JPH0617460B2 - Epoxy resin composition for semiconductor device encapsulation - Google Patents

Description

TECHNICAL FIELD The present invention relates to an epoxy resin for encapsulating a semiconductor device, which gives a cured product having good lead sealability, excellent moisture resistance, adhesiveness and aluminum corrosion resistance. It relates to a composition.

Problems to be Solved by Conventional Techniques and Inventions Curable epoxy resins and curing agents, especially phenol novolac resins and epoxy resin compositions containing various additives added thereto are generally molded in comparison with other thermosetting resins. sex,
It is widely used as a semiconductor device encapsulating material because it has excellent adhesiveness, electrical characteristics, mechanical characteristics, moisture resistance, and the like.

However, the conventional epoxy resin composition, glass,
There is a problem in that the reliability with respect to moisture is inferior to the so-called hermetic sealing using metal, ceramic or the like as a sealing material. Particularly, recently, when mounting a semiconductor component on a circuit board, harsh conditions such as immersion in a solder bath at 250 to 300 ° C. and then a pressure cooker test at 120 to 150 ° C. and 100% RH are adopted. Therefore, there is a problem that the conventional sealing resin cannot cope with such a condition.

Further, in general, various mold release agents are added to the epoxy resin composition for semiconductor device encapsulation in order to improve the mold release from the mold when the semiconductor element is encapsulated by the transfer molding machine.
However, these release agents have a problem that the adhesive force at the interface between the semiconductor element or the lead frame and the sealing resin is reduced, and water penetrates from this interface, which significantly reduces the reliability of the semiconductor device. is doing.

Therefore, at present, it is desired to develop an epoxy resin composition having excellent moisture resistance and strong adhesion.

The present invention has been made in view of the above circumstances, and is excellent in moisture resistance, also has a strong adhesive force, does not enter water at the interface between the semiconductor element or the lead frame and the sealing resin, and is used in a high temperature and high humidity atmosphere. Even if it aims at providing the epoxy resin composition for semiconductor device sealing which gives a highly reliable semiconductor device.

Means and Actions for Solving Problems In order to achieve the above-mentioned object, the present inventors have conducted extensive studies on a mold release agent having excellent performance, particularly for an epoxy resin composition for semiconductor device encapsulation. An epoxy resin composition comprising an epoxy resin, a curing agent, and an inorganic filler, and (A) a higher fatty acid having 10 or more carbon atoms, an alcohol, an ester (fat or oil) thereof or a derivative thereof, and (B) the following general formula ( 1) (However, in the formula, R ¹ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, R ² is a hydrogen atom, —CH ₃ group, —C ₃ H ₇ group, or And a = 1 to 3, b = 1 to 3, and a + b = 1 to 4) are represented by the following formula: organosilicon compound (organosilane compound)
In a weight ratio of (A) / (B) = 1 to 15 and the reaction product obtained is preferably 0.1 to 100 parts by weight of the total amount of the epoxy resin and the curing agent. By adding 5 parts by weight, it is possible to obtain a cured product which is superior in moisture resistance to a cured product of a conventional epoxy resin composition and also has excellent adhesive strength, and the above reaction product becomes an excellent release agent. I found it. Further, in particular, the semiconductor device sealed with this epoxy resin composition has excellent lead sealability because the adhesiveness between the sealed resin and the semiconductor element or the lead frame is strong, and further under high temperature and high humidity conditions. However, we have found that it can be used with high reliability.

That is, the fatty acid, alcohol, ester thereof or derivative thereof modified with the organosilicon compound which is the reaction product used in the present invention acts as a releasing agent, but unlike conventional releasing agents, heat and It has a moisture-curing function. A resin-encapsulated semiconductor device is usually molded by transfer molding and then subjected to an after-cure process to completely cure the encapsulating resin. Generally, transfer molding conditions are 150 to 190 ° C. and 1 to 5 ° C.
And the condition of the after cure process is 160 to 1
90 ° C., 3 to 6 hours. On the other hand, the reaction product (release agent) used in the present invention is 160 to 190 ° C, 10 to 6
It is heat-cured in 0 minutes, or even if it is semi-cured, it is gradually and completely cured by moisture in the air. Therefore, the reaction product (release agent) of the present invention does not heat-cure during transfer molding and has an excellent effect as a release agent. However, since it heat-cures in the after-curing step, it may not be a semiconductor element or a lead frame. It does not exist as a free release agent at the interface of the sealing resin, and does not reduce the adhesive force. Therefore, the semiconductor device sealed with the epoxy resin composition of the present invention has less water entering the interface between the semiconductor element or the lead frame and the sealing resin, and is excellent in reliability under high temperature and high humidity. The inventors have found that the above-mentioned reaction product has very remarkable properties as a mold release agent for an epoxy resin composition for encapsulating a semiconductor device, and have completed the present invention.

Therefore, the present invention provides an epoxy resin composition containing an epoxy resin, a curing agent, and an inorganic filler, which is selected from (A) a higher fatty acid having 10 or more carbon atoms, an alcohol, an ester thereof, and a derivative thereof, or Two or more kinds, (B) the following general formula (1) (However, in the formula, R ¹ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, R ² is a hydrogen atom, —CH ₃ group, —C ₃ H ₇ group, or And a = 1 to 3, b = 1 to 3, and a + b = 1 to 4) are represented by the following formula: organosilicon compound (organosilane compound)
An epoxy resin composition for encapsulating a semiconductor device, characterized in that a reaction product obtained by reacting and in a weight ratio of (A) / (B) = 1-15 is blended. is there.

Hereinafter, the present invention will be described in more detail.

The epoxy resin composition of the present invention contains an epoxy resin and a curing agent. In this case, the epoxy resin is an epoxy resin having two or more epoxy groups in one molecule, and specifically, for example, cresol novolac type epoxy resin, phenol novolac type epoxy resin, bisphenol A.
Type epoxy resins, o-allylphenol novolac type epoxy resins, brominated products of the above epoxy resins, epoxy resins modified with organopolysiloxane, and heterocyclic epoxy resins such as triglycidyl isocyanate, and the like. Alternatively, two or more kinds are appropriately selected and used.

In addition, it is preferable that the content of hydrolyzable chlorine ions in these epoxy resins is as low as possible, and it is preferable that the content of the epoxy resin is 0.1% by weight or less.

Further, a phenol resin is suitable as a curing agent for the above epoxy resin, and as the phenol resin, phenol novolac resin, cresol novolac resin, tert-
Examples thereof include butylphenol novolac resin, nonylphenol novolac resin, resol-type phenol resin, bisphenol A-type novolac resin, and organopolysiloxane-modified phenol novolac resin, and one or more of these may be appropriately selected and used.

When these epoxy resins are used to cure the epoxy resin, 0.8 to 3 phenolic hydroxyl groups, preferably 1 epoxy group, per epoxy group of the epoxy resin.
It is preferable to add a phenolic resin to the epoxy resin so as to give 2 to 2, and if the phenolic hydroxyl group is less than 0.8, the cured product of the epoxy resin composition may have deteriorated electrical properties and mechanical properties. When the number of the hydroxyl groups is more than 3, the viscosity of the epoxy resin composition is too low,
When molding the epoxy resin composition, inconveniences such as occurrence of voids and deterioration of releasability may occur.

Further, in the present invention, it is preferable to use a curing accelerator for the purpose of accelerating the reaction between the above-mentioned phenol resin type curing agent and the epoxy resin. As the curing accelerator, various compounds generally used for curing an epoxy compound can be used, and examples thereof include imidazole, 2-methylimidazole, 2-ethylimidazole and 2,4-
Dimethyl imidazole, 2-ethyl-4-methyl imidazole, 2-undecyl imidazole, 2-heptadecyl imidazole, 1-vinyl-2-methyl imidazole, 2-phenyl-4,5-dihydroxymethyl imidazole, 2-phenyl imidazole, 2-phenyl-4
-Imidazoles such as methylimidazole, triethylamine, diethylenetriamine, triethylenetetramine, diethylaminopropylamine, N-aminoethylpiperazine, bis (4-amino-3-methylcyclohexyl) methane, metaxylyleneamine, menthanediamine, 3,9 -Bis (3-aminopropyl) -2,4
8,10-tetraoxaspiro (5.5) undecane,
1,8-diazabicyclo (5.4.0) undecene-7
Amine compounds such as, or triethylamine and B
Examples thereof include complex compounds composed of F ₃ , organophosphine compounds such as triphenylphosphine, and adducts of amine compounds and acid anhydrides such as trimellitic anhydride.

The amount of the curing accelerator used is not particularly limited, but a usual amount may be used.

These curing accelerators are not always available in 1
The use is not limited to only one type, and two or more types may be used in combination depending on the curing acceleration performance of the curing accelerator.

Furthermore, the epoxy resin composition of the present invention is one in which an inorganic filler is blended, and as the inorganic filler, those usually used in this type of epoxy resin composition can be used, for example, silica, Alumina, talc, mica, clay, kaolin, glass fiber, glass beads, asbestos, baryta, zinc white, antimony trioxide, calcium carbonate, aluminum hydroxide, calcium hydroxide,
Examples thereof include titanium oxide, silicon carbide, iron oxide and the like. Among these inorganic fillers, silica powder, antimony trioxide, high-purity alumina, glass fiber, etc. are particularly desirable,
The powdery filler preferably has an average particle diameter of 0.01 to 30 μm. The above-mentioned inorganic fillers can be used alone or in combination of two or more, but the compounding amount thereof is 200 per 100 parts by weight of the total amount of the above component epoxy resin and the curing agent. ~ 400 parts by weight, especially 2
It is preferably used in the range of 00 to 300 parts by weight.
If the amount used is too large, not only dispersion becomes difficult, but also physical properties such as moisture resistance and adhesiveness may be disadvantageous.

In the epoxy resin composition of the present invention, (A) one or more selected from higher fatty acids having 10 or more carbon atoms, alcohols, esters thereof and derivatives thereof, and (B) the following general formula (1) ) (However, in the formula, R ¹ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, R ² is a hydrogen atom, —CH ₃ group, —C ₃ H ₇ group, or And a = 1 to 3, b = 1 to 3, and a + b = 1 to 4) are represented by the following formula: organosilicon compound (organosilane compound)
(A) / (B) = 1 to 15 are reacted in a weight ratio, and a reaction product obtained by the reaction is blended. The reaction product is a lubricant or a release agent (A) component. (B) is modified with silane which is a component, and has an OR group such as an alkoxy group bonded to Si in the molecule, and the reaction product is blended with an epoxy resin composition to form a semiconductor device. When used as an encapsulating resin, it gradually hardens and becomes insoluble at the interface with the lead frame encapsulating resin of the semiconductor device, exhibits a strong adhesive force, and improves moisture resistance.

Here, among the lubricants or release agents of the component (A), the higher fatty acid is a higher fatty acid manufactured by Hoechst Wacker. (However, R represents an alkyl group having 28 to 32 carbon atoms) can be preferably used, and wax S (acid value 135 to 155),
Wax LP (acid value 115-130), wax SW
(Acid value 115 to 130) and the like can be used,
CH ₃ (CH ₂ ) ₁₄ COOH (paltimic acid), CH
₃ (CH ₂ ) ₁₆ COOH (stearic acid), CH
_{3 (CH 2) 7 CH =} CH (CH 2) 7 COOH ( oleic _{acid), CH} 3 _{(CH 2)} may be used 20 COOH (behenic acid) and the like.

Also, as higher alcohols, lauryl alcohol,
Examples include myristyl alcohol and the like.

Furthermore, examples of the ester include esters of higher fatty acids such as palmitic acid, stearic acid, oleic acid, and behenic acid with lower alcohols, esters with glycerin, and the like. Derivatives of these fatty acids, alcohols, and esters include acid amides. , Acid chlorides, glycerides (fats and oils), and the like.

On the other hand, as the organosilicon compound as the component (B), specifically, hydroentry alkoxysilane, methylhydridene dialkoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, γ- Aminopropyltripropenoxysilane,
γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltripropenoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, di- γ-glycidoxypropyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, β
Examples include-(3,4) epoxycyclohexylethyltrimethoxysilane and β- (3,4) epoxycyclohexylethylmethyldimethoxysilane.

In this case, the mixing ratio of the component (A) and the component (B) needs to be (A) / (B) = 1 to 15 in terms of weight ratio, and 1 to 7 is particularly preferable. When the ratio of (A) / (B) is less than 1, the amount of the component (A) contained in the mixture, such as higher fatty acid, is small, and the reaction product of the components (A) and (B) is sufficient. When the epoxy resin composition is cured, the releasability of the cured product from the mold becomes poor and the ratio of (A) / (B) is 1 when the epoxy resin composition is cured.
When it is more than 5, the amount of silane of the organosilicon compound contained in the mixture is small, so that the heat curing time of the epoxy resin composition is remarkably delayed, and the epoxy resin composition of the present invention sufficiently achieves the object. Can't do it.

As a method for producing the reaction product, various methods can be adopted depending on the kind of the lubricant or the release agent such as the higher fatty acid as the component (A), and the following methods can be mentioned.

That is, when the lubricant or release agent of the component (A) is a compound having an unsaturated bond in the molecule, the HSi≡ group in the organosilicon compound represented by the formula (1) of the component (B) is used. By using a compound having a functional group such as the above, the compound (A) reacts with the compound having an unsaturated bond in the presence of a platinum catalyst, and an HSi≡ group is added to the unsaturated site of the compound to react. The product is produced. In addition, the organic silicon compound is HS
Even when it has a (CH ₂ ) _1-3 Si≡ group, the addition reaction to the unsaturated bond part proceeds smoothly, and the reaction product is very easily produced.

Further, when the lubricant or release agent of the component (A) is a higher fatty acid having a carboxyl group, not only the above HSi≡ group but also R ² OSi is used as the organosilicon compound of the component (B).
≡ group, HO (CH ₂ ) _1-3 Si≡ group, H ₂ N (C
By selecting those having H ₂ ) _1-3 Si≡ groups and the like, the desired reaction product can be obtained by dehydrogenation reaction, esterification reaction, and other reactions. Further, even when the organic silicon compound as the component (B) has an epoxy group, an amino group, a mercapto group or the like, it can act on the carboxyl group to obtain a reaction product.

The amount of the reaction product is preferably 0.1 to 5 parts by weight, and particularly preferably 0.2 to 3 parts by weight, based on 100 parts by weight of the total amount of the epoxy resin and the curing agent. 0.
If the amount is less than 1 part by weight, the releasability may deteriorate.
If the amount is more than the weight part, phenomena such as "bleeding" to the surface of the molded product may occur.

In the present invention, a conventionally known release agent may be used in combination with the above reaction product.

If desired, various additives can be added to the composition of the present invention. For example, organic rubber-based or silicone-based flexibility-imparting agents, pigments such as carbon black, cobalt blue and red iron oxide, antimony oxide, flame retardants such as halogen compounds, surface treatment agents (γ-glycidoxypropyltrimethoxy). Silane etc.), epoxy silane, vinyl silane, boron compound, coupling agent such as alkyl titanate, antiaging agent, and one or more kinds of other additives.

In addition, the epoxy resin composition of the present invention, in the production thereof, uniformly stirs and mixes predetermined amounts of the above-mentioned components, and kneads and cools with a kneader, roll, extruder or the like which has been heated to 70 to 95 ° C. It can be obtained by a method such as crushing and crushing. Here, there is no particular limitation on the order of mixing the components.

As described above, the epoxy resin composition of the present invention is an IC,
It is used for sealing semiconductor devices such as LSIs, transistors, thyristors, and diodes, and can be effectively used for manufacturing printed circuit boards.

Here, when the semiconductor device is sealed, it is possible to adopt a conventionally used molding method, for example, transfer molding, injection molding, or method molding. In this case, the molding temperature of the epoxy resin composition is 150
~ 180 ℃, post cure at 150 ~ 180 ℃ 2 ~
It is preferably carried out for 16 hours.

EFFECTS OF THE INVENTION As described above, the epoxy resin composition for encapsulating a semiconductor device of the present invention contains a specific reaction product, thereby significantly improving the moisture resistance and giving a cured product having excellent adhesive strength. It has high reliability even at high temperature and high humidity.

Hereinafter, the present invention will be specifically described by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples.

Prior to showing the examples and the comparative examples, a synthesis example of a reaction product synthesized from the higher fatty acid and the organic silicon compound used in the examples and the comparative examples will be shown.

[Synthesis Examples 1 to 9] Stearic acid (CH ₃ (CH ₂ ) ₁₆ COOH) and first
The organosilicon compounds shown in the table were mixed in the proportions shown in Table 1, and the mixture was stirred and mixed at 120 to 140 ° C. for 2 hours and then cooled to obtain solids (reaction products A to I). The gelation time at 180 ° C. was measured for these reaction products. The results are shown in Table 1.

[Synthesis Examples 10 to 12] The types and amounts of fatty acids shown in Table 2 were mixed with the organosilicon compound in the proportions shown in Table 2, and the mixture was stirred and mixed at 130 to 150 ° C for 4 hours, and then cooled. To give a solid (reaction products JM). The gelation time at 180 ° C. was measured for these reaction products. The results are shown in Table 2.

Next, Examples and Comparative Examples will be shown, and various test methods performed on the epoxy resin composition are as follows.

(A) Releasability Good or bad releasability was judged by the ease of separation of the molded product from the mold when the epoxy resin composition was molded by a transfer molding machine.

(B) Adhesiveness I, II 6 × 11 × 0.25 mm test piece (shown by 1 in the figure)
The two tips are made to face each other with a distance of 2 mm from each other, and the resin is sealed in the shape shown in the drawing at 180 ° C for 2 minutes.
After-curing was performed at 0 ° C for 4 hours to obtain a molded product. The following adhesiveness was investigated using this molded product.

Adhesiveness I The test piece of the above-mentioned molded product was pulled in the direction of the arrow in the drawing to measure the adhesive force (kg).

Adhesiveness II The above molded product was pressure cooker (121 ° C, 2.
After standing at 1 atm) for 100 hours, the tensile adhesive force (kg) was measured in the same manner as in Adhesiveness I.

(C) Al wiring corrosion test I, II A test frame was prepared by mounting a Si chip on which Al wiring (film thickness 1 μ, line width 5 μ) was mounted on 14 PIN DIP.
After molding and sealing at 80 ° C. for 2 minutes, after-curing was performed at 180 ° C. for 4 hours.

Test I A pressure cooker (121 ° C, 2.
It was left to stand at 1 atm) and the breaking rate (%) was measured after 2000 hours.

Test II Immerse the above molded product in a solder bath (260 ° C) for 10 seconds,
Further, the wire breakage rate (%) after standing for 500 hours in a pressure cooker (121 ° C., 2.2 atm) was measured.

[Examples 1 to 9 and Comparative Examples 1 to 7] The components having the types and blending amounts shown in Table 3 were kneaded with an 8-inch roll heated to 70 to 90 ° C for about 10 minutes until uniform, and formed into a sheet. After molding, cooling, and pulverization, 16 types of epoxy resin compositions were obtained.

Next, with respect to the obtained 16 kinds of epoxy resin compositions,
The tests (a) to (c) above were performed.

The results are also shown in Table 3.

[Examples 10 to 12 and Comparative Example 6] Four types of epoxy resin compositions were obtained in the same manner as in Examples 1 to 9 by using the components in the types and blending amounts shown in Table 4.

For each of the four types of epoxy resin compositions obtained, Example 1
Various tests (a) to (c) were conducted in the same manner as in the case of ~ 9.

The results are also shown in Table 4.

From the results shown in Tables 3 and 4, the molded product encapsulated with the epoxy resin composition of the present invention has a good releasability, the adhesive force does not decrease even when subjected to high temperature treatment, and the Al wiring corrosion test is performed. It is recognized that there is no disconnection and an excellent molded product can be obtained from the epoxy resin composition of the present invention.

[Brief description of drawings]

FIG. 1 shows a molded product formed for measuring the adhesive strength,
(A) is a plan view and (B) is a sectional view. 1 ... Test piece, 2 ... Sealing resin.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location H01L 23/31 (72) Inventor Toshio Shiobara 2-13-1, Isobe, Gunma Prefecture Shin-Etsu Gakukogyo Co., Ltd. Silicone Electronic Materials Research Laboratory (56) Reference JP-A-60-69129 (JP, A)

Claims (4)

[Claims] 1. An epoxy resin composition containing an epoxy resin, a curing agent and an inorganic filler, which comprises (A) one or more selected from higher fatty acids having 10 or more carbon atoms, alcohols, esters thereof and derivatives thereof, or Two
Or more, and (B) the following general formula (1) (However, in the formula, R ¹ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, R ² is a hydrogen atom, a —CH ₃ group, —C ₃ H ₇ or And a = 1 to 3, b = 1 to 3, and a + b = 1 to 4) in a weight ratio of (A) /
(B) An epoxy resin composition for semiconductor device encapsulation, comprising a reaction product obtained by reacting at a ratio of 1 to 15. 2. The epoxy resin composition for encapsulating a semiconductor device according to claim 1, wherein a phenol resin is used as a curing agent. 3. The semiconductor device encapsulation according to claim 1 or 2, wherein the compounding amount of the reaction product is 0.1 to 5 parts by weight per 100 parts by weight of the total amount of the epoxy resin and the curing agent. Epoxy resin composition for use. 4. The method according to any one of claims 1 to 3, wherein the content of the inorganic filler is 200 to 400 parts by weight per 100 parts by weight of the total amount of the epoxy resin and the curing agent. Epoxy resin composition for semiconductor device encapsulation.