JP2000336246A - Epoxy resin composition for sealing semiconductor and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid epoxy resin composition for sealing semiconductors which is in a liquid state and has a low viscosity at an ordinary temperature and therefore exerts an excellent handleability, does not lose the advantage, a long pot-life, of conventional liquid sealing materials, and yields a cured product having a low elasticity which shows an excellent reliability in terms of humidity resistance and heat resistance of semiconductors and does not allow coagulation, floating in the upper layer of liquids or phase separation, and a semiconductor device sealed using such liquid epoxy resin composition. SOLUTION: This liquid epoxy resin composition for sealing semiconductors contains (A) a cyanic ester, (B) an epoxy resin, (C) an inorganic filler, (D) a metal chelate and/or metal salt and (F) a gel silicone resin, wherein at least one of component (A) or component (B) is in a liquid state at a room temperature, and the weight ratios of each components are component (A)/component (B) = 0.76 to 1.43, component (C)/total composition = 0.60 to 0.95, 0.01 < component (F)/(total composition - component (C)) <0.3. A semiconductor device is prepared by sealing a semiconductor element using the liquid epoxy resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid epoxy resin composition used for encapsulating a semiconductor element and the like, and a semiconductor device sealed using the same.

[0002]

2. Description of the Related Art Conventionally, epoxy resin compositions have excellent electrical performance and adhesive strength, and are therefore used in various applications in the electric and electronic fields. In particular, since a high sealing reliability can be ensured for sealing a semiconductor element, a powdery molding material or a liquid potting material is widely used as a sealing material.

In recent years, as electronic devices have become more mobile and more sophisticated, semiconductor packages have been required to have higher integration, higher density, thinner, and lighter weights. BGA with high density achieved by array connection
New semiconductor package forms such as (ball grid array), CSP (chip scale package), and MCM (multi-chip module) have appeared.

[0004] In the sealing of these new semiconductor packages, there is a limit to the reduction in thickness in the conventional mold molding method using a powdery and granular sealing material, and there are problems such as wire sweep caused by a large number of wires. For this reason, liquid sealing materials have begun to be used. In addition, the mold molding method requires an expensive mold for each product type, which leads to an increase in cost. In addition, there is a possibility that the fine circuit on the BGA substrate may be cut by the mold. It is advantageous to use a liquid sealing method in which sealing is performed without using a mold by using a method.

Although the liquid sealing method has such advantages, the liquid sealing material used is inferior to the powdery and granular sealing material in terms of sealing workability and reliability. There was a drawback that. This is due to the fact that, since a phenolic curing agent is used as a curing agent in the powdery and granular sealing material, it is hardly hydrolyzed when subjected to a moisture resistance reliability test, and has a high adhesive strength to an element. In general, the sealing material used for performing the transfer molding method is a solid type (powder and granular form) at room temperature, and can be filled with a filler or Tg of a resin. And heat shock resistance.

[0006] On the other hand, the conventional liquid encapsulant has a restriction that it is liquid at room temperature, and is one-part and has a long pot life. Selection is limited, and amines and acid anhydrides are generally used. However, among the amine-based curing agents, liquid aromatic amines have too high a reactivity with epoxy and have a short pot life, so
Solid amines represented by (dicyandiamide) have a disadvantage of high viscosity. Further, it has a high moisture absorption rate and is inferior in electric characteristics. On the other hand, acid anhydride curing agents tend to have poor moisture resistance reliability because the ester structure in the crosslinked structure of the cured product is easily hydrolyzed, and also have low thermal adhesion reliability due to low chemical adhesion. In addition, the phenolic curing agent used in the powdery and granular sealing material to be molded is a solid at room temperature and has a very high viscosity when used in combination with liquid epoxy. It is difficult to use for applications. A solvent can be added to lower the viscosity, but voids are likely to be generated in the cured product due to the solvent, resulting in poor appearance and reliability deterioration, similar to the powdery and granular sealing materials that are molded in molds. It is difficult to exhibit the characteristics of.

[0007] Under these circumstances, in accordance with the liquid sealing method, a liquid sealing material having good sealing workability and exhibiting sealing reliability equal to or higher than that of a powdery and granular sealing material to be molded. Sealants are strongly desired. On the other hand, a sealing material is used by mounting a semiconductor chip such as a BGA or CSP on a printed circuit board and then overcoating the board. If the elastic modulus of the sealing resin is high, the warpage of the board becomes large. In other words, it cannot be put to practical use. Therefore, the sealing material usually contains a low elasticity agent.

[0008] Polybutadiene rubber, silicone powder, silicone oil, and the like are known as general low-elasticity agents. However, they have the following disadvantages. First, polybutadiene rubber has low long-term heat resistance due to thermal degradation (oxidation) of double bonds. Silicone-based resins are thermally stable and excellent, but powder-type resins have problems such as agglomeration of particles, floating to a liquid upper layer, and separation. Further, since the viscosity is too high to be uniformly dispersed, the low elasticity effect is small. Silicone oil has poor compatibility with the epoxy resin and low specific gravity, so that it is easy to phase-separate on the top of the sealing material. Also, it is easy to bleed out to the interface between the sealing material and the package substrate,
Since the component acts as a release agent, the adhesive force is reduced, which is likely to cause interfacial peeling. Thus, improvement of the low elasticity agent is also desired.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has the advantages of a conventional liquid sealing material that is liquid at room temperature, has low viscosity, has excellent handleability, and has a long pot life. For semiconductor encapsulation, it is possible to obtain a cured product of low elasticity without losing the properties, and furthermore, it is excellent in the moisture resistance and heat resistance reliability of the semiconductor, and does not cause agglomeration and floating to the upper layer of the liquid and phase separation. It is an object to provide a liquid epoxy resin composition. Another object is to provide a semiconductor device sealed using such a liquid epoxy resin composition.

[0010]

In order to solve the above-mentioned problems, a liquid epoxy resin composition for semiconductor encapsulation according to the present invention comprises (A) a cyanate ester, (B) an epoxy resin, and (C) an inorganic resin. In an epoxy resin composition containing a filler, (D) a metal chelate and / or a metal salt, and (F) a gel silicone resin, component (A) and component (B)
At least one of the components is liquid at room temperature, and the mixing ratio of each component is expressed by weight ratio, Component (A) / Component (B) = 0.76 to 1.43 Component (C) / Total amount of composition = 0.60 0.95 0.01 <(F) component / (total composition- (C) component) <
0.3. Further, in the semiconductor device according to the present invention, a semiconductor element is sealed with the liquid epoxy resin composition.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The epoxy resin composition of the present invention comprises:
(A) cyanate ester, (B) epoxy resin, (C) inorganic filler, (D) metal chelate and / or metal salt, and (F) It contains a gel-like silicone resin.

In the present invention, when the components (A) and (B) are mixed in order to make the resin composition liquid, it is necessary that the resin composition be liquid at room temperature. Therefore, at least one of the component (A) and the component (B) needs to be liquid at room temperature. The cyanate ester of the component (A) is a compound having a cyanate group (-OCN group). (A)
Specific examples of the cyanate ester as the component include 4,4'-ethylidenebisphenylene cyanate (A1) which is liquid at room temperature and 2,2-bis (4-cyanato) which is crystalline and solid at room temperature. Phenyl) propane, bis (4-cyanato-3,5-dimethylphenyl) methane, bis (4-
Examples thereof include cyanate ester polymers such as (cyanato-phenyl) thioether, and polymers obtained by pre-reacting these monomers to form a prepolymer. Among these, those which become liquid at room temperature when mixed with the epoxy resin as the component (B) can be used.

In the present invention, in particular, component (A)
It is preferable to include 4'-ethylidenebisphenylene cyanate (A1). 4,4'-Ethylidenebisphenylene cyanate (A1) is represented by the following chemical formula:

[0014]

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It has a structure having a cyanate group at both ends of a bisphenol E skeleton, and is a liquid of about 100 cps (centipoise) at room temperature. Other cyanate esters (for example, 2,2-bis (4
-Cyanatophenyl) propane and bis (4-cyanato-3,5-dimethylphenyl) having a dimethylphenyl skeleton
Methane) is very crystalline and is a solid at room temperature. Even if these crystalline cyanate esters are heated and dissolved in a liquid epoxy resin to be liquefied, there is a disadvantage that crystals are easily precipitated and solidified after cooling. However, they have found that solidification can be prevented by using in combination with 4,4'-ethylidenebisphenylene cyanate (A1) having a bisphenol E skeleton.

In the present invention, the compounding ratio of 4,4'-ethylidenebisphenylene cyanate (A1) is preferably (A1) / (A) component = 0.1 to 1 in terms of weight ratio. 5 to 1, more preferably 0.7
-1 is more preferable. The mixing ratio is 0.
If it is less than 1, it will be difficult to prevent solidification of the crystalline cyanate ester.

The epoxy resin of the component (B) contains 2
It is a compound having two or more glycidyl groups. As the epoxy resin as the component (B), it is preferable to use a liquid at room temperature, and it may be used alone, or may be a mixture of a liquid and a liquid, or a mixture of a liquid and a solid epoxy resin. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin, halogenated epoxy resin, glycidyl ester type epoxy resin, alicyclic epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, complex resin A ring-type epoxy resin can be exemplified, but is not limited thereto. Among these epoxy resins, bisphenol A and bisphenol F type epoxy resins obtained by molecular distillation and having n of 0 to 1 in the following formula are particularly preferred because of their low viscosity and very few ionic impurities.

[0018]

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The components (A) and (B) are mixed at a weight ratio of component (A) / component (B) = 0.76 to 1 from the viewpoint of the physical properties of the cured product and the reliability of sealing. .43, preferably 0.91 to 1.43, and 0.9
More preferably, it is 1 to 1.25. It is known that a cyanate ester causes a trimerization reaction alone in the presence of a metal catalyst to form a triazine ring. However, this reaction is mainly performed at a high temperature of 180 ° C. or higher. Also, in the composite resin system of cyanate ester and epoxy resin, since the reaction of cyanate group and epoxy group also occurs,
It is presumed that multiple reactions occur due to competitive reactions.
If the ratio of component (A) / component (B) is greater than 1.43, the amount of epoxy resin is insufficient, and in the case of curing at 160 ° C. or lower, a cyanate group that has not been completely reacted remains. An unreacted cyanate group is hydrolyzed into a carbamate group in a moisture resistance reliability test such as a PCT (pressure cooker test), and further causes a decarboxylation reaction to cause poor moisture resistance reliability. Conversely, component (A) /
If the component (B) is smaller than 0.76, an unreacted epoxy group remains because the epoxy resin becomes excessive. The remaining unreacted epoxy groups reduce the crosslink density of the cured product, causing a decrease in glass transition temperature and an increase in moisture absorption. For this reason, the coefficient of thermal expansion of the cured product increases, which causes deterioration in heat cycle and reflow reliability.

As the inorganic filler as the component (C), crystalline silica, fused silica, alumina, calcium carbonate, zinc oxide and the like can be used. In particular, the fused silica is desirably one having no corners or a spherical shape, in order to prevent damage to the passivation film on the surface of the semiconductor chip, and its size is preferably a maximum particle size of 100 μm or less, It is not limited to this.

The compounding ratio of the component (C) is as follows:
(C) Component / total amount of composition is preferably 0.60 to 0.95, more preferably 0.70 to 0.90, and even more preferably 0.75 to 0.85. When the compounding ratio of the component (C) is less than 0.60, the ratio of the resin component increases, so that the amount of shrinkage of the resin composition during semiconductor encapsulation increases, and the coefficient of thermal expansion also increases. Warpage increases and defects such as chip cracks when heat stress is applied tend to occur. In addition, the moisture absorption rate also increases, which may cause cracks during reflow. The compounding ratio of the component (C) is 0.95.
If it is more, the viscosity increases due to lack of liquid components,
It is difficult to handle as a liquid and cannot be sealed.

The metal chelate and / or metal salt of the component (D) is a curing catalyst for the cyanate ester of the component (A). Specific examples of the metal chelate include nonionic or ionic metal chelates having 1 to 6 or more chelate rings.
Examples thereof include iron, cobalt, zinc, tin, aluminum, and manganese. Examples of the ligand of the metal chelate include acetylacetonate, salicylaldehyde, and benzoylacetone. Examples of the metal salt include naphthenate and octenoate.

In the present invention, iron (III) is used as the component (D).
The following effects can be obtained by using the chelate (D1)) or the chelate (D2) of cobalt (III). It is known that a cyanate ester forms a triazine skeleton by causing a trimerization reaction at a high temperature of about 180 ° C. or higher with a metal chelate as a nucleus, and various metal chelates can be a catalyst for the sole curing of a cyanate ester. It is known. Since the attraction of the cyanate group of the curing catalyst varies depending on the type of metal, the speed of this trimerization reaction varies depending on the metal chelate used, and generally, zinc,
Metal chelates such as tin, copper, manganese, titanium, and aluminum are known. However, when an epoxy resin is contained as the resin component in addition to the cyanate ester as in the present invention, the reaction mechanism becomes very complicated. This is because, in parallel with the trimerization reaction of the cyanate group, a reaction occurs in which the cyanate group and the epoxy group react to form an oxazoline skeleton. In the present invention, a gel silicone resin is contained in the epoxy resin composition as a low elasticity component as described later. Resin systems containing this gel-like silicone resin tend to exhibit thixotropic viscosity. A thixotropic liquid material tends to have a convex shape due to a large surface tension. Therefore, it is necessary to form the sealing resin into a flat shape, such as a cavity-down type BGA, for semiconductor package sealing applications. It is disadvantageous as a sealing material for certain packages. However, by using iron (III) chelate (D1) as the metal chelate at this time, the thixotropy becomes extremely small, and high fluidity is exhibited. The ligand of the metal chelate is not particularly limited, and examples thereof include acetylacetonate, salicylaldehyde, and benzoylacetone. Since the amount of the curing catalyst used depends on the amount of the cyanate ester, the (D1) / (A) component is preferably 0.0001 to 0.01 by weight ratio, and 0.0005 to 0.005. More preferably, it is more preferably 0.001 to 0.003. When the amount of the curing catalyst used is within the above range, good curability and long pot life are exhibited.

On the other hand, when there is no dam or the like around the chip as in a COB (chip on board) package,
In order to efficiently seal a small area, it is required that the sealing resin has high thixotropy and does not flow as much as possible.
This is because the chips and wires are exposed when they flow, which causes a defect. In this case, high thixotropy can be realized by using a chelate (D2) of cobalt (III) as the metal chelate. The ligand of the metal chelate is not particularly limited, and examples thereof include acetylacetonate, salicylaldehyde, and benzoylacetone. Since the amount of the curing catalyst used depends on the amount of the cyanate ester, the component (D2) / (A) = 0.000 in weight ratio.
1 to 0.01, preferably 0.0005 to
0.005 is more preferable, and 0.001 to
More preferably, it is 0.003. When the amount of the curing catalyst used is within the above range, good curability and long pot life are exhibited.

The gel silicone resin (F) is a low-elasticity agent. By using a low-elasticity agent in combination, the elastic modulus of the sealing resin can be reduced and the warpage of the substrate can be suppressed. The gel silicone resin is located between the powder and the oil. Mix the silicone oil, which is the main component of the gel silicone resin, and the silicone oil, a curing agent, add the mixture while heating the epoxy resin, and stir with a mixer or the like while applying a strong shear to make the gel components fine. A sea-island structure can be formed by dispersing. Thereby, the low elasticity effect can be exhibited effectively without causing the problem of aggregation of particles, floating to the upper layer, and phase separation. The size of an island with a sea-island structure is 1
0 μm or less is desirable. For this purpose, the mixing ratio of the component (F) is 0.01 <(F) component / (total composition amount− (C) component) <0.3 by weight. 01 <(F)
It is preferable that component / (total composition-component (C)) <0.2. When the compounding ratio of the component (F) is 0.3 or more, the viscosity of the epoxy resin composition increases, and the handleability deteriorates. Further, when the compounding ratio of the component (F) is 0.01 or less, a low elasticity effect cannot be exhibited.

The gel silicone resin of the component (F) preferably comprises a silicone polymer represented by the following formula and a self-curing silicone rubber or gel.

[0027]

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In the above formula, R represents an alkyl group such as a methyl group or an ethyl group or a phenyl group. X represents a polyoxyalkylene group-containing group such as a polyoxyethylene group, a polyoxypropylene group, or a copolymer thereof. l, m, and n are integers of 1 or more. l / (l + m +
n) = 0.05 to 0.99 is preferable, and m / (l + m +
n) = 0.001 to 0.5, preferably n / (l + m +
n) = 0.001 to 0.8 are preferred. The silicone polymer may be a block copolymer or a random copolymer.

The self-curing silicone rubber or gel only needs to contain a vinyl group to which an SiH group can undergo an addition reaction, and is preferably an addition reaction type. One-component and multi-component systems are not limited. The inclusion of this silicone polymer can help disperse the self-curing silicone rubber or gel and form a fine sea-island structure, and is also expected to partially react with the self-curing silicone rubber or gel. .

The epoxy resin composition of the present invention can further contain an acid anhydride as the component (E). (E)
The acid anhydride of the component is an auxiliary curing agent for the reaction between the cyanate ester of the component (A) and the epoxy resin of the component (B).
By using an acid anhydride in combination, it is possible to reduce the thixotropic property of the epoxy resin composition, and a great effect is seen in improving the fluidity during sealing. Since the epoxy resin composition of the present invention is liquid, the acid anhydride of the component (E) needs to be liquid at room temperature.

The mixing ratio of component (E) is preferably component (E) / (total composition-component (C)) = 0.01 to 0.3, and more preferably 0.05 to 0.2. More preferably, it is more preferably 0.10 to 0.15. If the compounding ratio of the component (E) is less than 0.01, the above-mentioned effects are hardly obtained. If the compounding ratio of the component (E) is more than 0.3, the reactivity is reduced and the moisture resistance reliability is deteriorated. The acid anhydride of the component (E) and the component (B)
It has been found that almost no reaction occurs with only the epoxy resin as the component, but a system containing a cyanate ester as the component (A) and a metal chelate and / or metal salt as the component (D) exhibits good reactivity. Although the details of the reaction mechanism are unknown, it is presumed that the hydroxyl group and active hydrogen in the process of producing oxazoline in the reaction between the cyanate ester and the epoxy resin promote the reaction with the acid anhydride.

The epoxy resin composition of the present invention may further contain a titanate coupling agent as the component (G). Generally, a silane coupling agent having Si as a core metal such as epoxysilane or aminosilane is used as a coupling agent for the epoxy resin sealing material. However, in a system containing a cyanate ester and an epoxy resin, the present inventors have found that by using a titanate-based coupling agent having Ti as a core metal, it is possible to improve fluidity and express low-temperature rapid curing. Found. The mixing ratio of the component (G) is expressed in terms of weight ratio,
(G) component / (total composition-component (C)) = 0.001
~ 0.1, preferably 0.005-0.05
Is more preferable, and more preferably 0.01 to 0.03. When the compounding ratio is less than 0.001, it is difficult to obtain the effect of adding the component (G). 0.1
If it exceeds, the crosslink density of the cured product is lowered, and the reliability is deteriorated. In addition, the pot life is shortened.

The epoxy resin composition of the present invention may further contain an amine compound as the component (H).
The amine compound is used as a co-curing agent, and is a co-curing agent for the reaction between the cyanate ester of the component (A), the epoxy resin of the component (B), and the metal chelate and / or metal salt of the component (D). When a metal chelate and / or a metal salt is used as a curing catalyst in a resin-based reaction containing a cyanate ester and an epoxy resin, a high curing temperature is required, but the curing reactivity is low. This is because the metal chelates and / or metal salts hardly participate in the reaction with the epoxy resin. Therefore, an amine compound is used to promote the reaction of the epoxy resin and increase the curing reactivity.

The amine compound is not particularly limited, and examples thereof include imidazole, dicyanamide, and hydrazine compounds. Of these, amine compounds having active hydrogen are preferred, which promote ring opening of the epoxy group and increase reactivity. In addition, when an amine compound and an acid anhydride are used in combination as an auxiliary curing agent, foaming due to the acid anhydride and its decomposition product occurs, and the appearance of the sealed product is deteriorated. Therefore, it is better to avoid using these in combination. Amine compounds are effective in systems containing no acid anhydride as a co-curing agent.

The mixing ratio of the component (H) is preferably (H) / (B) = 0.001 to 0.2, more preferably 0.005 to 0.1.
More preferably, it is 0.01 to 0.05. When the amount of the amine compound is within the above range, good curability and long pot life are exhibited. Further, the epoxy resin composition of the present invention, if necessary, a flame retardant, a pigment,
Dyes, release agents, defoamers, surfactants, ion trapping agents, diluents, Si-based coupling agents, and the like can be added.

The epoxy resin composition of the present invention can be manufactured by uniformly mixing the above-mentioned components with a mixer, a blender or the like, and kneading with a roll, a kneader or the like. The order of compounding the components is not particularly limited. The liquid epoxy resin composition thus obtained can seal a semiconductor element by liquid sealing without using a mold, whereby a semiconductor device of the present invention can be obtained.

[0037]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. (1) The compounds used in Examples and Comparative Examples are as follows. [(A) component: cyanate ester] "L10" (AroCy L-10 manufactured by Asahi Ciba Co., Ltd.) 4,4'-ethylidenebisphenylene cyanate (having bisphenol E skeleton and liquid at room temperature) "B10" ( AroCy B-10 manufactured by Asahi Ciba Co., Ltd. 2,2-bis (4-cyanatophenyl) propane (having a bisphenol A skeleton and solid at room temperature) “M30” (AroCy M-30 manufactured by Asahi Ciba Co., Ltd.) (Having bisphenol F skeleton and solid at room temperature) [Component (B): epoxy resin] "YD8125" (manufactured by Toto Kasei Co., Ltd.) Bisphenol A of molecular distillation type having a viscosity of 40 poise at an epoxy equivalent of 175 and 25 ° C. Epoxy resin “Epicoat 828” (manufactured by Yuka Shell Co., Ltd.) Bisphenol A epoxy resin [Component (C): inorganic filler] Silica was used. [Component (D): metal chelate and / or metal salt] Iron (III) acetylacetone (CH ₃ COC
HCOCH ₃ ) ₃ Fe Cobalt (III) acetylacetone (CH ₃ COC
HCOCH ₃ ) ₃ Co manganese naphthenate [(E) component: acid anhydride] “B650” (Epiclon B650 manufactured by Dainippon Ink and Chemicals, Inc.) methylhexahydrophthalic anhydride, molecular weight 168 “B570” (Dainippon Ink Chemical Industry Co., Ltd.) Methyltetrahydrophthalic anhydride [Component (F): gel silicone resin] XE5818
(RTV silicone resin manufactured by Toshiba Silicone Co., Ltd.) was used.

This was added in a predetermined amount to an epoxy resin “YD8125”, and was heated and dispersed by a disper at 80 ° C. for 3 hours to produce a resin. [(G) component: Coupling agent] "KR-TTS" (Preneact KR-TTS manufactured by Ajinomoto Fine Techno Co., Ltd.) Titanate-based coupling agent represented by the following chemical formula

[0039]

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Specific gravity 0.95, red-brown liquid "A187" (manufactured by Nippon Unicar Co., Ltd.) Epoxysilane coupling agent represented by the following chemical formula

[0041]

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[(H) component: amine compound] "2MA-OK" (Curesol 2 manufactured by Shikoku Chemicals Co., Ltd.)
MA-OK) 2,4-diamino-6- [2'methylimidazolyl-
(1 ′)]-Ethyl-s-triazine isocyanuric acid adduct “PN23” (Amicour PN-2 manufactured by Ajinomoto Co., Inc.)
3) (2) Preparation of epoxy resin composition Each raw material was blended at the blending ratio (parts by weight) shown in Tables 1 to 3, and after being uniformly mixed with a mixer, vacuum degassing was performed to obtain a liquid epoxy resin composition. (Examples 1 to 26, Comparative Examples 1 to 2)
6). (3) Performance evaluation Using each epoxy resin composition obtained in (2), various liquid properties, curability, and physical properties were measured. The silicon chip mounted on the circuit board and wire-bonded was sealed, heated at 120 ° C. for 1 hour, and then cured by heating at 150 ° C. for 3 hours. Various reliability evaluations were also performed using this.

The evaluation method of each performance is as follows. Viscosity The viscosity (initial viscosity) at 25 ° C. of the obtained liquid epoxy resin composition was measured using a B-type viscometer. In the thixotropic viscosity measurement method, the viscosity at a value at which the ratio of the number of rotations of the viscometer rotor was 1/10 was determined, and the value calculated by dividing the viscosity at low speed by the viscosity at high speed was used. Pot life The viscosity of the obtained liquid epoxy resin composition at 25 ° C. after storage at 5 ° C. for one month is measured using a B-type viscometer, and the viscosity after storage for one month is the above initial viscosity. The value calculated by dividing by. Gel time 0.5 g of the obtained liquid epoxy resin composition was applied on a hot plate kept at 150 ° C., and the time until stringing disappeared while mixing with a spatula was measured. Warpage 3 Flat glass epoxy board (thickness 0.5mm)
A silicone rubber dam (1m in height) around 5 x 35mm
m) is formed, and 2.0 g of the liquid epoxy resin composition is applied inside and cured. The amount of warpage of the cured substrate was measured with a surface roughness meter. Flow height Place a flat ceramic substrate on a 70 ° C hot plate,
0.65 g of the obtained liquid epoxy resin composition was applied,
It cures after standing for 5 minutes. The height of the cured product was measured. PCT reliability A 9 mm x 9 mm silicon chip (3M Al pattern circuit) mounted and mounted on a glass epoxy substrate is sealed with a liquid epoxy resin composition, and then heat-cured. , 100% relative humidity
Processing was performed under CT (pressure cooker test) conditions, and the time until the occurrence of circuit failure was evaluated. In addition, it implemented with n = 10. A test board similar to TCT reliability was tested at -55 ° C for 30 minutes in the gas phase,
One cycle was a temperature cycle of 5 minutes at room temperature and 30 minutes at 125 ° C., and a 1000 cycle process was performed. 100
The rate of occurrence failures at the end of the 0 cycle processing was determined. In addition, it implemented with n = 10. A test board having the same reflow reliability as above was left in a thermostat at 30 ° C. and a relative humidity of 60% for 192 h to absorb moisture. Thereafter, the film was treated twice in an infrared reflow furnace (peak temperature: 240 ° C., 10 seconds), and the rate of defective occurrence at that time was determined. Note that n = 1
0.

[0044]

[Table 1]

[0045]

[Table 2]

[0046]

[Table 3]

[0047]

The epoxy resin composition according to the present invention has the advantages of a conventional liquid encapsulant that is liquid at room temperature, has low viscosity, has excellent handleability, and has a long pot life. Moreover, the semiconductor has excellent moisture resistance and heat resistance reliability,
A cured product having low elasticity can be obtained without causing problems such as aggregation, lifting of the liquid to an upper layer, and phase separation.

According to the epoxy resin composition of the second aspect of the present invention, since it contains 4,4'-ethylidenebisphenylene cyanate which is liquid at room temperature in a specific ratio, it can be used in combination with a cyanate ester which is solid at room temperature. In addition, solidification of the resin composition can be prevented. According to the epoxy resin composition of the third aspect of the present invention, since it contains an iron (III) chelate, thixotropy is extremely small, and high fluidity is exhibited. Therefore, it is advantageous in applications where the shape of the sealing resin needs to be flat, such as BGA.

According to the epoxy resin composition of the fourth aspect of the present invention, since it contains a cobalt (III) chelate, high thixotropy can be realized. This is advantageous when there is no dam or the like around the chip as in the case of a COB package. According to the epoxy resin composition of the fifth aspect, since it contains a liquid acid anhydride, it is possible to reduce the thixotropy of the epoxy resin composition, and a great effect is seen in improving the fluidity during sealing. Improved fluidity and low-temperature quick-curing properties can be realized.

According to the epoxy resin composition of the sixth aspect of the present invention, since a titanate-based coupling agent is contained, improvement in fluidity and low-temperature rapid curing can be realized. According to the epoxy resin composition of the invention of claim 7, since the epoxy resin composition contains an amine compound, the reaction of the epoxy resin is promoted, and the curing reactivity is enhanced. In the semiconductor device according to the eighth aspect of the present invention, since the semiconductor encapsulation is performed by the liquid encapsulation method using the epoxy resin composition according to the present invention, high integration, high density, and thinness of the semiconductor package are achieved. Light weight is possible, and
The semiconductor has excellent moisture resistance and heat resistance reliability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 23/31 // (C08L 63/00 83:04) (72) Inventor Kenji Kitamura Kadoma, Osaka 1048 Kadoma Matsushita Electric Works Co., Ltd.F-term (reference) 4J002 CD001 CD021 CD041 CD051 CD061 CD071 CD101 CD121 CD141 CP032 DE107 DE147 DE237 DJ017 EE018 EE048 EG040 EG048 EL139 ER006 EU189 FD017 FD148 FD149 FD200 GQ05 4M05 EB04 EB04 EB09 EB12 EB19 EC01 EC03 EC04 EC05 EC20

Claims (8)

[Claims] 1. An epoxy resin composition comprising (A) a cyanate ester, (B) an epoxy resin, (C) an inorganic filler, (D) a metal chelate and / or metal salt, and (F) a gel silicone resin. In at least one of the component (A) and the component (B) is a liquid at room temperature, and the mixing ratio of each component is expressed as a weight ratio: component (A) / component (B) = 0.76 to 1.43 (C ) Component / total amount of composition = 0.60 to 0.95 0.01 <component (F) / (total amount of composition−component (C)) <
0.3, a liquid epoxy resin composition for semiconductor encapsulation. 2. The component (A) contains 4,4′-ethylidenebisphenylene cyanate (A1), and its mixing ratio is (A1) / (A) component = 0.1 to 1 by weight.
The liquid epoxy resin composition for semiconductor encapsulation according to claim 1, which is: 3. An iron (III) chelate (D1) is contained as the component (D), and its compounding ratio is (D)
The liquid epoxy resin composition for semiconductor encapsulation according to claim 1, wherein 1) / (A) component = 0.0001 to 0.01. 4. The composition according to claim 1, wherein said component (D) is cobalt (III).
3) The liquid epoxy resin for semiconductor encapsulation according to claim 1 or 2, which comprises a chelate (D2), and the compounding ratio thereof is (D2) / (A) component = 0.0001 to 0.01 in weight ratio. Composition. 5. The composition further comprises a liquid acid anhydride as the component (E), and the mixing ratio thereof is (E) / (the total amount of the composition− (C)) = 0.01 to 0.3 by weight. The liquid epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 4, which is: 6. The composition further comprises a titanate-based coupling agent as a component (G), and the mixing ratio thereof is (G)
Component / (total composition-component (C)) = 0.001 to 0.
The liquid epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 5, which is 1. 7. The composition further comprises an amine compound as the component (H), and the mixing ratio thereof is (H) component / (B) in weight ratio.
The liquid epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 4, wherein the component is 0.001 to 0.2. 8. A semiconductor device in which a semiconductor element is encapsulated with an epoxy resin composition, wherein the epoxy resin composition is a liquid epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 7. A semiconductor device characterized by being used.