JPH05206764A - Mount structure of transistor - Google Patents

Abstract

PURPOSE:To reduce a heat resistance by improving heat dissipation of a high output transistor(TR) used for a microwave band. CONSTITUTION:A radiator/with elasticity formed by sealing a thermal conductive fluid into a conductive rubber is interposed among a TR 7, a shield case 5 and a cover 4 in face contact. Thus, the shield effect is improved and the thermal conductivity is improved through convection of the fluid in the inside of the radiator.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is used for heat dissipation of a high frequency element. The present invention relates to a transistor mounting structure capable of enhancing the heat radiation effect of a high frequency power amplification transistor.

[0002]

2. Description of the Related Art Conventionally, as a high frequency power amplification transistor used in a microwave band or the like, as shown in FIG. 3, a high frequency circuit grounding surface and a heat radiation surface are commonly used. Is performed from only one surface where the transistor 7 and the shield case 5 are in contact with each other. Further, since the microwave band transistor is connected to the circuit via the microstrip line 9, the ground plane of the transistor case is an electrically important part for the connection with the microstrip line 9, and the heat radiation is eliminated. It was used without being able to change the structure because of.

[0003]

Although the performance of the transistor is improved and the output of the transistor is increased, the amount of heat generated by the transistor is also increased. The microwave transistor is difficult to increase the heat radiation surface of the transistor because the size of the matching circuit and the size of the inside of the shield case are limited by the wavelength of the frequency used, and the ventilation characteristics deteriorate due to heat radiation. Therefore, there is a problem that it cannot be adopted.

An object of the present invention is to solve such a problem, and an object thereof is to provide a mounting structure capable of efficiently radiating heat with a simple structure and maximally utilizing the capability of the transistor.

[0005]

According to the present invention, there is provided a transistor mounting structure in which a transistor is internally provided in a shield case having a U-shaped cross section and which is covered by a cover.
Between the transistor and the cover, formed by a flexible material mixed with conductive particles, a heat radiator into which a heat conductive fluid is injected is interposed, and the upper surface of the transistor and the shield case One of the surfaces of the radiator is brought into contact with both inner surfaces and the inner surface of the cover.

[0006]

[Function] The upper surface of the transistor, both inner side surfaces of the shield case, and the inner surface of the cover are respectively contacted with one surface of the radiator, and the heat generated from the transistor is contacted through the heat conductive fluid in the radiator. Be transmitted to.

As a result, the thermal conductivity is improved and the performance of the transistor can be maximized.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. 1A is a plan view showing the shape of a radiator used in the embodiment of the present invention, FIG. 1B is a front view thereof, FIG. 1C is a side view thereof, and FIG. 2 is a mounting example according to the embodiment of the present invention. It is a partial cross section figure which shows.

In the embodiment of the present invention, the transistor 7 is provided in the shield case 5 having a U-shaped cross section and covered by the cover 4. As a feature of the present invention, the transistor 7 is provided between the transistor 7 and the cover 4. It is made of a flexible material mixed with conductive particles, and the radiator 1 having the heat conductive fluid 2 injected therein is interposed therein, and the upper surface of the transistor 7, both inner side surfaces of the shield case 5, and the cover 4 are covered. One of the surfaces of the radiator 1 is brought into contact with each of the inner surfaces.

In this embodiment, silver or an equivalent metal is used as the conductive particles, silicon rubber is used as the flexible material, and ethylene glycol is used as the heat conductive fluid.

The radiator 1 is formed of these materials in the shape shown in FIG. 1, and is arranged so as to be buried between the upper surface of the transistor 7 inscribed in the shield case 5 and the cover 4 as shown in FIG. To be done.

If the radiator 1 is made of only silicon rubber, the shielding effect is improved but the thermal conductivity cannot be expected. Therefore, the inside of the radiator 1 is made hollow and ethylene glycol having good thermal conductivity is formed therein. Liquid is injected.

Since the radiator 1 is in contact with the transistor 7, the shield case 5, and the cover 4, the heat conduction area is increased, and the heat conduction is promoted by the convection phenomenon of the liquid inside, so that the heat conduction area between the transistor 7 and the shield case 5 is increased. Thermal resistance is reduced.

[0014]

As described above, according to the present invention, it is possible to reduce the thermal resistance between the transistor and the shield case and maximize the performance of the transistor with a simple structure without damaging the high frequency shield. effective.

[Brief description of drawings]

1A is a plan view showing the shape of a radiator used in an embodiment of the present invention, FIG. 1B is a front view thereof, and FIG. 1C is a side view thereof.

FIG. 2 is a partial cross-sectional perspective view showing a mounting example according to the embodiment of the present invention.

FIG. 3 is a partial cross-sectional perspective view showing a mounting example of a conventional example.

[Explanation of symbols]

 1 Heat Dissipator 2 Thermal Conductive Fluid 3 Cavity 4 Cover 5 Shield Case 7 Transistor 8 Dielectric Substrate 9 Microstrip Line 10 Screw

Claims (2)

[Claims] 1. In a mounting structure of a transistor in which a transistor is provided in a shield case having a U-shaped cross section and covered with a cover, conductive particles are mixed between the transistor and the cover. A radiator formed of a flexible material and having a thermally conductive fluid injected therein is interposed, and one of the radiators is provided on the upper surface of the transistor, both inner side surfaces of the shield case, and the inner surface of the cover. The transistor mounting structure is characterized in that the surfaces of the transistors are in contact with each other. 2. The transistor mounting structure according to claim 1, wherein the conductive particles are silver, the flexible material is silicon rubber, and the thermally conductive fluid is ethylene glycol.