JP2900669B2 - Semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an L band (390-1500
MH _Z) used in the above microwave band, to a high power transistor with a built-in internal matching circuit.

[0002]

2. Description of the Related Art A conventional high output transistor for a microwave band will be described with reference to FIGS.

[0003] As shown in FIG. 3 (a), a semiconductor chip 15 is attached to a projection 12 welded to the heat sink 1 through a brazing material 14.
Is mounted.

Usually, in order to prevent the brazing material 14 from flowing out,
Side walls and grooves are provided.

In the first method, as shown in FIG. 3 (b), conductive side walls 13a,
13 b is formed to prevent the brazing material 14 from flowing into the heat sink 1.

In the second method, as shown in FIG. 3C, the mounting projections 12 of the heat sink 1 are coated with insulating films 16a and 16b having a width of 0.15 mm and a thickness of 50 μm, and the brazing material 14 is formed. Plays a repelling role even if it flows out to the heat sink 1.

In the third method, as shown in FIG. 3D, a groove 18 is provided in the heat sink 1 to prevent the brazing material from flowing and expanding.

[0008]

When the conductive side walls 13a and 13b are formed as shown in FIG. 3 (b), there is a possibility that the bonding wire 17 comes into contact and short-circuits. There is a problem that the wire bonding cannot be performed with a small sag (the shortest distance).

The insulating films 16a and 16b coated as shown in FIG. 3 (c) repel the brazing material 14, but it is difficult to apply a uniform coating of 50 μm thickness so as not to be wavy or interrupted.

As shown in FIG. 3 (d), even if a groove 18 is provided to prevent a rise from below, a flow from above cannot be prevented.
For this reason, there is a problem that a position shift occurs when the internal matching circuit (chip capacitor) is mounted.

[0011]

According to the present invention, there is provided a semiconductor device comprising:
On one main surface of the heat radiating plate, a mounting brazing material flow preventing side wall of the chip having an insulating film formed on the upper surface is formed so as to surround the microwave band semiconductor chip mounting portion, and an input is provided outside the brazing material flow preventing side wall. An internal matching circuit corresponding to the side and the output side is formed, and the semiconductor chip and the internal matching circuit are sealed with a cap covering one main surface of the heat sink.

[0012]

FIG. 1 (a) shows a first embodiment of the present invention.
This will be described with reference to a plan view of FIG.

A projection 12 for mounting the transistor 7 as a semiconductor chip is provided on the heat dissipation plate 1 made of copper or the like and having excellent heat dissipation effect and conductivity. 0.15 mm width and 5 height to prevent the flow of brazing material 11
Insulating films 9a and 9b are formed on 0 μm side walls 10a and 10b. The insulating films 9a and 9b having a width of 0.15 μm and a height of 20 μm can be coated with liquefied Teflon or silicone by brush coating.

On the input side and output side of the transistor 7, dielectrics 4c and 4d are attached, respectively.
An input side internal matching circuit 8a is formed on the input side dielectric 4c, and an output side internal matching circuit 8a is formed on the output side dielectric 4d.
b is formed.

On the input side and the output side of the transistor 7, dielectrics 4a, 4b,
4e and 4f are formed, and lead extraction electrodes 6a and 6f are formed thereon.
b is formed. The lead extraction electrodes 6a and 6b are connected to the matching circuit 8
Electrical connection is made by bonding wires 3c and 3d made of gold wires inside the container side wall 2 corresponding to a and 8b.

The lead electrodes 6a and 6b are brazed to the outside of the container side wall 2 of each of the lead extraction electrodes 5a and 5b. The space between the container side wall 2 and the lead extraction electrodes 5a and 5b is insulated by dielectrics 4g and 4h, respectively.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

In this embodiment, two transistors 7 which are semiconductor chips are mounted, and insulating films 9a, 9b and 9c are simultaneously coated to prevent the flow of brazing material between the transistors 7.

[0019]

According to the present invention, the side wall made of a metal conductor at the protrusion for mounting a transistor as a semiconductor chip is lowered, and an insulating film is coated thereon. As a result, there is no danger that the bonding wire will make electrical contact with the metal conductor of the container and cause a short circuit, and the flowing brazing material can be prevented from being repelled by the insulating film.

The minimum width is 0.15 μm by coating,
A thin insulating film having a minimum height of 20 μm can be easily formed.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view showing a first embodiment of the present invention. (B) is AB sectional drawing of (a).

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a state where a conventional transistor chip is mounted.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Heat sink 2 Container side wall 3a, 3b, 3c, 3d Bonding wire 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h
Dielectric 5a, 5b Lead extraction electrode 6a, 6b Lead electrode 7 Transistor for microwave band 8a Internal matching circuit for input 8b Internal matching circuit for output 9a, 9b, 9c Coated insulating film 10a, 10b Side wall 11 Brazing material 12 Chip Mounting projection 13 Side wall 14 Brazing material 15 Transistor for microwave band 16a, 16b Coated insulating film 17 Bonding wire 18 Mounting brazing material flow prevention groove

Claims (1)

(57) [Claims] 1. A mounting brazing material flow preventing side wall of a chip having an insulating film formed on an upper surface surrounding a semiconductor chip mounting portion for a microwave band on one main surface of a heat radiating plate. A semiconductor device in which an internal matching circuit corresponding to an input side and an output side is formed outside a side wall, and the semiconductor chip and the internal matching circuit are sealed with a cap covering one main surface of the heat sink.