JPH05287054A - Liquid epoxy resin composition, its cured product, and semiconductor device sealed therewith - Google Patents

Abstract

PURPOSE:To obtain the title composition which can give a cured product excellent in humidity resistance and high-temperature electrical properties and can be desirably used for, e.g. sealing a semiconductor device. CONSTITUTION:The title composition consists essentially of a curable epoxy resin, a curing agent and an inorganic ion exchanger of the general formula: AxOy(NO3)z(OHw.h (H2O) (wherein A is at least one kind of a trivalent to pentavalent transition metal; x=1-5; y=1-7; z=0-3; w=0.2-3; and h=0-2) and has a viscosity of 10,000 P or below at 25 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a semiconductor device encapsulant, and a liquid epoxy resin composition suitable for use as an adhesive in various fields, a cured product thereof, and a cured product of the above composition. The present invention relates to a semiconductor device.

[0002]

2. Description of the Related Art Epoxy resins and epoxy resin compositions containing an inorganic filler and the like are generally superior in moldability, as compared with other thermosetting resins.
Due to its excellent adhesiveness, electrical properties, mechanical properties, moisture resistance, etc., it has been widely used as various molding materials, powder coating materials, electrical insulation materials, etc., especially semiconductor sealing materials, potting materials, and coatings recently. It is used as a material.

For such applications, liquid epoxy resin compositions have recently been attracting attention, but liquid epoxy resins are limited to usable materials because they are liquid, and they are not limited to ordinary epoxy resin compositions. Compared with this, the electrical characteristics at high temperature may become worse, and when a semiconductor device is sealed by using this, a leak current flows between the electrodes of this sealing device, and normal semiconductor characteristics are no longer exhibited, or IC When the resin is sealed with a resin and subjected to a deterioration test under high temperature and high humidity, the aluminum wire used for the wiring of the chip is corroded in a short time, which causes a disconnection. Therefore, a liquid epoxy resin composition suitable for semiconductor encapsulation and having excellent moisture resistance and high-temperature electrical properties is desired.

The present invention has been made in view of the above circumstances.
An object of the present invention is to provide a liquid epoxy resin composition that gives a cured product having excellent moisture resistance and high-temperature electrical properties, a cured product thereof, and a semiconductor device encapsulated with the cured product.

[0005]

Means and Actions for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that the viscosity at 25 ° C. containing a curable epoxy resin and a curing agent is 10,0.
For a liquid epoxy resin composition of 00 poise or less, the following general formula (1) A _x O _y (NO ₃ ) _z (OH) _w · h (H ₂ O) (1) (where A is 1 Or 3 or more trivalent pentavalent transition metals, x = 1 to 5, y = 1 to 7, z = 0 to 3, w =
0.2-3 and h = 0-2. When the inorganic ion exchanger represented by the formula (1) is blended, the inorganic ion exchanger surely captures free impurities such as hydrolyzable chlorine and bromine, so that corrosion of aluminum wiring by a cured product of the composition is effective. The present invention has been accomplished based on the finding that it can be suitably used as a semiconductor encapsulating material, etc., because it has excellent curability and excellent curability of the composition.

Therefore, the present invention comprises (A) a curable epoxy resin, (B) a curing agent, and (C) an inorganic ion exchanger represented by the above general formula (1) as essential components, and has a viscosity at 25 ° C. Provided is a liquid epoxy resin composition characterized by being 10,000 or less, a cured product thereof, and a semiconductor device encapsulated with the cured product.

The present invention will be described in more detail below. First, the curable epoxy resin (A) constituting the liquid epoxy resin composition of the present invention is one having two or more epoxy groups in one molecule. There are no particular restrictions on the molecular structure, molecular weight, etc. as long as it can be used and can be cured with various curing agents as described below, and various conventionally known ones can be used. Specifically, for example, an epoxy resin synthesized from various novolac resins including epichlorohydrin and bisphenol, an alicyclic epoxy resin or an epoxy resin into which a halogen atom such as chlorine or bromine atom is introduced can be mentioned. Among them, the glycidyl ether derivative of bisphenol A or bisphenol F is preferably used to obtain a low-viscosity composition that is liquid at room temperature. The epoxy resin is not necessarily limited to one type of use in its use.
You may use it, mixing 2 or more types.

Further, as the epoxy resin, it is preferable to use one having a softening point of a mixture with a curing agent described below of 30 ° C. or less and a viscosity at 25 ° C. of 500 poise or less. It is preferable in terms of obtaining a resin composition.

When using the above epoxy resin,
The monoepoxy compound may be appropriately used in combination. Specific examples of the monoepoxy compound include styrene oxide, cyclohexene oxide, propylene oxide, methyl glycidyl ether, ethyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, octylene oxide, and dodecene oxide.

Next, as the curing agent (B), specifically, diaminophenylmethane, diaminophenylsulfone,
Amine-based curing agents typified by metaphenylenediamine, acid anhydride-based curing agents such as phthalic anhydride, pyromellitic dianhydride, and benzophenonetetracarboxylic anhydride, or 1 such as phenol novolac and cresol novolac
Examples include phenol novolac curing agents having two or more hydroxyl groups in the molecule. Among these, an acid anhydride-based curing agent that gives an epoxy resin composition having a low viscosity and a low stress is preferably used.

The amount of these curing agents used may be a usual amount, but is 50 to 150 equivalent%, particularly 80 to 110 equivalent% relative to the equivalent of the epoxy groups of the epoxy resin.
It is preferable to set it as the range.

Further, in the composition of the present invention, various curing accelerators, such as imidazole or its derivatives, are used for the purpose of promoting the reaction between the curing agent and the epoxy resin.
There is no problem in using a tertiary amine derivative, a phosphine derivative, a cycloamidine derivative or the like in combination. In addition, the compounding amount of these curing accelerators can also be made into the usual range.

The composition of the present invention further comprises an inorganic ion exchanger represented by the following general formula (1) A _x O _y (NO ₃ ) _z (OH) _w · h (H ₂ O) (1) Compound.

The inorganic ion exchanger of the above formula (1) has an effect of capturing free impurity ions in the epoxy resin composition. Here, in the formula (1), A is 1
Or two or more trivalent pentavalent transition metals, x = 1 to 5, y
= 1 to 7, and a specific example of A _x O _y is Sb _{2
O 3, Al 2 O 3,} Bi 2 O 3 and the like. Further, z, which represents the number of NO ₃ groups in the formula (1), is 0 to 3, but preferably 0.02 or more from the viewpoint of the effect of trapping impurities.
In particular, it is 0.02-0.2. When z is larger than 0.2, the curability of the composition deteriorates. Further, in the formula (1), w is 0.2 to 3, preferably 0.5 to 1.5,
h is 0 to 2, preferably 0.2 to 1.

Specific examples of the inorganic ion exchanger of the above formula (1) are as follows: Al ₂ O _2.2 (OH) _0.8 · 0.5H ₂ O Sb ₂ Bi _1.2 O _6.8 (OH) _0.8 · 0.5H ₂ O Sb ₂ Bi _1.2 O _6.4 (NO ₃ ) _0.5 (OH) _0.9 · 0.5H ₂ O Sb ₂ Bi _1.2 O _6.8 (NO ₃ ) _0.08 (OH) _0.8 · 0.4H ₂ O can be mentioned. Of these, the compound of the following formula (1a) is more preferably used because the effect of retaining the curing characteristics of the composition and the effect of trapping free impurities are good.

Sb _a Bi _b O _c (NO ₃ ) _d (OH) _e · fH ₂ O (1a) (where a and b are 1 to 2 respectively, c is 4 to 10,
d is 0.02 to 0.2, e is 0.5 to 1.5, and f is 0.
It is 2-1. )

The average particle size of the inorganic ion exchanger is preferably 5 microns or less, and particularly preferably 0.1 to 2 microns in order to enhance the effect of trapping impurity ions.

Further, in the composition using glycidyl ether of bisphenol A and bisphenol F and its derivative as the curable epoxy resin, particularly in the composition using the curable epoxy resin and the curing agent acid anhydride, the above-mentioned inorganic ion is used. The use of exchangers is preferred. Further, excellent effects can be obtained by using a composition containing a low stress agent, for example, a silicone-modified epoxy shown in Japanese Patent No. 1575649 in these compositions.

The blending amount of the above inorganic ion exchanger is
It is preferably 0.5% (% by weight, the same applies hereinafter) or more, especially 1 to 5% of the total composition, and if the content is less than 0.5%, the trapping property of impurity ions may decrease. ..

There is no problem in incorporating an inorganic filler into the composition of the present invention, and there is no limitation on the type of inorganic filler used, a single use or a combination of a plurality of types.
It is appropriately selected depending on the application of the epoxy resin composition. For example, one or more kinds selected from natural silica such as crystalline silica and amorphous silica, synthetic high-purity silica, synthetic spherical silica, talc, mica silicon nitride, boron nitride, and alumina can be used. ..

The blending amount of the above-mentioned inorganic filler is not necessarily limited, but is 50 to 700%, especially 100% with respect to 100% of the total amount of the curable epoxy resin, the curing agent and the curing accelerator.
It is preferably set to ˜600%. If the compounded amount is less than 50%, the expansion coefficient of the obtained epoxy resin composition is large, and satisfactory results may not be obtained in terms of physical properties such as crack resistance, and if it exceeds 700%, the composition of the composition The viscosity may become extremely high.

The composition of the present invention further comprises a low-stress agent, a carbon-functional silane for improving adhesion, waxes, a release agent for fatty acids such as stearic acid and metal salts thereof, pigments such as carbon black, dyes, and the like. An antioxidant, a surface treatment agent (γ-glycidoxypropyltrimethoxysilane, etc.), various conductive fillers, thixotropy-imparting agents, and other additives can also be added. In addition, the compounding amount of these additives can be a usual amount as long as the effect of the present invention is not impaired.

The viscosity of the epoxy resin composition of the present invention is B
Measured at 4 rpm with an H-type rotational viscometer, the value at 25 ° C is 10,000 poise or less, particularly 5,000 poise or less, more preferably 5 to 3,000.
It is 0 poise, and it is desirable to adjust the blending amounts of the above essential components and optional components so as to maintain this low viscosity.

The epoxy resin composition of the present invention can be obtained by uniformly stirring and mixing a predetermined amount of the above-mentioned product. Further, it may be diluted with an organic solvent such as acetone, toluene, xylene or the like, if necessary. There is no particular limitation on the order of mixing the components.

The curing conditions for the composition of the present invention are preferably, for example, a curing temperature of 80 to 180 ° C. and 30 to 480 minutes. In addition, in order to suppress the generation of bubbles on the surface or inside when curing, so-called step cure may be employed in which the heating temperature is changed not only in one step but also in two or more steps for curing.

The liquid epoxy resin composition of the present invention is an IC,
It is preferably used for sealing LSIs, transistors, diodes and the like, specifically, flip-chip sealing, tape automated bonding (TAB), semiconductor sealing of chip awning board (COB) and the like. When the semiconductor device is sealed, general dipping, coating with a dispenser, casting, or the like can be adopted.

[0027]

EFFECTS OF THE INVENTION The liquid epoxy resin composition of the present invention, having the above-mentioned constitution, gives a cured product having excellent moisture resistance and high-temperature electrical characteristics, and can be suitably used for encapsulation of semiconductor devices and the like. ..

[0028]

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

Prior to the examples and comparative examples, reference examples show the method for producing the low stress agent used in each example.

[Reference Example] 300 g of epoxidized phenol novolac resin (epoxy equivalent 195) having a softening point of 80 ° C. was placed in a four-necked flask having an internal volume of 1 liter equipped with a reflux condenser, a thermometer, a stirrer and a dropping funnel. While stirring at 110 ° C., a mixture of 32 g of 2-allylphenol and 1 g of tributylamine was added dropwise at a dropping time of 10 minutes, and stirring was continued at 110 ° C. for 2 hours. Unreacted 2-allylphenol and tributylamine were distilled off from the obtained content under reduced pressure to obtain an allyl group-containing epoxy resin (allyl equivalent 1490, epoxy equivalent 235).

Next, in a four-necked flask similar to the above, 100 g of the allyl group-containing epoxy resin obtained by the above method, 100 g of methyl isobutyl ketone, 200 g of toluene, 2
0.4 g of a 2-ethylhexanol-modified chloroplatinic acid solution having a platinum concentration of 0.1% was added to each and azeotropic dehydration was performed for 1 hour, and 81 g of an organopolysiloxane represented by the following formula (2) was added at a reflux temperature for a dropping time of 30. The reaction mixture was added dropwise at the same temperature for 4 hours with stirring, and the resulting contents were washed with water and the solvent was distilled off under reduced pressure to give a compound containing 44% by weight of diorganopolysiloxane unit. (Low stress agent) was obtained.

[0032]

[Chemical 1]

Examples and Comparative Examples Epoxy resin (epoxidized bisphenol A having an epoxy equivalent of 184), acid anhydride (4-methylhexahydrophthalic anhydride), and the diorganopolysiloxane unit obtained in the above reference example were used. An antimony-bismuth-based oxidizing agent represented by the above formula (1a) [IXE680] as a low-stress agent and an inorganic ion exchanger to be contained.
(Manufactured by Toagosei) and a quaternary salt of a curing accelerator DBU [U-cat5002 (manufactured by San Apollo)] or 2-phenyl-4-methyl-5-hydroxymethylimidazole (manufactured by Shikoku Chemicals), an inorganic filler. As average particle size 1
A liquid epoxy resin composition was prepared by using 5 μm of fused silica in the blending amount shown in Table 1, further adding 1 part by weight of γ-glycidoxypropyltrimethoxysilane, and uniformly mixing.

For comparison, a liquid epoxy resin composition was prepared in the same manner as in the examples except that the inorganic ion exchanger was not blended.

The moisture resistance of the obtained composition is evaluated as follows.
Made by way. The results are shown in Table 1. Moisture resistance Formed aluminum pattern on silicone wafer
A test device with a simulated IC mounted on a glass epoxy substrate
Drop the fat composition, 120 ℃ / 1hr, 150 ℃ /
The test element was sealed by curing for 2 hours.

This sealing element was tested with a pressure cooker tester (manufactured by Hirayama Seisakusho, model PC-242S) to obtain 12
After processing at 1 ° C. and 2 atm for 400 hours, the number of pattern conduction defects was examined.

[0037]

[Table 1]

From the results shown in Table 1, it is recognized that excellent moisture resistance can be imparted by incorporating an inorganic ion exchanger into the liquid epoxy resin composition.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Dobashi 1 Hitomi, Oita, Matsuida-cho, Usui-gun, Gunma 10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory

Claims (3)

[Claims] 1. An (A) curable epoxy resin, (B) a curing agent, (C) an inorganic ion exchanger represented by the following general formula (1), A _x O _y (NO ₃ ) _z (OH) _w. h (H ₂ O) (1) (wherein A represents one or two or more trivalent to pentavalent transition metals, x = 1 to 5, y = 1 to 7, z = 0 to 0) 3, w =
0.2-3 and h = 0-2. Is added as an essential component, and the viscosity at 25 ° C. is 10,000 poise or less, a liquid epoxy resin composition. 2. A cured product obtained by curing the liquid epoxy resin composition according to claim 1. 3. A semiconductor device encapsulated with the cured product of the liquid epoxy resin composition according to claim 1.