JPH09111012A - Production of composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composite material having high insulation resistance and excellent soldering heat-resistance after moisture-absorption treatment by dispersing inorganic particles having an average particle diameter of <=1,000nm in a reinforcing material, impregnating a varnish containing an addition-type polyimide resin into the material, drying the product and forming the obtained prepreg. SOLUTION: A reinforcing material containing 1-30 pts.wt. (based on 100 pts.wt. of the reinforcing material) of inorganic particles having an average particle diameter of <=1,000nm is surface-treated, before impregnating a varnish, with a surface-treating agent containing an N-phenyl-γ-aminopropylsilane coupling agent expressed by the formula C6 H5 -NH-C3 H6 SiX3 (X is OCH3 , OC2 H5 , OC3 H7 or Cl).

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 composite material produced by impregnating a reinforcing material with a varnish containing an addition type polyimide resin and then drying the resulting prepreg.

[0002]

2. Description of the Related Art As a recent trend of materials used for electronic devices, there is an attempt to realize high speed and high density as well as miniaturization and weight reduction. Leadless chip carrier (LCC) is one of the means to achieve the purpose.
Surface mounting technology (SMT) of the. For example, when the LCC of alumina is directly mounted on the printed circuit board, if the thermal expansion coefficients of the alumina and the printed circuit board are different,
Cracks occur in the solder at the joint due to thermal history. Therefore, in the case of direct mounting, the thermal expansion coefficient of the printed circuit board should be the same as that of the LCC (7 ppm for alumina).
/ ° C) is desirable. further,
There have also been attempts to directly mount bare silicon chips in leadless fashion. For that purpose, the thermal expansion coefficient of the printed circuit board must be the same as that of silicon (3-4 ppm /
(° C) is desirable.

As a means for reducing the coefficient of thermal expansion of a printed circuit board, the inventors of the present invention have filed Japanese Patent Application No. 6-108.
No. 816 is a composite material in which a resin is reinforced by a reinforcing material composed of strands formed by bundling monofilaments, and the strands have an average particle diameter of 1000 nm.
A low thermal expansion composite material containing the following inorganic particles in a proportion of 1 part by weight or more based on 100 parts by weight of the reinforcing material is proposed. However, in this composite material, it was found that swelling may occur when a solder test is performed after moisture absorption treatment such as PCT treatment. One of the reasons for this is considered to be that the inclusion of the inorganic particles in the strands creates a gap in the strands where the resin is less likely to enter, resulting in pores (small cavities). Therefore, the present inventors have found that by improving the impregnation method and the molding method, it is possible to produce a composite material having no pores and excellent solder heat resistance after moisture absorption treatment, and Japanese Patent Application No. 7-151850 and Wishhei 7-1518
No. 69 proposes a new manufacturing method. But,
Further investigation, even if such an impregnation method or a molding method is improved, depending on the method of surface treatment of the reinforcing material containing inorganic particles, insulation resistance after moisture absorption treatment of the obtained composite material or after moisture absorption treatment It has become clear that there may be a problem in solder heat resistance.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a reinforcing material composed of strands formed by bundling monofilaments with an average particle diameter of 1000 nm. After containing the following inorganic particles, the reinforcing material is impregnated with an addition-type polyimide resin-containing varnish, and then a method for manufacturing a composite material which is manufactured by molding a prepreg obtained by drying, after a moisture absorption treatment. It is intended to provide a method capable of obtaining a composite material having excellent insulation resistance and solder heat resistance after moisture absorption treatment.

[0005]

According to a first aspect of the present invention, there is provided a method for producing a composite material, wherein a reinforcing material composed of strands formed by bundling monofilaments has an average particle diameter of 1000 nm.
1 to 100 parts by weight of the following inorganic particles
30 parts by weight, then the reinforcing material containing the inorganic particles is impregnated with a varnish containing an addition type polyimide resin, dried to obtain a prepreg, and then the prepreg is molded to produce a composite material. In the method, the reinforcing material containing the inorganic particles before being impregnated with the varnish is surface-treated using a surface-treating agent containing an N-phenyl-γ-aminopropylsilane coupling agent represented by the following formula. Is characterized by.

C ₆ H ₅ --NH--C ₃ H ₆ SiX ₃ ---- (X represents OCH ₃ , OC ₂ H ₅ , OC ₃ H ₇ or Cl.) A composite material according to claim 2 The manufacturing method is the manufacturing method according to claim 1, wherein the surface treatment of the reinforcing material containing inorganic particles is performed such that the amount of the surface treatment agent adhered to the reinforcing material is 100 parts by weight of the reinforcing material containing inorganic particles after the surface treatment. In contrast,
It is characterized in that it is applied in an amount of 0.05 to 1.0 part by weight.

According to a third aspect of the present invention, in the method for producing a composite material according to the first or second aspect, the reinforcing material is glass cloth, and the material of the inorganic particles having an average particle diameter of 1000 nm or less is silica. Is characterized in that.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As the reinforcing material in the present invention,
The thing which consists of the strand which a monofilament bundled is used. The monofilament preferably has low thermal expansion, but is not particularly limited. The material of the monofilament is not particularly limited, but is preferably one or more kinds of glass (for example, E glass, D glass, Q glass, S glass, T glass, etc.) and aramid resin. Regarding the length of the strand, long fibers or short fibers may be used. From the viewpoint of low thermal expansion, the form of the reinforcing material is preferably such that the resin content is as small as possible. The reinforcing material in such a form is not particularly limited, but examples thereof include mats, sheets, cloths (for example, plain weave, satin weave, and the like), and fiber moldings such as composites thereof. . Of the above-mentioned reinforcing materials, glass cloth is particularly preferable. The reason is that since the cross shape is dense, the resin content can be reduced and the filament continuity is high, which is effective in reducing the thermal expansion of the composite material. Further, glass is preferable because it is inexpensive and
This is because long fibers can be stably obtained.

The inorganic particles having an average particle size of 1000 nm or less contained in the reinforcing material are themselves materials having low thermal expansion. The coefficient of thermal expansion is not particularly limited, but is 10
It is preferably ppm / ° C. or less. If the coefficient of thermal expansion of the inorganic particles is larger than 10 ppm / ° C, the coefficient of thermal expansion of the composite material will be alumina (7 ppm / ° C) or silicon (3 to 4).
(ppm / ° C.) is too large. The amount of the inorganic particles having an average particle size of 1000 nm or less is 1 to 3 parts by weight with respect to 100 parts by weight of the reinforcing material before the inorganic particles are contained.
It is important to be in the range of 0 parts by weight. This amount is 1
If the amount is less than 10 parts by weight, a composite material having a small coefficient of thermal expansion cannot be obtained, and if the amount of the inorganic particles exceeds 30 parts by weight with respect to 100 parts by weight of the reinforcing material before the inorganic particles are contained, the composite material is obtained. This is because there arises a problem that the moisture resistance of the material is likely to deteriorate.

The reason for using the inorganic particles having an average particle size of 1000 nm or less is as follows. Since the monofilaments that compose the strands are usually several μm thick, the gap between the monofilaments is on the order of microns. Therefore, in order to easily include the inorganic particles even inside the strands, the average particle size is 1 μm. (= 1000
This is because it is preferably less than or equal to (nm). further,
Inorganic particles having a small average particle diameter are preferable because they are easily monodispersed in a treatment liquid containing water or the like as a medium.

The average particle size of the inorganic particles is 1
More preferred are ~ 100 nm colloidal particles. This is because such an inorganic particle has a smaller particle size, so that it can enter the gap between the narrower strands. However, the smaller the average particle size of the colloidal particles, the better. If it is less than 1 nm, the specific surface area of the colloidal particles becomes very large, which makes it difficult to control the interface with the resin. The lower limit of the average particle size is 1
nm.

The inorganic particles having an average particle diameter of 1000 nm or less are not particularly limited, but submicron-order commercially available particles such as fused silica and fine particle alumina are preferable. The colloidal particles having a smaller particle size are not particularly limited, but sol such as silica sol, alumina sol, titania sol, ultrafine particle silica, and ultrafine particle titania are preferable. Among these colloidal particles, silica is particularly preferable. The reason is that silica is
This is because the coefficient of thermal expansion is low (0.55 ppm / ° C.) among particles that are easily available. In addition to the particles described above, submicron particles and colloidal particles can be obtained by mechanically crushing with a ball mill or the like by using balls having a small diameter. Here, since the material to be crushed is desired to be a low thermal expansion material, silica glass, E glass, glass such as T glass, crystallized glass in which β-spodumene is precipitated, boron nitride, silicon nitride, mullite. , Aluminum nitride, cordierite, aluminum titanate (Al ₂ O ₃ TiO ₂ ), β-eucryptite and the like are preferable.

The strands may contain only inorganic particles having an average particle diameter of 1000 nm or less as a low thermal expansion material. In addition to the inorganic particles, a reaction product of a metal alkoxide also serves as a low thermal expansion material. It is also possible to include it. The metal alkoxide is completely soluble in a solvent such as alcohol. Therefore, the metal alkoxide has the property of being able to easily enter the inside of the strand by impregnating the treatment liquid containing the metal alkoxide into the reinforcing material, similarly to the above-mentioned inorganic particles. Since the reaction product of the metal alkoxide generally forms an inorganic film which is a continuous phase, it is different from the inorganic particles having an average particle size of 1000 nm or less in the present invention. The metal alkoxide is not particularly limited, but silicon alkoxide, titanium alkoxide, aluminum alkoxide, magnesium alkoxide, lithium alkoxide and the like are preferable. The reason is that the reaction product of the metal alkoxide can be easily obtained by using these raw materials. Among these metal alkoxides, silicon alkoxide is more preferable. This is because silicon alkoxide is inexpensive and has high stability among the above metal alkoxides, and the thermal expansion coefficient of silica, which is a reaction product thereof, is low (0.55 ppm / ° C.).

The method of incorporating the inorganic particles having an average particle diameter of 1000 nm or less in the reinforcing material in the present invention is not particularly limited, but for example, the inorganic particles are dispersed in a medium such as water or alcohol to prepare a treatment liquid. Is adjusted, the reinforcing liquid is impregnated with the treatment liquid, and then dried.

In the present invention, the surface-treating agent containing the N-phenyl-γ-aminopropylsilane coupling agent represented by the above formula is used as the reinforcing material containing the inorganic particles before being impregnated with the varnish containing the addition type polyimide resin. Then, the surface is treated. The method is not particularly limited,
A method of impregnating a reinforcing material containing inorganic particles with a solution prepared by dissolving the silane coupling agent in a medium such as water or alcohol and then heat-treating the solution can be mentioned. Then, the surface treatment of the reinforcing material containing the inorganic particles is performed such that the amount of the surface treatment agent attached to the reinforcing material is 0.05 to 1.0 part by weight with respect to 100 parts by weight of the reinforcing material containing the inorganic particles after the surface treatment. It is desirable to apply it so that The reason is that if the amount is less than 0.05 parts by weight, the effect of the surface treatment that makes the insulation resistance after the moisture absorption treatment and the solder heat resistance after the moisture absorption treatment excellent is not remarkable, and
This is because the above-mentioned effect of the surface treatment does not increase even if the amount of adhesion exceeds 1.0 part by weight.

In the present invention, an addition type polyimide resin is used as the resin reinforced with the reinforcing material. Examples of the type include polyamino bismaleimide resin, but there is no particular limitation. Then, in the present invention, a varnish containing an addition type polyimide resin is impregnated into the surface-treated reinforcing material and dried to obtain a prepreg, and then the prepreg is molded to manufacture a composite material. The method, molding conditions, etc. are not particularly limited and may be appropriately determined according to the application. However, the molding is preferably carried out under reduced pressure from the viewpoint that the solder heat resistance after moisture absorption is excellent.

[0017]

EXAMPLES Examples of the present invention and comparative examples will be described below, but the present invention is not limited to the following examples.

(Example 1) E-glass plain weave cloth (manufactured by Asahi Schwebel, product number 216AS450, thickness 100 μ
m, fiber diameter 7 μm, driving density (number of strands / 2
5mm): Length 60 / 25mm, Width 55 / 25mm]
First, a colloidal silica aqueous solution (manufactured by Nissan Chemical Industries,
The product was impregnated with Snowtex OL (trade name), colloidal silica having an average particle diameter of 45 nm, and colloidal silica content of 20% by weight), and then pulled up at a speed of 3 cm / sec. Then 1
Heat treatment was performed at 50 ° C. for 5 minutes. By repeating this coating operation twice, a reinforcing material was obtained in which the adhered amount of colloidal silica was 15 parts by weight with respect to 100 parts by weight of the reinforcing material before containing colloidal silica.

After that, a reinforcing material containing colloidal silica was replaced with N-phenyl-γ-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product number KBM57) which is an N-phenyl-γ-aminopropylsilane coupling agent.
After being immersed in a solution of 3% in concentration of 1% by weight, passed through a squeezing roll, and then heat-treated at 110 ° C. for 5 minutes, the amount of the surface-treating agent adhering to the reinforcing material is reinforced including inorganic particles after the surface treatment. A reinforcing material having 0.43 parts by weight with respect to 100 parts by weight of the material was obtained.

Next, the surface-treated reinforcing material obtained above was impregnated with a varnish containing a polyamino bismaleimide resin, which is an addition-type polyimide resin, and was squeezed with a roll having a gap of 0.2 mm. Then, it was dried at 130 ° C. for 5 minutes to obtain a prepreg. Next, the obtained prepreg is 1
0 sheets stacked, under reduced pressure of 200 Torr, 200 ℃,
A substrate (composite material) was obtained by press molding for 90 minutes under a molding condition of 30 kg / cm ² .

Example 2 Regarding the surface treatment of the reinforcing material containing colloidal silica, the reinforcing material was N-phenyl-γ.
-Immersing in a 2 wt% solution of aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product number KBM573),
After passing through the squeezing rolls, heat treatment was performed at 110 ° C. for 5 minutes so that the amount of the surface treatment agent attached to the reinforcing material was 0.8 with respect to 100 parts by weight of the reinforcing material containing the inorganic particles after the surface treatment.
A substrate (composite material) was obtained in the same manner as in Example 1, except that the reinforcing material was 3 parts by weight.

Example 3 Regarding the surface treatment of the reinforcing material containing colloidal silica, the reinforcing material was N-phenyl-γ.
-Aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product number KBM573) was immersed in a 0.01 wt% concentration solution, passed through a squeeze roll, and then heat-treated at 110 ° C for 5 minutes to form a surface on the reinforcing material. The amount of the treatment agent attached is 100 parts by weight of the reinforcing material containing the inorganic particles after the surface treatment,
Except that the reinforcing material is 0.02 parts by weight,
The same operation as in Example 1 was performed to obtain a substrate (composite material).

Example 4 Regarding the surface treatment of the reinforcing material containing colloidal silica, the reinforcing material was N-phenyl-γ.
-Immersing in a 4 wt% solution of aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product number KBM573),
After passing through the squeezing rolls, heat treatment was performed at 110 ° C. for 5 minutes so that the amount of the surface treatment agent attached to the reinforcing material was 1.5 with respect to 100 parts by weight of the reinforcing material containing the inorganic particles after the surface treatment.
A substrate (composite material) was obtained in the same manner as in Example 1, except that the reinforcing material was 1 part by weight.

Comparative Example 1 A substrate (composite material) was obtained in the same manner as in Example 1 except that the surface treatment of the reinforcing material containing colloidal silica was omitted.

Comparative Example 2 Regarding the surface treatment of the reinforcing material containing colloidal silica, the reinforcing material was an aqueous solution of γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product number KBM403) at a concentration of 1% by weight. After being passed through a squeezing roll and heat-treated at 110 ° C. for 5 minutes, the amount of the surface treatment agent adhering to the reinforcing material is 0 with respect to 100 parts by weight of the reinforcing material containing the inorganic particles after the surface treatment. Substrate (composite material) was prepared in the same manner as in Example 1 except that the surface-treated reinforcing material of 0.61 parts by weight was obtained.
I got

The amount of the surface treatment agent attached to the reinforcing material in each of the above-mentioned Examples and Comparative Examples was measured as follows. First, the reinforcing material containing the inorganic particles after the surface treatment is dried at 90 ° C. for 1 hour to remove water. Next, after measuring the weight of the reinforcing material from which the water is removed, the reinforcing material is heat-treated at 300 ° C. for 2 hours, the weight is measured again, and the weight reduced by the heat treatment at 300 ° C. for 2 hours. To calculate. The weight reduced by this heat treatment is regarded as the weight of components other than Si of the silane-based compound, and based on this weight and the structural formula of the aminosilane-based coupling agent or silane-based compound used as the raw material, the surface treatment agent ( The amount of adhesion of the surface treatment agent to the reinforcing material was determined by calculating the amount of adhesion of the aminosilane coupling agent or silane compound).

Further, with respect to the substrates obtained in each of the examples and the comparative examples, an insulation resistance test after moisture absorption treatment and a solder heat resistance test after moisture absorption treatment were conducted as follows, and the results are shown in Table 1. . Regarding insulation resistance after moisture absorption treatment, JIS
Insulation resistance after immersion in boiling water at 100 ° C. for 2 hours was measured according to C6481. Regarding the solder heat resistance after the moisture absorption treatment, the sample was exposed to saturated steam at 135 ° C. for 2 hours (PCT treatment), and then immediately immersed in a solder bath at 260 ° C. for 60 seconds to examine whether blistering occurred. This test was conducted on 5 samples. When all 5 did not blister. ○ When all 5 blistered, x. No blistered and blistered in 5 bulges. In the case where the materials and the materials are mixed, it is shown as Δ in Table 1.

[0028]

[Table 1]

From the results shown in Table 1, it was confirmed that the examples of the present invention yielded a substrate having excellent insulation resistance after the moisture absorption treatment and solder heat resistance after the moisture absorption treatment, as compared with the comparative examples.

[0030]

According to the inventions of claims 1 to 3, the reinforcing material containing inorganic particles having an average particle diameter of 1000 nm or less before being impregnated with the varnish contains an N-phenyl-γ-aminopropylsilane coupling agent. Since the surface treatment is performed using the surface treatment agent, according to the inventions of claims 1 to 3, the thermal expansion coefficient is small, and the insulation resistance after the moisture absorption treatment and the solder heat resistance after the moisture absorption treatment are high. A polyimide resin-based composite material having excellent properties is obtained.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication B29K 105: 08 509: 08 C08L 79:08

Claims (3)

[Claims] 1. A reinforcing material composed of strands formed by bundling monofilaments, containing inorganic particles having an average particle diameter of 1000 nm or less at a ratio of 1 to 30 parts by weight with respect to 100 parts by weight of the reinforcing material. A reinforcing material containing particles is impregnated with a varnish containing an addition-type polyimide resin, dried to obtain a prepreg, and then, in the method for manufacturing a composite material in which the prepreg is molded to manufacture a composite material, the inorganic particles before impregnating the varnish are A method for producing a composite material, wherein the reinforcing material containing is surface-treated using a surface-treating agent containing an N-phenyl-γ-aminopropylsilane coupling agent represented by the following formula. _{C 6 H 5 -NH-C 3} H 6 SiX 3 --- (X represents _{OCH 3, OC 2 H 5,} OC 3 H 7 or Cl.) 2. The surface treatment of a reinforcing material containing inorganic particles is carried out such that the amount of the surface treatment agent attached to the reinforcing material is 0.05 to 1% with respect to 100 parts by weight of the reinforcing material containing inorganic particles after the surface treatment. The method for producing a composite material according to claim 1, wherein the amount is 0 part by weight. 3. The reinforcing material composed of strands formed by bundling monofilaments is glass cloth, and the material of the inorganic particles having an average particle diameter of 1000 nm or less is silica, according to claim 1 or 2. Composite material manufacturing method.