JPH064750B2 - Epoxy resin composition and cured product thereof - Google Patents

Description

TECHNICAL FIELD The present invention has good releasability, good appearance and imprintability of a molded article, and excellent lead sealability and moisture resistance, as well as adhesiveness and resistance. Gives a cured product with excellent aluminum corrosivity,
The present invention relates to an epoxy resin composition preferably used for sealing semiconductor devices and the like, and a cured product of the epoxy resin composition.

Conventional techniques and problems to be solved by the invention Conventionally, an epoxy resin composition containing a curing agent such as an epoxy resin and a phenol novolac resin, an inorganic filler, and various additives is generally another thermosetting resin composition. Since it gives cured products with superior moldability, adhesiveness, electrical properties, mechanical properties, and moisture resistance compared to other products, it is widely used as various molding materials, powder coating materials, semiconductor device encapsulation materials, etc. There is.

When this epoxy resin composition is used as a material for encapsulating a semiconductor device, for example, carnauba wax is added to the epoxy resin composition to improve releasability from a mold when a semiconductor element is encapsulated by a transfer molding machine. And the like release agent is added.

However, the conventional epoxy resin composition containing a release agent such as carnauba wax is more reliable as a sealing agent against moisture than the case of hermetic sealing using glass, metal, ceramics or the like as a sealing agent. In addition, it is inferior in performance, and when a release agent is added, the adhesive force at the interface between the semiconductor element or the lead frame and the encapsulation resin decreases, and water invades from the interface between the resin and the lead frame, resulting in encapsulation treatment. There is a drawback that the reliability of the subsequent semiconductor device in terms of moisture resistance is significantly reduced. Further, when a semiconductor device is sealed with an epoxy resin composition containing a release agent, the appearance of the semiconductor device is deteriorated, the commercial value is reduced, and the imprintability when printing on a molded article is reduced. There is also.

Furthermore, recently, when mounting a semiconductor component on a circuit board, after soldering at a high temperature of 215 to 260 ° C., for example, 12
Although harsh conditions such as performing a pressure cooker test at 0 to 150 ° C. and 100% RH are adopted, the conventional epoxy resin composition sufficiently handles as a sealing material under such a high temperature and high humidity atmosphere. However, it is difficult to achieve satisfactory resin sealing.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an epoxy resin composition and a cured product thereof that give a cured product having good mold releasability, moisture resistance, adhesiveness, and imprintability.

Means and Actions for Solving the Problems The present inventor, in order to achieve the above-mentioned object, has made earnest studies on a release material having excellent performance with respect to an epoxy resin composition suitably used for semiconductor device encapsulation and the like. As a result, the epoxy resin composition comprising an epoxy resin, a curing agent and an inorganic filler, (A) a silicone-modified epoxy resin or a phenol resin,
In particular, an alkenyl group-containing epoxy resin or phenol resin and the following formula (I) (In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group,
a is 0.01 to 0.1, b is 1.8 to 2.2, 1,81 <a + b <2.3, the number of silicon atoms in one molecule is an integer of 20 to 400, and the number of hydrogen atoms directly bonded to silicon atoms is 1 Is an integer of ~ 5. ) The copolymer obtained by the addition reaction with the organopolysiloxane represented by: and (B) a higher fatty acid having 10 or more carbon atoms, a higher alcohol, a higher fatty acid ester or a derivative thereof, preferably in a weight ratio. (A) ingredient / (B)
A melt reaction product obtained by performing a melt reaction in a ratio of component = 1 to 0.05 is used as a mold release agent, and the novel mold release agent is preferably added in a total amount of 10 parts by weight of an epoxy resin and a curing agent.
When 0.2 to 15 parts are mixed with 0 parts (parts by weight, the same applies hereinafter), the mold releasability is good, and the adhesiveness to semiconductor elements, lead frames, etc. is good, and it has excellent moisture resistance,
In addition, it gives a cured product with good appearance and imprintability, and demonstrates highly reliable and satisfactory performance even in a high temperature and high humidity atmosphere.
Therefore, it has been found that an epoxy resin composition that can be effectively used for semiconductor encapsulation and the like can be obtained.

That is, for example, when an epoxy resin composition containing a conventional release agent such as carnauba wax is used for sealing a semiconductor device, the resin-sealed semiconductor device is usually molded by a transfer molding machine. At that time, the epoxy resin composition of the encapsulant is pressurized and flows into the cavity through the runner, and at the same time when the epoxy resin is melted and flowed, the release agent compounded in the composition is also melted. Since it does not react with the epoxy resin and is not compatible with it, it flows from the runner to the cavity before the epoxy resin. Therefore, the release agent reduces the adhesiveness of the epoxy resin composition to the semiconductor device and the lead frame. On the other hand, the melt reaction product of the silicone-modified epoxy resin or phenol resin of the release agent according to the present invention and the higher fatty acid, higher alcohol, higher fatty acid ester or derivative thereof is used as an external release agent during transfer molding. The effect of the Transfer molding condition 150
~ 190 ° C, 1.5 ~ 5 minutes, after cure condition 160 ~
It reacts with the epoxy resin in the composition at 190 ° C. for 3 to 8 hours and gels, and hardly exists as a release agent at the interface between the semiconductor element or the lead frame and the sealing resin. The epoxy resin composition is strong without impairing the adhesiveness of the cured product with the semiconductor element or the lead frame even if a release agent is blended, is excellent in moisture resistance, and has good appearance and imprintability. Therefore, in the semiconductor device sealed with the epoxy resin composition of the present invention, the semiconductor element has less moisture intrusion into the interface between the lead frame and the sealing resin, is excellent in moisture resistance, and has releasability and appearance. The present invention was found to have good imprintability, high reliability under high temperature and high humidity, and that the above-mentioned molten reaction product has very remarkable properties as a mold release agent for epoxy resin compositions. It came to.

Incidentally, a copolymer obtained by an addition reaction of an alkenyl group-containing epoxy resin or phenol resin with an organopolysiloxane of the above formula (I) and an epoxy resin composition containing the same have been known for a long time (Japanese Patent Laid-Open No. 58-58). -214
17, No. 62-84147), the present inventors have newly found that the melt reaction product of such a copolymer and the component (B) is effective as a mold release agent for the epoxy resin composition. It is a thing.

Therefore, the present invention provides an epoxy resin composition containing an epoxy resin, a curing agent, and an inorganic filler, a silicone-modified epoxy resin or a silicone-modified phenol resin, and a higher fatty acid having 10 or more carbon atoms, a higher alcohol, and a higher fatty acid. Provided are an epoxy resin composition characterized by blending a melt reaction product obtained by a melt reaction with an ester or a derivative thereof, and a cured product obtained by curing the epoxy resin composition.

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

The epoxy resin composition of the present invention contains an epoxy resin, a curing agent, and an inorganic filler.

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 resin, o-allyl. Phenol novolac type epoxy resin,
Examples thereof include brominated products of the above epoxy resins, epoxy resins modified with organopolysiloxane, and heterocyclic epoxy resins such as triglycidyl isocyanate, and one or more of these may be appropriately selected and used.

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

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 an epoxy resin is cured using these phenolic resins, 0.8 to 3 phenolic hydroxyl groups, preferably 1 to 1 epoxy group per epoxy resin is used.
It is preferable to add a phenol resin to the epoxy resin so as to give two, and if the number of the phenolic hydroxyl groups is less than 0.8, the cured product of the epoxy resin composition may have poor electrical properties and mechanical properties. Three
If it is more than the above range, the viscosity of the epoxy resin composition is too low, so that voids and the like are likely to occur when the epoxy resin composition is molded, and the releasability may be deteriorated.

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. Examples of the curing accelerator include imidazole, 2-,
Methylimidazole, 2-ethylimidazole, 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,
Amine-based compounds such as 1,8-diazabicyclo (5.4.0) undecene-7, or triethylamine and BF ₃
Examples thereof include complex compounds consisting of and, 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.

Then, as the inorganic filler to be added to the composition of the present invention, the inorganic filler used in this kind of epoxy resin composition can be usually used, for example, silica, alumina, mica, clay, kaolin, glass beads. , Glass fiber, zinc white, antimony trioxide, calcium carbonate, aluminum hydroxide, BeO, AlN, boron nitride, titanium oxide, silicon carbide, iron oxide and the like.
Among these inorganic fillers, silica powder, antimony trioxide, high-purity alumina, and glass fiber are particularly preferable, and 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 blending amount thereof is 200 to 900 with respect to 100 parts of the total amount of the epoxy resin and the curing agent. Parts, especially 200-750
It is preferred to use within the range of parts. If the amount of the inorganic filler used is too large, it will be difficult to disperse, and moisture resistance,
It may be disadvantageous in terms of adhesiveness and other physical properties.

The epoxy resin composition for semiconductor encapsulation of the present invention contains the above-mentioned epoxy resin, curing agent and inorganic filler as essential components, and may further contain a curing accelerator if necessary. In the above, a melt reaction product of a silicone-modified epoxy resin or phenol resin and a higher fatty acid, a higher alcohol, a higher fatty acid ester or a derivative thereof together with these components is used. As described above, unlike the conventional mold release agent, it has good compatibility with the epoxy resin and partially heat-cures. Therefore, by blending the above reaction product as the mold release agent, the epoxy resin composition is bonded. The mold releasability can be improved without impairing the property, the moisture resistance, and the imprintability.

Here, as the silicone-modified epoxy resin and the silicone-modified phenol resin, particularly, an alkenyl group-containing epoxy resin or an alkenyl group-containing phenol resin and the following formula (I) (In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group,
a is 0.01 to 0.1, b is 1.8 to 2.2, 1.81 <a + b <2.3, the number of silicon atoms in one molecule is an integer of 20 to 400, and the number of hydrogen atoms directly bonded to silicon atoms is 1 to 5
Is an integer. It is preferable to use a copolymer obtained by addition-reacting with the organopolysiloxane represented by

Here, as the alkenyl group-containing epoxy resin or phenol resin, the alkenyl group-containing phenol resin is epoxidized with epichlorohydrin, or a conventionally known epoxy resin or phenol resin is partially reacted with 2-allylphenol or the like. It is possible to obtain the alkenyl group-containing novolac type epoxy resin or phenol resin represented by the following formulas (1) to (3).

(However, in the above formulas, p and q are usually 1 ≦ p ≦ 20,
It is an integer of 1 ≦ q ≦ 10. ) On the other hand, as the organopolysiloxane represented by the above formula (I), at least one It is sufficient to have both ends hydrogendiene methyl polysiloxane, both ends hydrogenene methylphenyl polysiloxane, both ends hydrogenene methyl.
(2-Trimethoxysilylethyl) polysiloxane is preferred.

The degree of polymerization of the above-mentioned organopolysiloxane of formula (I) is usually in the range of 20 to 400, preferably 30 to 200.

The copolymer of the present invention comprises the above-mentioned alkenyl group-containing epoxy resin or phenol resin and the compound of the formula (I) It can be obtained by heating and reacting with an organopolysiloxane having ## STR3 ## in the presence of a conventionally known addition catalyst, for example, a platinum-based catalyst such as chloroplatinic acid.

Specific examples of the above copolymer include JP-A-58-2141.
7 and the copolymers described in JP-A-62-84147,
Particularly, compounds represented by the following formulas (1) and (2) are preferably used.

(However, l, m, and n are 20 ≦ l ≦ 400, 1 ≦ m ≦ 1
0,1 ≦ n ≦ 20, R is a hydrogen atom, a methyl group or an ethyl group) Further, the higher fatty acid, the higher alcohol, the higher fatty acid ester and their derivatives have a carbon number of 10 or more, preferably 20 or more. These may be used alone or in admixture of two or more.

In this case, as the higher fatty acid having 10 or more carbon atoms, the following formula is used. (However, R represents an alkyl group having 25 to 32 carbon atoms.) The higher fatty acid manufactured by Hoechst Wacker Co., Ltd., can be preferably used, and specifically, wax S (acid value 135 to 16).
5), wax LP (acid value 115 to 130), wax SW (acid value 115 to 130) and the like can be used, as well as CH ₃ (CH ₂ ) ₁₄ COOH (palmitic 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.

Examples of higher alcohols having 10 or more carbon atoms include lauryl alcohol and myristyl alcohol.

Further, as the higher fatty acid ester having 10 or more carbon atoms,
For example, palmitic acid, stearic acid, oleic acid,
Examples thereof include esters of higher fatty acids such as behenic acid and lower alcohols, esters of glycerin, etc., and acid amides as derivatives of these resin acids, alcohols and esters,
Examples thereof include acid chloride and glyceride (oil and fat).

Here, a copolymer obtained by the addition reaction of the above-mentioned alkenyl group-containing epoxy resin or phenol resin and the organopolysiloxane of formula (I) (hereinafter referred to as component (A))
And a higher fatty acid having 10 or more carbon atoms, a higher alcohol, a higher fatty acid ester or a derivative thereof (hereinafter, referred to as a component (B)) in a polymerization ratio of (A) (B) = 1 to 0. 0
5, especially 0.5 to 0.05 is preferable. (A) /
If the ratio (B) is less than 0.05, the amount of the copolymer of the component (A) is small, and the molten reaction product of the component (A) and the component (B) cannot exhibit its performance sufficiently. In some cases, when this reaction product is blended with the epoxy resin composition as a mold release agent, the mold release agent is vaporized during molding and adheres before the epoxy resin reaches the lead surface of the semiconductor device, The lead sealability may be deteriorated, and a large amount of the release agent may adhere to the surface of the cured epoxy resin to reduce the imprintability. Further, if the (A) / (B) ratio is greater than 1, the amount of the copolymer of the component (A) compounded increases, and the surface of the cured product of the epoxy resin composition cannot be imprinted with a commercially available imprinting agent. There are cases.

The melt reaction between the component (A) and the component (B) can be carried out by various methods depending on the type of the copolymer of the component (A) and the higher fatty acid of the component (B). Reaction temperature 100 ~
The reaction is performed at 250 ° C. for 1 to 5 hours to give 10
The melt viscosity at 0 ° C. is preferably 0.4 to 20 poise.

The melting reaction product is blended in an amount of 0.2 to 15 parts, particularly 0.1 to 100 parts, based on 100 parts of the total amount of epoxy resin and curing agent.
It is preferably 5 to 10 parts, and if the blending amount is less than 0.2 part, the releasability of the cured product from the mold may deteriorate at the time of molding, and if it is more than 15 parts, the surface of the molded product may be deteriorated. There are cases in which phenomena such as bleeding out of the semiconductor and poor lead sealability of the semiconductor element occur.

In the present invention, as the release agent, in addition to the above-mentioned melt reaction product, other release agents conventionally known in the art may be used in combination as long as the curing of the present invention is not impaired.

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). Orchid), 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 is 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, the semiconductor device can be sealed by a conventionally used molding method such as transfer molding, injection molding, or casting method. In this case, the molding temperature of the epoxy resin composition is 1
The post-cure is preferably performed at 50 to 180 ° C. and 150 to 180 ° C. for 2 to 16 hours.

As described above, the epoxy resin composition of the present invention,
By incorporating a specific melt reaction product as a release agent, the release property is good, and the adhesiveness and moisture resistance are significantly improved, and the adhesiveness and moisture resistance are good even in a high temperature and high humidity atmosphere. Yes, it gives a cured product with excellent appearance and imprintability. Therefore, the composition of the present invention, when used as a semiconductor device encapsulant, is highly reliable even under conditions of 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.

In addition, prior to showing the examples and the comparative examples, a synthesis example of a melt reaction product synthesized from the higher fatty acid and the organosilicon compound used in the examples and the comparative examples will be shown.

[Synthesis example]

A silicone-modified epoxy resin or phenolic resin having the following structural formula is added to myricyl cerotate (C ₂₅ H ₅₁ COOC ₃₀ H
₆₁ , melting point 85 ° C., acid value 2.9 to 9.7, iodine value 14,
Saponification numbers 79 to 87) were added and mixed, and melt reaction was carried out at the reaction temperature and time shown in Table 1. Then, the reaction product was cooled to obtain solid melt reaction products A to E. The melt viscosity (100 ° C.) of the obtained reaction product was measured with a B-type viscometer and the results are shown in Table 1.

For comparison, the above silicone-modified epoxy resin or phenolic resin is mixed with caprylic acid (C ₈ H ₁₆ O ₂ , melting point 16).
℃, boiling point 239 ℃, specific gravity 0.908) are added and mixed,
After performing the melt reaction at the reaction temperature and time shown in Table 2, the reaction product was cooled to obtain solid reaction products FI. In addition,
The melt viscosity (100 ° C.) of the obtained reaction product is measured by a B-type viscometer, and the results are shown in Table 2.

[Examples 1 to 7 and Comparative Examples 1 to 6] Epoxy resin compositions having the compositions shown in Table 3 were prepared, and the following tests were performed on each composition. The results are also shown in Table 3.

(A) Adhesion test As shown in FIGS. 1 and 2, the tips of two test pieces 1 and 1 of 6 × 11 × 0.25 mm are opposed to each other with a distance of 2 mm from each other, and the test pieces 1 and 1 are opposed to each other. The part is covered with resin 2 at 37 × 14 × 4 mm, and the resin is sealed at 180 ° C. for 2 minutes.
Molded product 3 after after-curing at 180 ℃ for 4 hours
Got The following adhesiveness was investigated using this molded product.

Adhesiveness I The test pieces 1 and 1 of the above-mentioned molded product were pulled in mutually opposite directions, and the adhesive force (kg) was measured.

Adhesiveness II The above-mentioned molded article 3 was prepared by pressure cooker (121 ° C,
After standing at 2.1 atm) for 100 hours, the adhesive strength (kg) was measured by pulling in the same manner as in the adhesiveness I.

(B) Al wiring corrosion test An Al wiring (film thickness 1μ, line width 5μ) Si chip mounted on a 14PIN DIP was used as a test frame.
It was molded and sealed at 80 ° C. for 2 minutes, and after-cured at 180 ° C. for 4 hours to obtain a molded product.

Al wiring corrosion rate I The above molded product was pressure cooker (121 ° C, 2.
It was left to stand at 1 atm) and the breaking rate (%) was measured after 2000 hours.

Al Wiring Corrosion Rate II The above-mentioned molded product was immersed in a solder bath at 216 ° C. for 10 seconds and then left in a pressure cooker (121 ° C., 2.1 atm), and the disconnection rate (%) after 1000 hours was measured.

(C) Releasability test Good releasability was determined based on the ease of release of the molded product from the mold when the epoxy resin composition was molded by a transfer molding machine.

(D) Imprintability test Six test pieces of 10φ x 3 mm were molded under the molding conditions of 180 ° C.
Mold for 2 minutes at a molding pressure of 70 kg / cm ^{2 and then} at 180 ° C for 4
Stamping agent [Bonmark C, Markem 7224, 726 manufactured by Baba Inbo Co., Ltd.
After printing with 1], the marking agent is cured and MIL-ST
D-883C (Notice-4, Method2015-6Resist
ance to solvents) method to evaluate the imprintability.

Note: EOCH-1020-70: Orthocresol novolac type resin manufactured by Nippon Kayaku Co., Ltd. TD: 2093: Phenol novolac resin manufactured by Dainippon Ink and Chemicals YDB-340: Brominated epoxy resin manufactured by Tohto Kasei KBM-403: γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) From the results in Table 3, the molten reaction product of the silicone-modified epoxy resin or phenol resin according to the present invention and the higher fatty acid was separated. It was confirmed that the cured product of the epoxy resin composition blended as a mold has good adhesiveness, moisture resistance, releasability and imprintability, and also has excellent adhesiveness and moisture resistance even in a high temperature and high humidity atmosphere. Was done.

[Brief description of drawings]

FIG. 1 is a plan view of a molded product of a test piece sealed with an epoxy resin composition used for an adhesion test, and FIG. 2 is a sectional view thereof. 1 ... Test piece, 2 ... Sealing resin, 3 ... Molded product.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H01L 23/29 23/31

Claims (2)

[Claims] 1. An epoxy resin composition containing an epoxy resin, a curing agent, and an inorganic filler, and a silicone-modified epoxy resin or silicone-modified phenol resin and a higher fatty acid having 10 or more carbon atoms, a higher alcohol, or a higher fatty acid ester. Alternatively, an epoxy resin composition comprising a melt reaction product obtained by performing a melt reaction with these derivatives. 2. A cured product obtained by curing the epoxy resin composition according to claim 1.