JPH03215986A - Metal base wiring board - Google Patents

Abstract

PURPOSE:To improve a metal base wiring board in dielectric strength keeping it excellent in heat dissipating property by a method wherein a metal foil is provided to the upside and/or the underside of a metal plate in an integral structure through the intermediary of a boron nitride containing thermosetting resin layer. CONSTITUTION:A metal foil is provided to the upside and/or the underside of a metal plate in an integral structure through the intermediary of a boron nitride containing thermosetting resin layer. A plate of aluminum, iron, copper, zinc, nickel, or an alloy thereof, or a composite plate there of, can be used as the metal plate concerned, and moreover the surface of the metal plate can be improved in interlaminar adhesion by activating and roughening it through a physical treatment or a chemical treatment. The thermosetting resin layer is formed of a resin such as to polyurethane, or of a modified resin thereof or a mixture thereof, organic or inorganic filler can be mixed into the resin if necessary, but the resin is required to contain boron nitride. A sheet of copper, aluminum, ion, nickel, zinc, or an alloy thereof, or a composite sheet thereof is used as the metal foil concerned, and the adhesive surface of the foil is subjected to a physical or chemical surface treatment if necessary. By this setup, a metal base wiring board can be improved in dielectric strength keeping it excellent in heat dissipating property.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to electronic equipment, electrical equipment, biasing equipment, computing equipment, etc., and is particularly applicable to equipment that requires high voltage resistance (metal-based This invention relates to wiring boards.

[Conventional technology]

Conventional metal-based wiring boards are valued for their heat dissipation properties and are used for a variety of purposes, but they have the problem of relatively low withstand voltage.

[Problem that the invention seeks to solve]

As mentioned in the prior art section, conventional metal-based interconnects have a relatively low dielectric strength ratio. For this reason, attempts have been made to treat the aluminum surface with alumite or alumina spraying for aluminum-based substrates, but these methods have drawbacks such as deterioration of interlayer applicability and smoothness of the base metal surface. The present invention has been made in view of the above-mentioned problems in the prior art, and its object is to provide a metal-based wiring board with excellent withstand voltage.

[Means for Solving the Problems] The present invention provides a metal base wiring characterized in that metal foil is integrally disposed on the upper and/or lower surfaces of a metal plate via a boron nitride-containing thermosetting resin layer. Since the substrate is made of boron nitride with a low dielectric constant, the withstand voltage is greatly improved, and the above object can be achieved.The present invention will be described in detail below.

Metal plates used in the present invention include aluminum, iron, copper,
It can be used for individual, alloy, and composite sheet metals such as zinc and nickel, and the thickness is preferably 0.1 to 1Qff.
Furthermore, the surface of the metal plate can be activated and roughened by physical treatment or chemical treatment to completely improve interlayer adhesion. As the thermosetting resin layer, phenol resin, cresol resin, melamine resin, epoxy resin, unsaturated polyester resin,
It is composed of polyimide resins, isocyanate resins, polyurethane resins, etc. alone, modified products, and mixtures, and inorganic or organic fillers can be mixed as necessary, but it is necessary to contain phoron nitride. The amount of boron nitride added is preferably 10 to 100 times the amount of the resin (hereinafter simply referred to as the amount). That is, if it is less than IO%, it is difficult to improve the withstand voltage;
This is because when it exceeds 0%, interlayer visibility tends to decrease. The average particle size of boron nitride is preferably 0.1 to 5 microns (8. The resin layer is not particularly limited, and may be a coating layer, a film layer, a sheet layer, a resin-impregnated base material layer, etc. The thickness of the resin layer is not particularly limited, but it is preferably 10 to 250 microns.

As the metal foil, use individual, alloy, or composite plates of copper, aluminum, iron, nickel, zinc, etc., with a thickness of 0.018 to 9.07 m - the adhesive surface may be physically or chemically treated as necessary. It is preferable to carry out surface treatment.

The forming means is not particularly limited as long as it can integrate the # layer, such as a press, a roll, a double belt, etc.b0 The following description will be made based on all the embodiments of the present invention.

Example After polishing the surface of an aluminum plate with a thickness of IH with sandpaper, an epoxy resin face containing a total of 50 parts of boron nitride with an average particle size of 50 microns was applied to a thickness of 0. After drying, a 1 m glass cloth was impregnated with resin to a thickness of 50%, and then passed through one dried resin-impregnated base material to a thickness of Q. A laminate with 0.3 m of copper foil was molded at a molding pressure of 20 KQ/d and a temperature of 90° C. at 165°C.
A metal base wiring board was obtained by lamination molding for minutes.

Comparative Examples 1 to 3 The boron nitride was treated in the same manner as in the example except that magnesium oxide was used in comparative example 1, silica was used in comparative example 2, and alumina was used in comparative example 3. A metal base wiring board was obtained.

The performances of the metal-based wiring boards of Examples and Comparative Examples 1 to 3 are shown in Table 1.

Pot: 25φ electrode, 1 minute* O-5 m, A force, 9 to-off current [Effects of the Invention] The present invention is constructed as described above. The metal base wiring board having the structure described in the claims has the effect of improving the withstand voltage while maintaining heat dissipation.

Claims (1)

[Claims] (1) A metal-based wiring board characterized in that a metal foil is integrally disposed on the upper and/or lower surface of a metal plate via a boron nitride-containing thermosetting resin layer.