JPH08174736A - Laminated sheet - Google Patents

Abstract

PURPOSE: To obtain a low-cost laminated sheet for a printing circuit enhanced in blanking properties, dimensional change, and warpage level without deteriorating electric characteristics and other characteristics by a method wherein a surface layer is made of a thermosetting resin-impregnated fibrous substrate, and an intermediate layer is made of a composition prepared by mixing a specific amount of a glass fiber in a thermosetting resin per the total amount of the thermosetting resin. CONSTITUTION: In a laminated sheet, a surface layer is made of a thermosetting resin-impregnated fibrous substrate, and an intermediate layer is made of a composition prepared by mixing 5-100wt.% glass fiber in a thermosetting resin per the total amount of the thermosetting resin. In case the mixing ratio of glass fiber in the thermosetting resin in the intermediate layer is less than 5wt.%, the glass fibers less interlock and result in reduction of a strength. In case more than 100wt.%, blanking properties are deteriorated. Furthermore, by loading 10-200wt.% inorganic filler in the thermosetting resin in addition to the glass fiber, blanking properties and a dimensional stability can be kept and enhanced, a thermal expansion in a Z direction can be reduced, and a through hole reliability can be enhanced.

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 in electric equipment, electronic equipment, communication equipment and the like.

[0002]

2. Description of the Related Art Consumer electronic devices have become smaller and more sophisticated, and as a printed circuit board used for them, glass nonwoven fabric is used as an intermediate layer base material and glass woven fabric is used as a surface layer base material. A laminate (hereinafter referred to as a composite laminate) impregnated with a resin and heat-pressed is used. Recently, such composite laminates have been required to have the same punching workability and lower cost as those of the paper-based phenolic laminates conventionally used in this field.

Also in the field of industrial electronic equipment, composite lamellas which do not use woven glass cloth or whose use amount has been reduced have come to be used due to the need for cost reduction, but in view of performance, glass is used. It is inferior to the woven fabric substrate laminate in various points, and it has been required to have the same dimensional change and small warpage as those.

Further, in the composite laminated plate, a glass nonwoven fabric is used, but the length of the glass fiber is relatively long due to the restriction on the production of the nonwoven fabric. Therefore, the punching workability, the warpage and the dimensional change are large, and this improvement is desired. Was there. Further, it is difficult to reduce the cost because the cost of the nonwoven glass fabric is high.

[0005]

The present invention has been made as a result of various studies in order to solve the above-mentioned problems, and its purpose is to reduce electrical characteristics and other characteristics. It is an object of the present invention to provide a laminated board for a printed circuit, which has improved punching workability, dimensional change, and warp level, and is low in cost.

[0006]

According to the present invention, the surface layer comprises a fibrous base material impregnated with a thermosetting resin, and the intermediate layer comprises 5 to 100% by weight of the thermosetting resin and glass fiber with respect to the resin.
A laminated board characterized by comprising a composition formed by mixing,
And, the surface layer is made of a thermosetting resin-impregnated fiber base material, and the intermediate layer is made of thermosetting resin and glass fiber to the resin.
˜100% by weight, 10 to 100% by weight of inorganic filler with respect to the resin
The present invention relates to a laminate, which is composed of a composition in which 200% by weight is mixed.

The glass fiber used for the intermediate layer of the laminate of the present invention is a chopped strand having a length of usually 0.1 to 20 mm, preferably 1 to 7 mm. 0.1
If it is less than mm, the fibers are less entangled and the strength is lowered.
Also, if it exceeds 20 mm, the orientation of the fibers becomes remarkable,
It adversely affects dimensional changes and warpage. Fiber diameter is usually 6
˜20 μm, preferably 9 to 13 μm. 6 μm
If it is less than the above range, it is difficult to produce the glass fiber and the cost is increased. On the other hand, if it exceeds 20 μm, the fiber diameter becomes large and the punching workability deteriorates. The mixing ratio of the glass fiber to the thermosetting resin of the intermediate layer is 5 to 100% by weight, preferably 9 to
It is 20% by weight. If it is less than 5% by weight, the entanglement of glass fibers is small and the strength is lowered, and if it exceeds 100% by weight, the punching workability becomes poor. Further, when the glass fiber used is treated with a sizing agent such as starch or urethane and a coupling agent such as epoxysilane, the dispersibility in the resin varnish and the adhesiveness with the resin are improved.

Further, when an inorganic filler other than glass fiber is added to the thermosetting resin of the intermediate layer, punching workability and dimensional stability are maintained and improved, and thermal expansion in the Z direction is reduced, so that the through hole reliability is improved. It is also possible to improve. Such inorganic fillers include aluminum hydroxide, calcium carbonate, clay, talc, silica and the like, and the mixing ratio with respect to the resin is preferably 10 to 200% by weight. If it is less than 10% by weight, the effect of improving the reliability of through holes is small, and if it exceeds 200% by weight, it becomes difficult to mix the inorganic filler.

The thermosetting resin used in the present invention is preferably an epoxy resin, but in addition to this, a polyimide resin, a polyester resin, a phenol resin or the like can be used. Further, the fiber base material used for the surface layer is not particularly limited, such as glass fiber woven fabric, glass fiber nonwoven fabric, synthetic fiber woven fabric or nonwoven fabric, kraft paper, linter paper, but from the viewpoint of heat resistance and strength, glass fiber woven fabric. Is preferred.

[0010]

The laminated sheet of the present invention is a resin composition obtained by mixing glass fibers cut into a predetermined size in a thermosetting resin without using the glass nonwoven fabric used in the conventional composite laminated sheet in the intermediate layer. Are using. Therefore, since the glass fiber having a shorter fiber length than the fiber length of the glass nonwoven fabric is used, it is easy to mix the resin and the glass fiber, the molded laminate has good punching workability, and the orientation of the glass fiber is extremely high. Since it is small, it has excellent warpage and dimensional stability. Furthermore, by mixing an inorganic filler together with glass fiber in the intermediate layer, the above characteristics can be further improved and the reliability of through-hole plating can be improved.

Further, although the glass nonwoven fabric is expensive in the manufacturing process, the laminated plate of the present invention does not use the glass nonwoven fabric,
Since the glass fiber or the glass fiber and the inorganic filler are simply mixed with the thermosetting resin, cost reduction can be achieved.

[0012]

Examples of the present invention and comparative examples (conventional examples) are described below.
Indicates. "Parts" and "%" indicate "parts by weight" and "% by weight", respectively.

Example 1 The composition of a varnish containing an epoxy resin is as follows. (1) Brominated epoxy resin (Ep-1046 manufactured by Yuka Shell Co., Ltd.) 100 parts (2) Dicyandiamide 4 (3) 2-Ethyl-4-methylimidazole 0.15 (4) Methylcellosolve 30 (5) Acetone 60 The above materials Were mixed to prepare a uniform varnish. This varnish was woven into glass (Nitto Boseki WE-18K RB-8
4) was impregnated with a resin content of 30 to 40% and dried to obtain a woven glass prepreg [A]. Then, to 100 parts of the resin solid content of the epoxy resin-blended varnish, the following inorganic filler was added and mixed by stirring to prepare an inorganic filler-containing varnish [1]. (1) Silica (Tatsumori Crystallite VX-3) 25 parts (2) Gibbsite type aluminum hydroxide (Showa Denko, Heidilite H-42) 70 (3) Ultra fine powder silica (Shionogi Pharmaceutical Carplex) 5

A glass fiber having a fiber length of 3 mm and a fiber diameter of 10 μm was added to the inorganic filler-containing varnish [1] (Nitto Boseki C
S3J-254 silane treatment) was stirred and mixed so as to be 10% with respect to the total amount of the resin and the inorganic filler to prepare a varnish [2].

This varnish [2] was applied to one surface of the above-mentioned glass woven prepreg [A] by a knife coater so that the film thickness after drying was 0.6 mm, and dried to obtain a prepreg [B]. Next, two sheets of this prepreg [B] are laminated with the coated surface inside, and a copper foil with a thickness of 18 μm is further laminated on both surfaces, and the molding temperature is 165 ° C. and the pressure is 60 kg / cm ²
The laminate was molded for one minute to obtain a copper clad laminate having a thickness of 1.6 mm.

Example 2 A glass fiber having a fiber length of 3 mm and a fiber diameter of 10 μm (CS3J-254 manufactured by Nitto Boseki Co., Ltd.) per 100 parts of the resin solid content of the epoxy resin-blended varnish.
A varnish [3] was prepared by stirring and mixing 10% by weight of the silane treatment). Hereinafter, the varnish [3] was used instead of the varnish [2] in the previous period, and the prepreg and the copper foil were laminated and formed in the same manner as in Example 1 to obtain a copper-clad laminate having a thickness of 1.6 mm.

Comparative Example 1 The inorganic filler-containing varnish [1] obtained in Example 1 was added to a glass nonwoven fabric (Japan Vilene EP4075) so that the total content of the resin and the inorganic filler was based on the total amount of the intermediate layer. It was impregnated and dried to 90% to obtain a glass nonwoven fabric prepreg [C]. Next, this glass nonwoven fabric prepreg [C] was used as an intermediate layer, the glass woven fabric prepreg [A] obtained in Example 1 was placed on the upper and lower surface layers, and a copper foil having a thickness of 18 μm was laminated on both surfaces thereof, and Example 1 In the same manner as in (1) and (2) above, hot press molding was performed to obtain a copper-clad laminate having a thickness of 1.6 mm.

Comparative Example 2 The epoxy resin-blended varnish obtained in Example 1 was used as a glass non-woven fabric (manufactured by Japan Vilene E
P4075), the resin content is 9 with respect to the entire intermediate layer.
It was impregnated and dried to 0% to obtain a glass nonwoven fabric prepreg [D]. Next, this glass nonwoven fabric prepreg [C] was used as an intermediate layer, and the glass woven fabric prepreg [A] obtained in Example 1 was placed on the upper and lower surface layers, and 1 was placed on both sides thereof.
A copper foil having a thickness of 8 μm was overlaid and heat-pressed in the same manner as in Example 1 to obtain a copper-clad laminate having a thickness of 1.6 mm.

With respect to the copper clad laminates obtained in the above Examples and Comparative Examples, punching workability, dimensional change rate, bending strength, etc. were measured. Table 1 shows the results.

[0020]

[Table 1]

(Measurement method) 1. Punching processability: According to ASTM method, ◯: Good,
Δ: Slightly defective. 2. Warpage: The maximum amount of warpage was measured after heating a test piece of a copper clad laminate having a piece of 300 mm for 30 minutes at 170 ° C. 3. Dimensional change rate: The dimensional change rate of the hole spacing was measured after heating a test piece of a copper clad laminate having a hole spacing of 250 mm at 170 ° C. for 30 minutes. 4. Bending strength: According to JIS C 6481 5 Z-direction thermal expansion coefficient: The copper clad laminate is entirely etched,
The temperature was raised from room temperature to 200 ° C. at 10 ° C./min, and the coefficient of thermal expansion in the Z direction was obtained.

Regarding the manufacturing cost, the laminated plates obtained in Examples 1 and 2 did not use the expensive glass fiber nonwoven fabric from the manufacturing process, but thermosetting the glass fiber or the glass fiber and the inorganic filler. Since it is mixed with the resin to form the intermediate layer, the cost can be reduced by about 10 to 20% as compared with those obtained in Comparative Examples 1 and 2.

[0023]

EFFECT OF THE INVENTION The laminated sheet of the present invention has no deterioration in bending strength and the like, and is excellent in punching workability, warpage and dimensional stability.
Cost reduction can also be achieved.

Claims (2)

[Claims] 1. The surface layer is made of a thermosetting resin-impregnated fiber base material, and the intermediate layer is made of a composition in which glass fiber is mixed with the thermosetting resin in an amount of 5 to 100% by weight based on the resin. Laminated board. 2. The surface layer is made of a thermosetting resin-impregnated fiber base material, and the intermediate layer is a thermosetting resin containing 5 to 100% by weight of glass fibers with respect to the resin and an inorganic filler with respect to the resin. A laminated board comprising a composition in which 10 to 200% by weight of each is mixed.