JPS62125690A - Electric circuit forming substrate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of Industry-1-1] The present invention relates to a base for forming an electric circuit, and more specifically,
The present invention relates to a base for forming an electric circuit comprising a metal foil, an insulating layer, and a metal substrate that have excellent adhesive strength between the insulating layer and the metal substrate.

1 Conventional technology 1 Conventionally, the metal substrate, the insulating layer, and the metal foil are bonded together with an adhesive in the base for forming an electric circuit.
The metal substrate and the insulating layer may peel off or spontaneously peel off, resulting in a short circuit with other circuits or components, or the insulating layer may completely peel off from the metal substrate and separate, making it unusable. In addition, metal substrates are subjected to chromate treatment, phosphoric acid chromate treatment, and phosphorus phosphate treatment for rust prevention and paint adhesion.

Therefore, when a metal substrate such as iron or aluminum is used as a base for forming an electric circuit, general environmental concepts include heat resistance, cold resistance, and moisture resistance, but moisture resistance in particular is a problem. Become. That is, the metal substrate reacts with moisture that passes through the insulating layer, causing rust if no treatment is performed, and this brittle rust causes breakage and peeling.

In general, chromate treatment, phosphoric acid chromate treatment, and phosphate treatment are used as base treatments for painting, but in painting, it is only necessary that the paint adheres, and any treatment may be used. In order to mount parts, for example, in the case of a base such as a motor, a copper coil is mounted on the mount, and the electromagnetic lines of force of this coil may apply force to rotate a permanent magnet. Therefore, as explained above, there is a possibility that the insulating layer will peel off from the metal substrate, especially in a humid environment.

[Problem to be Solved by the Invention 1] As explained in 1-, the present invention solves the problem of peeling of the metal substrate and the insulating layer in the conventional electric circuit forming base made of metal foil, insulating layer, and metal substrate. In view of this, as a result of intensive research by the present inventors, we have discovered a surface treatment layer that will prevent the insulating layer from peeling off from the metal substrate in any humidity environment in the substrate for forming electric circuits, and based on this knowledge, we have created a surface treatment layer that has excellent peeling resistance. They developed a base for forming electrical circuits consisting of metal foil, an insulating layer, and a metal substrate.

Means for Solving Problem 1 The feature of the electric circuit forming board according to the present invention is that a phosphate film, an insulating layer, and a metal foil are provided in this order on a metal substrate.

The electric circuit forming base according to the present invention will be described in detail below.

First, the materials used in the electric circuit forming board according to the present invention will be explained.

Since the metal foil is a conductor, it is naturally made of copper, which has excellent conductivity, and preferably has a thickness of S = 70μ. Furthermore, this metal foil can be used for aluminum, copper alloy,
Nickel, silver, a conductive metal, or an alloy thereof is used.

The insulating layer is made of an adhesive, a heat-resistant insulating film, and an adhesive, and the adhesive and the heat-resistant insulating film will be explained below.

It is best to use an epoxy adhesive that has relatively good electrical insulation properties, and other adhesives that have good adhesion to metals and good electrical insulation properties, such as polyamide, etc.
Imide-based, silicone-based, acrylic-based, polyester-based, and polyurethane-based materials can also be used. In addition, the thickness of the adhesive should be determined based on the insulation required as an electrical insulation layer when combined with a heat-resistant insulation film, and is approximately 2.
The thickness is preferably 0 to 200μ.

The 14% Mffl film has no defects such as pinholes, can be melted by heating, has heat resistance, is unaffected by adhesives, and has excellent electrical insulation properties. For example, polyimide film is preferred. The thickness of this heat-resistant insulating film is preferably from 3-5 to 50 mm. In addition to the insulating film listed in L, polyester film, polyetherimide, polysulfonate film, etc. can also be used depending on the purpose. This insulating layer is not affected by pattern etching of the metal foil.

As the metal substrate, an ordinary steel plate with a thickness of 0.3 to 3.0 mm or a silicon steel plate with a thickness of 0.1 to 1.0 mm is used. Additionally, aluminum and aluminum alloys can be used.

The phosphate coating is provided by conventional phosphate treatment.

A chromate treatment film may also be considered, but if this chromate treatment is applied to an iron or aluminum substrate,
It is formed from trivalent and hexavalent chromates, but hexavalent chromium is water-soluble, and the hexavalent chromium is eluted by permeating moisture, causing the insulating layer to peel off from the iron or aluminum alloy substrate.

Therefore, as the phosphate film, a zinc phosphate film, a calcium phosphate film, an iron phosphate film, or a chromium phosphate film can be applied to the surface treatment of the electric circuit forming board according to the present invention, but it is particularly preferable to provide a zinc phosphate film. be.

In addition, in the case of an iron substrate, zinc or zinc alloy plating can be provided on one or both sides of the iron substrate by a normal electroplating method.

Next, to briefly explain the manufacturing method of the base for forming an electric circuit according to the present invention, an adhesive is applied to a long metal foil, and after heating, a heat-resistant insulating film is bonded to form a coil shape. An iron substrate coated with an adhesive and provided with a phosphate film (it may also be provided with zinc plating),
An adhesive and a phosphate film are bonded together to form a base material for forming an electric circuit, which is then cut into appropriate dimensions and further heated to form a base product for forming an electric circuit. Furthermore, in the case of an aluminum substrate, an electric circuit forming substrate can be manufactured in the same manner as the iron substrate described in section 1.

Therefore, in the electric circuit forming board according to the present invention shown in FIG. 1, the phosphate film on the zinc plating and the insulating layer are firmly adhered to the iron substrate, so that it can be used in any humidity environment. The iron substrate and the insulating layer will not peel off.

[Embodiment 1] An embodiment of the electric circuit forming board according to the present invention will be described.

Example: A material obtained by galvanizing an iron substrate (20 g on one side, plating on both sides) was treated by (1) phosphate treatment to form a zinc phosphate film, (2) chromate treatment to form a chromate film, and these two surfaces were Where J'! 1! An insulating layer (adhesive material, heat-resistant insulating film, adhesive) 5()μ was formed on the iron substrate, and a copper foil was bonded thereto. , 2-(1) and (2) were subjected to normal adhesive strength, wet adhesive strength and pressure Kunker tests, and the results are shown in Table 1.

From this Table 1, it can be seen that the electric circuit formation substrate according to the present invention is:
It can be seen that the adhesive strength in normal and wet conditions is superior to other examples, and no peeling occurred at all.

[Advantageous Effects of the Invention 1] As explained below-1, since the electric circuit forming substrate according to the present invention has the structure described below, the metal substrate and the insulating layer do not peel off and have excellent adhesive strength. It has this effect.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a substrate for forming an electric circuit according to the present invention, and FIG. 2 is an explanatory view for measuring adhesive strength. fl Figure-? Figure 2

Claims (1)

[Claims] A base for forming an electric circuit, characterized in that a phosphate film, an insulating layer, and a metal foil are provided in this order on a metal substrate.