JP2007238731A - Mold release restoring resin composition and method for producing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for encapsulating a semiconductor excellent in mold release restorability restoring mold release even when used in a small amount, causing no oil exudation and stain on the surface of a semiconductor device molded just after restoring mold release and maintaining the mold releasability for long period of time. <P>SOLUTION: This mold release restoring resin composition for encapsulating semiconductors is characterized by containing (A) an epoxy resin, (B) a phenol rein-based curing agent, (C) a curing accelerator, (D) an inorganic filler, (E) a carboxy group-containing butadiene-acrylonitrile copolymer (e1) and/or a reaction product (e2) of a carboxy group-containing butadiene-acrylonitrile copolymer (e1) and an epoxy resin, wherein the formulation amount as the (e1) component is 0.1-10 wt.%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a mold release recovery resin composition for sealing a semiconductor used for recovering the mold release property of a mold for sealing used in the manufacture of a resin sealed semiconductor device, and a semiconductor device using the same It is related with the manufacturing method.

  Epoxy resin composition for semiconductor encapsulation as the integration of semiconductor elements progresses year by year and the surface mounting of semiconductor devices is promoted in the market trend of downsizing, weight reduction and high performance of electronic devices in recent years. The demand for things has become increasingly severe. When using epoxy resin compositions for semiconductor encapsulation that use various resins and additives that meet this requirement, mold fouling occurs during continuous molding, and mold defects such as mold removal and unfilling. Therefore, it is normal to periodically clean the mold surface.

  Conventionally, a semiconductor sealing mold cleaning material consists of a resin having a high molding shrinkage such as an amino resin and a filler having high hardness such as crystal-crushed silica and glass fiber. The main thing was scraping off the dirt on the mold surface. After using the cleaning material, the mold surface will be clean, but the mold release agent will also be removed, so the cured resin of the semiconductor device molded immediately after cleaning is extremely releasable. There was a problem of getting worse. Therefore, after using the cleaning material, it is necessary to mold the mold release recovery resin composition, transfer the mold release agent in the mold release recovery resin composition to the mold surface, and apply it to recover the release properties. is there.

The function of the mold release recovery resin composition is to transfer and apply the release agent to the mold surface, and to quickly recover the release property, but if a large amount of release agent is transferred, After that, there is a problem of causing oil floating or dirt on the surface of the cured resin of the molded semiconductor device. If the release agent cannot be transferred sufficiently, it takes time to recover the release property, and the release recovery resin composition The problem that it is necessary to use a lot of things occurs. Furthermore, when the releasability after recovering the releasability cannot be sustained for a long time, there is a problem that it is necessary to frequently use a releasable recovery resin composition and the productivity is lowered.
For this reason, a technique for improving mold release sustainability by adding an antioxidant to a montanic acid ester wax or oxidized or non-oxidized polyethylene wax as a mold release agent is disclosed (for example, see Patent Document 1). ). Although this method improves mold release sustainability, since the main chain of the mold release agent is a carbon chain, it is relatively compatible with the epoxy resin composition for semiconductor encapsulation, and is formed on the surface of the molded semiconductor device. The problem of oil floating and dirt could not be solved sufficiently.

JP-A-4-259513 (pages 2-5)

  The present invention relates to a mold release recovery resin composition for semiconductor encapsulation used for recovering the mold release property of a mold for encapsulation used in the production of a resin-encapsulated semiconductor device. Mold release recovery resin composition for semiconductor encapsulation, which can maintain mold release characteristics without recovering oil floatation and dirt on the surface of the semiconductor device immediately after mold release recovery, and molding using the same It is an object of the present invention to provide a method for manufacturing a resin-encapsulated semiconductor device that recovers mold releasability.

The present invention
[1] (A) epoxy resin, (B) phenol resin-based curing agent, (C) curing accelerator, (D) inorganic filler, (E) butadiene-acrylonitrile copolymer having a carboxyl group (e1) and / or Or a reaction product (e2) of a butadiene-acrylonitrile copolymer (e1) having a carboxyl group and an epoxy resin, and the blending amount as the component (e1) is 0.1% by weight in the total epoxy resin composition Or more, 10% by weight or less, a mold release recovery resin composition for semiconductor sealing,

（ただし、上記一般式（１）において、ｘは１未満の正数。ｙは１未満の正数。ｘ＋ｙ＝１。ｚは５０〜８０の整数。） [2] Mold release recovery resin composition for semiconductor encapsulation, wherein the butadiene-acrylonitrile copolymer (e1) having a carboxyl group is a compound represented by the following formula (1):

(However, in the above general formula (1), x is a positive number less than 1. y is a positive number less than 1. x + y = 1. Z is an integer of 50 to 80.)

[3] In a method for producing a resin-encapsulated semiconductor device in which a semiconductor element is molded and encapsulated using a resin composition for encapsulating a semiconductor, a mold for encapsulating a semiconductor according to [1] or [2] A method for producing a resin-encapsulated semiconductor device, wherein the mold release property of the molding die is recovered using the release recovery resin composition;
It is.

  The mold release recovery resin composition for semiconductor encapsulation of the present invention can recover the mold release property by molding a few times, and oil is applied to the surface of the semiconductor device in the semiconductor seal molding immediately after the mold release recovery. It is industrially useful because it contributes to the improvement of productivity in the manufacture of semiconductor devices, because it can maintain a good release property for a long time without causing floating and dirt.

The present invention provides an epoxy resin, a phenol resin, a curing accelerator, an inorganic filler, a butadiene / acrylonitrile copolymer having a carboxyl group and / or a reaction product of a butadiene / acrylonitrile copolymer having a carboxyl group and an epoxy resin. By using the mold release recovery resin composition that contains the mold, the mold release can be restored by a small number of moldings, and the semiconductor can be encapsulated immediately after the mold release is restored. It is possible to obtain a remarkable effect that the mold release is not caused on the surface of the semiconductor device during molding, and a good releasability can be maintained for a long time.
Hereinafter, the present invention will be described in detail.

  The (A) epoxy resin used in the present invention is not particularly limited. For example, a phenol novolac epoxy resin, a cresol novolac epoxy resin, a biphenyl epoxy resin, a bisphenol epoxy resin, a stilbene epoxy resin, Triphenolmethane type epoxy resin, phenol aralkyl type epoxy resin, naphthalene type epoxy resin, alkyl-modified triphenolmethane type epoxy resin, triazine nucleus-containing epoxy resin, dicyclopentadiene modified phenol type epoxy resin, etc. May be used alone or in combination of two or more.

The (B) phenol resin-based curing agent used in the present invention is not particularly limited. Examples thereof include a cyclopentadiene-modified phenol resin, a phenol aralkyl resin having a phenylene and / or a diphenylene skeleton, and these may be used alone or in combination of two or more.
The blending ratio of the epoxy resin and the phenol resin is not particularly limited, but the ratio of epoxy group / phenolic hydroxyl group is preferably 0.7 or more and 1.5 or less, more preferably 0.9 or more, 1 .2 or less, more preferably 0.95 or more and 1.15 or less. If it deviates significantly from this range, the mold release recovery resin composition will not be sufficiently cured, and workability such as deterioration of mold release may be deteriorated.

  The (C) curing accelerator used in the present invention refers to a catalyst that can be a catalyst for a crosslinking reaction between the (A) epoxy resin and the (B) phenol resin curing agent. For example, tributylamine, 1,8 -Amine compounds such as diazabicyclo (5,4,0) undecene-7, organic phosphorus compounds such as triphenylphosphine and tetraphenylphosphonium / tetraphenylborate salts, and imidazole compounds such as 2-methylimidazole. However, it is not limited to these. Moreover, these hardening accelerators may be used individually by 1 type, or may use 2 or more types together.

  As the (D) inorganic filler used in the present invention, those generally used for epoxy resin compositions for semiconductor encapsulation can be used. Examples thereof include fused spherical silica, fused crushed silica, crystalline silica, talc, alumina, titanium white, silicon nitride and the like. These inorganic fillers may be used alone or in combination of two or more. These may be surface-treated with a coupling agent.

The present invention includes (E) a butadiene-acrylonitrile copolymer (e1) having a carboxyl group and / or a reaction product (e2) of an epoxy resin with a butadiene-acrylonitrile copolymer (e1) having a carboxyl group. And it is essential that the compounding amount as said (e1) component is 0.1 to 10 weight% in all the epoxy resin compositions. The carboxyl group-containing butadiene-acrylonitrile copolymer (e1) is a copolymer of butadiene and acrylonitrile, and a reaction product (e2) of (e1) and (e1) with an epoxy resin is blended in the resin composition. Then, the feature of improving the releasability can also be obtained. Since this carboxyl group has polarity, the dispersibility of the butadiene / acrylonitrile copolymer in the epoxy resin contained as a raw material for the epoxy resin composition for sealing is improved, and the mold surface oozes uniformly. , Continuous formability can be improved.
The butadiene-acrylonitrile copolymer (e1) having a carboxyl group is not particularly limited, but a compound having a carboxyl group at both ends of the structure is preferable, and a compound represented by the general formula (1) is more preferable. preferable.

（ただし、上記一般式（１）において、ｘは１未満の正数。ｙは１未満の正数。ｘ＋ｙ＝１。ｚは５０〜８０の整数。）

(However, in the above general formula (1), x is a positive number less than 1. y is a positive number less than 1. x + y = 1. Z is an integer of 50 to 80.)

  In general formula (1), x is a positive number less than 1, y is a positive number less than 1, x + y = 1, and z is an integer of 50 to 80. In addition, the resin composition of the present invention was prepared by melting and reacting in advance with the epoxy resin and a curing accelerator, as the component (E), all or part of the butadiene-acrylonitrile copolymer (e1) having a carboxyl group. The reaction product (e2) can also be used. The term “epoxy resin” as used herein refers to monomers, oligomers, and polymers in general having two or more epoxy groups in one molecule, and the molecular weight and molecular structure thereof are not particularly limited. The same can be used. In addition, the curing accelerator referred to here may be anything that promotes the curing reaction between the carboxyl group in the butadiene / acrylonitrile copolymer and the epoxy group in the epoxy resin. (C) The same thing as the hardening accelerator which accelerates | stimulates hardening reaction can be used. The blending amount as the component (e1) used in the present invention is essential to be 0.1% by weight or more and 10% by weight or less in the total epoxy resin composition. When the blending amount as the component (e1) is within the above range, the mold release agent can sufficiently migrate to the mold surface, and good mold mold release recoverability can be obtained. Further, when the blending amount as the component (e1) is within the above range, the mold release agent does not exude excessively on the mold surface, and there is a possibility that oil floating may occur in the semiconductor device molded immediately after the mold release is recovered. Absent.

  The acrylonitrile content y in the butadiene-acrylonitrile copolymer (e1) having a carboxyl group used in the present invention is preferably 0.05 or more and 0.30 or less, more preferably 0.10 or more and 0.25 or less. is there. The acrylonitrile content y affects the compatibility with the epoxy resin matrix. If the acrylonitrile content is within the above range, the carboxyl group-terminated butadiene / acrylonitrile copolymer (e1) and the epoxy resin matrix are appropriately compatible with each other to achieve dispersibility. Since it becomes favorable, a mold release effect can be imparted to the mold by causing the mold release agent to ooze out uniformly on the mold surface without causing poor filling due to a decrease in fluidity. This makes it possible to maintain a good mold release property for a long time without causing oil floating or dirt on the package surface in the semiconductor sealing molding immediately after the mold release property is recovered.

  The number average molecular weight of the butadiene-acrylonitrile copolymer (e1) having a carboxyl group used in the present invention is preferably 2000 or more and 5000 or less, more preferably 3000 or more and 4000 or less. By making it in the above range, filling failure at the time of molding due to lowering of fluidity does not occur, and a mold release effect can be uniformly imparted to the mold.

  The carboxyl group equivalent of the butadiene-acrylonitrile copolymer (e1) having a carboxyl group used in the present invention is preferably 1200 g / eq or more and 3000 g / eq or less, more preferably 1700 g / eq or more and 2500 g / eq or less. . By making it within the above range, the molded product is less likely to be soiled without lowering the fluidity and releasability at the time of molding the resin composition, and the effect that the continuous moldability is particularly good is obtained.

  In the mold release recovery resin composition for semiconductor encapsulation of the present invention, in addition to the components (A) to (E), if necessary, a mold release agent such as carnauba wax, stearic acid, montanic acid wax, Low stress components such as organopolysiloxane, silane coupling agents such as epoxy silane, mercapto silane, amino silane, alkyl silane, ureido silane, vinyl silane, titanate coupling agent, aluminum coupling agent, aluminum / zirconium coupling agent, etc. Coupling agents, phosphorus antioxidants, nitrogen atom-containing antioxidants, sulfur atom-containing antioxidants, antioxidants such as phenolic antioxidants including hindered phenols, and colorants such as carbon black These additives may be used as appropriate.

  The mold release recovery resin composition for semiconductor encapsulation of the present invention is obtained by mixing the raw materials sufficiently uniformly using a mixer or the like, then melt-kneading with a hot roll or kneader, etc., cooling and pulverizing. .

Examples of the present invention are shown below, but the present invention is not limited thereto. The blending ratio is parts by weight.
Example 1
Orthocresol novolac type epoxy resin (softening point 65 ° C., epoxy equivalent 209)
20.2 parts by weight Phenol novolac resin (softening point 90 ° C., hydroxyl group equivalent 104) 10.0 parts by weight 1,8-diazabicyclo (5,4,0) undecene-7 (hereinafter referred to as DBU)
0.2 parts by weight Fused spherical silica (average particle size 21 μm) 67.0 parts by weight

Butadiene / acrylonitrile copolymer 1 of the following formula (1) (manufactured by Ube Industries, HYCAR CTBN 1008-SP, in formula (1), x = 0.82, y = 0.18, and the average value of z is 62 , Number average molecular weight 3550, carboxyl group equivalent 2200 g / eq)
2.0 parts by weight

Carnauba wax 0.3 parts by weight Carbon black 0.3 parts by weight After kneading each component using a mixer, the kneading was obtained by kneading 20 times using a biaxial roll having surface temperatures of 95 ° C and 25 ° C. The pulverized material of 4 mesh or less, which was pulverized after cooling the product sheet, was tableted. The characteristics of the obtained resin composition were evaluated by the following methods. The evaluation results are shown in Table 1.

Evaluation Method Mold Release Recovery: Using a melamine resin-based cleaning material (EMEC3, manufactured by Sumitomo Bakelite Co., Ltd.) for cleaning the mold surface, the molded product was molded three times with a mold for load release evaluation. After removing the mold release agent component on the surface of the mold, the mold release recovery resin composition was molded three times, and the mold temperature was 175 ° C., the injection pressure was 6.9 MPa, and the curing time was 2 minutes. The material for evaluation was transfer molded, and the release load at the time of product extraction was measured. The unit is MPa. The judgment criteria were 30 MPa or higher as rejected and 30 MPa or lower as acceptable. The mold for load release evaluation consists of an upper mold, a middle mold, and a lower mold, and a push-pull gauge from the upper hole of the middle mold into a circular molded product with a diameter of 14 mm and a thickness of 1.5 mm attached to the middle mold after molding And the load applied when the molded product was protruded was measured. As an evaluation material, Sumitomo Bakelite Co., Ltd., epoxy resin molding material EME-7351 for semiconductor encapsulation was used.

  Mold release sustainability: Using a melamine resin-based cleaning material (EMEC3, manufactured by Sumitomo Bakelite Co., Ltd.) for cleaning the mold surface, the molded product was molded three times with a mold for load release evaluation, After removing the mold release agent component on the mold surface, the mold release recovery resin composition was molded three times, and then the evaluation material was obtained at a mold temperature of 175 ° C., an injection pressure of 6.9 MPa, and a curing time of 2 minutes. Transfer molding was performed, and the mold release load at the time of product extraction was measured. The mold release load was molded using a mold for load evaluation at the time of mold release consisting of an upper mold, a middle mold, and a lower mold, and after molding, a circular molded product having a diameter of 14.5 mm and a thickness of 1.5 mm was attached. A push bull gauge was applied from the upper hole of the middle mold, and the load applied when the molded product was projected. Subsequently, 200 shots of the evaluation material were molded, and the change in the release load for each shot was measured. At this time, the number of shots when the load was 80 MPa or more was described in the results. 200 <means 200 shots or more, and expresses that the load is 80 MPa or less even after 200 shots. The judgment criteria were less than 150 shots as unacceptable and 150 shots or more as acceptable.

  Molded product appearance: Immediately after the use of the mold release recovery resin composition, oil floating and dirt on the molded product surface of the molded evaluation material were visually confirmed. The case where oil float or dirt occurred on the product surface was expressed as x, and the case where there was no oil float or dirt was expressed as ○.

Examples 2-7, Comparative Examples 1-2
It compounded according to Table 1, the epoxy resin composition was obtained like Example 1, and it evaluated similarly to Example 1. FIG. The results are shown in Table 1.
Components used in Examples other than Example 1 are shown below.
Biphenyl type epoxy resin: manufactured by Japan Epoxy Resin Co., Ltd., YX-4000, melting point 105 ° C., epoxy equivalent 195
Phenol aralkyl resin: manufactured by Mitsui Chemicals, XL-225, softening point 79 ° C., hydroxyl group equivalent 174

Butadiene / acrylonitrile copolymer 2 of the following formula (1): Ube Industries, Ltd., HYCAR CTBN 1008 × 13, in formula (1), x = 0.74, y = 0.26, and the average value of z is 54 , Number average molecular weight 3150, carboxyl group equivalent 2000 g / eq

Molten reaction product A: bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin, YL-6810, epoxy equivalent 170 g / eq, melting point 47 ° C.) 66.6 parts by weight was heated and melted at 140 ° C. to obtain a butadiene / acrylonitrile copolymer 1 (Ube Industries, Ltd., HYCAR CTBN 1008-SP, x = 0.82, y = 0.18, z average value is 62, number average molecular weight 3550, carboxyl group equivalent 2200 g / eq) 33.3 weight And 0.1 part by weight of triphenylphosphine were added and melt mixed for 30 minutes to obtain a molten reactant A.
Montanic acid wax

Examples 1 to 7 are (E) a reaction product (e2) of a butadiene-acrylonitrile copolymer (e1) having a carboxyl group and / or a butadiene-acrylonitrile copolymer (e1) having a carboxyl group and an epoxy resin. A mold release recovery resin composition for semiconductor encapsulation, wherein the blending ratio as the component (e1) is 0.1% by weight, 2.0% by weight, 10.0% by weight with respect to the total resin composition In addition, the type of component (E), the type of combination of (A) epoxy resin and (B) phenolic resin curing agent, and (D) the blending ratio of inorganic filler, etc. are included. In all cases, good mold release recovery, mold release sustainability, and appearance of the molded product were obtained.
On the other hand, in Comparative Example 1 in which the component (E) was not used, the molded product surface of the evaluation material molded immediately after use of the mold release recovery resin composition had no oil floating or dirt, but the mold release The recovery effect was insufficient, and the release property of the evaluation material could only be sustained up to about 20 shots. Further, in Comparative Example 2 in which the component (E) was used in excess, an evaluation material molded immediately after use of the mold release recovery resin composition, although a good release recovery effect and release sustaining effect were obtained. Oil float and dirt were generated on the surface of the molded product, and the appearance of the molded product was x.
As described above, the resin compositions of Examples 1 to 7 in which the component (E) is blended at a specific ratio can recover the releasability by molding a small number of times, and the semiconductor encapsulation immediately after the releasability is recovered. It has been found that oil releasing and dirt are not generated on the surface of the semiconductor device in the stop molding, and a better release property can be maintained for a long time.

  The mold release recovery resin composition for semiconductor encapsulation of the present invention can recover the mold release property by molding a few times, and oil is applied to the surface of the semiconductor device in the semiconductor seal molding immediately after the mold release recovery. It is industrially useful because it contributes to the improvement of productivity in the manufacture of semiconductor devices, because it can maintain a good release property for a long time without causing floating and dirt.

Claims (3)

(A) epoxy resin, (B) phenol resin curing agent, (C) curing accelerator, (D) inorganic filler, (E) butadiene-acrylonitrile copolymer (e1) and / or carboxyl group having a carboxyl group And a reaction product (e2) of an epoxy resin with a butadiene-acrylonitrile copolymer (e1) having a content of 0.1% by weight or more in the total epoxy resin composition. A mold release recovery resin composition for semiconductor encapsulation, characterized by being no more than wt%. A mold release recovery resin composition for semiconductor encapsulation, wherein the butadiene-acrylonitrile copolymer (e1) having a carboxyl group is a compound represented by the following formula (1).

(However, in the above general formula (1), x is a positive number less than 1. y is a positive number less than 1. x + y = 1. Z is an integer of 50 to 80.) In the manufacturing method of the resin sealing type semiconductor device which shape-seals a semiconductor element using the resin composition for semiconductor sealing, the mold release recovery resin composition for semiconductor sealing of Claim 1 or Claim 2 is provided. A method for manufacturing a resin-encapsulated semiconductor device, wherein the mold release property of the molding die is recovered.