JPS62187721A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition having excellent mechanical strength and cracking resistance, a low coefficient of thermal expansion and a high glass transition temperature, by mixing a curable epoxy resin with a curing agent, an inorganic filler and a specified organopolysiloxane gel. CONSTITUTION:A crosslinking agent and, optionally, a catalyst (e.g., tetramethylammonium hydroxide) are added to an organo-polysiloxane obtained by reacting methylvinylpolysiloxane with methylhydrogenpolysiloxane and the organopolysiloxane is slightly crosslinked to obtain an organopolysiloxane gel (b) having a consistency as measured according to JIS K 2808 of 30-130 and a modulus of 10<3>-10<5> dyn/cm. 100pts.wt. total of a curable epoxy resin (A) and a curing agent (B) (e.g., diamino-diphenylmethane) is mixed with 10-1000pts.wt. inorganic filler (e.g., crystalline silica) and 1-50pts.wt. component D or organopolysiloxane composition which can form component D, and the mixture is melt-kneaded at 70-95 deg.C.

Description

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

Epoxy resins, curing agents, and epoxy resin compositions containing inorganic fillers generally have better moldability and adhesive properties than other thermosetting resins. Due to its excellent electrical properties, mechanical properties, moisture resistance, etc., it is widely used as various molding materials, powder coating materials, electrical insulation materials, etc., and recently it has been especially used in large quantities as a material for encapsulating semiconductor devices. has been done.

However, 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, and are susceptible to excessive stress. The device had defects such as deterioration of the device's function and easy breakage due to deformation of the device.

In order to solve these problems, the present inventors have developed an epoxy resin composition in which organopolysiloxane is blended with a curable epoxy resin (Japanese Unexamined Patent Publication No. 56-129246), and furthermore an aromatic polymer and an organopolysiloxane. An epoxy resin composition to which a block copolymer is added (JP-A-58-2
No. 1417) was proposed to improve the crank resistance of epoxy resin compositions.

Despite the improvements in crack resistance mentioned above, in recent years, the characteristics required for semiconductor device encapsulation materials have become increasingly strict.
Currently, there is a desire to develop materials that have properties such as superior crank resistance, a high glass transition point, a low coefficient of expansion, and no loss of bending strength.

Furthermore, the silicone-modified compounds used in the epoxy resin composition proposed above are all expensive, which has a considerable impact on the price of the epoxy resin composition and, therefore, the various molded and processed products to which it is applied. In some cases, this became an obstacle to lowering prices.

The present invention was developed in view of the above circumstances, and has excellent fluidity and mechanical strength such as bending strength and bending modulus, as well as a low coefficient of expansion (and high glass transition temperature), and excellent crack resistance. The purpose of the present invention is to provide an excellent and economically advantageous epoxy resin composition.

5. In order to achieve the above object, the present inventors have made extensive studies and have developed an epoxy resin composition containing a curable epoxy resin, a curing agent, and an inorganic filler. It has been discovered that a simple method of containing and compositing a specific organopolysiloxane gel is effective.

That is, when an organopolysiloxane having two or more reactive functional groups in one molecule is blended and dispersed in the above-mentioned epoxy resin composition, the internal stress is lowered without lowering the glass transition point and the crack resistance is improved. In addition, this type of organopolysiloxane is relatively inexpensive and provides an economically advantageous epoxy resin composition. When a semiconductor device is sealed using an epoxy resin composition, it migrates to the interface with the lead frame, causing problems such as poor marking and poor adhesion. Furthermore, when an epoxy resin composition is stored in an uncured state for a long period of time, similar migration of organopolysiloxane and agglomeration of silicone dispersed particles occur, resulting in a significant change in dispersion. The problem also arises that it is difficult to obtain certain functions.

In contrast, such organopolysiloxanes are reacted and slightly crosslinked to achieve consistency and elastic modulus within a specific range.
That is, the consistency measured according to JIS-2808 is 30~
130, elastic modulus is 103-105 dynes/elm”
When an organopolysiloxane gel with a low crosslinking state of The fluidity and dispersion state of the epoxy resin composition do not deteriorate, which is observed when the silicone rubber compound of This discovery led to the completion of the present invention.

Therefore, the present invention provides a curable epoxy resin, a curing agent,
For epoxy resin compositions containing inorganic fillers, J
Consistency measured according to IS-2808 is 30-130
, an epoxy resin composition containing an organopolysiloxane gel having an elastic modulus of 103 to 105 dynes/ctn2, or an organopolysiloxane composition capable of forming the organopolysiloxane gel. .

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 which substituted or unsubstituted novolak type epoxy resins and bisphenol A type epoxy resins. is suitable.

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, as a curing agent, an amine curing agent represented by diaminodiphenylmethane, diaminodiphenylsulfone, metaphenylene diamine, etc., an acid anhydride curing agent such as phthalic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, or Examples include phenol novolak curing agents having two or more hydroxyl groups in one molecule, such as phenol novolak and cresol novolak.

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 used is the amount normally used,
The amount of the curing accelerator can also be within a normal range.

If the inorganic filler used in the present invention is less than 100 parts by weight with respect to the total fi of 100 parts by weight of the epoxy resin and curing agent, the expansion coefficient of the obtained epoxy resin composition is large and the result is satisfactory in terms of physical properties such as crack resistance. On the other hand, if it exceeds 1,000 parts by weight, fluidity may deteriorate and it may be difficult to disperse the inorganic filler, so it is preferably 100 to 1,000 parts by weight, more preferably 250 ~750 parts by weight. Note that there are no restrictions on the type of inorganic filler, whether it is used alone or in combination, and it may be selected appropriately depending on the purpose and use of the epoxy resin composition. , synthetic high-purity silica, synthetic spherical silica, talc, mica, silicon nitride, silicon carbide, aluminum nitride, poron nitride, alumina, and the like can be used.

The organopolysiloxane gel blended into the epoxy resin composition of the present invention is produced by reacting organopolysiloxanes having at least two or more reactive functional groups in one molecule, as described above, to create a slightly cross-linked organopolysiloxane gel. An organopolysiloxane in a low crosslinked state obtained by
Consistency measured according to IS-2808 is 30-130
The elastic modulus is 103 to 105 dynes/cfflz. Organopolysiloxane gel consistency is 30
or if the modulus is less than 103 dynes/cm
If it is less than 2, although favorable results are obtained for the fluidity of the epoxy resin composition containing this organopolysiloxane gel, problems tend to occur in the sealing properties and printing properties of the epoxy resin composition after curing, and This is not practical because it causes deterioration in mechanical strength. (ttr way,
If the consistency of the organopolysiloxane gel exceeds 130, or if the modulus of elasticity exceeds 10'dynes/cm'', the fluidity and dispersibility of the epoxy resin composition containing the organopolysiloxane gel will decrease. Furthermore, it is not suitable for the purpose of the present invention in that it cannot provide sufficient curing to reduce the stress of the epoxy resin composition after curing, and therefore cannot improve crack resistance. .

Here, the organopolysiloxane gel blended into the epoxy resin composition of the present invention is an organopolysiloxane having at least two or more reactive functional groups in one molecule, a crosslinking agent, and, if necessary, platinum. , sulfuric acid, hydrochloric acid, caustic potash, tetramethylammonium hydroxide, tetrabutylphosphonium hydroxide, phosphonitrile chloride, etc., by reaction-curing an organopolysiloxane composition containing an appropriate amount of one or more of known catalysts such as phosphonitrile chloride. be able to.

The organopolysiloxane used to obtain such an organopolysiloxane gel should contain at least 2
There is no particular restriction as long as it has at least 2 reactive functional groups, but for example, the following general formula (1) % formula % (1) (wherein R is hydrogen or a substituted or unsubstituted monovalent represents a hydrocarbon group, a is 1.5 to 2.05), and one type of reactive functional group such as a vinyl group, an aminopropyl group, a glycidoxypropyl group, a mercaptopropyl group, etc. Or organopolysiloxane having at least two or more types in one molecule, specifically, the following formulas - MezSiO+zz
00. ”, ■ (hereinafter abbreviated as M) Me2SiO...■ (hereinafter abbreviated as D) 11Mt4siO+zz 0
．． '40. ■ (Hereinafter, abbreviated as Ml+.) (CHz = CH)MeSiO=-■ (Hereinafter, abbreviated as DV.) φ2SiO...■ (Hereinafter, abbreviated as Dφ.) (CHz-C8) MezSiO+7=
”'・・・'■ (hereinafter abbreviated as MV) MeSiOsz□ ・・・・・・
・■ (hereinafter abbreviated as T) NH2CHzCtlz ・Me2SiO+zz
``'-■ (hereinafter abbreviated as MN) (hereinafter abbreviated as D') Each organosiloxane bond unit has the following ratio (
Organopolysiloxanes (11 to (mol%)) bonded with
7] Organopolysiloxane (1) M: Dv: D=0.8: 1.6: 97.
6 organopolysiloxane (2) MUMv:T:D =4.03: 0.75: 5.6
2: 89.60 organopolysiloxane (3) M: D': D4:D=0.8: 1.6: 1
．． 6: 96.0 Organopolysiloxane (4) M':D=10:90 Organopolysiloxane (5) MAD' :D=20:30:50 Organopolysiloxane (6) MN:D=10:90 Organopoly Siloxane (7) M:Df: D=0.8: 1.6: 97.6
One or more of these may be used.

Further, the crosslinking agent for obtaining the organopolysiloxane gel according to the present invention is not particularly limited as long as it is a compound capable of crosslinking by reacting with the reactive functional group of the organopolysiloxane described above, but for example, Examples include organopolysiloxanes having two or more active hydrogen atoms.

In particular, as the combination of organopolysiloxane and crosslinking agent for obtaining the organopolysiloxane gel according to the present invention, the above-mentioned organopolysiloxanes (methyl vinyl polysiloxanes such as 11 to (3)) are used as the organopolysiloxane, It is preferable to use a methylhydrodiene organopolysiloxane as a crosslinking agent, and an organopolysiloxane gel obtained by reacting these methylvinyl polysiloxane and methylhydrodiene polysiloxane in the presence of a platinum catalyst. , which can be suitably used as the organopolysiloxane gel according to the present invention.

Among them, trimethylsilylmethylvinylpolysiloxane at both ends and/or trimethylsilylmethylvinylphenylpolysiloxane at both ends is used as the methylvinylpolysiloxane, and hydrodiene dimethylpolysiloxane and/or at both ends as the methylhydrogen polysiloxane.
Alternatively, those using hydrogen-terminated hydrodiene methylphenyl polysiloxane are more suitable for the purpose of the present invention.

The blending amounts of organopolysiloxane and crosslinking agent to obtain the organopolysiloxane gel according to the present invention are as follows:
When using the above-mentioned methylhydrodiene polysiloxane as a crosslinking agent, both can be blended in any ratio, and there is no particular restriction, but the number of reactive functional groups of both should be adjusted to be approximately the same ratio. is preferred.

In addition, in order to effectively achieve the purpose of the present invention, the amount of the organopolysiloxane gel according to the present invention is 1 to 50 parts by weight per 100 parts by weight of the total amount of the curable epoxy resin and the curing agent.
Parts by weight, particularly 5 to 30 parts by weight, are preferred; if the above-mentioned amount is less than 1 part by weight, it is difficult to provide a stress reduction sufficient to contribute to the desired improvement in crack resistance. Moreover, if it exceeds 50 parts by weight, the mechanical strength of the epoxy resin composition after curing tends to decrease, which is not preferable for the purpose of the present invention in either case.

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 T-glycidoxypropyl trimethoxysilane, etc. , and other additives may be blended.

Although there are no particular limitations on the method for producing the epoxy resin composition of the present invention, the following production methods (i) to (iv) can be suitably employed.

(i) Organopolysiloxane, a crosslinking agent, and a reaction catalyst thereof are kneaded directly into an epoxy resin composition such as a curable epoxy resin, a curing agent, and an inorganic filler to simultaneously cure the epoxy resin composition. A method that also allows reaction formation of gels.

(ii) A method in which an organopolysiloxane gel is reacted and formed from an organopolysiloxane and a crosslinking agent in a solution in the presence of a catalyst if necessary, and then the solvent is distilled off and the gel is blended into an epoxy resin composition and kneaded.

(iii) Add an inorganic filler such as silica to the organopolysiloxane and the crosslinking agent, stir and mix in a solution, if necessary in the presence of a catalyst, to react and form an organopolysiloxane gel. A method in which the inorganic filler adsorbs the obtained organopolysiloxane gel to an epoxy resin composition such as a curable epoxy resin and a curing agent and kneads the inorganic filler.

(iv) Combination of (i) to (iii) above, for example (
A method of obtaining an epoxy resin composition using an organopolysiloxane gel-adsorbed inorganic filler obtained in the manufacturing process according to the manufacturing method of iii), and further following the method of (i) and/or (ii).

In addition, 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 for 7 days.
It can be obtained by heating to 0 to 95°C, kneading with a kneader, 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, as well as for IC1LSI, l
- It can be effectively used for sealing semiconductor devices such as run-risks, silicon-risks, and diodes, and for manufacturing printed circuit boards.

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

As explained above, the epoxy resin composition of the present invention comprises a curable epoxy resin, a curing agent, an inorganic filler, and a JIS
- contains an organopolysiloxane gel having a consistency of 30 to 130 and a modulus of elasticity of 10'' to 10S dyne/c+n'' as measured in accordance with 2808, or an organopolysiloxane composition capable of forming the organopolysiloxane gel. As a result, it has a low expansion coefficient and a high glass transition temperature without impairing fluidity, mechanical strength such as bending strength and bending modulus, and has excellent crack resistance. The amount of deformation of the electrode is small, and it is also economically advantageous, so that an epoxy resin composition can be obtained that is suitably used for encapsulating semiconductor devices.

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, prior to showing Examples and Comparative Examples, the following measurement items (A) to (E) adopted in Examples and Comparative Examples and their measurement methods, and manufacturing examples of organopolysiloxane gels will be shown.

(a) Spiral reflow direct 175℃ using a mold that complies with EMMI standards.

The measurement was carried out under the condition of "70 kg/am".

(b) shellfish straightness (bending strength and bending elastic force) J
175℃, 7 Q kg according to IS-K6911
/cm”.

Measurements were made on a 110 x 4 x 1001 bending rod that was molded under conditions of a molding time of 2 minutes and post-cured at 180° C. for 4 hours.

(c)'-, Glass'': Using a test piece of 15 m in diameter, the value was measured using a diradometer when the temperature was raised at a rate of 5°C per minute.

(d) A silicon chip measuring 4.5 x 0.5 m was glued to a 14PrN-IC frame (4270), and an epoxy resin composition was applied to it under molding conditions of 180°C.
After molding for 2 minutes and post-curing at 180°C for 4 hours, thermal cycles of -196°C x 1 minute to 260°C x 30 seconds were repeated, and the resin crack occurrence rate after 50 cycles was measured. (n=50) (e) Aluminum electrode
A deformation measurement element made of a 3°3,4 x 10.2 x 0.3 dragon-sized silicon chip with an aluminum electrode deposited on it was bonded to a 14PrN-IC frame (4270I), and an epoxy resin composition was applied to this. Molding conditions 180
After molding at ℃ x 2 minutes and post-curing at 180℃ for 4 hours, heat cycles from -196℃ x 1 minute to 150℃ x 1 minute were repeated, and the amount of deformation of the aluminum electrode after 200 cycles was investigated. .

(n=3) [Production Examples 1 to 7] The following formulas (A) to (E) <
IE (J
B. Blend the compound represented by (3) in the proportion shown in Table 1, and add it to a platinum concentration of 10p.
After adding pm of platinum catalyst 2-ethylhexanol modified chloroplatinic acid, the mixture was heated at 150'C for 30 minutes to prepare an organopolysiloxane.

Regarding the obtained organopolysiloxane gel, JIS-
The consistency was measured using a 174-inch micro-consistency meter according to 2808, and the elastic modulus was measured using a viscoelasticity spectrometer.

The measurement results are included in Table 1.

[Examples 1 to 8. Comparative Examples 1 to 5] An epoxidized cresol novolac resin having an epoxy equivalent weight of 200 (curable epoxy resin CI in the table) was used. ), copolymer of allyl group-containing epoxidized novolac resin and organopolysiloxane obtained by the following method (indicated by copolymer (n) in the table), phenol novolac resin with ff1llO of phenol, Production Examples 1 to 7 The organopolysiloxane gels obtained in (indicated by organopolysiloxane gels (1) to [■] in the table), triphenylphosphine (
It is indicated by TPP in the table. ') and 1.8-diazabicycloundecene-7 (indicated by OBU in the table) were used in the amounts shown in Table 2, and 7 parts of brominated epoxy novolac resin and 260 parts of fused silica powder were added to this. , 1.5 parts of 3-glycidoxypropyltrimethoxysilane, 81.0 parts of wax.
5 parts of carbon black and 1.0 parts of carbon black were uniformly melted and mixed using two heated rolls to obtain 11 types of epoxy resin compositions (Examples 1 to 8, Comparative Examples 1 to 3). Manufactured.

In addition, the copolymer of allyl-containing epoxidized novolank resin and organopolysiloxane was prepared in a container equipped with a reflux condenser, a thermometer, a stirrer, and a dropping funnel.
1. Allyl group-containing epoxy resin 120 in a 4-bottle flask
g, methyl isobutyl ketone 100g, toluene 200g
g, 0.04 g of 2-ethylhexanol-modified chloroplatinic acid solution with a platinum concentration of 2% was added, stirred and heated, and from the time the reflux temperature was reached, 80 g of a compound represented by the following formula (F) as an organopolysiloxane was added. was added dropwise for 30 minutes, and after the addition was completed, the reaction was continued at the same temperature for 4 hours.
It is manufactured by washing the obtained contents with water and drying under reduced pressure, and the obtained product has a melt viscosity of 7 at 150°C.
It was a 60 cp white yellow opaque solid.

The various tests (a) to (e) described above were conducted on the epoxy resin composition obtained by the above method.

The results are included in Table 2.

From the results in Table 2, the epoxy resin composition of Comparative Example 3 which does not contain organopolysiloxane gel and the epoxy resin of Comparative Example 1.2 which contains organopolysiloxane gel whose consistency or elastic modulus is outside the range of the present invention. All of the compositions had poor crack resistance and deformation of the aluminum electrode was observed, whereas the epoxy resin composition of the present invention did not exhibit cracking or deformation of the aluminum electrode under the measurement conditions adopted. The effectiveness of the present invention was confirmed because the mechanical strength, expansion coefficient, and glass transition temperature as seen in fluidity, bending strength and bending modulus also cleared practical levels. In addition, in the epoxy resin composition of Comparative Example 1, poor appearance and poor marking occurred due to silicone seeping onto the surface of the molded product.

Claims (1)

[Claims] 1. A curable epoxy resin, a curing agent, an inorganic filler,
Consistency measured according to JIS-K2808 is 30-13
0, an epoxy resin composition comprising an organopolysiloxane gel having an elastic modulus of 10^3 to 10^5 dynes/cm^2 or an organopolysiloxane composition capable of forming the organopolysiloxane gel. thing. 2. The epoxy resin composition according to claim 1, wherein the curable epoxy resin is one or more selected from substituted and unsubstituted novolak epoxy resins and bisphenol A epoxy resins. 3. The epoxy resin composition according to claim 1 or 2, wherein the organopolysiloxane gel is obtained by reacting methylvinylpolysiloxane and methylhydrodienepolysiloxane. 4. Methylvinylpolysiloxane is trimethylsilylmethylvinylpolysiloxane at both ends and/or trimethylsilylmethylvinylphenylpolysiloxane at both ends, and methylhydrodienepolysiloxane is hydrogenate dimethylpolysiloxane at both ends and/or hydrogenmethylphenyl at both ends. The epoxy resin composition according to claim 3, which is a polysiloxane. 5. The organopolysiloxane gel is blended in an amount of 1 to 50 parts by weight per 100 parts by weight of the total amount of the curable epoxy resin and curing agent, according to any one of claims 1 to 4. Epoxy resin composition. 6. The epoxy according to any one of claims 1 to 5, wherein the inorganic filler is blended in an amount of 100 to 1000 parts by weight per 100 parts by weight of the curable epoxy resin and curing agent. Resin composition.