JPH115276A - Laminated plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated plate wherein the inter-layer strength between a surface layer and an intermediate layer is excellent, the thickness precision is excellent by reducing a flow at the time of lamination forming, and the cost is reduced by not using a glass non-woven fabric which is expensive. SOLUTION: A surface layer comprises a base material wherein a glass woven fabric of which one surface or both surfaces are raised is impregnated with a thermosetting resin, and an intermediate layer comprises a composition wherein 10-300 wt.%, based on the resin, of an inorganic filler material is mixed with the thermosetting resin, and these are heat-press-formed to obtain this laminated plate, and it is preferable that the raised fiber length of the glass woven fabric is 50 μm or longer. Also, it is preferable to blend an inorganic fiber or an organic fiber in addition to the inorganic filler material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated board for a printed circuit used particularly for electric equipment, electronic equipment, communication equipment and the like.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for printed circuit boards to be smaller and more sophisticated in order to reduce the weight and weight of electrical equipment. In particular, a laminated board for a multilayer circuit board used for a printed circuit board, a glass cloth base epoxy resin laminate, a CEM3 type epoxy resin composite laminate (a glass non-woven fabric as an intermediate layer base material, and a glass woven cloth as a surface layer base material) With such a base material configuration, a laminate obtained by impregnating these with an epoxy resin and heat-press molding) has been strongly required to improve the thickness accuracy (uniformity) of the laminate. Further, there is an increasing demand for cost reduction while maintaining the performance of the epoxy resin composite laminate.

Conventionally, in a laminated plate using a glass woven fabric, a phenomenon in which resin flows out from an end face during lamination molding (hereinafter, referred to as a resin).
(Referred to as a flow), the thickness of the peripheral portion of the laminated plate is reduced. More recently, in a composite laminate developed by the present inventors that does not use a glass nonwoven fabric (Japanese Patent Laid-Open No. 9-254331), the flow during molding is large due to the absence of the glass nonwoven fabric, and good molding cannot be performed. There was a problem. Also, in this composite laminate, it has been a major problem to improve the adhesiveness (interlayer adhesiveness) between the glass woven fabric and the resin of the intermediate layer.

[0004]

SUMMARY OF THE INVENTION The present inventor has made various studies for the purpose of improving interlayer adhesion, improving bending strength and impact resistance, improving formability by reducing the flow during lamination molding, and reducing costs. As a result, by raising one or both sides of the glass woven fabric, it is possible to suppress the flow of the resin of the intermediate layer during molding, and to improve the adhesion between the surface layer glass woven fabric and the resin composition of the intermediate layer. It has been found that bending strength and impact resistance are preferably improved by adding inorganic fibers to the intermediate layer, and the present invention has been completed by conducting various studies based on this finding.

[0005]

According to the present invention, both surface layers are provided.
At least the inner surface side is made of a base material in which a thermosetting resin is impregnated in a glass woven fabric having a raised surface, and the intermediate layer is made of a composition obtained by mixing a thermosetting resin with an inorganic filler in an amount of 10 to 300% by weight based on the resin. The present invention relates to a laminate characterized in that these are formed by heating and pressing. Preferably, a glass woven fabric having one or both sides raised on the surface and having a raised length of 50 μm or more is used. Further, in order to further improve the bending strength and impact resistance of the laminate, the intermediate layer is formed by adding inorganic fibers or organic fibers to the thermosetting resin in an amount of 0.01 to 50 in addition to the inorganic filler.
% By weight, and the inorganic or organic fiber preferably has a fiber diameter of 15 μm.
It is as follows.

[0006] 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, the thickness 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.

[0008] In the laminated board of the present invention, the ratio of the total amount of the thermosetting resin and the inorganic filler (including inorganic fibers or organic fibers when they are blended) to the brushed glass woven fabric is 2. 0 to 10.0 is preferred. Within this range, the brushed glass woven fabric has an effect of preventing the flow of the thermosetting resin composition containing the inorganic filler, and the properties of the laminate are equivalent to or higher than those of the conventional laminate. 2.
If it is less than 0, the characteristics as a composite laminate, that is,
Good workability, low cost, etc. are not exhibited, and if it exceeds 10.0, the portion of the glass woven fabric is reduced, and mechanical properties such as strength are reduced. Preferably it is 2.5-6.5.
For a standard 1.6 mm thick laminate, this value is preferably on the order of 5.0-6.0.

In the laminate of the present invention, the intermediate layer is formed by adding an inorganic filler to a thermosetting resin to maintain and improve the punching workability and the dimensional stability, and to increase the thermal expansion in the thickness direction (Z direction). , The through hole reliability can be improved. Conventionally, the glass fiber nonwoven fabric is used for the intermediate layer, but by not using this, voids (remaining air bubbles) in the intermediate layer can be greatly reduced. 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.

In the present invention, preferably, in order to further improve the bending strength and impact resistance of the laminate, the thermosetting resin of the intermediate layer is mixed with an inorganic fiber or an organic fiber together with an 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, and more preferably 7 μm or less from the viewpoint of ease of mixing with the 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. If the length is longer than this, mixing with the resin is not easy, but if the fiber diameter is 15 μm or less, mixing with the resin is easy even if the fiber length is longer than this. And can be used up to at least about 20 mm.

In the present invention, the thermosetting resin 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 thickness of the intermediate layer is determined by the thickness of the final laminated board and the thickness of the raised glass woven fabric on both surface layers. However, since the glass woven fabric has a raised surface on the intermediate layer side, the thickness of the intermediate layer is Even at about 2.0 mm, the flow during molding can be sufficiently stopped. 0.1m thickness of middle layer
Below m, the thickness of the intermediate layer is small, the flow is small, and it is not necessary to use a brushed glass woven fabric. Usually 0.2 to 2.0 mm, preferably 0.3 to 1.8 mm,
It is more preferably 0.4 to 1.6 mm, and most preferably 0.6 to 1.4 mm. 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 alone, but when an inorganic filler such as aluminum hydroxide is added, tracking resistance can be imparted.

The laminated board of the present invention uses a brushed glass woven fabric for the surface layer and a thermosetting resin composition containing an inorganic filler for the intermediate layer. And the adhesion between the surface layer and the intermediate layer is excellent. Therefore, despite the fact that no glass nonwoven fabric is used for the intermediate layer, the thickness accuracy of the laminate is extremely good, the punching workability and dimensional stability are maintained and improved, and the thermal expansion in the thickness direction (Z direction) is reduced. Therefore, it is possible to improve through hole reliability. Also,
By blending an inorganic fiber or an organic fiber with the inorganic filler in the intermediate layer, the bending strength and impact resistance are further improved. Therefore, the performance of the laminated plate is maintained and improved, and the yield at the time of molding is improved. In addition to using no expensive glass nonwoven fabric, cost reduction can be achieved. In addition, by increasing the length of the brushed,
It was also found that the strength of the woven fabric itself was reduced, which was effective in improving workability such as punching.

The method for producing the laminate of the present invention includes:
For example, there are the following methods. That is, a thermosetting resin mixed with an inorganic filler is applied at a predetermined thickness to a raised surface of a glass woven fabric having at least an inner surface raised, and a brushed glass woven fabric similar to the above is formed with the raised surface facing the inside. And overlap. Thereafter, a thermosetting resin is applied from both surfaces of the laminate as necessary, and is heated and dried to such an extent that curing does not proceed.
By subjecting the composite prepreg thus obtained to heat and pressure molding, a target laminated board can be obtained. The brushed glass woven fabric used as the surface layer can be impregnated with a thermosetting resin in advance, and in this case, the step of impregnating the laminate with the resin before molding can be omitted. The heating and pressurizing conditions at the time of molding depend on the fluidity of the applied resin composition, but the pressure is slightly lower in order to suppress the flow at the time of molding or equivalent to the ordinary molding conditions of the composite laminate. That is, a temperature of 150 to 180
C., a pressure of 20 to 70 kg / cm ² and a time of 60 to 120 minutes are appropriate.

[0014]

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 An epoxy resin varnish [1a] was prepared with the following composition. (1) 100 parts of brominated epoxy resin (Ep-1046 manufactured by Yuka Shell) (2) dicyandiamide 4 (3) 2-ethyl-4-methylimidazole 0.15 (4) methylcellosolve 30 (5) acetone 60 The solid content of this epoxy resin varnish [1a] is 100
The following inorganic filler was blended with respect to each part to prepare an inorganic filler-containing varnish [2a]. (1) 25 parts of silica (Crystalite VX-3, manufactured by Tatsumori) (2) Gibbsite type aluminum hydroxide (Hygilite H-42, manufactured by Showa Denko) 70 (3) Ultrafine powdered silica (Carplex manufactured by Shionogi Pharmaceutical) 5 Next, a single-piece glass woven fabric of 210 g / m ² (Nitto Boseki W
One side of E-18K RB-84) is 600 ~ 800μm with needle cloth
The inorganic filler-containing varnish [2a] is coated on the raised surface with a knife coater so that the film thickness after drying is 1.4 mm, and 150 mm is applied with a heating device.
C. for 3 minutes. A glass woven fabric with a single weight of 210 g / m ² (Nitto Boseki W
E-18K RB-84) is overlapped so that the raised surface is on the inside, and then the varnish [1a] is applied to both surfaces by a roll coater, and heated and dried at 150 ° C. for 3 minutes with a heating device to prepare a composite prepreg. I got This prepreg is cut to a predetermined length (2 m), and copper foil having a thickness of 18 μm is laminated on both surfaces thereof, and is molded at a molding temperature of 165 ° C., a pressure of 30 kg / cm ² and a pressure of 90 kg.
For 1.6 minutes, thickness 1.6 mm, thickness of intermediate layer 1.
A 4 mm copper-clad laminate was obtained.

Example 2 The epoxy resin varnish [1a] used in Example 1 was mixed with the following inorganic filler with respect to 100 parts of the solid content to prepare a varnish [2b] containing the inorganic filler. did. (1) 25 parts of silica (Crystalite VX-3, manufactured by Tatsumori) (2) Gibbsite type aluminum hydroxide (Hygilite H-42, manufactured by Showa Denko) 70 (3) Ultrafine powdered silica (Carplex manufactured by Shionogi Pharmaceutical) 5 (4) Alumina fiber (Nichias T / # 5100) 5 Fiber diameter 2.5 μm, fiber length average 15 mm or less, through the same process as in Example 1, thickness 1.6 mm,
A copper-clad laminate having an intermediate layer with a thickness of 1.4 mm was obtained.

Comparative Example 1 The varnish [2a] containing the inorganic filler used in Example 1 was
One surface of a glass woven fabric (WE-18K RB-84 manufactured by Nitto Boseki Co., Ltd.) with a single weight of 210 g / m ² that has not been raised is coated with a knife coater so that the film thickness after drying is 1.4 mm. And dried by heating at 150 ° C. for 3 minutes using a heating device. A glass woven fabric of 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 [1a] is coated on both surfaces by 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. Thereafter, 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 2 Comparative Example 1 was repeated except that the inorganic filler-containing varnish [2b] used in Example 2 was used in place of the inorganic filler-containing varnish [2a] used in Example 1. In the same manner as in Example 1, a copper-clad laminate having a thickness of about 1.6 mm was obtained. As in Comparative Example 1, 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 3 (Conventional Example) The varnish [2a] containing the inorganic filler used in Example 1 was applied to a glass nonwoven fabric (EP4075 manufactured by Nippon Vilene) and the total content of the resin and the inorganic filler relative to the entire intermediate layer. And dried by heating at 150 ° C. for 3 minutes with a heating device to obtain a glass nonwoven fabric prepreg. On the other hand, the epoxy resin varnish [1a] used in Example 1 was impregnated into a glass woven cloth (WE-18K RB-84 manufactured by Nitto Boseki Co., Ltd.) that had not been brushed so that the resin content was 40%, and heated. 1 on device
It was dried by heating at 50 ° C. for 3 minutes to obtain a glass woven prepreg. Next, the three glass non-woven fabric prepregs were laminated to form an intermediate layer, glass woven prepregs were disposed as both surface layers, and a copper foil having a thickness of 18 μm was further laminated on both surfaces thereof, at a molding temperature of 165 ° C. and a pressure of 60 kg / cm ^2. For 90 minutes to obtain a copper-clad laminate having a thickness of 1.6 mm.

Example 3 A varnish [2c] containing an inorganic filler was prepared with the following composition. (1) 100 parts of brominated epoxy resin (Ep-1046 manufactured by Yuka Shell) (2) Dicyandiamide 4 (3) 2-ethyl-4-methylimidazole 0.15 (4) Gibbsite type aluminum hydroxide (manufactured by Showa Denko, (Heidilite H-42) 80 (5) Ultrafine powder 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 (Witto Nitto Boseki)
One side of E-18K RB-84) is 600 ~ 800μm with needle cloth
The inorganic filler-containing varnish [2c] is coated on the raised surface with a knife coater so as to have a dried film thickness of 1.4 mm.
C. for 3 minutes. A glass woven fabric with a single weight of 210 g / m ² (Nitto Boseki W
E-18K RB-84) was overlapped so that the brushed side was inside. Next, an epoxy resin varnish [3a] having the following composition was applied to both surfaces by a roll coater, and dried by heating at 150 ° C. for 3 minutes with a heating device to obtain a composite prepreg. (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 200 After cutting this composite prepreg to a predetermined length (2 m),
A copper foil with a thickness of 18 μm is overlaid on top and bottom of the
It was heated and pressed at 5 ° C. under a pressure of 20 kg / cm ² for 90 minutes to produce a 1.6 mm-thick copper-clad laminate.

Example 4 The varnish [2c] containing an inorganic filler used in Example 3 was
A 1.6 mm-thick copper-clad laminate was produced in the same manner as in Example 3, except that the following varnish containing an inorganic filler [2d] was used. The composition of the inorganic filler-containing varnish [2d] is as follows. (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) Gibbsite-type aluminum hydroxide (manufactured by Showa Denko, Hijilite H-42) 80 (6) Ultrafine powdered silica (Carplex manufactured by Shionogi Pharmaceutical Co., Ltd.) 20 (7) Alumina fiber (manufactured by Nichias T / # 5100) 5 Fiber diameter 2.5 μm, fiber length average 15 mm (8) Methyl cellosolve 50

Example 5 An epoxy resin varnish [1b] 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 (2) dicyandiamide 4 (3) 2-ethyl-4-methyl Imidazole 0.15 (4) Methyl cellosolve 30 (5) Acetone 60 A varnish [2e] 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 fabric of a single weight of 210 g / m ² (W
One side of E-18K RB-84) is 600 ~ 800μm with needle cloth
The inorganic filler-containing varnish [2e] is coated on the raised surface with a knife coater so that the film thickness after drying is 1.4 mm, and 150 mm is applied with a heating device.
C. for 3 minutes. A glass woven fabric with a single weight of 210 g / m ² (Nitto Boseki W
E-18K RB-84) is overlapped so that the raised surface is on the inside, and then the epoxy resin varnish [1b] is applied to both surfaces.
Is applied by a roll coater, and heated at 150 ° C.
The resultant was dried by heating for 3 minutes to obtain a composite prepreg. This prepreg is cut into a predetermined length (2 m), and 18 μm
m thick copper foil, forming temperature 165 ° C, pressure 30kg /
It was laminated and molded at 90 cm ² for 90 minutes to obtain a copper-clad laminate having a thickness of 1.6 mm.

Example 6 The varnish [2e] containing an inorganic filler used in Example 5 was
A 1.6 mm-thick copper-clad laminate was produced in the same manner as in Example 5, except that the following varnish [2f] containing an inorganic filler was used. The composition of the inorganic filler-containing varnish [2f] 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 4 The varnish [2e] containing an inorganic filler used in Example 5 was
One surface of a glass woven fabric (WE-18K RB-84 manufactured by Nitto Boseki Co., Ltd.) with a single weight of 210 g / m ² that has not been raised is coated with a knife coater so that the film thickness after drying is 1.4 mm. And dried by heating at 150 ° C. for 3 minutes using a heating device. A glass woven fabric (210 g / m ² single weight, WE-18K RB-84, manufactured by Nitto Boseki Co., Ltd.) that has not been brushed similarly is superposed on the upper surface, and the epoxy resin varnish [1b] is coated on both surfaces by 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. Thereafter, 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 5 Comparative Example 4 was repeated except that the inorganic filler-containing varnish [2f] used in Example 6 was used in place of the inorganic filler-containing varnish [2e] used in Example 5. 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 6 (Conventional Example) An epoxy resin varnish [2 g] 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 [2 g] is impregnated into a glass nonwoven fabric (EP4075 manufactured by Japan Vilene) so that the total content of the resin and the inorganic filler is 90% with respect to the entire intermediate layer. Then, it was dried by heating at 150 ° C. for 3 minutes with a heating device to obtain a glass nonwoven fabric prepreg. On the other hand, the epoxy resin varnish [1b] used in Example 5 was added to a glass woven fabric (WE-18K RB-84, manufactured by Nitto Boseki Co., Ltd.) that had not been brushed to have a resin content of 4%.
It was impregnated so as to have a concentration of 0% and dried by heating at 150 ° C. for 3 minutes with a heating device to obtain a woven prepreg of glass fabric. Next, three pieces of the glass nonwoven fabric prepreg are laminated to form an intermediate layer,
A glass woven prepreg was disposed as both surface layers, and a copper foil having a thickness of 18 μm was laminated on both surfaces thereof.
Lamination molding was performed at a temperature of 60 ° C. and a pressure of 60 kg / cm ² for 90 minutes to obtain a copper-clad laminate having a thickness of 1.6 mm.

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.

[0028]

[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).

[0030]

Since the laminated board of the present invention uses a brushed glass woven fabric, the interlayer adhesion between the surface layer and the intermediate layer is excellent. And since the flow at the time of lamination molding is small or almost nonexistent, the lamination plate has excellent thickness accuracy. By not using an expensive glass nonwoven fabric and improving the yield at the time of molding, the cost of the laminated board can be reduced. 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.

Claims (8)

[Claims] 1. Both surface layers are made of a substrate in which a thermosetting resin is impregnated into a glass woven fabric having at least an inner surface raised,
The laminate is characterized in that the intermediate layer is made of a composition in which a thermosetting resin is mixed with an inorganic filler in an amount of 10 to 300% by weight based on the resin, and these are formed by heating and pressing. 2. The laminate according to claim 1, wherein the intermediate layer is made of a composition in which inorganic fibers or organic fibers are mixed at 0.01 to 50% by weight with respect to the thermosetting resin. 3. The laminate according to claim 2, wherein the fiber diameter of the inorganic fiber or the organic fiber mixed with the resin of the intermediate layer is 15 μm or less. 4. The ratio of the total amount of the thermosetting resin and the inorganic filler contained in the entire laminate to the glass woven fabric of the surface layer is 2.0 to 10.0. A laminate as described. 5. The laminated board according to claim 1, wherein the raised length of the glass woven fabric is 50 μm or more. 6. The laminate according to claim 1, wherein the intermediate layer has a thickness of 0.2 to 2.0 mm. 7. The laminate according to claim 6, wherein the thickness of the intermediate layer is 0.6 to 1.4 mm. 8. The intermediate layer is composed of a composition obtained by mixing a thermosetting resin with an inorganic filler in an amount of 100 to 150% by weight based on the weight of the resin. A laminate as described.