JP3343722B2 - Method for producing composite prepreg and laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an electric / electronic device,
The present invention relates to a prepreg for a laminated board suitable for a printed circuit board used for communication equipment and the like, and a method for manufacturing a laminated board using the same.

[0002]

2. Description of the Related Art Consumer electronic devices have become smaller and more sophisticated, and a printed circuit board used for the same has a structure in which a glass nonwoven fabric is used as an intermediate layer base material and a glass woven fabric is used as a surface layer base material. A laminate impregnated with a resin and molded by heating and pressurizing (hereinafter, referred to as a composite laminate) is used. In recent years, such composite laminates have been required to have the same punching workability and cost reduction as paper-based phenolic laminates conventionally used in this field.

In the field of industrial electronic equipment, composite laminates which do not use glass woven fabric or reduce the amount of glass woven fabric have been used due to the need for cost reduction. It is inferior in various respects to the woven fabric laminate, and it is required to have the same dimensional stability and small warpage.

[0004] In response to the various demands described above for a composite laminate, the use of a resin varnish containing glass fibers without using a glass nonwoven fabric as an intermediate layer base material has been studied (Japanese Patent Application Laid-Open No. 9-1997). Although the dimensional change and warpage are improved, there are various production problems such as insufficient adhesion between the surface layer and the intermediate layer, and resin flowing out from the end face during molding. Has not been reached yet. On the other hand, reducing the ratio of the glass woven fabric or nonwoven fabric to reduce the cost is also considered, but it is not easy to reduce the cost due to performance or manufacturing restrictions.

[0005] Under such circumstances, the present inventors have conducted various studies with the aim of achieving cost reduction while maintaining and improving the performance as a composite laminated board. A method of applying a thermosetting resin varnish, superposing a glass fiber nonwoven fabric on the varnish application surface, and heating to obtain a prepreg has been found (JP-A-8-2).
No. 67664). However, in this method, there is no problem in the case of a solvent-free varnish, but when a varnish containing a general solvent is used, in the heating step after laminating the glass nonwoven fabric, voids due to evaporation of the solvent are generated in the prepreg. In some cases, these voids remain in the laminated board after molding, and adversely affect electrical performance such as insulating properties.

[0006]

SUMMARY OF THE INVENTION The present inventor has improved the adhesion between the surface layer and the intermediate layer, improved the bending strength and the impact resistance,
As a result of various studies aimed at improving moldability by reducing the flow at the time of lamination molding, reducing cost, etc., it is possible to suppress the flow of resin in the intermediate layer during molding by raising one or both sides of the glass woven fabric. It has been found that the adhesiveness between the surface layer glass woven fabric and the resin composition of the intermediate layer is improved, and preferably, the bending strength and impact resistance are further improved by adding inorganic fibers or organic fibers to the intermediate layer. Further, based on this finding, various studies have been made to complete the present invention.

[0007]

SUMMARY OF THE INVENTION The present invention comprises a step of applying a thermosetting resin containing an inorganic filler to the raised surface of a long glass fiber substrate having one or both surfaces raised, and heating the resin. A method for producing a composite prepreg, comprising a step of superimposing a glass fiber substrate with one or both surfaces raised on the application surface with the raised surface inside, and a method of heating and pressing the composite prepreg. It is related to a method for manufacturing a laminated board, and it is possible to continuously obtain a composite prepreg, so that the manufacturing process is simple,
And continuous molding is possible. Further, the performance such as punching property, thickness accuracy, bending strength and the like is equal to or higher than that of the conventional composite laminate, and a laminate without voids can be obtained. Furthermore, cost reduction can be achieved by not using a nonwoven fabric.

FIG. 1 schematically shows an example of steps up to the production of a composite prepreg in the present invention. A thermosetting resin varnish (2) blended with an inorganic filler forming an intermediate layer is provided on the raised surface of a long glass fiber substrate (1) with one or both surfaces raised from the unwinding device. Coating is performed by a coater (3) to a predetermined thickness. Examples of the long base material include glass woven fabric and glass nonwoven fabric, and glass woven fabric is preferable from the viewpoint of heat resistance and mechanical strength.

In the present invention, the glass woven fabric used for the surface layer is at least used to suppress the flow of the resin composition of the intermediate layer at the time of forming the laminate and to increase the adhesion between the surface layer and the intermediate layer. The raised surface is formed on the inner surface side, that is, on the intermediate layer side. The length of the raised hair is not limited, but is preferably 50 μm or more in order to effectively suppress the flow of the resin composition during molding and improve the interlayer adhesion, and it is particularly necessary to stop the flow almost completely. In some cases, it is preferably 300 μm or more. If it is less than 300 μm, the flow cannot be completely stopped by the raised fibers. If it is less than 50 μm, there is a flow of the resin composition during molding, and the variation in the thickness of the laminate may increase.

The length of the raised hair has its limit depending on the method of raising the hair, and is about 1500 μm at the maximum. In addition, although it depends on the thickness of the laminate and the fluidity of the resin composition of the intermediate layer, the effect of stopping the flow is generally almost satisfied at 300 μm or more, and the effect of stopping this flow is not improved even at about 1000 μm or more. There is no need to brush to any longer length. The method of forming a brush on the surface of the glass woven fabric,
There are a loop weaving method, a method using a needle punch, a brush, an emery, a needle cloth, a method using a water jet, and the like, and any method may be used. The glass woven fabric may be of any type, but preferably has a weight (single amount) per square meter of 20 to 300 g / m ² . 300
If it exceeds g / m ² , workability with a drill or the like will deteriorate,
If it is less than 20 g / m ² , the strength becomes weak, and it is difficult to raise the hair.

In the present invention, the thermosetting resin in the thermosetting resin varnish containing the inorganic filler used for the intermediate layer is preferably an epoxy resin. In addition, a polyimide resin, a polyester resin, a phenol resin and the like can be used. . The thermosetting resin used for impregnating the glass woven fabric with the raised surface layer is also preferably an epoxy resin, but a polyimide resin, a polyester resin, a phenol resin or the like can be used similarly to the intermediate layer. Such a thermosetting resin can be used with only the resin,
When an inorganic filler such as aluminum hydroxide and calcium carbonate is added, tracking resistance and the like can be imparted.
The amount is 100% by weight or less, preferably 30 to 80% by weight, based on the resin content.

[0012] In the laminate of the present invention, the intermediate layer contains a thermosetting resin and an inorganic filler to maintain and improve the punching property and dimensional stability, and to have a thermal expansion in the thickness direction (Z direction). , The through hole reliability can be improved. Conventionally, a glass fiber nonwoven fabric is used for the intermediate layer, but by not using this, it is easy to greatly reduce voids (remaining air bubbles) in the intermediate layer. Examples of the inorganic filler used for the intermediate layer include aluminum hydroxide, calcium carbonate, clay, talc, and silica. Preferably, the main component is aluminum hydroxide for improving the flame resistance, and it is preferable to mix ultrafine silica for improving the dispersion of the inorganic filler. The mixing ratio with respect to the resin is usually in the range of 10 to 300% by weight. If it is less than 10% by weight, the flow of the resin composition at the time of molding is large, and the effect of improving the reliability of the through hole is small. If it exceeds 300% by weight, it becomes difficult to mix the inorganic filler into the resin and mold the laminate. . From the viewpoint of the mixing of the inorganic filler, the formation of the laminate and the properties of the obtained laminate, preferably 30 to 200% by weight,
More preferably, the content is 60 to 160 parts by weight. The solid content of the thermosetting resin varnish is usually 65 to 90% by weight (the inorganic filler is also calculated as the solid content).

In the present invention, in order to further improve the bending strength and impact resistance of the laminated board, inorganic fibers or organic fibers are mixed with the thermosetting resin of the intermediate layer together with the inorganic filler. By blending inorganic fibers or organic fibers, the flow of the resin composition during molding can be further suppressed. As the inorganic fiber, alumina fiber, glass fiber, etc., and the compounding ratio to the resin is 0.01 to 50% by weight.
Is preferred. If it is less than 0.01% by weight, the effect of improving bending strength and impact resistance is small, and if it exceeds 50% by weight, mixing of inorganic fibers and press molding become difficult. The blending amount of the inorganic fibers is more preferably 0.1 to 10% by weight, and most preferably 1 to 5% by weight. The organic fiber is a synthetic fiber, pulp, or the like, and can be added in a larger amount than the inorganic fiber, more preferably 0.1 to 15% by weight, and the most preferable compounding ratio is 1 to 15. 10% by weight.

The fiber diameter of these fibers is preferably 15 μm or less, more preferably 7 μm or less from the viewpoint of easy mixing with resin. If the thickness is larger than 15 μm, the workability using a drill or the like may cause a large abrasion, which may cause the breakage of the drill. The length of the fiber is usually 6 mm or less, and if it is longer than this length, mixing with the resin becomes difficult,
When the fiber diameter is 15 μm or less, even if the fiber length is longer than this, mixing with the resin is easy, and at least 20 mm
It can be used up to a degree. As for the dilution of the inorganic filler-containing thermosetting resin varnish with a solvent, a solvent-free varnish that does not undergo solvent dilution is preferable if the varnish before dilution has a certain low viscosity. The coating amount of the inorganic filler-containing varnish varies depending on the resin used, the amount of the brushed glass fiber base material (weight per unit area), and the like, but usually, the varnish solid content is 500 to 1600 g per 1 m ^{2 of the} base material. The coating thickness (after heating and drying) is usually 0.2 to 2.0 m
m. This coating thickness is determined by the thickness of the final laminated board and the thickness of the brushed glass woven fabric of both surface layers. Since the glass woven fabric has a brushed surface on the intermediate layer side, the thickness of the intermediate layer is 2 mm. Even at about 0.0 mm, the flow during molding can be sufficiently stopped. When the thickness of the intermediate layer is 0.1 mm or less, the flow of the intermediate layer is small because the thickness of the intermediate layer is small, and it is not necessary to use a brushed glass woven fabric. This coating thickness is
Preferably 0.3-1.8 mm, more preferably 0.4-
1.6 mm, most preferably 0.6-1.4.
mm.

As the coater (3), there are a comma roll coater, a knife coater, a die coater, a reverse coater and the like. However, since the coating thickness is as large as 0.2 to 2.0 mm, it is necessary to increase the varnish viscosity. is there. For this reason, a method capable of applying a high-viscosity varnish, for example, a comma roll coater or a knife coater is preferable. Thereafter, the mixture is passed through a heating device (4) to carry out a reaction of the resin, evaporation of the solvent and the like. The heating conditions vary depending on whether or not a solvent is used, the kind of the solvent or the amount thereof, but it is usually from 80 to 160 ° C. for about 60 to 600 seconds. Thus, a glass woven fabric coated with the inorganic filler-containing thermosetting resin is obtained.

On the other hand, the above-mentioned resin-coated glass woven fabric containing an inorganic filler is provided with the long surface of the long glass fiber substrate (5) unwound from one or both surfaces unwound from another unwinding device facing the inside. And a composite prepreg (6) is obtained. The timing of the overlapping step is desirably when the thermosetting resin containing the inorganic filler is melted by heat. The composite prepreg (6) thus obtained is cut into a predetermined length, or is continuously heated and pressed without being cut into a laminate. In this molding, usually, a metal foil is laminated on one or both surfaces of the composite prepreg and molded. During this heating and pressurization, of the inorganic filler-containing thermosetting resin in the composite prepreg,
The molten resin component further penetrates into the glass woven fabric. Therefore, in the obtained laminate, usually, a sufficient amount of resin is present in the glass woven fabric constituting the surface layer.

However, in this heat-press molding, the resin may not sufficiently penetrate into the glass woven fabric constituting the surface layer. In this case, as described below, a thermosetting resin varnish (7) is provided on both outer surfaces of the composite prepreg (6).
Is applied. This application is usually performed by a roll coater (8),
This is performed according to (9), but is not limited to this. The thermosetting resin varnish to be applied is used to compensate for the resin component of the thermosetting resin containing the inorganic filler that is not sufficiently impregnated in the raised base material. In order to uniformly impregnate the resin, one having a resin solid content of about 20 to 60% by weight is usually used. Thereafter, by heating through a heating device (10), a composite prepreg (11) in which a thermosetting resin is impregnated on a surface substrate is obtained. The heating condition was set to be slightly stronger than usual since the total thickness of the composite prepreg was large.
0 to 180 ° C. for about 1 to 5 minutes. Thereafter, the composite prepreg (11) can be cut to a predetermined length by a cutter (12), or can be subjected to continuous molding without cutting.

The composite prepreg (11) thus obtained is formed into a laminate by heating and pressing. This molding is usually performed using a prepreg 1 cut to a predetermined length.
This is performed by heating and pressing with a multi-stage press on sheets, but it is also possible to continuously heat and press a long prepreg that is not cut. When the thermosetting resin is an epoxy resin, the former molding method is usually performed. This molding condition depends on the degree of flow of the impregnated resin, but is usually performed at a pressure similar to or lower than that of the conventional composite laminate. That is, temperature 150-180 ° C, pressure 20-70kg
/ Cm ² and a time of 60 to 120 minutes are appropriate. When low pressure molding is possible, a continuous molding method can be adopted.

The composite laminate can be obtained by the above-mentioned steps. In the present invention, a thermosetting resin varnish containing an inorganic filler is coated to a predetermined thickness on a fibrous base material such as a glass woven fabric having a raised material. After applying and heating, the fiber base material having the same brushing as above is further superimposed, so that the application and impregnation process is simple even when the resin varnish is applied to both sides of the later superimposed prepreg. This eliminates the use of a costly intermediate-layer glass nonwoven fabric, which is also advantageous in terms of cost. In addition, by using a brushed glass fiber substrate, the flow of resin is suppressed during molding, so that moldability is good, and the use of a glass nonwoven fabric can easily prevent generation of voids due to a solvent. Therefore, troubles during the production of the laminated board can be reduced, and the cost can be reduced.

[0020]

Examples of the present invention and comparative examples (conventional examples) are described below.
Is shown. “Parts” and “%” indicate “parts by weight” and “% by weight”, respectively.

Example 1 A glass woven fabric having a single weight of 210 g / m ² (WE-18K manufactured by Nitto Boseki)
RB-84) and unroll one side with a rag.
The resin was brushed to a length of 00 μm, and the epoxy resin varnish A containing the following inorganic filler was coated on the raised surface with a knife coater so that the film thickness after drying would be 1.4 mm. C. and dried for 3 minutes. (Blending of Varnish A) (1) 96 parts of brominated epoxy resin (Ep-1046 manufactured by Yuka Shell) (2) dicyandiamide 4 (3) 2-ethyl-4-methylimidazole 0.15 (4) aluminum hydroxide 80 (Heidilite H-42 manufactured by Showa Denko) (5) Ultrafine powdered silica (Carplex manufactured by Shionogi Pharmaceutical Co., Ltd.) 20 (6) Methyl cellosolve 50

Next, a glass woven fabric with a single weight of 210 g / m ² (Nitto Boseki Co., Ltd.) having one surface brushed on the upper surface in the same manner as described above.
WE-18K RB-84) were continuously superimposed such that the brushed surface was on the inside. Next, an epoxy resin varnish C having the following composition was applied to both outer surfaces by a roll coater. (Blend of varnish C) (1) 96 parts of brominated epoxy resin (Ep-1046 manufactured by Yuka Shell) (2) dicyandiamide 4 (3) 2-ethyl-4-methylimidazole 0.15 (4) methylcellosolve 230 The mixture was heated at 160 ° C. for 3 minutes to obtain a composite prepreg comprising a resin-impregnated raised glass woven fabric on the surface and a resin containing an intermediate inorganic filler. After cutting the obtained composite prepreg to a predetermined length (2 m), a copper foil having a thickness of 18 μm is laminated on the upper and lower sides of the prepreg, and heated and pressed at a temperature of 165 ° C. and a pressure of 20 kg / cm ² for 90 minutes. A 1.6 mm-thick copper-clad laminate was produced.

Example 2 A copper-clad laminate having a thickness of 1.6 mm was produced in the same manner as in Example 1 except that the varnish A in Example 1 was changed to the following epoxy resin varnish B containing an inorganic filler. (Blending of Varnish B) (1) 96 parts of brominated epoxy resin (Ep-1046 manufactured by Yuka Shell) (2) dicyandiamide 4 (3) 2-ethyl-4-methylimidazole 0.15 (4) aluminum hydroxide 80 (Heidilite H-42, manufactured by Showa Denko) (5) Alumina fiber (Nichias T / # 5100) 5 Fiber diameter 2.5 μm, fiber length average 15 mm (5) Ultrafine powdered silica (Shionogi Pharmaceutical Carplex) 20 (6) Methyl cellosolve 50

Comparative Example 1 The following epoxy resin varnish D for FR-4 was applied and impregnated on a glass woven fabric (WE-18K RB-84, manufactured by Nitto Boseki) by a dipping method, and dried to prepare a prepreg for a surface layer. (Blending of varnish D) (1) 96 parts of brominated epoxy resin (Ep-1046 manufactured by Yuka Shell) (2) dicyandiamide 4 (3) 2-ethyl-4-methylimidazole 0.15 (4) methylcellosolve 100 and Then, the varnish D was applied to a glass nonwoven fabric (EP-4075 manufactured by Japan Vilene Co., Ltd.) by a dipping method and dried to prepare a prepreg for an intermediate layer. Then, a predetermined number (four) of prepregs for the intermediate layer are stacked, prepregs for the surface layer are stacked on the upper and lower sides thereof, and a copper foil having a thickness of 18 μm is stacked on the upper and lower sides thereof. A laminated laminate was produced.

Comparative Example 2 A woven prepreg for a surface layer was prepared in the same manner as in Comparative Example 1. On the other hand, an inorganic filler-containing epoxy resin varnish E having the following composition was prepared. (Blend of Varnish E) (1) 96 parts of brominated epoxy resin (Ep-1046 manufactured by Yuka Shell) (2) Dicyandiamide 4 (3) 2-ethyl-4-methylimidazole 0.15 (4) Aluminum hydroxide 80 (Heidilite H-42, manufactured by Showa Denko) (5) Ultra-fine powder silica (Carplex, manufactured by Shionogi Pharmaceutical Co., Ltd.) 20 (6) Methyl cellosolve 65 This varnish E is made of glass non-woven fabric (EP-, manufactured by Nippon Vilene).
4075) by dipping, impregnated and dried to prepare a prepreg for an intermediate layer. Next, a predetermined number (three) of the intermediate layer prepregs are stacked, the surface layer prepregs are stacked above and below the prepregs, and a copper foil of 18 μm in thickness is stacked above and below the prepregs. A copper-clad laminate was produced.

Example 3 An epoxy resin varnish [F] was prepared with the following composition. (1) 80 parts of brominated epoxy resin (Ep-1046 manufactured by Yuka Shell) (2) Novolak type epoxy resin (E-180 manufactured by Yuka Shell) 20 (3) dicyandiamide 4 (4) 2-ethyl-4-methyl Imidazole 0.15 (5) Methyl cellosolve 30 (6) Acetone 60 An epoxy resin varnish [G] containing an inorganic filler was prepared with the following composition. (1) 60 parts of brominated epoxy resin (Ep-1046 manufactured by Yuka Shell) (2) Novolak type epoxy resin (E-180 manufactured by Yuka Shell) 40 (3) dicyandiamide 4 (4) 2-ethyl-4-methyl Imidazole 0.15 (5) Aluminum hydroxide 110 (Heidilite H-42, manufactured by Showa Denko) (6) Silica (Crystalite VX-3, manufactured by Tatsumori) 20 (7) Ultrafine silica (Carplex manufactured by Shionogi Pharmaceutical Co., Ltd.) 20 (8) Methyl cellosolve 50

Next, a glass woven cloth (WE-18K RB-84, manufactured by Nitto Boseki Co., Ltd.) with a single weight of 210 g / m ² was unwound, and one side thereof was brushed with a needle cloth to a length of 600 to 800 μm, and the brush was raised. The varnish [G] containing an inorganic filler was coated on the surface with a knife coater so that the film thickness after drying was 1.4 mm, and heated and dried at 150 ° C. for 3 minutes with a heating device. A glass woven fabric having a single weight of 210 g / m ² (Nitto Boseki WE-18K RB-84), similarly brushed on one side, is overlapped on the upper surface so that the brushed surface is on the inner side, and then the varnish is applied to both surfaces. [F] is applied by a roll coater, and 1
The resultant was dried by heating at 50 ° C. for 3 minutes to obtain a composite prepreg. This prepreg was cut into a predetermined length (2 m), and copper foil having a thickness of 18 μm was laminated on both surfaces thereof.
Laminate molding at 0 kg / cm ² for 90 minutes, thickness 1.6m
m of the copper-clad laminate was obtained.

Example 4 A varnish containing an inorganic filler [G] used in Example 3 was changed to a varnish containing an inorganic filler [H] described below, and a varnish [H] having a thickness of 1.6 mm was used. A copper-clad laminate was produced. The composition of the inorganic filler-containing varnish [H] is as follows. (1) 60 parts of brominated epoxy resin (Ep-1046 manufactured by Yuka Shell) (2) Novolak type epoxy resin (E-180 manufactured by Yuka Shell) 40 (3) dicyandiamide 4 (4) 2-ethyl-4-methyl Imidazole 0.1 (5) Aluminum hydroxide 110 (manufactured by Showa Denko, Heidilite H-42) (6) Silica (Tatsumori Crystallite VX-3) 10 (7) Fibrous pulp (Nippon Paper KC Floc W) -100) 10 (8) Ultrafine silica (Carplex, Shionogi Pharmaceutical Co., Ltd.) 20 (9) Methyl cellosolve 50

Comparative Example 3 A varnish containing an inorganic filler [G] used in Example 3 was prepared by using a glass woven fabric (WE-18K RB-84, manufactured by Nitto Boseki Co., Ltd.) having a single weight of 210 g / m ² without a raising treatment. One side was coated with a knife coater so that the film thickness after drying was 1.4 mm, and heated and dried at 150 ° C. for 3 minutes with a heating device. A glass woven fabric having a single weight of 210 g / m ² (Nitto Boseki WE-18K RB-84), which is also not brushed, is superposed on the upper surface, and the epoxy resin varnish [F] is coated on both surfaces with a roll coater. It was applied and heated and dried at 150 ° C. for 3 minutes with a heating device to obtain a composite prepreg. Hereinafter, in the same manner as in Example 1,
A copper-clad laminate having a thickness of about 1.6 mm was obtained. The obtained copper-clad laminate had a large flow from the end face at the time of molding, and therefore had a very poor thickness accuracy.

Comparative Example 4 Comparative Example 4 was repeated except that the varnish containing inorganic filler [H] used in Example 4 was used instead of the varnish containing inorganic filler [G] used in Example 3. In the same manner as in Example 4, a copper-clad laminate having a thickness of about 1.6 mm was obtained. As in Comparative Example 4, the obtained copper-clad laminate had a large flow from the end face at the time of molding and had a significantly poor thickness accuracy.

Comparative Example 5 An epoxy resin varnish [J] containing an inorganic filler was prepared with the following composition. (1) 80 parts of brominated epoxy resin (Ep-1046 manufactured by Yuka Shell) (2) Novolak type epoxy resin (E-180 manufactured by Yuka Shell) 20 (3) dicyandiamide 4 (4) 2-ethyl-4-methyl Imidazole 0.1 (5) Aluminum hydroxide 70 (Heidilite H-42 manufactured by Showa Denko) (6) Silica (Crystalite VX-3 manufactured by Tatsumori) 10 (7) Ultrafine silica (Carplex manufactured by Shionogi Pharmaceutical Co., Ltd.) 20 (8) Methyl cellosolve 50 This inorganic filler-containing varnish [J] is impregnated into a glass non-woven fabric (EP4075 manufactured by Nippon Vileen Co., Ltd.) so that the total content of the resin and the inorganic filler is 90% with respect to the entire intermediate layer. And
The resultant was dried by heating at 150 ° C. for 3 minutes using a heating device to obtain a glass nonwoven fabric prepreg. On the other hand, the epoxy resin varnish [F] used in Example 3 was impregnated into a glass woven fabric (WE-18K RB-84, manufactured by Nitto Boseki Co., Ltd.) that had not been brushed so that the resin content was 40%, and heated. It was dried by heating at 150 ° C. for 3 minutes using an apparatus to obtain a woven prepreg of glass fabric. An intermediate layer then superposed three sheets of the nonwoven glass fabric prepreg, a glass fabric prepreg was arranged as both surface layers, further superimposed copper foil 18μm thick on both sides, the molding temperature 165 ° C., a pressure 60 kg / cm ² For 90 minutes with a thickness of 1.6
mm copper-clad laminate was obtained.

The following characteristics were measured for the copper-clad laminates obtained in the above Examples and Comparative Examples. Table 1 shows the results. In Example 6, the result that the punching property was more excellent than the other examples was obtained.

[0033]

[Table 1]

<Measurement Method> Flow of Laminate Molding When a laminate having a size of 500 × 500 mm was molded, the maximum flow length of the resin flowing out from the end face of the prepreg was measured. 2. Interlayer peel strength After removing the copper foil by etching, laminate
After cutting to a width of m, the adhesive strength between the surface layer and the intermediate layer was measured with Tensilon. 3. Flexural strength (longitudinal direction) Measured according to JIS-C6481. 4. Falling ball impact test A 250 g iron ball was dropped on the laminate, and the height at which the laminate broke was measured. 5. Solder heat resistance A test piece of a copper-clad laminate of 25 mm square was floated in a solder bath at 260 ° C., and the time required until the test piece was blown was measured. 6. Punchability Measured according to ASTM D617. 7. Thickness Accuracy Four corner portions and four center portions and a center portion of a 1000 mm square copper-clad laminate were measured with a micrometer, and variations were obtained by the following calculation. [(Maximum value of measurement-minimum value) / average value] X100
(%) 8. Thermal expansion coefficient in Z direction The expansion coefficient in the thickness direction of the substrate when heated from 50 ° C to 200 ° C was measured (by TMA). Regarding the production cost, the method of the embodiment is simple in steps and eliminates the use of expensive glass fiber nonwoven fabric, so that the laminate obtained in the embodiment is obtained in Comparative Example 2, 3 or 6. The cost can be reduced by about 30% as compared with the obtained laminated plate.

[0035]

According to the method for producing a composite prepreg and a laminated board of the present invention, a brushed glass woven fabric is used and a thermosetting resin containing an inorganic filler is used as an intermediate layer. The flow is suppressed. Therefore, the obtained laminate has excellent interlayer adhesion between the surface layer and the intermediate layer,
It has excellent thickness accuracy and may not use a glass nonwoven fabric, and has good punching workability. Further, since the composite prepreg is manufactured continuously, the molding process is simple, and the yield during molding is improved. And since the cost reduction of a laminated board can be achieved by not using an expensive glass nonwoven fabric, it is suitable as an industrial laminated board manufacturing method. In addition, when an inorganic filler or an inorganic fiber or an organic fiber is added to the resin of the intermediate layer in addition to the inorganic filler, the bending strength and the impact resistance are improved.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing steps up to producing a composite prepreg of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Brushed long base material 2 Varnish containing inorganic filler 3 Coater 4 Heating device 5 Brushed long base material 6 Composite prepreg 7 Varnish 8, 9 Roll coater 10 Heating device 11 Composite prepreg 12 Cutter

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI B32B 17/04 B32B 17/04 A 27/04 27/04 Z C08J 5/08 C08J 5/08 // B29K 105: 08 B29K 105 : 08 C08L 63:00 C08L 63:00

Claims (6)

(57) [Claims] 1. A step of applying a thermosetting resin containing an inorganic filler to the raised surface of a long glass fiber base material having one or both surfaces raised, and heating the resin-coated surface, wherein one or both surfaces are raised. A method for producing a composite prepreg, comprising a step of superposing the obtained glass fiber base material with the raised surface inside. 2. A step of applying a thermosetting resin containing an inorganic filler to the raised surface of a long glass fiber base material having one or both surfaces raised, and heating the resin-coated surface, wherein one or both surfaces are raised. A method for producing a composite prepreg, comprising: a step of superposing the glass fiber base material with the raised surface inside, and a step of applying and heating a thermosetting resin to both superposed surfaces. 3. The method for producing a composite prepreg according to claim 1, wherein the raised length of the glass woven fabric is 50 μm or more. 4. The thermosetting resin containing an inorganic filler, wherein the ratio of the inorganic filler to 100 parts by weight of the thermosetting resin is 10 to 300 parts by weight.
A method for producing the composite prepreg according to the above. 5. The thermosetting resin containing an inorganic filler, wherein the thermosetting resin contains an inorganic fiber or an organic fiber.
5. The method for producing a composite prepreg according to 3 or 4. 6. A method for producing a laminate, comprising subjecting the composite prepreg according to claim 1, 2, 3, 4, or 5 to heat and pressure molding.