JPS598720A - Liquid epoxy resin composition for sealing semiconductor - Google Patents

Abstract

PURPOSE:To prepare the titled composition having excellent moisture resistance, normal pressure castability, high temperature curability, and high temperature hydrolysis resistance, by compounding a liquid epoxy resin with an acid anhydride, a tertiary amine containing aromatic hydroxyl group, an inorganic filler and a coupling agent. CONSTITUTION:The objective composition is prepared by compounding (A) a liquid epoxy resin (e.g. liquid novolak epoxy resin) with (B) an acid anhydride (e.g. hexahydrophthalic anhydride) as a curing agent, (C) a tertiary amine containing aromatic hydroxyl group [e.g. 4-(imidazol-1-yl)phenol] as a cure accelerator, (D) an inorganic filler (e.g. crystalline silica) and (E) a coupling agent (e.g. gamma-glycidoxy-propyl trimethoxysilane). Preferably, the amount of the component (B) is 0.4-1.2 equivalent per 1 equivalent of the component (A), the amounts of the components (C) and (D) are 0.1-3.0pts.wt. and 100-600pts.wt. per 100pts.wt. of the component (A), respectively, and that of the component (E) is 0.1-3pts.wt. per 100pts.wt. of the component (D).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid epoxy resin composition for semiconductor encapsulation that has excellent moisture resistance, and also excellent normal pressure injection properties, high temperature curability, and high temperature hydrolysis resistance.

Currently, resin encapsulation methods are widely used to encapsulate semiconductor devices such as LSIs and LSIs using silicone resin or epoxy resin. Because it is inexpensive, it is widely used as a resin for semiconductor encapsulation.

Conventional epoxy resin compositions for semiconductor encapsulation are made by blending an epoxy resin with a curing agent, a curing accelerator, etc., or by allowing the curing reaction to proceed to an appropriate point, making it solid, and then turning it into powder, which is then formed into a tablet. It had been. To seal the semiconductor device, the tablet is placed in the cylinder of the Seisugi machine, heated and melted at high temperature, and then placed in a heated mold with a pressure of 20 Q/am or more. It was injected and cured by heating.

There have been many problems in manufacturing such conventional resin compositions for semiconductor encapsulation and in encapsulating semiconductor elements. In other words, when manufacturing resin compositions for semiconductor encapsulation, the process up to tablet molding is complicated, and heating and melting takes a long time, resulting in decreased productivity and increased product costs. . Furthermore, when encapsulating semiconductor elements, high-pressure molding reduces resin utilization efficiency, requires the use of expensive mold clamping presses and high-pressure resistant molds, and, in addition, requires the use of expensive mold clamping presses and high-pressure resistant molds. This often causes deformation, misalignment, wire breakage, etc., leading to high V-equipment costs and a decrease in product characteristics and yield.

Under these circumstances, efforts have been made to develop various liquid resins for encapsulating semiconductors, but they have not yet been put to practical use in applications that require high reliability.

The biggest reason for this is that the above-mentioned drawbacks can be almost eliminated if liquid epoxy resin is used, but the aluminum wiring of resin-sealed semiconductors corrodes under high temperature and high humidity, and moisture resistance is poor. This is because a new problem has arisen that leads to an extreme decline.

In addition, various curing agents have been studied, but in liquid epoxy resin compositions using amine-based curing agents, amine-based curing agents are inherently highly reactive and can be injected under normal pressure in a short period of time after compounding. Not only does it decrease, but it also has strong hydrophilicity,
Furthermore, during curing, the reaction between the active hydrogen of the amine curing agent and the epoxy group generates new highly hydrophilic alcoholic hydroxyl groups, which greatly increases water absorption and leads to a decrease in moisture resistance in a short period of time.

Also, in liquid epoxy resin compositions using phenolic resin curing agents, the reaction between phenolic hydroxyl groups and epoxy groups produces highly hydrophilic alcoholic hydroxyl groups, and the hydrogen bonding of the phenolic hydroxyl groups makes them semi-solid. However, to improve this, modifiers such as low-molecular phenol compounds and diluents are usually added. This also causes a decrease in moisture resistance in a short period of time.

On the other hand, in liquid epoxy resin compositions using acid anhydrides as curing agents, low-viscosity acid anhydrides can be blended in large numbers, so the viscosity of the resin compositions is extremely low and casting molding is possible. It is possible. Therefore, it is not necessary to add a deforming agent such as a diluent to lower the viscosity, and various properties such as heat deformation temperature do not deteriorate. Furthermore, the reaction between the acid anhydride group and the epoxy group in the presence of a curing accelerator produces an ester bond with weak hydrophilicity and no active hydrogen.
The moisture resistance does not deteriorate in a short time, and unlike the above two types of curing agents, it has a possibility of being applied as a resin composition for semiconductor encapsulation that requires high reliability such as LSI.

However, the ester bonds of epoxy resins using the acid anhydride as a curing agent are gradually hydrolyzed by the action of a curing accelerator such as a normal 6th-class amino acid, and because they contain active hydrogen, they have a tendency to become wet. There was a problem in that it produced high levels of carboxylic acid groups and alcoholic hydroxyl groups, resulting in poor moisture resistance over a relatively long period of time.

Therefore, in the future, high humidity resistance and ! 71 thin! It can be applied to LSI and VLSI that require
At present, there is a strong desire to develop a liquid epoxy resin composition for semiconductor encapsulation that has excellent moisture resistance and high-temperature hydrolysis resistance, as well as excellent normal-pressure injectability and high-temperature hardening resistance.

In view of these circumstances, the present inventors have conducted extensive research into the relationship between ester formation of epoxy resins using acid anhydrides as curing agents, hydrolysis reactions, and curing accelerators, and have found that acid anhydride-based curing The present invention was achieved based on the discovery that extremely favorable results can be obtained only when a specific compound is selected and used as a curing accelerator used together with the curing agent.

That is, the present invention provides a tM-resistant epoxy resin in which an acid anhydride is blended as a curing agent, an aromatic hydroxyl group-containing 6th-class amine is blended as a curing accelerator, and an inorganic photonic agent and a coupling agent are further blended into a liquid epoxy resin. The present invention relates to a liquid epoxy W flit composition for semiconductor encapsulation which has excellent properties such as high temperature curability and high temperature hydrolysis resistance when injected under normal pressure.

Such a liquid epoxy resin composition for semiconductor sealing which has excellent moisture resistance, normal pressure injectability, high temperature curability, and high temperature hydrolysis resistance can be obtained by using a normal 6th class amine as a curing accelerator. This is possible only when an aromatic hydroxyl group-containing 6th class amine is used as a curing accelerator.

Generally, the reaction between an acid anhydride and an epoxy resin requires a long time at a high temperature, so the raj during the fZ nL reaction is attempted to be shortened by using a curing accelerator such as a tertiary amine in combination. If a normal 6th class amine is used, the curing time can be reduced by increasing the amount added or using a highly active 6th class amine, but on the other hand, this will impair 1fIi normal pressure injectability. Such 6th class amine liberated in the cured product is also active in hydrolytic reactions such as ester bonds formed at high wet temperatures, and promotes the formation of carboxylic acid groups, alcoholic hydroxyl groups, etc., and as a result, Decreases moisture resistance and high temperature hydrolysis resistance. On the other hand, if the amount added is reduced, the above-mentioned disadvantages will not occur, but the high-temperature hardness will be poor.

On the other hand, when the aromatic hydroxyl group-containing 6th-class amine is used as the curing accelerator of the present invention, the aromatic hydroxyl group-containing 6th-class amine does not react well with the acid anhydride as the curing agent and the epoxy resin. The aromatic hydroxyl group reacts with the evoquine group and becomes a component of the cured epoxy resin matrix, greatly restricting the molecular movement of the accelerator even when exposed to high temperature and high humidity. This makes it difficult to promote hydrolysis reactions such as ester bonds, and it has excellent moisture resistance, and also has normal pressure injection properties and high 71IIX
A liquid epoxy resin composition for sealing conductors with excellent curability and high-temperature hydrolysis resistance is available.

Although various types of epoxy resins such as liquid alicyclic epoxy resins can be used, it is preferable to use liquid novolak thread epoxy resins which have excellent high temperature properties. These epoxy resins can be used alone or in combination of two or more. In addition to these liquid epoxy resins, if necessary, solid epoxy resins such as brominated novolac epoxy resins and brominated bisphenol A epoxy resins may be added in an amount that does not impair workability during normal pressure injection and low pressure injection. If so, they can be used together as appropriate.

Examples of the acid anhydride used as a curing agent in the present invention include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride,
Although maleic anhydride, hexachloroendomethylenetetrahydrophthalic anhydride, and the like can be used, it is preferable to use hexahydrophthalic anhydride and tetrahydrophthalic anhydride because of their excellent high-temperature properties and normal pressure injection properties. These acid anhydrides can be used alone or in combination of two or more, and the amount used is usually 0.4 to 100% per liquid epoxy resin.
1.2 equivalents, preferably in the range of 0.6 to 1.0 equivalents. If the amount is less than 0.4 equivalent, it will not cure sufficiently, resulting in poor mechanical properties, a decrease in heat distortion temperature and moisture resistance,
Moreover, if the amount is more than 1 or 2, the moisture resistance will be low due to the influence of the excess acid anhydride, which is not preferable.

Aromatic water used as a curing accelerator, which is a feature of the present invention.
imidazo-1-lyl)phenol, 4-(IH-1+2
．． 4-) lyalyl)phenol, 4-(dimethylaminemethyl)phenol, 2,4.6-)I
Js(dimethylamino7)phel, 4-(dimethylamino)7er, 2-(dimethylaminomethyl)-6
-Hydroxypyridine, 2-bromo-6-pyridinol, 2,6-cyhydroxypyridine, 2-hydroxy-6
-Methylpyridine, 5-chloro-hydroquinoline, 5
-Hydroxypyridine, 2,4-dihydroxy-6-methylpyrimidine, 2,4-dihydroxy-5,6-dimethylpyrimidine, 4,6-cyhydroxy-2-methylpyrimidine, 6,6-dihydroxypyridazine, 9 -Hydroxy-acridine, etc. can be used, but 4-(imidazo-1-lyl)phenol, 4-
(IH-1,2,4-triacyl-lyl)phenol, 4-(dimethylaminomethyl)phenol, 2,
4.6-tris(dimethylaminomethyl)phenol,
Particular preference is given to using 4-(dimethylamino)phenol, 2-(dimethylaminomethyl)-6-hydroxypyridine. These curing accelerators can be used alone or in combination of two or more packs, and the amount used is usually 0.1 to 6.0 parts per 100 parts of epoxy resin (weight M (hereinafter the same). part, preferably in the range of 0.2 to 2.0 parts.If it is less than 0.1 part, the curing accelerating effect will be poor and the composition will have poor curability, and if it is more than 6M, the moisture resistance and storage stability will be poor. It is undesirable because it causes a decrease in sexual performance.

In the present invention, for example, crystal 1
1 Silica, fused silica, alumina, antimony trioxide,
Glass fiber, mica, talc, clay, etc. can be used, but it is especially preferable to use crystalline silica, fused silica, alumina, and antimony, which have excellent filling properties. Camphor or higher can be used, and the usage h1 varies depending on the specific type, but generally it is preferably in the range of 100 to 600 parts per 100 parts of liquid epoxy resin.If it is less than 100 parts, the expansion coefficient will be low. Larger, poorer crack resistance, 6
If the amount exceeds 0.00 parts, the viscosity becomes high and the normal pressure injectability becomes poor, which is not preferable.

In the present invention, as a coupling agent, for example, r-
Glycidoxyprobyltrimethoxysilane, β-(3,
(4-epoxycyclohexyl)ethyl) IJ methoxysilane, vinyltri-2-methoxysilane, γ-aminepropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, etc. can be used, but in particular, anti-1i5 properties with fillers and epoxy resins can be used. Excellent γ−
Glycidoxyprobyltrimethoxysilane, β-(3,
Preference is given to using 4-epoxycyclohexyl)ethyltrimethoxysilane. These cambling agents can be used alone or in combination of two or more, and the usage range is 0.1 to 6 parts, preferably 0.2 to 2 parts, per 100 parts of the filler.
This is within the scope of the department. If it is less than 0.1 part or more than 6 parts, the adhesiveness between the filler and the epoxy resin will be poor.
This is undesirable because it causes a decrease in moisture resistance.

A coloring agent such as carbon black, a mold release agent such as carnauba wax or polyethylene wax, and a flame retardant may be added to the composition of the present invention, if necessary.

The composition of the present invention can be easily prepared by using known mixing devices such as rolls, kneaders, and mixers used in the preparation of conventional epoxy resins and silicone resins.

The present invention will be described below with reference to Examples, Comparative Examples, and Reference Examples.

Examples 1 to 9 and Comparative Examples 1 to 9 and Reference Examples The components of epoxy resin, acid anhydride, curing accelerator, filler, flame retardant, coupling agent, coloring agent, and mold release agent are shown in Table 1 and Table 1. They were blended at the vj ratios (parts by weight) shown in Table 2, and vacuum mixed using a kneader at a temperature of 40°C for 10 minutes to obtain an epoxy resin composition. The normal pressure injectability, curability, hydrolysis resistance and moisture resistance of the obtained composition were tested on W4, and the obtained results are shown in Tables 6 and 4, respectively.

The normal pressure injectability was evaluated based on the viscosity at 40°0. Curability was evaluated using gel time at 170°O. Regarding hydrolysis resistance, after vacuum casting into a shape of 3 x 5 x 20 mm, 121 ° o, 2 atm, relative temperature 1
POT under 00% condition (Pressure 0ook
erTe8t) and then evaluated using infrared spectroscopy.

As for moisture resistance, moisture-resistant silicone elements for needlers were formed by vacuum casting, and the time required for defects to occur when left under the above conditions was investigated.

In addition, as a reference example, we investigated the gelation time at 170°0 of a commercially available product (resin for solid transfer molding), and the failure occurrence time in the above-mentioned POT atmosphere of a semiconductor element for evaluating moisture resistance that was transfer molded using this commercially available product. Ta. The results are shown in Table 5.

As is clear from Tables 3 and 4, the liquid epoxy resin composition for sealing a conductor according to the present invention has excellent normal pressure injection properties, good high temperature curing properties, high temperature hydrolysis resistance,
It is found that it has excellent moisture resistance and is extremely useful as a liquid sealing resin composition for semiconductor devices.

Hand A, 1c Ura Masagi (spontaneous) +1, Commissioner of the Office 1, 1, Incident display 12. rt Sho 57-119579 No. 2, Name of the invention Liquid epoxy resin composition for cattle conductor earthworks 3 Name of person making the amendment Name (601j Representative of Mitsubishi Electric Corporation Kata)
Yujin Part 8 (1) Contents of amendments in package 6 of "Detailed Description of the Invention" of the specification (1) "In addition, various curing agents are being considered" on page 5, lines 5-6 of the specification. is corrected to ``that is.''

that's all

Claims (1)

[Scope of Claims] (1) A liquid epoxy resin is blended with an acid anhydride as a curing agent, an aromatic hydroxyl group-containing 6th class amine as a curing accelerator, and further contains an inorganic photonic agent and a coupling agent. A liquid epoxy resin composition for semiconductor encapsulation. (2) The aromatic hydroxyl group-containing 6th amine is 4-(imidazo-1-lyl)phenol, 4-(IH-1,2
, 4-triacyl-1-lyl)phenol, 4-(dimethylaminomethyl)phenol, 2.4r6-)lis(dimethylaminomethyl)phenol, 4-(dimethylamino)phenol) J:H2-(dimethylaminomethyl) The liquid epoxy resin composition for semiconductor encapsulation according to claim 1, characterized in that the composition is at least one selected from the group consisting of 3-hydroxypyridine. (8) The number of aromatic hydroxyl group-containing 6th class amines used in MJ is 0.1 to 6 per 100 parts of liquid epoxy resin.
Featured in being a heavy company, the special fl
The liquid epoxy resin composition for semiconductor encapsulation according to item 1) or item (2). (4) A liquid epoxy resin for semiconductor book sealing according to claim 1, 2, or 3, wherein the epoxy resin is a liquid novolak epoxy resin. Composition. (5) Claim (1), characterized in that the acid m hydrate is methylhexahydrophthalic anhydride and/or methyltetranohydrophthalic anhydride;
The liquid epoxy resin composition for semiconductor encapsulation according to item (2) or item (3). (6) The semiconductor according to claim (1), (2) or (8), wherein the inorganic photonic agent is crystalline silica and/or fused silica. Liquid epoxy resin composition for sealing. (7) A special feature characterized in that the coupling agent is γ-glycidoxypropyltrimethoxysilane and/or β-(3,4-ebocycitalohexyl)ethyltrimethoxysilane! f. A liquid epoxy resin composition for semiconductor confinement pressure according to claim (1), (2) or (8).