JPS6054860B2 - Copper-clad phenolic resin laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in copper-clad phenolic resin laminates, and its purpose is to improve tracking resistance while maintaining the excellent heat resistance and punching workability of copper-clad phenolic resin laminates. The aim is to improve one's sexuality.

Conventionally, in order to improve the tracking resistance, which is a drawback of copper-clad phenolic resin laminates, large amounts of melamine resin, epoxy resin, etc., which have good tracking resistance, are mixed into phenolic resin varnish. The excellent performance as a phenolic resin was lost, which became a problem.

In order to eliminate these conventional drawbacks, the present invention provides a tracking-resistant material layer with good adhesion to copper and phenolic resin with a thickness of 0.025 to 0.1 wL between the prepreg and copper foil, and laminates copper-clad phenolic resin. The plate has improved tracking resistance so that it can be safely used in tracking generation applications such as electronic parts.

Next, the method of the present invention will be explained in detail.

The substrates for laminates used in the present invention are general substrates for laminates, such as woven fabrics and nonwoven fabrics made of inorganic fibers such as paper and glass fibers, or organic fibers (such as cotton and polyamide fibers). The phenolic resin varnish to be impregnated into the base material is a general phenolic resin varnish for laminated boards made by diluting a novolac type or resol type phenol resin with an organic solvent or water to a resin content of about 50%. The copper foil has a purity of 99.5% or more and a thickness of 0.
018 to 0.105 wgn, which is generally used for copper-clad laminates. Tracking-resistant film materials include epoxy resin 30-7% (hereinafter simply referred to as %), polyvinyl butyral resin 30-70%, and melamine resin 0-10%.
% mixture is used. That is, if the epoxy resin content is less than 30%, the heat resistance will decrease, and if it exceeds 70%, the adhesive strength will decrease. This is because if the polyvinyl butyral resin content is less than 30%, the adhesive strength will decrease, and if it exceeds 70%, the heat resistance will decrease. This is because if the melamine resin content exceeds 10%, the heat resistance and adhesive strength will decrease. First, phenols and formaldehydes are mixed in a predetermined molar ratio, a catalyst is added, the reaction is made, and the phenol resin varnish obtained by diluting with an organic solvent or water to a predetermined resin content is applied to paper, cloth. A pre-preg is obtained by impregnating and drying a base material such as, a predetermined number of sheets are laminated, and a laminate is obtained by layering copper foil on the top or both sides, and epoxy resin 3 is applied between the prepreg and the copper foil.
0-70%, polyvinyl butyral resin 30-70%,
An anti-tracking material consisting of 0 to 10% melamine resin is applied to the prepreg surface or copper foil surface to a thickness of 0.025 to 0.17 m, or it is inserted in the form of a film or paper, cloth, etc. It is provided by inserting it in the form of a prepreg impregnated into a base material.

That is, if the thickness of the tracking-resistant material layer is less than 0.025 mm, the tracking resistance is insufficient, and if the thickness is less than 0.1 Tmm.
This is because if it exceeds this, the punching processability will deteriorate. In this way, a tracking-resistant material layer is provided between the prepreg and the copper foil, and then heated and pressure molded to form a material, which improves the tracking resistance of the copper-clad phenolic resin laminate and improves electrical insulation resistance. A copper-clad phenolic resin laminate with good punching workability is obtained. Next, the present invention will be explained based on examples.

Examples 1 to 4 The phenolic resin varnish used in the present invention contains 1.6 formaldehyde per mole of phenol.
After adjusting the pH to 8.6 with sodium hydroxide and reacting at reflux temperature for 10 minutes, this was thickened with a phenolic resin varnish that had been dehydrated under reduced pressure and diluted with methyl alcohol to a resin content of 50%. A prepreg was obtained by impregnating and drying kraft paper with a thickness of 0.1 Twt to a resin content of 48 to 53%. Eight sheets of this prepreg were laminated, and the top surface was further covered with copper foil with a thickness of 0.0357 m on the back side. A tracking-resistant material layer having the composition shown in Table 1 was formed to a thickness of 0.03w0n.
After applying and drying one sheet of copper foil so that the copper side is on the outside, molding pressure is 120k91cIt11.
Lamination molding was carried out at 55° C. for 60 minutes to obtain a copper-clad phenolic resin laminate having a thickness of 1.6 wt.

The epoxy resin used was a mixture of Epicure DX22O (trade name, manufactured by Shell Chemical Co., Ltd.) and Epicure DXl2O (trade name, manufactured by Shell Chemical Co., Ltd.) as a curing agent. Polyvinyl butyral resin is a commercially available product.
For melamine resin, add 2.6 moles of formaldehyde to 1 mole of melamine, and adjust the pH to 9 with sodium hydroxide.
A melamine resin varnish diluted with methyl alcohol to a resin content of 50% was used. Example 5 Film 1 was obtained by using the same prepreg as in Example 1, laminating 8 sheets of this prepreg, and then drying the same tracking resistant material as in Example 1 on the top surface to a thickness of 0.1 mm. On top of the stacked sheets, one sheet of the same copper foil as in Example 1 was layered and treated in the same manner as in Example 1 to obtain a copper-clad phenolic resin laminate.

Example 6 Using the same prepreg as in Example 1, 8 sheets of this prepreg were laminated, and the same tracking resistant material as in Example 4 was impregnated into kraft paper with a thickness of 0.1 Tfn on the upper surface and dried to form one sheet of prepreg. On top of the stack, one sheet of the same copper foil as in Example 1 was stacked and treated in the same manner as in Example 1 to obtain a copper-clad phenolic resin laminate.

Comparative Examples 1 to 5 Using the same prepreg and copper foil as in Example 1, an anti-tracking material having the composition shown in Table 2 was applied to the back side of the copper foil to a thickness of 0.03 Trfm for Comparative Examples 1 to 3, and for Comparative Example 4. The copper foil was coated to a thickness of 0.02710 nm, and the copper foil coated to a thickness of 1.6 mm was treated in the same manner as in Example 1, except that Comparative Example 5 was coated with a copper foil coated to a thickness of 0.1 mm and dried. A copper-clad phenolic resin laminate was obtained.

The epoxy resin, polyvinyl butyral resin, and melamine resin used as the anti-tracking material were the same as in the examples. The performance of these laminates is shown in Table 3, and it was confirmed that the laminates of the present invention have good tracking resistance, heat resistance, and punching workability, and are superior to the present invention.

Claims (1)

[Claims] 1. A laminate made by laminating a required number of prepregs impregnated with phenolic resin varnish and drying on a base material such as paper or cloth, and further layering copper foil on the top or both sides of the laminate by heating and pressurizing the laminate to integrate it. A copper-clad phenolic resin laminate, characterized in that a tracking-resistant material layer with good adhesion to copper and phenolic resin is provided between the prepreg and the copper foil with a thickness of 0.025 to 0.1 mm. Phenolic resin laminate. 2 The tracking-resistant material layer is made of epoxy resin 30 to 70
% by weight, polyvinyl butyral resin 30-70% by weight,
The copper-clad phenolic resin laminate according to claim 1, characterized in that the melamine resin is contained in a proportion of 0 to 10% by weight. 3. The copper-clad phenolic resin laminate according to claim 1, wherein the tracking-resistant material layer is provided by coating on the prepreg surface or the copper foil surface. 4. The copper-clad phenolic resin laminate according to claim 1, wherein the tracking-resistant material layer is provided in the form of a film. 5. The copper-clad phenolic resin laminate according to claim 1, wherein the tracking-resistant material layer is provided in the form of a prepreg impregnated into a base material such as paper or cloth.