JP2002161190A - Method of manufacturing resin composition for recovering mold releasability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide method of manufacturing a resin composition excellent in recovering mold releasability of a metal mold for sealing a semiconductor. SOLUTION: The resin composition essentially consists of (A) an epoxy resin, (B) a phenol resin, (C) an accelerator (D1) urethanes of a microcrystallin oxide wax and a polyethylene oxide wax, (E) an antioxidant and (F) an inorganic filler, they are respectively heated, kneaded and cooled to be 4 mesh or less grinded particles. The resin composition is obtained by adding (D2) urethanes of a microcrystallin oxide wax and a polyethylene oxide wax to the grinded particles and mixing; [(D1)+(D2)]=0.1-2 wt.%, [(D2)]/[(D1)+(D2)]>=25 wt.%, the particle size of (D2) is 16 mesh or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a mold release recovery resin composition for encapsulating a semiconductor.

[0002]

2. Description of the Related Art In recent market trends of miniaturization, weight reduction, and high performance of electronic devices, as semiconductor devices become more highly integrated year by year and surface mounting of semiconductor devices is promoted,
Demands for epoxy resin compositions for semiconductor encapsulation are becoming increasingly stringent. Epoxy resin compositions for semiconductor encapsulation using various resins and additives that meet this requirement are subject to mold contamination during continuous molding, mold removal, and molding defects such as unfilling. Therefore, it has become common to periodically clean the mold surface.

Conventionally, a cleaning material for a semiconductor encapsulating mold is made of a resin having a large molding shrinkage such as an amino resin and a filler having a high hardness such as crystal-crushed silica and glass fiber. It was mainly used to remove dirt on the mold surface by using. After using the cleaning material, the mold surface becomes clean, but since the mold release agent on the mold surface is also removed, there is a problem that the semiconductor device molded immediately after cleaning has extremely poor releasability. . Therefore, after the use of the cleaning material, it is necessary to use the mold release recovery resin composition to transfer and apply the release agent in the mold release recovery resin composition to the mold surface to restore the mold releasability. is there.

The function of the mold release recovery resin composition is to transfer and apply the release agent to the surface of the mold to quickly recover the release property. When you put it,
After that, there is a problem that oil is floated or stained on the surface of the molded semiconductor device, and when the release agent cannot be sufficiently transferred, the releasability cannot be recovered, and it is necessary to use a large amount of the release recovery resin composition. The problem occurs. Further, if the releasability after release recovery cannot be maintained for a long time, it is necessary to frequently use the release recovery resin composition, and the productivity is reduced.
In order to improve productivity and the like, a mold release recovery resin composition for semiconductor encapsulation that is more excellent in mold release recovery is demanded.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a mold release-recovery resin composition obtained by a specific manufacturing method. An object of the present invention is to provide a method for producing a mold-releasing resin composition for semiconductor encapsulation, which can maintain a long releasability without causing oil floating or contamination on the surface of a semiconductor device immediately after recovery.

[0006]

The present invention provides (A) an epoxy resin, (B) a phenolic resin, (C) a curing accelerator,
(D1) urethane compounds of oxidized microcrystalline wax and polyethylene oxide and / or oxidized microcrystalline wax and polyethylene oxide;
(E) An antioxidant and (F) an inorganic filler are essential components, and the above components are heated, kneaded and cooled to obtain a crushed product of 4 mesh or less, and the crushed product contains (D2) oxidized microcrystalline wax and polyethylene oxide wax. And / or a mold release recovery resin composition obtained by adding and mixing a urethane compound of an oxidized microcrystalline wax and a oxidized polyethylene wax, and the mixing ratio [(D1) + (D
2)] is 0.1 to 2% by weight of the total resin composition, [(D
2)] / [(D1) + (D2)] ≧ 25% by weight and (D
2) A method for producing a mold-recovery resin composition for semiconductor encapsulation, wherein the particle size is 16 mesh or less.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The epoxy resin used in the present invention is not particularly limited. For example, phenol novolak epoxy resin, cresol novolak epoxy resin, biphenyl epoxy resin, bisphenol epoxy resin, stilbene Type epoxy resin,
Triphenol methane type epoxy resin, phenol aralkyl type epoxy resin, naphthalene type epoxy resin, alkyl-modified triphenol methane type epoxy resin, triazine nucleus containing epoxy resin, dicyclopentadiene modified phenol type epoxy resin, etc. You may mix and use.

The phenolic resin used in the present invention is not particularly limited. For example, phenol novolak resin, cresol novolak resin, naphthol aralkyl resin, triphenolmethane resin, terpene-modified phenol resin, dicyclopentadiene-modified phenol Examples thereof include a resin, a phenol aralkyl resin having a phenylene and / or diphenylene skeleton, and these may be used alone or as a mixture. The mixing ratio of the epoxy resin and the phenol resin is not particularly limited, but the epoxy group / fernol hydroxyl group ratio is as follows:
0.9-1.2 is preferable, and 0.95-1.2 is more preferable.
1.15 is desirable. If the amount deviates greatly from this range, the resin composition may not be sufficiently cured, and the workability may deteriorate such as a decrease in releasability.

[0009] The curing accelerator used in the present invention includes:
Refers to those that can be a catalyst for the crosslinking reaction between the epoxy resin and the phenol resin, for example,
1,8-diazabicyclo (5,4,0) undecene-7
And the like, an organic phosphorus-based compound such as triphenylphosphine, tetraphenylphosphonium / tetraphenylborate salt, and an imidazole compound such as 2-methylimidazole, but are not limited thereto. These curing accelerators may be used alone or as a mixture.

The oxidized microcrystalline wax used in the present invention is obtained by oxidizing a microcrystalline wax containing n-paraffin and branched hydrocarbon obtained from a heavy oil fraction, and contains a carboxyl group or a hydroxyl group. Generally, a microcrystalline wax containing n-paraffin and a branched hydrocarbon has poor compatibility with a resin component, increases the viscosity of a resin composition, and excessively exudes to the surface of a mold during molding. Although excellent in the release recovery effect, there is a drawback in that the semiconductor device formed immediately after the recovery from the release property has oil floating and dirt. Therefore, when the oxidized microcrystalline wax is used, it is possible to prevent oil floating and dirt on the product due to appropriate compatibility with the resin component, to further impart fluidity, and to achieve excellent mold release recovery.

The oxidized polyethylene wax is obtained by oxidizing a polyethylene wax obtained as an ethylene polymerization method or a thermal decomposition product of polyethylene, and contains a carboxyl group or a hydroxyl group. Molecular weight 1000-1000
A value of about 0 is generally used. Although the molecular weight is not particularly limited, it is preferable to use one having a low molecular weight in order to lower the viscosity of the release recovery resin composition. In general, polyethylene wax has a high melting point, poor compatibility with resin components, excessive oozing on the mold surface during molding, and contamination of the molded semiconductor device immediately after recovery from mold release. There is. Thus, the use of oxidized polyethylene wax makes it possible to prevent contamination due to appropriate compatibility with the resin component.

In the present invention, urethane compounds of the above-mentioned oxidized microcrystalline wax and oxidized polyethylene wax can be used. These are intended to prevent oil floating and contamination on the molded semiconductor device immediately after the release property is recovered, to reduce the viscosity, and to exhibit a release recovery effect. The method of urethanization is not particularly limited, but is performed by, for example, reacting isocyanates such as methylene diisocyanate and toluene diisocyanate with hydroxyl groups or carboxyl groups of oxidized microcrystalline wax and oxidized polyethylene wax. In the present invention, a urethane compound of oxidized microcrystalline wax and a urethane compound of polyethylene oxide wax may be used, or a urethane compound obtained by previously mixing an oxidized microcrystalline wax and a polyethylene oxide wax may be used as a release agent. You may. The ratio of urethanization is not particularly limited, but a content of 0.3 to 5% by weight of nitrogen in the obtained wax is desirable. If there are too many urethane parts, the viscosity of the wax itself will increase and it will be difficult to materialize.

The compounding amount of the oxidized microcrystalline wax and the polyethylene oxide and / or the urethane compound of the oxidized microcrystalline wax and the polyethylene oxide used in the present invention is not particularly limited, but is not limited to 0.1 in the total resin composition. The content is preferably 1 to 2% by weight, more preferably 0.5 to 1.5% by weight. 2
If the amount is more than 10% by weight, there is a problem that the semiconductor device is excessively soaked in the metal mold and oil is floated on the semiconductor device immediately after the recovery from the mold release. If the content is less than 0.1% by weight, the release agent does not sufficiently migrate to the surface of the mold, and the expected mold release recovery may not be obtained. In the method for producing a mold release resin composition for semiconductor encapsulation of the present invention, the compounding amount of the wax (D1) added in the first half of the production process and the wax (D2) added in the second half of the production process [(D1) + (D2)] is 0.1 to 2% by weight in the whole resin composition, and its compounding ratio [(D2)]
/ [(D1) + (D2)] ≧ 25% by weight, and (D
The particle size of 2) is 16 mesh or less.

If the particles are too small, part of the wax melted by the heat during molding will be compatible with the resin component,
Exudation to the surface of the mold is reduced, and a sufficient effect of restoring releasability is not obtained, so that the amount of the release-restoring resin composition to be added increases and productivity decreases. If the particles are too large, the excessively exuded wax is gradually oxidized by the heat from the mold, and the releasability is lowered, and it is difficult to maintain the releasability for a long time, which is not preferable. When [(D2)] / [(D1) + (D2)] is less than 25% by weight, the releasability of the release-recovery resin composition itself is sufficient, but the amount of wax that can be transferred to the mold surface and applied is small. And a sufficient demolding recovery effect cannot be obtained.

The antioxidant used in the present invention has the function of suppressing the oxidation of the wax that has exuded onto the mold surface and is intended to maintain the releasability for a long time. The amount is not particularly limited, but may be 0.1 to 0.1 in the entire resin composition.
5% by weight is desirable. If the amount is less than 0.1% by weight, the effect is insufficient. If the amount exceeds 0.5% by weight, there is a problem that the antioxidant bleeds out and stains of a molded article occur.
The antioxidant used here is, for example, a BHT derivative such as 2,6-di-tert-butyl-p-cresol,
Examples thereof include quinone derivatives such as benzoquinone, sulfur-based antioxidants such as dilaurylthiopropionate, catechol, vitamin C and vitamin E. Examples of the inorganic filler used in the present invention include fused spherical silica and crystal-crushed silica.

The mold release recovery resin composition of the present invention includes:
In addition to the components (A) to (F), a release agent such as carnauba wax, stearic acid, or montanic acid wax, or an additive such as a coupling agent or a coloring agent such as carbon black may be used as necessary. . The mold release recovery resin composition of the present invention comprises (A) an epoxy resin, (B) a phenol resin,
(C) a curing accelerator, (D1) a urethane compound of oxidized microcrystalline wax and polyethylene oxide and / or oxidized microcrystalline wax and polyethylene oxide, (E) an antioxidant, and (F) an inorganic filler as a mixer or the like. And then kneading by heating using a heating kneader, a hot roll, an extruder, etc., followed by cooling and pulverization to obtain a pulverized product of 4 mesh or less.
2) It is obtained by adding and mixing oxidized microcrystalline wax and polyethylene oxide having a particle size of 16 mesh or less and / or urethane compound of oxidized microcrystalline wax and polyethylene oxide, and then forming a tablet. When mixing a pulverized product of 4 mesh or less and (D2) of 16 mesh or less, a mixing method that generates heat is used,
(D2) is melted and becomes compatible with the resin, and as a release-releasing resin composition, the wax cannot sufficiently migrate to the mold surface during use and cannot be applied, so that a sufficient release-recovery effect cannot be exhibited. It is not preferable.

[0017]

The present invention will be specifically described below with reference to examples.
The mixing ratio is by weight. Example 1 Composition 1 Orthocresol novolak type epoxy resin 21.4 parts by weight Phenol novolak resin 10.1 parts by weight 1,8-diazabicyclo (5,4,0) undecene-7 (hereinafter referred to as DBU) 0.2 Parts by weight Spherical fused silica 66.6 parts by weight Oxidized microcrystalline wax (melting point 92 ° C) 0.2 parts by weight Oxidized polyethylene wax (melting point 96 ° C) 0.2 parts by weight Carnauba wax 0.3 parts by weight 2,6-ditertiary After mixing each component with 0.1 part by weight of butyl-p-cresol and 0.3 part by weight of carbon black using a mixer, the surface temperature was 9%.
A kneaded material sheet obtained by kneading 20 times using a biaxial roll at 5 ° C. and 25 ° C. was cooled and pulverized. 0.6 part by weight of a urethane compound of oxidized microcrystalline wax was mixed and tabletted. The properties of the obtained resin composition were evaluated by the following methods. Table 1 shows the evaluation results.

Evaluation method Spiral flow: Using a mold for measuring spiral flow according to EMMI-1-66, a mold temperature of 175 ° C.
The measurement was performed at an injection pressure of 70 kg / cm ² and a curing time of 2 minutes.
The unit is cm. Mold release property: A molded product was molded with a mold for load evaluation at the time of mold release using a melamine resin-based cleaning material for cleaning the mold surface, and the mold release agent component on the surface of the mold was removed. Then, after the mold release recovery resin composition was molded three times, the evaluation material was transfer molded at a mold temperature of 175 ° C., an injection pressure of 70 kg / cm ² , and a curing time of 2 minutes, and the mold release load at the time of product withdrawal Was measured. The mold for load evaluation at the time of mold release consists of an upper mold, a middle mold and a lower mold. A 14 mmΦ 1.5 mm thick circular molded product adhered to the middle mold after molding, and a push bull gauge is inserted through the upper hole of the middle mold. Then, the load applied when the molded product was pushed out was measured. As an evaluation material, an epoxy molding material EME-7351 for semiconductor encapsulation manufactured by Sumitomo Bakelite Co., Ltd. was used. Mold release durability: Molded products are molded with a mold for load evaluation at mold release,
After removing the release agent component from the surface of the mold, the mold release recovery resin composition was molded three times, and then the mold temperature was 175 ° C.
The material for evaluation was transfer-molded at an injection pressure of 70 kg / cm ² and a curing time of 2 minutes, and the release load at the time of extracting the product was measured. The mold release load is formed 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 is formed into a circular molded article having a thickness of 14.5 mmΦ and a thickness of 1.5 mm attached to the middle mold after molding. A push bull gauge was applied from the upper hole of the middle mold to determine the load applied when the molded product was protruded. Subsequently, 200 shots of the evaluation material were formed, and the change in the release load for each shot was measured. At this time, 3
Expressed as the number of shots in which the release load increased by 0% or more. 2
00 <expresses that the release load is 30% or less of the initial release load in 200 shots or more. Product stain: Oil floating and stain condition on the molded product surface of the evaluation material molded immediately after the use of the mold release recovery resin composition were confirmed. Those that could be wiped off when the surface was wiped were judged to be oily, and those that could not be removed were judged to be dirty. When the surface of the product was stained, x was shown, when there was no stain, but oil was floating, and when none was found, it was expressed as o.

Examples 2 to 5, Comparative Examples 1 to 5 According to the formulations shown in Tables 1 and 2, the same compositions as in Example 1 were obtained. The biphenyl type epoxy resins used in Examples 4 and 5 and Comparative Examples 4 and 5 have a melting point of 105 ° C. and an epoxy equivalent of 195. The phenol aralkyl resins used in Examples 4 and 5 and Comparative Examples 4 and 5 have a softening point of 72 ° C. and a hydroxyl equivalent of 165. Wax 1 of Examples 2 and 5 was a mixture of oxidized microcrystalline wax and polyethylene oxide modified with toluene diisocyanate (melting point 89, acid value 1)
6, saponification value 60) The wax 2 of Example 3 is a toluene diisocyanate-modified product of a mixture of oxidized microcrystalline wax and polyethylene oxide (melting point 82, oxidized 18, saponification value 50). Mp 90 ° C. The melting points of the polyethylene waxes of Comparative Examples 1 and 2 were 92 ° C. The melting point of the oxidized polyethylene wax of Comparative Example 3 is 96 ° C.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

After using the mold release recovery resin composition for semiconductor encapsulation obtained by the manufacturing method of the present invention, the molded semiconductor device is free from oil floating and dirt, and has good mold release recovery. It is excellent and can maintain the releasability for a long time, contributing to an improvement in productivity.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08K 5/00 C08K 5/00 C08L 91/06 C08L 91/06 H01L 23/29 B29K 61:04 23/31 63:00 // B29K 61:04 105: 16 63:00 H01L 23/30 R 105: 16 F term (reference) 4F070 AA44 AA46 AA53 AA63 AC23 AC37 AC43 AC50 AC55 AC94 AE01 AE03 AE17 DA41 FA11 FA17 FB07 FB09 4F202 AA37 AA39 AB03 AB06 AB16 AH37 CA11 CB01 CM41 CM45 CM62 CM82 CM90 4J002 AE033 AE034 AE035 CC03X CC04X CC05X CD02W CD04W CD05W CD06W CD13W CE00X CK024 CK025 DJ018 EE056 EH076 EJ016 EJ026 EN027 EU007 AC117 FD017 FD017 EF017 FD017 EF017 FD017 FD017 FD017 DC05 DC41 DC46 DD07 DD09 FA05 FA10 FA12 FB02 FB07 FB18 JA07 KA06 4M109 AA01 CA21 EA02 EB03 EB04 EB06 EB08 EB09 EB13 EB18 EC20

Claims (1)

[Claims] (A) an epoxy resin, (B) a phenolic resin, (C) a curing accelerator, (D1) a urethane compound of oxidized microcrystalline wax and polyethylene oxide and / or oxidized microcrystalline wax and polyethylene oxide wax, (E) an antioxidant, and (F)
An inorganic filler is an essential component, and the above components are heated, kneaded and cooled to form a pulverized product of 4 mesh or less.
A mold release recovery resin composition obtained by adding and mixing an oxidized microcrystalline wax and a polyethylene oxide wax and / or a urethane compound of an oxidized microcrystalline wax and a polyethylene oxide wax, wherein the compounding ratio [(D1) + ( D2)] in all the resin compositions.
1-2% by weight, [(D2)] / [(D1) + (D2)]
≧ 25% by weight, and the particle size of (D2) is 16 mesh or less.