JPH03183155A - High-frequency and high-output hybrid integrated circuit - Google Patents

Abstract

PURPOSE:To reduce the height of an integrated circuit, to improve a thermal resistance and to shorten the length of a bonding wire by a method wherein the thickness in a mounting part of a transistor chip on an insulating substrate is made thin. CONSTITUTION:An insulating substrate 2 in a mounting part of a transistor chip 6 is made thinner than in other parts of the insulating substrate 2; as a result, the whole height of a hybrid integrated circuit can be made thin. Alumina or the like is used generally for the insulating substrate 2 because its cost is low; however, its resistance is high. When the insulating substrate 2 in the mounting part of the transistor chip is made thin, a thermal resistance can be improved. An interval between the upper part of the transistor chip 6 and the insulating substrate 2 can be made small; as a result, the length of bonding wires 7 can be made short.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an insulating substrate for a high frequency, high power hybrid integrated circuit.

[Conventional technology]

FIG. 2 is a cross-sectional view of a conventional high frequency, high power hybrid integrated circuit. In the figure, (1) is a grounding metal plate made of steel that also serves as a radiator, (2) is an insulating board mounted on the grounding metal plate (1), and (3) is an insulating board mounted on the insulating board (2). (4) is a metal plate, (5) is an emitter bridge,
(6) is a transistor chip, and (7) is a bonding wire.

Next, the operation will be explained.

The high-frequency, high-output hybrid integrated circuit is connected to a surface conductor layer (3) provided on an insulating substrate (2) by a bonding wire (7) made of a gold wire or the like, and functions as a transistor. Here, in order to shorten the length of the bonding wire (7), the emitter bridge (5)
are using.

[Problem to be solved by the invention]

Conventional high-frequency, high-output hybrid integrated circuits were constructed as described above, and all components were connected vertically, resulting in an overall high height. The thickness of the bonding wire is the same as that of other parts, and the thermal resistance of the insulating substrate is generally large, so special considerations for heat dissipation are required, and the length of the bonding wire is relatively long. There was a problem in that the length of the transistor wires had to be long to meet each other.

The present invention has been made to solve the above-mentioned problems, and is a hybrid integrated circuit that reduces the height of the hybrid integrated circuit, reduces thermal resistance, shortens the bonding wire length, and improves high frequency characteristics. The purpose is to obtain a circuit.

[Means to solve the problem]

The high-frequency, high-output hybrid integrated circuit according to the present invention reduces the height of the integrated circuit by reducing the thickness of the transistor chip mounting portion of the insulating substrate to 4, and improves thermal resistance.
The high-frequency, high-output hybrid integrated circuit of the present invention probably aims to shorten the length of the bonding wire. At the same time, thermal resistance is improved, and high frequency characteristics are improved because the bonding wire is shortened.

〔Example〕 An embodiment of the present invention will be described below with reference to the drawings.

In Figure 1, (1) is a grounding metal plate that also serves as a heatsink, and (2) is an insulating substrate that is connected to the grounding metal plate (1) by fusion bonding or the like. Desired areas are made with a thinner thickness than other areas. (3) is a surface conductor layer such as a thick film patterned and installed on an insulating substrate (21), (4) is a metal plate provided on the surface conductor layer,
It is provided in a thin portion of the insulating substrate (2) to improve the heat dissipation effect. (6) is a transistor chip, and the metal plate (
4) Mounted on top. (5) shows an emitter bridge for emitter wire bonding.

The resulting hybrid integrated circuit is a transistor chip (6)
Each of the upper electrodes is connected to the surface four-layer (3) or the emitter bridge (5) or the like by a bonding wire (7).

Next, the operation will be explained below.

1) Insulating substrate (2) for installation part of transistor chip (6)
) is thinner than the other part of the insulating board (2).

The overall height of the hybrid integrated circuit can be reduced.

2) Alumina or the like is generally used for the insulating substrate (2) because it is inexpensive, but because of its high thermal resistance, when using a high-output transistor chip (6), Conventionally, special considerations were required, but since the insulating substrate (2) in the transistor chip mounting area is thinner, thermal resistance can be improved.

3) Because the distance between the upper part of the transistor chip (6) and the insulating substrate (2) is reduced, the bonding wire (7)
) length can be shortened. Bonding wire (
7) is a button that itself acts as an inductor, so if the wire length is shortened, the inductor component is reduced accordingly, and the high frequency characteristics can be improved. In the embodiment, a case is shown in which a metal plate (4) is used for improving heat radiation, but this metal plate (4) may not be used.

[Effects of the invention j As described above, according to the present invention, the insulating substrate is simply made thinner, and it has the effect of making a high-frequency, high-output hybrid integrated circuit both effective and high-performance.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a high frequency, high power integrated circuit according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional high frequency, high power hybrid integrated circuit. In the figure, (1) is a grounding metal plate, (2) is an insulating substrate, (3) is a surface conductor layer, (4) is an Fi metal plate, (5) is an emitter bridge, (6) is a transistor chip, (7) is
indicates bonding wire. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A high-frequency, high-output hybrid integrated circuit characterized in that the thickness of the insulating substrate at the transistor-fused portion of the insulating substrate, which is provided on a metal conductor plate that also serves as a radiator, is made thinner.