JPS6398438A - Metallic base substrate - Google Patents

Abstract

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

Description

[Detailed description of the invention] [Technical field〕 The present invention relates to a metal base substrate with excellent heat dissipation properties.

[Background technology]

As electronic components become smaller, the number of components mounted on printed circuit boards also increases.

When electronic components including LEDs and transistors are mounted at high density, a large amount of heat is locally generated by the electronic components, so a substrate with good heat dissipation is required.

Therefore, substrates based on metals with high heat dissipation properties were developed, and in order to further improve heat dissipation properties, a thermally conductive layer was added to the insulating resin layer interposed between the metal base and the metal foil forming the conductive layer. The inclusion of fillers such as good alumina and magnesium oxide is being practiced. However, since alumina containing alumina is hard, when machining is performed using a mold, etc., the wear of the mold is extremely large. In addition, in the resin layer containing magnesium oxide, the moisture absorption amount of magnesium oxide itself is extremely large.
Insulating properties could not be maintained in humid environments, and tensile strength was poor.

[Purpose of the invention]

The present invention was made to solve these problems, and aims to provide a metal base substrate that exhibits a high heat dissipation effect and does not have the above problems.

[Disclosure of the invention]

In order to achieve the above object, the present invention provides a metal base substrate in which a metal foil is laminated on the surface of the metal base via an insulating resin layer containing magnesium oxide powder, in which particles of the magnesium oxide powder are oxidized. The gist thereof is a metal-based substrate characterized by being coated with a silicon layer.

The present invention will be explained in detail below based on examples.

FIG. 1 shows an embodiment of a metal base substrate according to the present invention. As shown in the figure, this metal base board is
A metal foil 3 is laminated on the surface of a metal base 1 with an insulating resin layer 2 interposed therebetween. As shown in FIG. 2, the resin N2 contains magnesium oxide powder particles 4 coated with a silicon oxide layer 5 as a filler.

For the metal base, alloys such as iron, copper, aluminum, nickel, and silicon steel plate can be used. The surface of this metal base is chemically or physically roughened to improve adhesion, if necessary.

The insulating resin layer is formed by applying, on the surface of the metal base, a resin having excellent heat resistance such as an epoxy resin or a polyamide resin, to which magnesium oxide powder particles coated with a silicon oxide layer are added. The resin A containing magnesium oxide powder particles coated with a silicon oxide layer may be formed into a sheet, or the resin A may be formed into a sheet of glass fiber cloth, an organic synthetic fiber cloth such as polyester or polyamide, or a nonwoven fabric. The impregnated base material is laminated on the metal base. For the insulating resin layer, the mechanical strength of the insulating resin layer is improved when the base material is impregnated with resin, and the resin layer is less likely to deform under mechanical pressure than when the base material is only a resin layer. This is preferable because it is almost non-existent.

In this invention, the surface of the magnesium oxide powder particles is coated with a silicon oxide layer that is inert to water and chemically stable, so that moisture absorption of magnesium oxide can be prevented and it can be used even under high humidity conditions. However, high insulation properties are maintained.

Magnesium oxide is not as hard as alumina. Furthermore, since the insulating resin layer contains these fillers, the coefficient of thermal expansion of the insulating layer approaches that of metal, improving heat resistance, as in the past.

The metal foil can be made of the same material as the metal base, and may be coated with an adhesive if necessary.

When laminating these layers, a normal molding method such as heating and pressure molding is used.

Using an aluminum plate for the metal base, copper foil for the metal foil, and an epoxy resin-impregnated glass base material for the insulating resin layer, a metal base substrate was obtained that contained the fillers in Table 1 below as fillers for the resin layer, and the quality of each was evaluated. Examined.

As shown in the table, the metal base substrate according to the example has better insulation properties even in a humid environment than the substrate of comparative example 1, which contains only magnesium oxide as a filler in the insulating resin layer.
It was excellent in both strength. Furthermore, it was superior in heat dissipation and strength compared to substrates containing alumina.

When the Examples and Comparative Example 2 containing alumina as a filler in the insulating resin layer were punched using a mold, no wear occurred in the Examples, but the mold was worn in Comparative Example 2.

The metal base substrate according to the present invention is not limited to the embodiments described above. This also includes those with a circuit already formed on the metal foil on the surface.

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to obtain a metal base substrate that has excellent insulation properties, tensile strength, and high heat dissipation properties even in a humid environment.

[Brief explanation of the drawing]

FIG. 1 is a schematic illustration of the layer structure of an embodiment of a metal base substrate according to the present invention, and FIG. 2 is a schematic illustration of magnesium oxide powder particles coated with a silicon oxide layer. It is an explanatory diagram without hail. 1... Metal base 2... Insulating resin layer 3... Metal foil 4... Magnesium oxide powder particles 5... Silicon oxide layer

Claims (1)

[Claims] (1) A metal base substrate in which a metal foil is laminated on the surface of the metal base via an insulating resin layer containing magnesium oxide powder, characterized in that the particles of the magnesium oxide powder are covered with a silicon oxide layer. Metal base board.