JPH01312890A - Manufacture of hybrid integrated circuit - Google Patents

Abstract

PURPOSE:To lengthen the lifetime of a press die by press punching a substrate in an insulation layer area near an insulation resin thin-layer. CONSTITUTION:An insulation layer 4 is formed in a region other where an insulation resin thin layer 3 containing an intense heat conductive filler 2 is printed. A substrate 1 in an insulation layer 4 area in the vicinity of the resin thin layer 3 is press punched by a press die 7 and separated to individual hybrid integrated circuit 8. In this way, the hybrid integrated circuit 8 for low heat resistance is formed without press punching the insulation resin layer 3 containing the intense heat conductive filler 2 by the press die 7. As a result, the press die 7 is not worn, and the lifetime of the press die 7 can be lengthened markedly.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method of manufacturing a hybrid integrated circuit using a low thermal resistance circuit board.

(b) Prior Art The applicant of the present application has already developed a low thermal resistance circuit board using a metal substrate suitable for incorporating a thick film hybrid integrated circuit in Japanese Patent Publication No. 46-13234. The board is made by anodizing the surface of an aluminum plate and coating it with an aluminum oxide film, and the copper foil is bonded to the surface with an epoxy resin approximately 30μ thick, so the thermal resistance is per 1cm" area. It was about 1.3"C/W.

Recently, due to the demand for integration, low thermal resistance substrates that can incorporate even higher output circuits have been proposed. This board has a large amount of alumina (
A! , On) has a structure in which a thin epoxy resin layer is attached, and even though the thickness of the resin layer has doubled to 60μ, the thermal resistance has been improved to 0.8℃/W. .

(c) Problems to be Solved by the Invention However, a major problem arose when a hybrid integrated circuit was produced using the above-mentioned substrate. This is a process in which a large number of hybrid integrated circuits are formed on one board and then each hybrid integrated circuit is punched out using a press.
1,000 shots, whereas this board wears out after 5,000 shots. The cause of this is alumina. That is, the Mohs hardness of alumina is 9, and the Mohs hardness of the hardened steel forming the press die is about 6.5, and the side surface of the press die is ground. That is, there was a major problem in that the life of the press mold was significantly reduced.

(d) Means for solving the problems The present invention has been made in view of the above-mentioned problems,
A strip-shaped metal substrate is prepared, and an insulating resin thin layer containing a highly thermally conductive filler is screen printed on a plurality of predetermined areas on the substrate, and the insulating resin thin layer containing the highly thermally conductive filler is printed. After forming an insulating layer on the substrate area other than the area covered by the substrate, forming a circuit conductor in a desired shape on the thin insulating resin layer containing the high thermal conductivity filler, and fixing a circuit element on the circuit conductor. , the substrate in the insulating layer region near the insulating resin thin layer is press punched and separated into individual hybrid integrated circuits.

(f) Function As described above, according to the present invention, since the insulating WM thin layer containing a highly thermally conductive filler is not directly cut with a press die, the thermal resistance is low, which greatly improves the problems of the conventional method. A hybrid integrated circuit using a circuit board can be provided.

(f) Example An embodiment of the present invention will be described in detail below with reference to the drawings.

The first step of the present invention is to prepare a strip-shaped metal substrate (1), as shown in FIG. 1A. Aluminum is suitable for the metal substrate (1), and an insulating metal plate is used in which a thin layer of aluminum oxide is formed on the surface of the aluminum plate by anodizing. On such a metal substrate <1), a thin insulating resin layer (3) containing a highly thermally conductive filler (2) is formed by screen printing on a predetermined area at a predetermined interval, that is, an area that will become a low thermal resistance circuit board. It adheres to a film thickness of .

The thin insulating resin layer (3) is made of epoxy resin, polyimide resin,
Resins such as phenol resin and brachyral resin are used, and the resin contains 8λ*Os, AρN, SiC, diamond, and BN, which have a higher Mohs hardness than that of the press mold.
The filler (2) is mixed in a weight ratio of 10% to 80%.

As shown in FIG. 1B, the second step of the present invention is to form an insulating layer (4) in an area other than the printed insulating resin thin layer 1 (3) containing a highly thermally conductive filler (2). It is in.

The insulation layer (4) is the same as the insulation resin thin layer (3)! A thin layer of insulating resin (3) is applied using screen printing so that it has the same thickness as the thin insulating resin layer (3). It is also possible to include a highly thermally conductive filler in the insulating layer (4). In this case, the highly thermally conductive filler used has a hardness smaller than the Mohs hardness of the press mold.

In the third step of the present invention, as shown in FIG. 1C, a circuit conductor 5) having a desired shape is formed on the insulating resin thin layer (3), and a plurality of circuit elements ( 6) Fix.

The circuit conductor (5) includes an insulating resin thin layer (3) and an insulating layer (4)
Copper foil is pasted on the entire surface and etched so that the circuit conductor (5) is formed only on the thin insulating resin layer (3). At this time, adhesive has been applied to one side of the steel foil in advance, and the adhesiveness with the thin insulating resin layer (3) and the insulating layer (4>) is sufficient.

A plurality of circuit elements (6) such as transistors, integrated circuits, chip parts, etc. are fixed on the circuit conductor (5), and the necessary ones are connected to the neighboring circuit conductor (5) by wires or the like.

The fourth step of the present invention is to press punch the substrate (1) in the insulating layer (4) area near the insulating resin thin layer (3) using a press die (7) as shown in the first diagram. As shown in E,
It is separated into individual hybrid integrated circuits (8).

At this time, the press surface of the press mold (7) is the circuit element (6).
) is desirably formed in a concave shape so as not to come into contact with the

According to the present invention, a hybrid integrated circuit (8) for low thermal resistance can be produced without press punching an insulating resin thin layer (3) containing a highly thermally conductive filler (2) using a press die (7).
can be formed, the press die (7) is not worn out, and the life of the press die (7) can be significantly extended.

(G) Effects of the Invention As detailed above, according to the present invention, the life of the press mold can be significantly extended because the thin insulating resin layer containing a highly thermally conductive filler is not directly punched by the press mold. Similarly, hybrid integrated circuits for low thermal resistance can be individually separated.

In addition, in the present invention, since the thin insulating resin layer is not directly press punched with a press mold, a filler with high Mohs hardness can be contained in the thin insulating resin layer, making it possible to easily produce a hybrid integrated circuit with high thermal conductivity. can be provided.

[Brief explanation of the drawing]

FIGS. 1A to 1E are cross-sectional process diagrams illustrating details of the present invention. (1)...Metal substrate, (2)...High thermal conductivity filler, (3)...Insulating resin thin layer, (4)...Insulating layer, (5)...Circuit conductor, ( 6)...Circuit element, (7)...Press mold.

Claims (4)

[Claims] (1) Prepare a strip-shaped metal substrate, screen print an insulating resin thin layer containing a highly thermally conductive filler on a plurality of predetermined areas on the substrate, and then screen print the insulating resin thin layer containing the highly thermally conductive filler. An insulating layer is formed on the substrate area other than the printed layer, a circuit conductor having a desired shape is formed on the insulating resin thin layer containing the highly thermally conductive filler, and a circuit element is formed on the circuit conductor. After fixing, press punching the substrate in the insulating layer region near the insulating resin thin layer,
A method for manufacturing a hybrid integrated circuit, characterized by separating it into individual hybrid integrated circuits. (2) The method for manufacturing a hybrid integrated circuit according to claim 1, wherein the Mohs hardness of the highly thermally conductive filler is greater than the Mohs hardness of the press die for press punching. (3) The method of manufacturing a hybrid integrated circuit according to claim 1, wherein the insulating layer contains at least a highly thermally conductive filler having a Mohs hardness smaller than the Mohs hardness of the press mold. (4) The method of manufacturing a hybrid integrated circuit according to claim 1, wherein the metal substrate is an aluminum substrate treated with insulation.