JPS61148899A - Manufacture of substrate for circuit - 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 Use] The present invention relates to a circuit board having an electrical insulation layer between a metal core plate and a conductive metal foil, which function as a heat sink material, a magnetic AT material, etc. Concerning new manufacturing methods.

[Conventional technology]

As electronic devices have become lighter and smaller in recent years, circuit boards having the above-mentioned structure are required to have even better withstand voltage characteristics.

Conventionally, circuit boards have been manufactured by interposing and adhering a film of an organic polymer having excellent heat resistance and electrical insulation properties, such as diriimide, between a metal core plate and a conductive metal foil.

[Problems to be solved]

By the way, since commercially available organic polymer films have pinholes in some places, a substrate having a film having pinholes as the insulator 1 has extremely low electrical characteristics. As a separate note, the quality of conventional products varied in terms of voltage resistance and was inferior in reliability.As a result of intensive research, the present inventors developed a water-soluble or water-dispersible electrodeposited varnish. Electrodeposited film 1/
It was discovered that 1k111 has stable voltage resistance characteristics9 and is suitable as electrical insulation for circuit boards.

However, the electrodeposited insulation 1 generally has a problem of poor peeling strength and peeling due to heating during circuit soldering.

[Means for solving problems]

The present invention provides a novel method for manufacturing a circuit board with excellent voltage resistance and peeling resistance. The purpose is to

That is, the method for manufacturing a circuit board of the present invention includes providing an electrically insulating layer on a metal core plate and/or a conductive metal foil by electrodeposition, and then bonding the metal core plate and the conductive metal via the electrical insulation layer. When a circuit board is manufactured by adhering a foil, the metal surface is mechanically roughened in an electrodeposition treatment field prior to the electrodeposition treatment described above.

In the present invention, the metal core plate is a heat sink plate made of a metal with good thermal conductivity such as AV aluminum or steel;
A magnetic shielding plate made of a magnetic metal such as iron, silicon steel, stainless steel, or other iron-based material is used. When the object to be electrodeposited is an AV aluminium plate, it is generally difficult to electrodeposit AV aluminium, so it is desirable to plate the surface with copper, especially copper such as F-Cl 1 zinc, prior to the electrodeposition process. When the electrified object is a silicon steel plate, since commercially available silicon steel plates are coated with a rust preventive agent on both sides, it is desirable to remove the rust preventive agent using a caustic aqueous solution or the like. As the conductive metal foil, a highly conductive metal foil such as copper or nickel V is used.

In the present invention, the metal core plate may be subjected to electrodeposition treatment, and the metal core plate and the conductive metal foil may be bonded together via the formed electrodeposited film, or vice versa.

Furthermore, both the metal core plate and the conductive metal foil may be subjected to electrodeposition treatment, and the formed electrodepositions 1 may be adhered to each other.

In any case, in the present invention, the metal surface to be electrodeposited is roughened in advance by a mechanical method. This surface roughening can be performed using, for example, a polishing roll or a polishing sheet. By roughening the surface using these methods and subjecting it to the NK111 adhesion treatment, it is possible to form Denkei Zetsu#chi which has excellent peeling resistance. In general, if the surface is lightly roughened, the peeling resistance of the electrodeposited film will not be improved sufficiently, while if the surface is excessively roughened, the protrusions on the metal surface will concentrate the electric field. This will reduce the withstand voltage strength of the insulation. This sixth, polishing roughness 200~t, o o o count, especially 8
It is desirable to roughen the surface by the above-mentioned method using a number of 00 to 800.

Electrodeposition treatment on roughened metal surfaces may be carried out by the usual method, and electrodeposition varnishes such as those used in the manufacture of magnet wires, such as acrylic varnishes and epoxy -Ak 13kl-based varnish is suitable, and in order to obtain an electrodeposited film with excellent voltage resistance, the electrodeposition 1 may be heated with high-temperature steam at 100 to 700°C or room temperature to high temperature, such as 200°C, before baking. Dimechi V Ho V
It is desirable to treat with a hydrophilic solvent such as Muamide.

□ [Effects of the Invention] According to the present invention, it is possible to manufacture a large circuit board with stable voltage resistance and peeling resistance, so the present invention promotes -1 lighter weight and smaller size of electronic and electrical equipment. It is very useful.

[Example, comparative example]

Example 1 After uniformly polishing the copper-plated surface of a steel Mefkia V minium plate (thickness 0.8 mm) with 500-grit sandpaper to make it rough, one side was covered with a vinyl chloride adhesive sheet to form a mask. Using epoxy-acrylic water dispersion varnish (manufactured by Ryoden Kasei Co., Ltd., V-551-20, varnish concentration 20 weight 196) with the non-mask copper-plated surface of this steel-plated aluminum plate as an anode, the varnish temperature was 80°C. Charging conditions 7.5
Electrodeposition was performed under the conditions of mAIcd, 7 seconds, and an interelectrode distance of 80fi to form electrodeposition 1. Next, the aluminum plate with this electrodeposition was immersed in N,N-dimethylformamide at 80°C for 10 seconds to treat the electrodeposition W, and then the mask sheet provided on one side of the aluminum plate was peeled off and removed. The electrodeposition was heated for 40 minutes at 150 DEG C. for the first time.

Next, an adhesive (Pyflux, LF-, manufactured by DuPont, USA) was applied on the primary air-deposited electrodeposited @ (thickness: 40 μm).
0100, thickness 25 pm), and then heat-pressed an 85 μm O copper foil at 200° C. for 40 minutes at 20 #/d to obtain a circuit board with an aluminum heat sink. Ta.

Example 2 A circuit board with a silicon steel plate was obtained using a method and conditions different from Example 1 except that a silicon steel plate (thickness Q, 51EI) from which the surface anti-corrosion layer had been removed was used instead of the aluminum plate. .

Comparative Examples 1 and 2 Circuit boards were manufactured using a method different from Example 1 or 2, respectively, only in that electrodeposition was performed before polishing.

〔Evaluation test〕

2 of the circuit boards obtained in Example 1.2 and Comparative Examples 1 and 2
The peeling cost of the T-peel between the metal core plate and the electrical insulation board was measured before and after heat treatment at 60° C. for 60 minutes. The results are shown in the table.

Claims (1)

[Claims] 1. An electrically insulating layer is provided on a metal core plate and/or a conductive metal foil by electrodeposition, and then the metal core plate and the conductive metal foil are bonded via the electrically insulating layer. A method for manufacturing a circuit board, which comprises mechanically roughening the surface of the metal to be electrodeposited prior to the electrodeposition process. 2. The manufacturing method according to claim 1, wherein the metal core plate is a copper-plated aluminum plate, and the copper-plated surface is mechanically roughened and electrodeposited. 3. The manufacturing method according to claim 1, wherein the metal core plate is one selected from iron-based plates such as silicon steel plates, iron plates, and stainless steel plates, and at least one side of the iron-based plate is subjected to electrodeposition treatment. . 4. The manufacturing method according to claim 1, wherein a copper foil is used as the conductive metal foil, and the copper foil is subjected to an electrodeposition treatment. 5. The manufacturing method according to claims 1 to 4, wherein the surface to be electrodeposited is roughened with a polishing roll or a polishing sheet having a polishing roughness of 200 to 1,000.