JPH0378404B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a semiconductor encapsulating resin composition for encapsulating semiconductor elements, which has particularly excellent reliability such as moisture resistance and high-temperature electrical properties, and is not difficult to mold during molding. The present invention relates to a resin composition for semiconductor encapsulation that has good marking properties on molded products obtained. [Prior art] Conventionally, a hermetic method using metals, ceramics, etc. has been used as a encapsulation technology for semiconductor devices, but resin encapsulation has become more economically advantageous in terms of productivity and cost, so resin encapsulation has become more popular in recent years. encapsulation is becoming mainstream. As such semiconductor encapsulating resins, low-pressure molding epoxy resins that can be subjected to low-pressure transfer molding methods suitable for mass production are widely used. In order to enable the molded semiconductor to be removed from the mold in such a transfer molding method, it is a common practice to add an internal mold release agent to the epoxy resin composition in advance. Conventionally used internal mold release agents include long chain fatty acids such as stearic acid, long chain fatty acid metal salts such as zinc stearate, long chain fatty acid ester waxes such as carnauba wax, and ethylene bis. Bisamide-based waxes such as stearic acid amide are known, but all of these conventional mold release agents have poor moisture resistance, reliability such as high-temperature electrical properties, mold releasability, and imprintability on the surface of molded products. I couldn't say it was satisfactory. That is, long-chain fatty acids and their metal salts have mold release properties,
Although the imprintability is relatively good, it has been found that defects are likely to occur and the moisture resistance is poor in reliability tests such as the pressure Jakartsker test and the pressure Jagsker bias test. Furthermore, although ester waxes have excellent mold releasability and reliability, they are inferior in stamping properties, and in particular, as the number of molding increases, the stamping properties deteriorate extremely. Although bisamide waxes have excellent reliability and imprintability, they have the disadvantage of poor mold release properties. [Object of the Invention] The present invention was made as a result of intensive studies to solve the above-mentioned drawbacks, and it involves adding a specific divalent fatty acid bisamide compound as an internal mold release agent to the conventional epoxy resin for semiconductor encapsulation. By this,
It is an object of the present invention to provide a resin composition for semiconductor encapsulation that has excellent reliability in terms of moisture resistance, high-temperature electrical properties, etc., good mold releasability, and also has good imprintability on the resulting IC encapsulation molded product. [Structure of the Invention] The present invention provides (1) a resin composition for semiconductor encapsulation, characterized in that it contains an epoxy resin and a divalent fatty acid bisamide compound represented by formula [A] in an amount of 0.01 to 10% by weight, CH ₃ (−CH ₂ )− _l NHCO(−CH ₂ )− _n CONH(−CH ₂ )−
_o CH ₃ [A] (l, n are integers of 14 or more, m is an integer of 3 or more) and (2) the divalent fatty acid bisamide compound is a divalent fatty acid with 5 or more carbon atoms and a long chain aliphatic group with 15 or more carbon atoms. The resin composition for semiconductor encapsulation according to claim 1, characterized in that it is formed by condensing with a primary amine, and (3) the divalent fatty acid bisamide compound has a melting point of 80°C or more.
The present invention relates to a resin composition for semiconductor encapsulation according to claim 1, characterized in that the temperature is 140°C. The epoxy resins used in the present invention include bisphenol A type epoxy resins, novolak type epoxy resins, resorcinol type epoxy resins, halogenated epoxy resins, glycidyl ester type epoxy resins,
Polymeric epoxy resins, etc., and curing agents include amine curing agents, aliphatic polyamines, polyamide resins, aromatic diamines, acid anhydride curing agents, Lewis acid complex compounds, aromatic polyamines, polycarboxylic acids, polycarboxylic Acid hydrazide, boron trifluoride monoethylamine, dicyandiamide, imidazole, phenolic resin, melamine resin, acrylic resin, urea resin, isocyanate, etc. Fillers include glass fiber, metal whisker, carbon fiber, Kevlar fiber, polyester fiber, Polyamide fibers, pulp, asbestos, crystalline silica, fused silica, alumina, calcium carbonate, magnesium carbonate, calcium hydroxide, aluminum hydroxide, antimony trioxide, talc, titanium oxide, etc. can be added. Other additives that may be added include coloring agents such as carbon black and iron oxide, and coupling agents. Further, a conventional curing accelerator may also be added as necessary. The mold release agent used in the present invention, a divalent fatty acid bisamide compound, is represented by formula [A]. CH ₃ (−CH ₂ )− _l NHCO(−CH ₂ )− _n CONH(−CH ₂ )−
_o CH ₃ (l and n are integers of 14 or more, m is an integer of 3 or more) In addition, it is also possible to use a conventionally commonly used mold release agent. The amount of divalent fatty acid bisamide compound added is not particularly limited, but preferably
0.01 to 10% by weight is desirable. That is, if the divalent fatty acid bisamide content is less than 0.01%, it will not be effective as a mold release agent, and if it exceeds 10%, the crosslinking density after curing the epoxy resin will decrease significantly, which will affect the mechanical properties, electrical properties, etc. of the cured product. This is because the protection function of the semiconductor element cannot be fulfilled. Further, the divalent fatty bisamide compound represented by formula [A] can be obtained by condensing a divalent fatty acid having 5 or more carbon atoms with a long-chain aliphatic primary amine having 15 or more carbon atoms. The present invention is to use a divalent fatty acid bisamide compound represented by formula [A] as an internal mold release agent for an epoxy resin, and a semiconductor that satisfies all of reliability, mold releasability, imprintability, etc. by the method of the present invention. It has become possible to provide a sealing resin composition. Conventional amide waxes have better heat resistance than other waxes, and are therefore widely used as internal mold release agents for molding materials. In other words, even if the molding process is repeated for a long time in a high-temperature mold, the wax that oozes out onto the mold surface has good heat resistance, so it does not gel and accumulate inside the mold, which significantly improves the appearance of the molded product. There's nothing to lose. This is for the reason. However, while the conventional amide waxes, which have excellent continuous moldability, have good reliability and imprintability, they have insufficient mold releasability. Most conventional amide-based waxes are made by reacting intramolecular polyamide compounds or higher fatty acids with ammonia, which are obtained by condensing higher fatty acids such as stearic acid, behenic acid, and montanic acid with polyvalent amines such as ethylenediamine. It is an intramolecular polyamide compound that is methylolated and condensed with formalin, and has high polarity and is highly compatible with epoxy resins, etc., so it can be used in waxes such as other higher fatty acids, metal salts of higher fatty acids, and higher fatty acid esters. It is thought that even if the same amount of internal mold release agent is added, the amount of wax that oozes out onto the surface of the molded product and the mold is extremely small, resulting in inferior mold release properties. In addition, these higher fatty acid intramolecular polyamide compounds have high crystallinity and a melting point of 115℃~
The high temperature of 160°C is also one of the reasons for poor mold release properties. In addition to intramolecular polyamide compounds, there are higher fatty acid terminal amide compounds that are amidated by reacting higher fatty acids with ammonia, and unsaturated fatty acid intramolecular polyamide compounds, which have a relatively low melting point of 80 to 130°C. However, all of them had poor heat resistance and were not satisfactory in terms of long-term moldability. Therefore, the present inventors have made extensive studies to take advantage of the heat resistance, reliability, and good marking properties of amide waxes to further improve mold releasability, and have found that divalent saturated fatty acids with carbon numbers of 0.5 or more and carbon number
A divalent fatty acid bisamide compound obtained by condensing with a long chain aliphatic primary amine of 15 or more has a melting point of 80~
With the knowledge that it has a lower melting point of 140°C than conventional amide waxes, good mold releasability, and satisfies all aspects such as long-term moldability, reliability, and imprintability, we have completed the present invention. It is ivy. The number of carbon atoms in the divalent saturated fatty acid is limited to 5, and the number of carbon atoms in the long-chain aliphatic primary amine is specifically limited to 15 or more. This is because it cannot exhibit mold releasability, and especially when divalent fatty acids having carbon atoms of 4 or less are used, the crystallinity becomes high and the melting point becomes 140° C. or higher, which also causes a decrease in mold releasability. [Effects of the Invention] The present invention is characterized in that a specific divalent fatty acid bisamide compound is blended as an internal mold release agent into an epoxy resin composition consisting of an epoxy resin, a curing agent, a filler, and various additives. It is suitable for molding a large number of electronic parts by transfer molding, injection molding, etc., and can satisfy all aspects such as reliability, stampability, mold releasability, and continuous moldability. Next, the present invention will be specifically explained using examples. [Example] In the following, parts refer to parts by weight unless otherwise specified. Example 1 Adipic acid [HOOC( _-CH2 ) _-4COOH ] 146g
(1 mol), stearylamine [C ₁₈ H ₃₇ NH ₂ ] 538
(2 mol) and toluene 100 c.c. were placed in a three-necked flask (No. 1) equipped with a thermometer, reflux condenser, and stirrer, and heated to 120° C. with stirring.
The condensation reaction between carboxylic acid and amine becomes active at 120°C to 130°C.
Keep at ℃. Next, the temperature was gradually raised to 180°C over 2 hours to complete the condensation reaction. Toluene remaining in the reaction system is removed by reduced pressure,
The product was taken out at a temperature above 130°C and solidified by cooling. The melting point of the reaction product was measured and found to be 136°C. On the other hand, when the infrared absorption spectrum of the product was measured, the carbonyl absorption at 1710 cm ^-1 of the starting carboxylic acid completely disappeared, and instead the amide carbonyl absorption appeared at 1640 cm ^-1 , indicating that the dihydric carboxylic acid and amine The condensation reaction occurred almost quantitatively, and the resulting reaction product was confirmed to be the desired divalent fatty acid bisamide compound. Next, 5.5 parts of this divalent fatty acid bisamide compound was used as an internal mold release agent, 100 parts of cresol novolac epoxy (epoxy equivalent: 220), 30 parts of brominated phenol novolac epoxy (epoxy equivalent: 300), and a phenol novolac hardener (molecular weight: 750). ) 60 copies,
0.5 parts of 2-ethyl-4-methylimidazole, 400 parts of crystalline silica powder, 2.0 parts of silane coupling agent
30 parts antimony trioxide, carbon black
A molding material obtained by blending, mixing, and kneading with 2.0 parts was used as a resin composition for semiconductor encapsulation. Example 2 Suberic acid [HOOC(-CH ₂ )- ₆ COOH] 174g
(1 mol), 538 g (2 mol) of stearylamine, and 130 c.c. of toluene were reacted in the same manner as in Example 1 to obtain a divalent fatty acid bisamide compound. The melting point of this compound was 128°C. Then this compound
A resin composition for semiconductor encapsulation was obtained by blending 3.5 parts as an internal mold release agent in the same composition as in Example 1. Example 3 Sepacic acid [HOOC(-CH ₂ )- ₈ COOH] 202g
(1 mol), 538 g (2 mol) of stearylamine, and 150 c.c. of toluene were reacted in the same manner as in Example 1 to obtain a higher fatty acid intramolecular monoamide compound.
The melting point of this compound was 123°C. Subsequently, 2.5 parts of this compound was blended as an internal mold release agent in the same composition as in Example 1 to obtain a resin composition for semiconductor encapsulation. Example 4 Divalent fatty acid bisamide compound obtained in Example 1
An epoxy resin composition for semiconductor encapsulation was obtained by blending 5.0 parts of carnauba wax and 0.5 parts of carnauba wax as an internal mold release agent in the same composition as in Example 1. Comparative Examples 1 to 6 Six types of epoxy resin compositions for semiconductor encapsulation were obtained by blending the same compositions as in Example 1 except for those listed in Table 1 below as internal mold release agents.

[Table] The above composition was pressurized using a transfer molding machine.
A molded product was molded under the conditions of 60 kg/cm ² , a mold temperature of 175°C, and 2 minutes and 30 seconds, and then post-cured at 175°C for 4 hours to obtain a semiconductor sealed product. The mold releasability during molding, long-term moldability, reliability of the molded product, and stampability were as shown in Table 2. Evaluation of each characteristic was performed as follows. (a) Mold release property Continuous molding is performed with only the lower mold having a dowel pin, and the upper mold (without a dowel pin)
Evaluation was made based on the number of moldings until the molded product adhered to the surface and could no longer be easily released from the mold. (b) Long-term moldability It was expressed as the number of molding times when the surface of the molded product became dirty and the appearance began to become cloudy when continuous molding was performed using a mold with a mirror-like surface. (c) Reliability The obtained IC encapsulation was subjected to pressure checker test (PCT: 120℃ steam, 2 atmospheres)
The corrosion of the aluminum wiring was investigated. The occurrence of open circuits due to aluminum corrosion was detected and expressed as the initial failure occurrence time. (d) Imprintability The surface of the obtained IC encapsulation was imprinted using #7224 silver ink manufactured by Markem, and after curing the ink at 150°C for 1 hour, a peeling test was performed with cellophane tape to ensure that even the slightest character was missing. If there is, it is considered defective.

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Claims (1)

[Scope of Claims] 1. A resin composition for semiconductor encapsulation, comprising 0.01 to 10% by weight of an epoxy resin and a divalent fatty acid bisamide compound represented by formula [A]. CH ₃ (−CH ₂ )− _l NHCO(−CH ₂ )− _n CONH(−CH ₂ )−
_o CH ₃ (l, n are integers of 14 or more, m is an integer of 3 or more) 2 The divalent fatty acid bisamide compound combines a divalent fatty acid with 5 or more carbon atoms and a long-chain aliphatic primary amine with 15 or more carbon atoms. The resin composition for semiconductor encapsulation according to claim 1, characterized in that it is formed by condensation. 3 The melting point of the divalent fatty acid bisamide compound is 80~
The resin composition for semiconductor encapsulation according to claim 1, characterized in that the temperature is 140°C.