JPS6072931A - Production of paper-base phenolic resin laminate - Google Patents

Abstract

PURPOSE:To obtain the titled laminated excellent in low-temperature punchability, electrical properties, etc., and low in warpage and twist, by laminating and molding prepregs formed by impregnating paper bases containing an inorganic filler and a silane coupling agent with a specified phenolic resin varnish. CONSTITUTION:Paper bases containing an inorganic filler and a silane coupling agent are impregnated with a phenolic varnish formed by mixing a phenolic resin with 5-50wt% inorganic filler and 0.5-2wt%, based on the inorganic filler, silane coupling agent and dried to obtain prepregs. These prepregs are laminated and molded. The paper base must contain the silane coupling agent because this improves adhesion among the paper base, the filler, and the phenolic resin. The silane coupling agent is added to the phenolic resin because this improves the affinity of the resin for the filler and allows smooth mixing of both.

Description

Detailed Description of the Invention The present invention provides low-temperature punching workability, moisture resistance, heat resistance, electrical properties,
Excellent insulation properties and dimensional stability after boiling treatment, no warping,
This invention relates to a method for producing an inexpensive paper phenolic resin laminate with little twist.

Paper phenolic resin laminates and copper foil-clad laminates, which are generally used as printed circuit boards, are of course required to have electrical, thermal, and mechanical properties, but from the viewpoint of processing the laminates, , low-temperature punchability, low warpage and twisting, and excellent dimensional stability are required.

Conventional paper-based phenolic resin laminates and copper foil-clad laminates are linter paper impregnated with phenolic resin varnish. Sarashi kraft paper. Mixed paper (Sarashi Craft (50~
Laminated boards are widely used, which are made by laminating the required number of base materials such as linter (90%) (50-10%) and forming them under heat and pressure in a molding press, but because they are impregnated with resin, It has the disadvantage of poor dissipation properties and large expansion and contraction due to heat, and therefore, when used, it is easy to cause local overheating due to various heat shocks in the printed board processing process, and as a result, the dimensions There is a disadvantage that changes, warpage, twisting, etc. become large. In the case of copper foil-clad laminates, due to the difference in linear expansion coefficient between the copper foil and these impregnated varnishes, stress is generated due to heat shock during lamination work and the printed board processing process, causing warping and twisting, and There is a problem with adhesion. The present invention has been made in view of these points, and is made by adding 5 to 50% by weight of an inorganic filler in a phenol resin and a silane coupling agent as an inorganic filler to a paper base material containing an inorganic filler and a silane coupling agent. This method is characterized by laminating and molding prepregs impregnated with a phenolic resin varnish added and mixed in an amount of 0.5 to 2% by weight and dried.

That is, the present invention uses paper base materials (Sarashi Kraft paper, linter paper, mixed paper (Sarashi Kraft (50
Inorganic fillers such as clay, fused silica glass, silica, aluminum oxide, calcium carbonate, calcium oxide, acitimony oxide, titanium oxide, etc. are added to the paper base (~90%) and linter paper (50~10%). 5 to 30% by weight,
A paper base material in which 0.5 to 2% by weight of silane coupling material is injected into the paper base material is used, and on the other hand, clay fused silica glass is added to the phenolic resin constituting the above laminate and copper foil clad laminate. 5 to 50% by weight of an inorganic filler such as silica, aluminum oxide, calcium carbonate, calcium oxide, antimony oxide, titanium oxide, etc. and 0.5 to 2% by weight of a silane coupling agent based on the amount of the inorganic filler are added. It is characterized by impregnating the above-mentioned inorganic filler mixed paper with the phenolic resin, laminating the required number of dried phenolic resin-impregnated papers, and molding them under heat and pressure in a molding press.

In the present invention, the amount of inorganic filler mixed into the paper base material (added amount) is limited to 5 to 30% by weight for the following reasons:
If it exceeds 0% by weight, the tensile strength of the paper base material will be greatly reduced when the inorganic filler is mixed, and there is a high possibility that the paper base material will be cut during the impregnation operation with the phenol resin. Moreover, if the impregnating property exceeds 30% by weight, the impregnating properties will be very poor, and efficiency problems will occur during actual work. If it is less than 5% by weight, the effect of contamination is difficult to be seen.

Similarly, the reason why the amount of inorganic filler added in the phenolic resin for impregnation was limited to 5 to 50% by weight is that if the amount added is less than 5% by weight, satisfactory results such as dimensional stability cannot be obtained.
Furthermore, if the amount exceeds 50% by weight, the viscosity of the phenolic resin varnish increases, which adversely affects workability and impregnation properties, and adversely affects the properties of the laminate. This is because, in some cases, such drawbacks can be largely eliminated and the effects of the present invention can be achieved.

The main purpose of applying the silane coupling agent at the same time when applying the filler into the paper base material is to improve the adhesion between the paper base material, the filler, and the impregnated phenolic resin. The reason for adding and mixing the silane coupling agent is that if the silane thread coupling agent is not added and mixed, it will be difficult to mix the phenol resin and the inorganic filler smoothly, which will improve solder heat resistance, heat resistance, bending strength, and electrical properties. However, when a silane coupling agent is added and mixed, the affinity between the phenolic resin and the inorganic filler improves, allowing for smooth mixing, which adversely affects the properties of the laminate such as water absorption. This is because various properties such as thermal expansion, shrinkage, and dimensional changes can be improved without adversely affecting the properties.

The most suitable method for adding the inorganic filler fine powder to uniformly disperse it in the phenolic resin is, for example, a colloid mill, a homo mixer, a Laikai machine, a roll kneading method, or the like.

If filler sedimentation is likely to occur during use of filler-containing phenolic resin, use a small amount of a thixotropic agent such as colloidal or silica to prevent sedimentation without impairing workability. be able to.

Further, it is also possible to mix paper with an inorganic filler that has been treated with a silane coupling agent in advance.

Example 1 Phenol resin (tung oil amount: 30%): 100 parts by weight Silica powder: 21 Amino silane coupling agent: 0.21 The varnish composition was adjusted to have a non-volatile content of 55 to 60% by weight using a solvent. , paper base material made of Sarashi Kraft paper with inorganic filler and silane coupling agent (Sarashi Kraft 100)
% by weight, clay: 20% by weight, silane coupling agent 1% by weight) and dried to obtain a phenolic resin-impregnated paper having a resin content of 50 to 55% by weight and having no tackiness at room temperature.

Layer the required number of sheets, pressure 1, 50kg/cm2, temperature 1
Molding was carried out at 65° C. for 60 minutes to produce a single-sided copper foil-clad laminate having a thickness of 1.6 mm.

Example 2 Phenol resin (tung oil amount: 30%): 100 parts by weight Clay: 35 Amino silane coupling agent: 0.35 The non-volatile content of the varnish composition was adjusted to 55 to 60% by weight using a solvent, Paper base material made of Sarashi kraft paper with inorganic filler and silane coupling agent (Sarashi kraft paper 100)
25 parts by weight of silica powder, 1.0 parts by weight of silane coupling agent) and dried to obtain a phenolic resin-impregnated paper having a resin content of 50 to 55% by weight and having no tackiness at room temperature. A required number of sheets were stacked and molded at a pressure of 150 kg/cm2 and a temperature of 165° C. for 60 minutes to produce a single-sided copper foil-clad laminate having a thickness of 1.6 mm.

Example 3 Phenol resin (tung oil amount: 30%): 100 parts by weight Fused silica glass: 50 Amino silane coupling agent: 0.50 The non-volatile content of the varnish composition was adjusted to 55 to 60% by weight using a solvent. A paper base made of Saran/Kraft paper with inorganic filler and silane/coupling agent (Saran/Kraft paper 1)
00 parts by weight, 30 parts by weight of clay, and 1 part by weight of a silane coupling agent) and dried to obtain a phenolic resin-impregnated paper having a resin content of 50 to 55% by weight and having no tackiness at room temperature.

Layer the required number of sheets, pressure 150 kg/cm2, temperature 16
Molding was carried out at 5° C. for 60 minutes to produce a single-sided copper foil-clad laminate having a thickness of 1.6 mm.

Example 4 A required number of sheets of the phenol resin-impregnated paper prepared in Example 1 were stacked together and molded at a pressure of 150 kg/cm 2 and a temperature of 165° C. for 60 minutes to form a laminate with a thickness of 1.6 mm.

Comparative Example 1 A sample was prepared in the same manner as in Example 1 except that no silane coupling agent was added to the paper base material and phenolic resin.

Comparative Example 2 A sample was prepared in accordance with Example 1 except that the inorganic filler and silane coupling agent were not added to the paper base material and phenolic resin.

The properties of the single-sided copper-clad laminate obtained above are shown in Table 1. (Test method: JISC6481) As is clear from the results in Table 1, in the examples of the present invention, the laminate properties such as electrical insulation resistance after boiling, bending strength, soldering heat resistance, air heat resistance, surface resistance uL beer etc. Comparative Example 1, in which only an inorganic filler was added, and Comparative Example 2, in which an inorganic filler and a silane coupling agent were not added, had the best properties such as expansion rate and contraction rate. However, there are some problems and it is hard to say that it is satisfactory.

As explained above, paper phenol copper-clad laminates and paper phenol laminates using inorganic filler and silane coupling paper as the paper base material and using inorganic filler and silane coupling agent in phenolic resin are boiled. It has excellent laminate properties such as insulation resistance, bending strength, solder heat resistance, air heat resistance, UL beer, surface resistance, etc., as well as expansion rate and contraction rate after treatment, and has good dimensional stability and resistance to warping and twisting. It is something.

Claims (1)

[Claims] 1. Paper base material containing inorganic filler and silane coupling,
Prepreg is laminated and molded by impregnating and drying a phenolic resin varnish made by adding and mixing 5 to 50% by weight of an inorganic filler and 0.5 to 2% by weight of a silane coupling agent based on the amount of inorganic filler in a phenolic resin. A method for producing a paper-based phenolic resin laminate, characterized by: