JPH0994915A - Manufacture of composite laminate and manufacture of thermosetting sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a used amount of solvent by a method wherein settling of a filter is removed by using highly viscous resin for a core material layer of a composite laminate. SOLUTION: A thermosetting sheet 13 wherein a glass chopped strand is scattered is used as a core material, a prepreg 12 using a woven cloth as a base material is superimposed as a surface material on its both sides, and a copper foil 11 is arranged on the surface material, which is heated and pressurized. For the thermosetting sheet 13 wherein the glass chopped strand is scattered, the thermosetting resin wherein the glass chopped sheet is scattered is applied onto a film, which is heated to harden the thermosetting resin to a stage B.

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 laminated board which is a substrate for a printed wiring board, and a method for producing a thermosetting resin sheet suitable as a core material for the composite laminated board.

[0002]

2. Description of the Related Art A composite laminated plate is a laminated plate composed of two kinds of base materials, a woven cloth as a surface material, and a non-woven fabric or paper as a core material. Currently, many products are manufactured using epoxy resin as a matrix resin, glass woven fabric as the surface material, and glass non-woven fabric (glass paper) as the core material, because they have excellent electrical properties and room temperature punchability. , Has come to occupy one field as a substrate for printed wiring boards.

[0003]

The varnish impregnated into the base material of the core material has a viscosity of 5 to 300 mPa · s and uses a large amount of solvent. However, the matrix resin of the core material contains a filler, but since the varnish has a low viscosity, the filler tends to settle and the distribution of the filler may become uneven. As a result, uneven coating of the varnish and defects such as voids and scratches caused by it occur. If the viscosity of the varnish is increased, sedimentation of the filler can be prevented, but on the contrary, it becomes difficult to uniformly disperse the filler and impregnate the base material.

The present invention relates to a method for producing a composite laminate using a highly viscous varnish as a core material of the composite laminate,
It is also an object of the present invention to provide a method for producing a resin sheet used in this production method.

[0005]

According to the present invention, a thermosetting resin sheet 13 in which glass chopped strands are dispersed is used as a core material, and a prepreg 12 having a woven fabric as a base material is superposed on both sides of the core material. This is a method for producing a composite laminate, which comprises arranging a copper foil 11 on a surface material and applying heat and pressure (see FIG. 1).

The thermosetting resin sheet 13 in which the glass chopped strands are dispersed is coated with the thermosetting resin 2 in which the glass chopped strands 1 are dispersed on the film 7 and heated to reach the B stage. It is manufactured by curing (see FIG. 2).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A glass chopped strand having a fiber diameter of 7 to 12 μm and a cut length of 5 to 15 mm is suitable. When the fiber diameter exceeds 12 μm, it is difficult to disperse in the resin, and when the fiber diameter is less than 7 μm, the electrical insulating property of a laminated plate is deteriorated. If the cut length exceeds 15 mm, the fibers are entangled with each other and it is difficult to similarly disperse. If the cut length is less than 5 mm,
The resin flow at the time of molding the laminated plate is large and the plate thickness accuracy is deteriorated.
The compounding amount of the glass chopped strands is preferably 10 to 30 parts with respect to 100 parts (parts by weight, the same applies hereinafter) of the thermosetting resin. If it is less than 10 parts, the rigidity is poor, and if it exceeds 30 parts, it is difficult to disperse.

A conventionally known filler is used as the filler. The compounding amount is 70 to 15 with respect to the resin solid content.
It is preferably 0 part. The viscosity of the thermosetting resin varnish is adjusted by the compounding amount of the solvent so as to be 1 to 3 Pa · s in the state where the filler is mixed.

Thermosetting resin varnish 2 containing a filler
And the glass chopped strand 1 are kneaded and dispersed, and are extruded and applied onto the continuously running film 7 by the extruder 3. Then, the resin is hardened to the B stage while being careful to prevent foaming by the solvent. . The heating and drying conditions are such that the temperature and time are adjusted according to the coating amount, particularly according to the volatilization amount of the solvent. It is preferable to apply it so that it becomes a resin sheet with the core material thickness of the composite laminated board, but if the thickness is too large, it will be difficult for the internal solvent to evaporate, so some resin sheets thinner than the core material thickness should be manufactured. You may make it overlap. The drying oven has a low temperature first drying chamber 4 and a high temperature second drying chamber 4.
It is preferable to provide a drying chamber 5. The solvent is removed in the first drying chamber, and the curing reaction of the resin is advanced to the B stage in the second drying chamber. Cutting machine 6 for the resin sheet coming out of the drying room
Then, the desired resin sheet 13 is obtained.

[0010]

Example: Epoxy resin 100 parts, aluminum hydroxide 70 parts, talc 30 parts, fiber diameter 10 μm, cut length 13
A solvent was added to 12 parts of a glass chopped strand having a size of 8 mm and kneaded to have a viscosity of 1 Pa · s and applied onto a film. This was sent to a first drying chamber having a length of 7 m kept at 150 ° C. and then to a second drying chamber having a length of 8 m kept at 175 ° C. at a rate of 1.5 m / min and a thickness of 1.2 mm. A resin sheet was obtained. 0.2mm thick on both sides of this resin sheet
Place the epoxy prepreg based on the glass woven fabric of
Furthermore, arranging a 35 μm thick copper foil, 175 ° C.,
Heating and pressurizing at 2.5 MPa for 90 minutes, thickness 1.6 mm
A composite laminate of was obtained. No abnormality was found in the appearance of the obtained composite laminate, and the maximum thickness was 1.53 mm, the minimum was 1.46 mm, and the deviation was 0.015 mm.
Met. Regarding the heat resistance examined in the normal state, 2 hours after the moisture absorption treatment and 4 hours after the moisture absorption treatment, neither swelling nor measling occurred. Insulation resistance is 5.0 × 10 ^{14 in} normal state
Ω, moisture absorption treatment 2 hours later 5.7 × 10 ¹³ Ω, moisture absorption treatment 4
After time, it was 5.2 × 10 ¹² Ω.

Comparative Example A prepreg was obtained by impregnating and drying a varnish obtained by adding a solvent to 100 parts of an epoxy resin, 70 parts of aluminum hydroxide and 30 parts of talc to a glass nonwoven fabric having a thickness of 0.2 mm. Three prepregs were superposed, epoxy prepregs having a thickness of 0.2 mm of glass woven fabric as a base material were arranged on both sides thereof, and copper foil having a thickness of 35 μm was further arranged at 175 ° C. and 2. 5
It was heated and pressed at 90 MPa for 90 minutes to obtain a composite laminate having a thickness of 1.6 mm. No abnormalities were found in the appearance of the obtained composite laminate, and the maximum thickness was 1.5.
It was 1 mm, the minimum was 1.42 mm, and the deviation was 0.017 mm. Regarding the heat resistance examined in the normal state, 2 hours after the moisture absorption treatment and 4 hours after the moisture absorption treatment, neither swelling nor measling occurred. The insulation resistance was 6.0 × 10 ¹⁴ Ω in the normal state, 8.0 × 10 ¹³ Ω after 2 hours of the moisture absorption treatment, and 8.7 × 10 ¹² Ω after 4 hours of the moisture absorption treatment.

[0012]

According to the present invention, by kneading the glass chopped strands and the thermosetting resin, it is possible to perform treatment with a high viscosity, and the filler compounded in the thermosetting resin does not sediment. . At the same time, the amount of solvent used can be reduced, which is economically and work hygiene beneficial.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a material structure according to an embodiment of the present invention.

FIG. 2 is a schematic view illustrating a resin sheet manufacturing apparatus.

[Explanation of symbols]

 1 Glass Chopped Strand 2 Thermosetting Resin 11 Copper Foil 12 Prepreg Based on Woven Fabric 13 Thermosetting Resin Sheet

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Claims (2)

[Claims] 1. A thermosetting resin sheet in which glass chopped strands are dispersed is used as a core material, and prepregs having a woven fabric as a surface material are laminated on both sides of the core material, and copper foil is arranged on the surface material. And a method of manufacturing a composite laminate, which comprises heating and pressing. 2. A method for producing a thermosetting resin sheet, characterized in that a thermosetting resin having glass chopped strands dispersed therein is applied onto a film and heated to cure the thermosetting resin to the B stage.