JPS5931091A - Hybrid integrated circuit device - 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 The present invention relates to a hybrid integrated circuit device in which a ceramic substrate on which a hybrid integrated circuit is constructed is fixed on a heat sink.

High-power hybrid integrated circuit devices are made of ceramic (generally alumina) on top of a heat-dissipating metal plate to improve heat dissipation.
The board is fixed with low melting point solder.

A conventional hybrid integrated circuit device of this type has a plan view and a front view showing the structure of the base portion in FIGS. 1A and 1B. (1) is a ceramic substrate with a metallized layer on the entire bottom surface and a metalized wiring pattern (not shown) on the top surface, (2) is a heat dissipation metal plate, and (3) is this heat dissipation metal. This is a low melting point solder layer on which a ceramic substrate (1) is fixed.

In the conventional device described above, the ceramic substrate (1) has a significantly different coefficient of thermal expansion from the heat dissipation metal plate (2), so heat generation during operation of the integrated circuit or external mechanical shock may cause the ceramic substrate (1) to ) cracks occur, resulting in a defective product. If it is due to heat generation, the heat source is the ceramic substrate (1)
If the crack is located at the center of the hole, the crack will often occur in the direction A as shown in the figure. As a measure to prevent the occurrence of such defects, it may be possible to divide the ceramic substrate (1) into multiple small pieces in advance, but this would increase the number of parts and the number of assembly steps. In addition, there are problems such as difficulty in automating assembly.

As a prior art for dealing with such problems, Fig. 2 (A
) and (B) show the structure of the base part in a plan view and a front view. At the time of manufacturing, the ceramic substrate (4) is made with a snap line (4a) consisting of a groove with a ■-shaped cross section on the top surface, in a place where there will be no problem even if a crack occurs in the middle part.
(ab) is formed. The ceramic substrate (4) is fixed onto the heat dissipating metal plate (2) with solder (3).

In this prior art, even if a large stress is generated in the ceramic substrate (4) due to heat generation during operation of the hybrid integrated circuit or the action of an external force, the snap line (4a) is maintained.

(This is to prevent stress from concentrating on the snap lines (4b) and causing cracks, which will not affect the hybrid integrated circuit. In other words, due to the circuit configuration, electrical connections cannot be made across these snap lines (4a) and (4b). If necessary, metal wires,
Connect with metal rods, etc.

However, in the prior art device described above, cracks may occur at locations outside the snap lines (4a) and (4b) depending on the size and shape of the ceramic substrate and the manner of drilling, and cracks occur 100% of the time at the snap lines. (4a
) + (ab). In other words, substrate cracking is likely to occur at through-holes or notches on the edge of the substrate, where stress concentration is large, and if stress concentration is smaller at snap lines ('aa) and (ab), cracks may occur at through-holes or notches on the edge of the substrate. Cracks will occur first.

Thus, although prior art devices improve upon prior art devices, they are not perfect and still have problems.

This invention is a further improvement on the prior art device described above, in which a snap line that induces cracking is formed at an intermediate position on a ceramic substrate, and a through hole is formed in the substrate at a position above the snap line or at the end of the snap line. By providing a notch on the end face of the position, or by providing both of these, even if a board crack occurs, it will occur reliably along the snap line, eliminating defective products and creating highly reliable hybrid integrated circuits. The purpose is to provide equipment.

FIGS. 3 and 4 are a plan view and a front view showing the structure of a base portion according to an embodiment of the present invention, (2).

(3), (4a), and (ab) are the same as the apparatus shown in FIG. 2 above, and their explanation will be omitted. The ceramic substrate (5) has snap lines (4a) formed during manufacturing.
), (4b) A plurality of through holes (6) are formed in front of the upper layer. In this way, when thermal stress or external force due to heat generated during operation of the integrated circuit acts on the ceramic substrate (5), the snap lines (4a), (4b) and the through holes (6 ) If a large stress concentration occurs at the portions exceeding the strength limit of the substrate (5), cracks will occur at the snap lines (4a) and (4b). If cracks occur in the snap lines (4a) and (4b), similar to the prior art device described above, the 1-
ing.

FIG. 4 is a child view and a front view showing the structure of a base portion according to another embodiment of the present invention. V-shaped notches (8) are formed in the end faces of the ceramic substrate (7) at the end positions of the snap lines (4a) + (4b). In this way, the substrate cracks form the snap line (4a).

This is to prevent substrate cracking from occurring in other portions of the substrate (7) due to being attracted by the portion (4b).

In addition, in the above embodiment, the snap lines (4a), (4
1)) Two strips were formed, but the number may be increased or decreased as necessary.

Moreover, in the above embodiment, the snap line (4a).

Although the through hole (6) or the notch (8) is provided along the line (4b), both may be provided depending on the case.

As described above, according to the present invention, a snap line is formed in advance in a predetermined direction on a ceramic substrate brazed onto a heat dissipating metal plate, and a through hole is provided at a position on the snap line, or a through hole is provided at the end of the snap line. Since a notch is provided on the end face of the position, or both of these are provided,
Even if a ceramic substrate cracks due to thermal strain or external impact, it will now crack reliably along the snap line, without complicating the integrated circuit assembly process, and preventing cracks from causing fatal damage to hybrid integrated circuits. damage is avoided,
Confidence can be increased.

[Brief explanation of drawings]

FIGS. 1(A) and (B) are a plan view and a front view showing the structure of the base part of a conventional hybrid integrated circuit device, and FIGS. 2(A) and (B) are the structure of the base part according to the prior art. A plan view and a front view, FIGS. 3A and 3B are a plan view and a front view, and FIG.
A) and (B) are a plan view and a front view showing the structure of a base portion according to another embodiment of the present invention. 2... Heat dissipation metal plate, 3... Solder layer, 4a, 4b.
...Snap line, 5...Ceramic substrate, 6...
Through hole, 7 - Ceramic substrate, 8... Cut portion Note that the same reference numerals in the drawings indicate the same or equivalent parts. Agent Makoto Kuzuno - (1 other person) Figure 1 Figure 2

Claims (1)

[Claims] In a hybrid integrated circuit configured on a ceramic substrate that is brazed and fixed on a heat-dissipating metal plate, a snap line is formed on the surface of the ceramic substrate in a predetermined direction, and at least a through hole is formed at a position on the snap line. 1. A hybrid integrated circuit device characterized in that stress concentration at the snap line portion is increased by providing either a cut portion or a notch portion on the end face at the end position of the snap line portion.