoxy equivalent of 180 to 280 ppm or less. 4. The epoxy resin according to any one of claims 1 to 3, using a curing agent with a free Na and Cl content of 2 ppm or less as a curing agent for curing the curable epoxy resin. Composition. 5. The epoxy resin composition according to any one of claims 1 to 4, wherein the curing agent for curing the curable epoxy resin is a novolac type phenolic resin. 6. The curing agent for curing the curable epoxy resin has a free phenol content of 1% or less and a softening point of 50 to 120°C.
The epoxy resin composition according to claim 5, which is a novolac type phenolic resin in the range of . 7. The curing agent for curing the curable epoxy resin is the epoxy group (a) of the curable epoxy resin and the epoxy group (a)
and the reactive group (b) of the curing agent that undergoes a curing reaction, the molar ratio (a/b) of the curing agent being 0.8 to 1.5. The epoxy resin composition according to item 1. 8. Claims 1 to 7, wherein the carboxyl group-containing silicone compound represented by the above formula (A) has a melting point of 180°C or lower and lower than the heating temperature when molding the epoxy resin composition. The epoxy resin composition according to any one of Items. 9. Claim 1, in which 0.2 to 10 parts by weight of the carboxyl group-containing silicone compound represented by the above formula (A) is blended per 100 parts by weight of the total amount of the curable epoxy resin and the curing agent for curing it. Any one of paragraphs to paragraphs 8
The epoxy resin composition described in . 10. The inorganic filler is 200 to 800 parts per 100 parts by weight of the total amount of the curable epoxy resin and the curing agent for curing it.
The epoxy resin composition according to any one of claims 1 to 9, wherein the epoxy resin composition is blended in parts by weight.