JPS58171887A - Board for electronic 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] [Contact Field of the Invention] The present invention relates to an electronic circuit board such as a hybrid integrated circuit that requires heat dissipation, and particularly to an electronic circuit board in which a conductor layer is formed by thermal spraying. [KM.

[Technical foreground of invention]

・For hybrid integrated circuits/download modules in which semiconductor elements with high heat loss such as armature elements are incorporated, a substrate with excellent heat dissipation is required.

In Fig. 1(a) to (ω) respectively show the structure of a conventional board. 1llb), a steel foil is pasted on a resin board 1 of phenol or plus oxide, and conductors are formed by cutting and cutting. The laminated board on which the arm turn 2 is formed, No. 15A) is an aluminum board in which the same AgPd-based paste is printed on the aluminum board 3 and is fired at a high temperature to form the conductor/mantle turn 4.

Figure 1-) is an aluminum laminate board that has excellent heat dissipation properties as well as aluminum laminate boards.

In this aluminum laminate, an insulating layer σ is formed on an aluminum substrate 5, and a conductor/mother turf 1 is formed by etching VC@foil on the insulating layer 6. A thermal sprayed substrate shown in FIG. 1(d) is a substrate that has even better heat dissipation than this aluminum laminated board. This thermal sprayed substrate is formed by thermally spraying a layer 9 of, for example, aluminum oxide ceramic on a metal substrate 8 made of, for example, aluminum, and on top of this thermal sprayed double-layer 9, a conductor layer 10t of, for example, copper is also formed by thermal spraying. -It is something that forms.

However, since there are connected pores in the thermally sprayed ceramic layer 9, the insulation resistance deteriorates during a long-term life test (humidity test), and the withstand voltage characteristics deteriorate. A method to prevent this is to compensate for the above drawback by impregnating the pores with a thermosetting resin, but even if the conductor layer 10 is formed by thermal spraying on the resin-impregnated ceramic layer 9, the ceramic
The surface of the layer is smooth and round, and the adhesive strength is extremely high.

Therefore, the applicant previously proposed a method of forming a conductor layer having a desired 0'' turn on a ceramic layer by thermal spraying, and impregnating both the ceramic layer and the conductor layer with a heat-facilitating resin. According to this method, it was possible not only to improve insulation resistance and withstand voltage characteristics, but also to improve adhesive strength and soldering properties.

However, when conductive thermal spraying was carried out using a metal powder containing finer particle size of metal powder, there were interlayer points.

[Interlayer point of snowscape technology]

That is, 1. *The thin metal powder inside the pair is easily oxidized, resulting in poor soldering properties. Therefore, when parts such as C11 Pro for heat dissipation are soldered, the adhesive strength becomes weak, and there is a problem in drop impact resistance.

2. The impregnability of the thermosetting resin deteriorates. Therefore, the electrical characteristics (withstand voltage, insulation resistance) change.

[Purpose of the invention]

This invention has been made in view of the above-mentioned circumstances, and its purpose is to provide nine electronic circuit substrates with excellent electrical and mechanical properties.
[t-To provide.

[Summary of the invention]

This invention improves resin impregnation by undercutting the average particle size of thermal sprayed metal powder, resulting in improved electrical properties (withstanding voltage, insulation resistance) and improved mechanical soldering properties. The purpose is to improve strength (drop impact resistance).

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

First, as shown in FIG.
After roughening the surface of the 5sa+ aluminum plate 21 by spraying coarse 11 of iK Aloona (mu40s) to 10~20μ, apply powder with an average thickness of tllSS~40μ to the def1.
Al layer 2 deposited by thermal spraying and having a thickness of 150 to 200μ
form 2. Further, as shown in FIG. 2 Th)K, a steel layer 21 is selectively formed on the alumina layer 22 by thermal spraying using copper powder having an average particle size of 10 to 74 μm through a metal master. Next, the aluminum plate 21 was heated to 100°C.
After being placed on a metal plate (not shown), the aluminum layer 22 and the steel layer 2S are impregnated with a thermosetting epoxy resin 24. Thereafter, the resin remaining on the aluminum layer 22 and the steel layer zso*m is wiped and heated at 10150° C. for 2 hours to turn the impregnated resin into ta, and then the surface is polished with a sandpaper to expose the steel layer XS.

Thermal spray base prepared in this way! With LK, the thin thermal sprayed copper powder with an average particle size of 10 μm or less is undercut, so the following characteristics were obtained compared to conventional thermal sprayed substrates. That is, 1 for soldering and 10 for sex.
0 g It became wet. Regarding drop strength, 13
2. In a test in which a 90m long KEL-plated material was soldered onto a 2J steel layer and dropped onto a steel plate from a height of 100m, the material that conventionally peeled off after 1~2＠ , 10
The 0-wheel block did not come off even if it was dropped over g1.

2. Regarding the impregnability of the thermosetting epoxy resin 24, although the insulating layer was conventionally 1504211 and had a withstand voltage DC 2 kV, a value of I)C4.5 kV or more was obtained.

In the above embodiment, the alumina layer 22 was used as the ceramic and scrap, but steatite (Mg0.810.) and phthulsterite (2Mg
0 ・810m), No/L' core (Zr01-B
%O), magnesia (MtO), spinel (MiO・
A40m), aluminum nitride (AtN), and gelon nitride (IN) may be used alone or as a mixture.

★9. As for the thermal spray metal powder, it may be 2. Kerro, Al ζ, 811% tin, Zm, etc. Regarding the upper limit of the average particle size of the metal powder. It is possible to use more than 74 curses, but the ・datan becomes rough, so 1
00μ or less is desirable.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a high-quality electronic circuit board with excellent electrical and mechanical properties.

[Brief explanation of drawings]

FIGS. 1(a) to (11) are sectional views showing conventional electronic circuit boards, and FIGS. 2(b) to ←) are sectional views showing the manufacturing process of a thermal sprayed board according to an embodiment of the present invention. Melt. 21... Aluminum plate, ZX-/alumina layer, 11
・-Copper layer, 24...Thermosetting resin.

Claims (3)

[Claims] (1) In an electronic circuit board in which a conductor layer is formed by thermal spraying on a support substrate, the conductor layer has an average particle size of 10 to 1
An electronic circuit board 1fi characterized in that it is formed using metal powder of the 00μ group. (2) The electronic circuit board according to claim 1, wherein the support base is formed by forming a ceramic layer on a metal plate by thermal spraying. (3) The electronic circuit board according to claim 2, wherein the conductor layer and the ceramic layer are impregnated with a thermosetting resin.