JP2003002949A - Liquid 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, with low viscosity at normal temperature, excellent in treatability, having a long pot life, i.e., a merit of conventional liquid sealants, giving semiconductors excellent in moistureproof and heatproof and, especially, excellent in lead-free solder reflow reliability, and to provide a semiconductor device obtained by sealing with the liquid epoxy resin composition. SOLUTION: This liquid epoxy resin composition comprises (A) a cyanate ester, (B) an epoxy resin, (C) an inorganic filler and (D) a metal chelate and/or a metal salt, wherein the epoxy resin (B1) is contained as the (B) component, and the resin (B1) is liquid at a room temperature and has a naphthalene skeleton, and (B1)/(B) component >= 0.1, (A) component/(B) component = 0.76 to 1.43, (C) component/composition total = 0.60 to 0.95 4,4'-Ethylidenebisphenylene cyanate (A1) is contained (A) component and (A1)/(A) component=0.1 to 1.0. The semiconductor device is provided by sealing a semiconductor element with 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 or the like, and a semiconductor device encapsulated with the liquid epoxy resin composition.

[0002]

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

As electronic devices have become more mobile and more sophisticated in recent years, it has become necessary to make semiconductor packages highly integrated, highly dense, thin, and lightweight. BGA that achieved high density with array connection
(Ball grid array), CSP (chip scale package), MCM (multi-chip module) and other new semiconductor package forms have been introduced.

For sealing of these new semiconductor packages, there is a limit to thinning with a conventional die 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 encapsulants have begun to be used. In addition, since the die molding method requires an expensive die for each product type, the cost is increased, and the fine circuit on the BGA substrate may be cut by the die, so that a liquid sealing material is used. A liquid encapsulation method in which encapsulation is performed without using a mold is advantageous.

Although the liquid encapsulating system has such advantages, the liquid encapsulating material used is inferior to the powder-granular encapsulating material molded by a mold in terms of sealing workability and reliability. There was a drawback that This is because the powdery and granular encapsulating material uses a phenolic curing agent as a curing agent, and is therefore resistant to hydrolysis when subjected to a moisture resistance reliability test and has a high adhesive force with the element. Further, generally, the encapsulating material used for carrying out the transfer molding method is solid (powder-granular) at room temperature, and it is possible to increase the filling of the filler and the Tg of the resin. And heat shock resistance can be demonstrated.

On the other hand, the conventional liquid encapsulant is limited in that it is liquid at room temperature, and is one-part and has a long pot life. The selection is limited, and amine-based or acid anhydride is generally used. However, among amine-based curing agents, liquid aromatic amines have too high a reactivity with epoxy and have a short pot life.
The solid amines represented by (dicyandiamide) have the drawback of high viscosity. In addition, it has a high moisture absorption rate and inferior electrical characteristics. On the other hand, in the acid anhydride curing agent, the ester structure in the cross-linked structure of the cured product is easily hydrolyzed, so that the moisture resistance is inferior, and the chemical adhesion is low, so that the heat resistance tends to be low. In addition, since the phenolic curing agent used in the powder-molded encapsulant that is molded by a mold is solid at room temperature and has a very high viscosity when used in combination with liquid epoxy, a liquid encapsulant containing a filler is used. It is difficult to use for purposes. Although it is possible to reduce the viscosity by adding a solvent, voids are likely to occur in the cured product due to the solvent, resulting in poor appearance and reliability deterioration. It is difficult to exert the characteristics of.

On the other hand, a semiconductor package such as BGA or CSP in which a semiconductor chip is sealed with a liquid or powder sealing material is
Solder chips are mounted on a printed circuit board called a mother board. In recent years, lead-free solder has come to be used with the increasing environmental protection movement. Conventionally, the peak temperature during solder reflow was 240 ° C., but when using lead-free solder, the temperature during reflow has risen to 260 ° C. This 20 ℃
This temperature difference is very severe for the reliability of the semiconductor package described above, and peeling and cracks at the interface between the chip and the resin, which did not occur at 240 ° C., often occur at 260 ° C.

The cause of the peeling and cracks is that the water absorbed while being left at room temperature accumulates in the periphery of the chip and the interface between the resin and the substrate and explosively vaporizes and expands at the time of reflowing at 260 ° C.

In order to prevent this, means such as (i) reducing absorbed water content, (ii) increasing strength under heat, (iii) increasing adhesion force, etc. can be considered.

The above-mentioned transfer molding type powder encapsulant exhibits the effects (i) and (ii) due to the high filling rate, and the effect (iii) due to the phenolic curing agent.
Although it shows excellent reflow resistance, the liquid encapsulant
Since the characteristics of (i) to (iii) are inferior for the above reason, 2
In the 60 ° C. reflow, package defects frequently occur.

Under these circumstances, the sealing workability is better than that of the liquid sealing method, and the sealing reliability is equal to or higher than that of the powder type sealing material, especially the high solder resistance for lead-free solder reflow. There is a strong demand for a liquid sealing material having

[0012]

The present invention has been made in view of the above circumstances, and has the advantages of the conventional liquid encapsulant that is liquid at room temperature, has low viscosity, is excellent in handleability, and has a long pot life. It is an object of the present invention to provide a liquid epoxy resin composition for encapsulating a semiconductor, which is excellent in the moisture resistance and heat resistance reliability of the semiconductor, particularly in the lead-free solder reflow reliability, without losing the temperature. It is also an object to provide a semiconductor device which is sealed with such a liquid epoxy resin composition.

[0013]

In order to solve the above problems, a liquid epoxy resin composition for semiconductor encapsulation according to the present invention comprises (A) cyanate ester, (B) epoxy resin and (C) inorganic material. In a liquid epoxy resin composition containing a filler and (D) a metal chelate and / or a metal salt, an epoxy resin (B1) which has a naphthalene skeleton and is liquid at room temperature is contained as a component (B), and its mixing ratio is In a weight ratio, (B1) / (B) component ≧ 0.1,
The mixing ratio of the (A) component is a weight ratio, and the (A) component / (B)
Component = 0.76 to 1.43, the mixing ratio of the (C) component is a weight ratio, and the (C) component / the total amount of the composition = 0.60.
0.95, which contains 4,4'-ethylidene bisphenylene cyanate (A1) as the component (A), and the mixing ratio thereof is a weight ratio of (A1) / (A) component = 0.1 to 1.
It is characterized by being 0. Further, the semiconductor device according to the present invention has a semiconductor element sealed with the liquid epoxy resin composition.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The epoxy resin composition of the present invention comprises
It is based on a cyanate ester and an epoxy resin, and contains (A) cyanate ester, (B) epoxy resin, (C) inorganic filler, and (D) metal chelate and / or metal salt.

In the present invention, when the component (A) and the component (B) are mixed in order to make the resin composition liquid, it is preferable that they are liquid at room temperature. Therefore, the components (A) and (B) are preferable. It is preferred that at least one of the components is liquid at room temperature.

The cyanate ester as the component (A) is a compound having a cyanate group (-OCN group). Specific examples of the cyanate ester as the component (A) include 4,4′-ethylidene bisphenylene cyanate (A1) which is liquid at room temperature and 2,2-bis (4) which is crystalline and solid at room temperature. Cyanate ester polymers such as -cyanatophenyl) propane, bis (4-cyanato-3,5-dimethylphenyl) methane, bis (4-cyanato-phenyl) thioether, and prepolymerization by prereacting these monomers The polymerized product can be exemplified. Among these, those which become liquid at room temperature when mixed with the epoxy resin of the component (B) can be used.

In the present invention, 4,4'-as the component (A)
Includes ethylidene bisphenylene cyanate (A1).
4,4'-Ethylidene bisphenylene cyanate (A
1) is represented by the following chemical formula:

[0018]

[Chemical 1] It has a structure having cyanate groups at both ends of the 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 having a bisphenol A skeleton and bis (4 having a dimethylphenyl skeleton)
-Cyanato-3,5-dimethylphenyl) methane etc.)
Is very crystalline, and is a solid at room temperature by itself. These crystalline cyanate esters have a drawback that crystals are likely to precipitate and solidify after cooling even if they are liquefied by being heated and dissolved in a liquid epoxy resin. However,
It was found that solidification can be prevented by using together with 4,4′-ethylidene bisphenylene cyanate (A1) having a bisphenol E skeleton.

In the present invention, the blending ratio of 4,4'-ethylidene bisphenylene cyanate (A1) is (A1) / (A) component = 0.1 to 1.0 by weight ratio,
It is preferably 0.5 to 1.0, and 0.7 to 1.0
Is more preferable. If the blending ratio is less than 0.1, it becomes difficult to prevent the solidification of the crystalline cyanate ester.

The epoxy resin as the component (B) contains an epoxy resin (B1) which has a naphthalene skeleton and is liquid at room temperature, and the mixing ratio thereof is (B1) / (B) component ≧.
It is characterized by being 0.1. The liquid state at room temperature (23 ± 2 ° C.) shown here is a liquid at room temperature,
It may rarely crystallize and solidify due to heat history because it is purified by molecular distillation, but it also includes those having the property of returning to the original liquid state when heated to 60 to 80 ° C. and cooled to room temperature. As the room temperature liquid epoxy resin (B1) having a naphthalene skeleton, specifically, a structure having two glycidyl groups in the naphthalene skeleton, 1,
6-diglycidylnaphthalene (the following formula) is mentioned.

[0021]

[Chemical 2] By including 1,6-diglycidylnaphthalene, the viscosity is low, the sealing property is excellent, and the reflow property is also excellent.

The epoxy resin having a solid type naphthalene skeleton can be used within a range in which the composition can be liquefied in combination with the above-mentioned 1,6-diglycidylnaphthalene or other liquid epoxy resin. As the epoxy resin having a solid naphthalene skeleton, a tetrafunctional and solid compound represented by the following formula,

[0023]

[Chemical 3] Polyfunctional and solid compound represented by the following formula (wherein n is 1
~ 5)

[0024]

[Chemical 4] Is mentioned. As the epoxy resin having these naphthalene skeletons, those having a high purity and a low content of chlorine ions, bromine ions and the like are preferable.

Other epoxy resins having a naphthalene skeleton which can be used in combination with the liquid epoxy resin (B1) at room temperature are not particularly limited, but those which are liquid at room temperature and have a bifunctional or higher functional epoxy group. preferable. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, halogenated epoxy resin, glycidyl ester type epoxy resin, alicyclic epoxy resin, biphenyl type epoxy resin, heterocyclic epoxy resin, etc. Can be illustrated,
It is not limited to these. Among these epoxy resins, bisphenol A and bisphenol F type epoxy resins having n of 0 to 1 in the following formula, which are obtained by molecular distillation, are particularly preferable because they have low viscosity and very little ionic impurities.

[0026]

[Chemical 5] The mixing ratio of the component (A) and the component (B) is (A) component / (B) component = 0.76 to 1.43 in terms of weight ratio in terms of physical properties of the cured product and sealing reliability. Yes, 0.91
It is preferably 1.43, and more preferably 0.91 to 1.25. It is known that cyanate ester alone undergoes a trimerization reaction in the presence of a metal catalyst to form a triazine ring. However, this reaction is 1
The main reaction is at a high temperature of 80 ° C or higher. Further, in a composite resin system of cyanate ester and epoxy resin, a reaction between a cyanate group and an epoxy group also occurs, so it is speculated that a plurality of reactions occur as competitive reactions. (A) component /
If the component (B) is larger than 1.43, the epoxy resin will be insufficient, and in the case of curing at 160 ° C. or lower, the cyanate groups that have not reacted will remain. The unreacted cyanate group hydrolyzes into a carbamate group during a moisture resistance reliability test such as PCT (pressure cooker test),
Further, it causes a decarboxylation reaction, resulting in poor moisture resistance reliability. On the other hand, when the ratio of the component (A) / the component (B) is less than 0.76, the epoxy resin becomes excessive, and unreacted epoxy groups remain. The remaining unreacted epoxy group lowers the crosslink density of the cured product, which lowers the glass transition temperature and increases the moisture absorption rate. Therefore, the coefficient of thermal expansion of the cured product becomes large, which causes deterioration of heat cycle and reflow reliability.

The inorganic filler as the component (C) preferably contains spherical fused silica having a maximum particle size of 40 μm or less and a specific surface area of 2.0 m ² / g or less. In the above-mentioned semiconductor packages such as BGA and CSP, the number of wires tends to increase, for example, from 100 wires / chip to 300 wires / chip, and further to 500 wires / chip, as the functionality of the chip increases. However, there is a limit to the increase in chip size, and the wire pitch is becoming narrower. Conventionally, the gap between the wires was about 100 μm, but recently, it has become 50 μm or 30 μm. Along with that, the size of the inorganic filler contained in the encapsulant is also limited to the maximum particle size because it is necessary for the encapsulant to go under the wire, and it is preferably 40 μm or less. Fused silica, which has excellent physical properties, is preferable as the type of inorganic filler. Furthermore, as the particle size decreases, the specific surface area increases, resulting in an increase in viscosity and thixotropy, which results in insufficient fluidity during sealing and an increase in moisture absorption rate due to a low filler ratio and thermal expansion coefficient. And the reflow resistance reliability is lowered. As a countermeasure, fused silica, which has a spherical shape and whose specific surface area is reduced as much as possible, is preferable for achieving both a maximum particle size of 40 μm or less and a low viscosity and high fluidity. The shape is close to a sphere like a pearl, and the specific surface area is 2.0m ^2.
/ G or less, more preferably 0.5 m ² / g or less.

The blending ratio of the component (C) is a weight ratio,
(C) component / composition total amount = 0.60 to 0.95,
It is preferably 0.70 to 0.90, and 0.75 to
It is more preferably 0.85. If the mixing ratio of the component (C) is less than 0.60, the ratio of the resin component becomes high, so that the shrinkage amount of the resin composition at the time of encapsulating the semiconductor becomes large and the coefficient of thermal expansion also becomes large, so that the substrate The amount of warp becomes large, and defects such as chip cracks when heat stress is applied are likely to occur. Further, since the moisture absorption rate becomes large, it also causes cracks during reflow.
When the blending ratio of the component (C) is more than 0.95, the liquid component is insufficient and the viscosity becomes high, so that it is difficult to handle as a liquid and sealing cannot be performed.

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 include iron, cobalt, zinc, tin, aluminum and manganese. Examples of the ligand of the metal chelate include acetylacetonate, salicylaldehyde, and benzoylacetone. Further, examples of the metal salt include naphthenate and octenoate.

In the present invention, iron (III) is used as the component (D).
Chelate (D1) and aluminum chelate (D
By using 2), the following effects can be obtained.

Cyanate ester is known to undergo a trimerization reaction at a high temperature of about 180 ° C. or higher with a metal chelate as a nucleus to form a triazine skeleton, and various metal chelates serve as a catalyst for the single curing of cyanate ester. Is known. Since the suction of the cyanate group of the curing catalyst differs depending on the type of metal, the speed of this trimerization reaction differs depending on the metal chelate used, and in general, zinc,
Metal chelates of tin, copper, manganese, titanium, cobalt and the like are known. However, when an epoxy resin is included as a resin component in addition to the cyanate ester as in the present invention, the reaction mechanism becomes very complicated. This is because a reaction between the cyanate group and the epoxy group to form an oxazoline skeleton also occurs in parallel with the trimerization reaction of the cyanate group.

In the present invention, as a result of studying various metal chelates, it was found that the iron (III) chelate (D1) serves as an excellent reaction catalyst between the cyanate ester and the epoxy resin. When iron (III) chelate (D1) is used, 12
It was found that even at a low temperature of 0 ° C., it was sufficiently cured. However, in a resin system using this iron (III) chelate (D1), the viscosity tends to gradually increase even at room temperature. In that respect, it was found that a resin system similarly using an aluminum chelate (D2) exhibits excellent viscosity stability at room temperature. However, at 120 ° C, curing tended to be slow.
Then, as a means to have both stability of viscosity at room temperature and curability at 120 ° C., a chelate of iron (III) (D1)
It has been found that it is effective to use a chelate of aluminum and aluminum chelate (D2) together. The blending ratio of the (D) component at that time is a weight ratio, and the (D) component / (A) component = 0.001.
The ratio of (D2) to (D2) / (D) = 0.1 to 0.4 is preferable. When the amount of component (D) / component (A) is less than 0.001, the curability is poor and the properties are insufficient. On the other hand, if it is more than 0.05, the thickening becomes large. Furthermore, (D2) / (D)
If the content is less than 0.1, iron (III) chelate (D
1) Viscosity stability is poor because it is the main component, and it gradually thickens at room temperature. If it is larger than 0.4, the curability at 120 ° C. becomes poor.

The epoxy resin composition of the present invention may further contain a solventless silicone oil type defoaming agent as the component (E). The mixing ratio is (E) by weight.
Ingredient / composition total = 0.001-0.02 is suitable. As the component (E), a solventless type aralkyl-modified methylpolysiloxane is preferable. It is necessary to avoid the one containing a solvent because it causes foaming at the time of curing.
Since the silicone oil type defoaming agent as the component (E) has an effect of lowering the surface tension of the resin composition, it has an effect of popping bubbles inside the resin when the bubbles float on the surface.
When the amount of the (E) component silicone oil-based defoaming agent is less than 0.001 of the total amount of the composition, the defoaming effect is small.
On the other hand, when it is more than 0.2, the defoaming effect is excellent, but bleeding out occurs on the surface of the cured product during curing, causing poor appearance. It also acts as a release agent at the adhesive interface and causes poor adhesion.

The epoxy resin composition of the present invention may further contain an acid anhydride as the component (F). (F)
The acid anhydride as the component is an auxiliary curing agent for the reaction between the cyanate ester as the component (A) and the epoxy resin as the component (B).
By using an acid anhydride together, the thixotropy of the epoxy resin composition can be reduced, and a great effect can be seen in improving the fluidity at the time of sealing. Since the epoxy resin composition of the present invention is liquid, it is preferable that the acid anhydride as the component (F) is also liquid at room temperature. Examples of the component (F) include, but are not limited to, methylhexahydrophthalic anhydride and methyltetrahydroanhydride.

The mixing ratio of the component (F) is preferably (F) component / (total amount of composition- (C) component) = 0.01 to 0.3, and 0.05 to 0.2. It is more preferable that it is 0.10 to 0.15. If the blending ratio of the component (F) is less than 0.01, it is difficult to obtain the above effect. When the blending ratio of the component (F) is more than 0.3, the reactivity decreases and the moisture resistance reliability deteriorates. The acid anhydride of the component (F) and (B)
It has been found that almost no reaction occurs with the component epoxy resin alone, but a system containing the component (A) cyanate ester and the component (D) metal chelate and / or metal salt 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 gel silicone resin as the component (G). The gel silicone resin as the component (G) is a low elasticity agent. By using the low elasticity agent together, the elastic modulus of the sealing resin can be lowered and the warp of the substrate can be suppressed.

The gel-like silicone resin is located between powder and oil. Mix the silicone oil, which is the main component of the gel-like silicone resin, with the silicone oil, which is the curing agent, add this to the heated epoxy resin, and stir it while applying a strong share with a mixer to make the gel component fine. A sea-island structure can be formed by dispersing. As a result, the low elasticity effect can be effectively exhibited without agglomeration of particles, floating to the upper layer, and the problem of phase separation. It is desirable that the size of the island having a sea-island structure is 10 μm or less. For that purpose, the mixing ratio of the component (G) is 0.01 <(G) component / weight ratio.
(Composition total amount- (C) component) <0.3 is preferable, and 0.01 <(G) component / (Composition total amount- (C) component) <0.2 is more preferable. When the mixing ratio of the component (G) is 0.3 or more, the viscosity of the epoxy resin composition becomes high and the handleability deteriorates. Further, if the mixing ratio of the component (G) is 0.01 or less, the low elasticity effect cannot be exhibited.

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

[0039]

[Chemical 6] 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 copolymerization group thereof. l, m,
n is an integer of 1 or more. l / (l + m + n) = 0.0
5 to 0.99 is preferable, m / (l + m + n) = 0.0
01-0.5 is preferable, and n / (l + m + n) = 0.0
01-0.8 is preferable. This silicone polymer may be a block copolymer or a random copolymer.

As the self-curing silicone rubber or gel, it is sufficient that it contains a vinyl group capable of undergoing an addition reaction with an SiH group, and an addition reaction type one is preferable. It does not matter whether it is a one-component system or a multi-component system.

By containing this silicone polymer, the self-curing silicone rubber or gel can be dispersed to form a fine sea-island structure, and a part of the reaction with the self-curing silicone rubber or gel is also possible. Be expected.

Further, in the epoxy resin composition of the present invention, if necessary, a flame retardant, a pigment, a dye, a release agent, a defoaming agent, a surfactant, an ion trap agent, a diluent and various coupling agents. Etc. can be added.

The epoxy resin composition of the present invention can be produced by uniformly mixing the above-mentioned components with a mixer, a blender or the like, kneading them with a roll, a kneader or the like, and finally degassing in a vacuum. The order of mixing 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. it can.

[0045]

The present invention will be described in more detail with reference to the following examples, but the present invention is not 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'-ethylidene bisphenylene cyanate (having a bisphenol E skeleton and being 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) [(B) component: epoxy resin] "HP4032D" (large Nihon Ink Co., Ltd. Epoxy equivalent of 1,6-diglycidylnaphthalene "EXA4700" of molecular distillation type having viscosity of 250 poise at 25 ° C, epoxy compound having a tetrafunctional glycidyl group (compound of [Chemical Formula 3]) "YD8125" (manufactured by Tohto Kasei Co., Ltd.) Epoxy equivalent molecular distillation type visph of viscosity 40 poise at 175,25 ° C Enol A-type epoxy resin "HP7200" (Epiclon HP7200 manufactured by Dainippon Ink and Chemicals, Inc.) Epoxy equivalent 258, dicyclopentadiene type epoxy resin "N665" with a softening point of 60 ° C (Epiclon N6 manufactured by Dainippon Ink and Chemicals, Inc.)
65) Cresol novolac type epoxy resin having an epoxy equivalent of 200 and a softening point of 64 ° C. ((C) component: inorganic filler) QS9 (manufactured by Mitsubishi Rayon Co., Ltd.) having an average particle size of 5 μm, a maximum particle size of 25 μm, and a specific surface area of 0. 5
A predetermined amount of m ² / g synthetic silica having a spherical shape was used. [Component (D): Metal Chelate and / or Metal Salt] Iron (III) acetylacetonate (CH ₃ COCHCOC)
H ₃ ) ₃ Fe Aluminum (III) acetylacetonate (CH ₃ CO
CHCOCH ₃ ) ₃ Al [(E) component: solvent-free silicone oil-based defoamer] "BYK323" (manufactured by Big Chemie Co., Ltd.) Aralkyl-modified methylpolysiloxane [(F) component: acid anhydride] "B650" (large EPICLON B650 manufactured by Nippon Ink Chemical Co., Ltd. Methyl hexahydrophthalic anhydride, molecular weight 168 "B570" (manufactured by Dainippon Ink and Chemicals, Inc.) Methyl tetrahydrophthalic anhydride [(G) component: gel silicone Resin] XE5818 (RTV silicone resin manufactured by Toshiba Silicone Co., Ltd.) was used.

A predetermined amount of this is added to the epoxy resin,
It was produced by heating and dispersing with a disper at 80 ° C. for 3 hours. (2) Preparation of Epoxy Resin Composition The raw materials are mixed at the mixing ratios (parts by weight) shown in Tables 1 to 3 and uniformly mixed with a mixer, and then vacuum degassing is performed to obtain a liquid epoxy resin composition. (Examples 1 to 19 and Comparative Examples 1 to 1)
5). (3) Performance evaluation The evaluation method of each performance is as follows. Viscosity The viscosity (initial viscosity) of the obtained liquid epoxy resin composition at 25 ° C. was measured using a B-type viscometer. In the thixotropic viscosity measurement method, the viscosity at a value at which the rotation speed ratio of the viscometer rotor became 1/10 was obtained, and the value calculated by dividing the low-speed viscosity by the high-speed viscosity was used. Pot life: The liquid epoxy resin composition obtained was stored at 5 ° C. for 1 month, and the viscosity at 25 ° C. was measured using a B-type viscometer. The value calculated by dividing by was used. 0.5 g of the obtained liquid epoxy resin composition was applied on a hot plate kept at a gel time of 150 ° C., and the time until the stringing disappeared was measured while mixing with a spatula. 3 of glass epoxy board (0.5mm thickness) with flat warpage
Silicon rubber dam (height 1m
m) is formed, 2.0 g of the liquid epoxy resin composition is applied to the inside, and cured. The amount of warpage of the cured substrate was measured with a surface roughness meter. Place a ceramic substrate with a flat flow height on a hot platen at 70 ° C,
0.65 g of the obtained liquid epoxy resin composition is applied,
Cure for 5 minutes. The height of this cured product was measured.

Various liquid properties, curability and physical properties were measured using each epoxy resin composition obtained in (2).
In addition, the silicon chip mounted on the circuit board and wire-bonded is sealed and heated at 120 ° C. for 1 hour, and then 1
It was cured by heating at 50 ° C. for 3 hours. Various reliability evaluations were also performed using this. Test obtained by sealing and heat-curing a wire-bonded silicon chip (3 μm width Al pattern circuit) of 9 mm × 9 mm mounted and mounted on a PCT reliability glass epoxy substrate using a liquid epoxy resin composition Board 12
Processing was performed under PCT (pressure cooker test) conditions of 1 ° C., 2 atm, and relative humidity of 100%, and the time until the occurrence of circuit defects was evaluated. In addition, it implemented by n = 10. A test board similar to TCT reliability was tested in the vapor phase at -55 ° C for 30 minutes.
A temperature cycle of 5 minutes at room temperature and 30 minutes at 125 ° C. was set as one cycle, and 1000 cycles were performed. 100
The rate of occurrence defects at the end of the 0 cycle treatment was determined. In addition, it implemented by n = 10. A test board having the same reflow reliability is left to stand in a constant temperature bath at 30 ° C. and a relative humidity of 60% for 192 hours to absorb moisture. Then, the infrared reflow furnace (peak temperature of 260 ° C., 10 seconds) was treated twice, and the rate of occurrence defects at that time was obtained. Note that n = 1
It was carried out at 0.

[0048]

[Table 1]

[0049]

[Table 2]

[0050]

[Table 3]

[0051]

EFFECTS OF THE INVENTION The epoxy resin compositions according to the inventions of claims 1 to 7 are liquid at room temperature, have low viscosity, are excellent in handleability, and do not lose the advantages of conventional liquid encapsulants such as long pot life. In addition, the semiconductor has excellent moisture resistance and heat resistance reliability, and particularly has excellent lead-free solder reflow reliability.

According to the epoxy resin composition of the invention of claim 2, since it contains 1,6-diglycidylnaphthalene having a structure having two glycidyl groups in the naphthalene skeleton, it has a low viscosity and is excellent in sealing property, Also, the reflow characteristics are excellent.

According to the epoxy resin composition of the third aspect of the present invention, since it contains an iron (III) chelate and an aluminum chelate, it is possible to have both viscosity stability at room temperature and curability at 120 ° C.

According to the epoxy resin composition of the fourth aspect of the present invention, the maximum particle size is 40 μm or less and the specific surface area is 2.0 m.
Includes ² / g or less of spherical fused silica. Maximum particle size is 40μ
When it is m or less, the sealing material can wrap around the wire even when the gap between the wires becomes narrower as the functionality of the chip becomes higher. The specific surface area is 2.
Since the shape is spherical at 0 m ² / g or less, low viscosity and high fluidity can both be achieved. In addition, fused silica has excellent physical properties.

According to the epoxy resin composition of the fifth aspect, since the solvent-free silicone oil-based defoaming agent is included, the bubbles inside the resin can be repelled when they float on the surface.

According to the epoxy resin composition of the sixth aspect of the present invention, since it contains a liquid acid anhydride, the thixotropy of the epoxy resin composition can be reduced, and a great effect on the improvement of the fluidity at the time of sealing. Can be seen.

According to the epoxy resin composition of the invention of claim 7, since the gel-like silicone resin is contained in a specific ratio, it is possible to reduce the elasticity without causing the problems of particle aggregation, floating to the upper layer and phase separation. realizable.

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 and high density of the semiconductor package, It can be thin and lightweight, and
The semiconductor has excellent moisture resistance and heat resistance reliability, especially lead-free solder reflow reliability.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4J036 AD01 AD08 AF06 DC32 FA05                       FB16 GA12 GA13 GA16 GA17                       JA07                 4M109 AA01 BA03 CA04 EA02 EB02                       EB04 EB13 EB18 EC01 EC05

Claims (8)

[Claims] 1. A liquid epoxy resin composition containing (A) a cyanate ester, (B) an epoxy resin, (C) an inorganic filler, and (D) a metal chelate and / or a metal salt. As an epoxy resin (B1) which has a naphthalene skeleton and is liquid at room temperature, and the mixing ratio thereof is (B1) / (B) component ≧ 0.1, and the mixing ratio of (A) component is weight. Ratio of (A) component / (B)
Component = 0.76 to 1.43, the blending ratio of the (C) component is a weight ratio, and the (C) component / the total amount of the composition = 0.60 to 0.95, and the (A) component is 4, 4'-ethylidene bis phenylene cyanate (A1) is contained, and the compounding ratio thereof is a weight ratio,
(A1) / (A) component = 0.1-1.0, Liquid epoxy resin composition for semiconductor encapsulation. 2. The liquid epoxy resin composition for encapsulating a semiconductor according to claim 1, which contains 1,6-diglycidylnaphthalene having a structure having two glycidyl groups in a naphthalene skeleton as the component (B1). 3. The component (D) contains an iron (III) chelate (D1) and an aluminum chelate (D2),
The mixing ratio of the (D) component is a weight ratio, and the (D) component / (A)
Component = 0.001 to 0.05, and the mixing ratio of (D2) is a weight ratio, (D2) / (D) component = 0.1
The liquid epoxy resin composition for semiconductor encapsulation according to claim 1 or 2, which is 0.4. 4. The maximum particle size of the component (C) is 40.
The liquid epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 3, which contains spherical fused silica having a specific surface area of 2.0 m ² / g or less and a specific surface area of 2.0 m ² / g or less. 5. A solvent-free silicone oil-based defoaming agent is further included as the component (E), and the mixing ratio thereof is a weight ratio.
The liquid epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the total amount of component (E) / composition is 0.001 to 0.02. 6. Further, a liquid acid anhydride is contained as the component (F), and the mixing ratio thereof is a weight ratio, and the component (F) / (the total amount of the composition−the component (C)) = 0.01 to 0.3. The liquid epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 5. 7. A gel silicone resin is further included as the component (G), and the blending ratio thereof is 0.01% by weight.
The liquid epoxy resin composition for semiconductor encapsulation according to claim 1, wherein (G) component / (total amount of composition− (C) component) <0.3. 8. A semiconductor device in which a semiconductor element is sealed with an epoxy resin composition, wherein the liquid epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 7 is used as the epoxy resin composition. A semiconductor device characterized by being provided.