JPH09237988A - Heat dissipating structure of transmission power amplifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a transmission power amplifier which is capable of being mounted with an active device of high power preventing the device from influencing other devices on a mother board by a method wherein heat is restrained from concentrating on a part of the mother board. SOLUTION: A transmission power supply amplifier is equipped with active devices such as transistors and FETs 23 and 24 mounted on a PA board 21 and a case 26 which covers the active devices and mounted on a mother board 6, wherein a heat conduction route is provided in such a manner that thermally conductive resins 25 and 27 of high thermal conductivity are provided onto the upsides of the active elements, and heat released from the active elements is directly conducted to the case 26 through the upsides of the active devices.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission power amplifier (hereinafter referred to as PA) mounted on a mother board in which active elements such as transistors and field effect transistors (hereinafter referred to as FET) are mounted on a substrate. Of heat dissipation structure.

[0002]

2. Description of the Related Art FIG. 4 is a side view showing a conventional example of a heat dissipation structure of this type of PA, FIG. 5 is a partial perspective view of the same conventional example, and FIG. 6 is a side view showing the operation of the conventional example. In the figure, 1 is P
A substrate, material is glass epoxy, and dielectric constant is 4.
8 and has a two-layer structure and a layer thickness of 0.8.

Numerals 2 and 3 are GaAs-FETs which are active elements.
2 is the first stage GaAs-FET, 3 is the last stage GaAs
-FET. Reference numeral 15 is a chip component forming a matching circuit. This PA has a structure in which the SAW filter is built in the PA, and the SAW filter 4 is built in the input stage. Numerals 7 to 14 are signal input / output and power supply terminals, which are formed side by side on the side surface of the PA substrate. GaAs
After mounting the FETs, chip parts, etc., the case 5 is covered, soldered, and mounted on the mother board 6.

With the above structure, conventionally, as shown by the arrow in FIG. 6, the initial stage GaAs-FET 2 and the final stage GaAs-F are used.
The heat generated from the ET3 is passed through a heat conduction through hole (not shown) provided in the PA substrate 1 to the mother board 6
I was running away.

[0005]

However, according to the prior art having the above-mentioned structure, the structure is such that heat is released to the mother board, so that it is not sufficient for radiating the high-power active element, and the heat is concentrated on a part of the mother board. However, there is a problem that other devices on the motherboard may be affected.

In view of the above problems, the present invention provides a structure in which heat is not concentrated on a part of a motherboard, prevents influence on other devices on the motherboard, and mounts a high-power active element. The aim is to realize a possible transmission power amplifier.

[0007]

In order to achieve the above object, the present invention provides high heat dissipation to the case side. That is, according to the present invention, an active element such as a transistor or an FET is mounted on a substrate, a case is placed on the upper surface of the active element, and then a heat dissipation structure of a transmission power amplifier mounted on a motherboard has high thermal conductivity. A heat conduction path for radiating heat from the upper surface of the active element to the case side is provided by installing a heat conductive resin or the like on the upper surface of the active element.

At this time, it is preferable to provide the case surface with irregularities.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a side view showing a first embodiment of the present invention, and FIG. 2 is a partial perspective view of the same embodiment. In the figure, 21 is a PA substrate, 22 is a device with a built-in PA such as a SAW filter, and 23 and 24 are FETs which are active elements.
23 is a first stage FET and 24 is a final stage FET.
The PA built-in device 22, the first-stage FET 23, the final-stage FET 24, and other chip components for impedance matching are mounted on the PA substrate 21, and are connected to the surface layer by microstrip lines.

Reference numerals 7 to 14 are signal input / output terminals and power supply terminals, which are formed side by side on the side surface of the PA substrate 21. Two
Reference numeral 5 denotes a heat conductive resin having a high heat conductivity installed on the upper surface of the first-stage FET 23, and the heat conductive resin 25 is a first-stage FET 23.
And the bottom surface of the case 26 are in contact with each other. Reference numeral 27 denotes a heat conductive resin having a high thermal conductivity, which is installed on the upper surface of the final-stage FET 24, and the thermal conductive resin 27 is in contact with the upper surface of the final-stage FET 24 and the bottom surface of the case 26.

The PA is the PA-containing device 22,
After the mounting of the first-stage FET 23, the final-stage FET 24, other impedance matching chip parts, the heat conductive resins 25, 27, etc., the case 26 is covered and soldered, and then mounted on the motherboard 6. The operation of the present embodiment having the above configuration is as follows. First stage FET 23, last stage F
The heat generated from the ET 24 escapes to the motherboard 6 through a heat conduction through hole (not shown) provided in the PA substrate 21, and the first stage FET 23 and the final stage FET 24
The heat conducting resins 25 and 27 are transmitted from the upper surface and escape to the case 26. The heat that escapes to the case 26 escapes from the surface of the case 26 into the air. Since the case 26 has a large surface area, it has a high heat dissipation effect.

FIG. 3 is a perspective view of an essential part showing a second embodiment of the present invention. In the figure, reference numeral 26 a denotes an unevenness provided on the case 26. The configuration other than this unevenness 26a is the same as that of the first embodiment shown in FIG. Second of the above configuration
In the embodiment, the unevenness 26 provided on the surface of the case 26 is
Since the surface area of the case 26 is increased by a, the efficiency of heat radiation into the air is further improved.

[0013]

With the above-described structure, the present invention mounts an active element such as a transistor or an FET on a substrate, covers the case on the upper surface of the active element, and then radiates heat of a transmission power amplifier mounted on a mother board. In the structure, a heat-conducting resin having a high heat conductivity is installed on the upper surface of the active element to provide a heat-conducting path for radiating heat directly from the upper surface of the active element to the case side. High heat dissipation can be achieved.

As a result, heat is prevented from concentrating on a part of the mother board, the influence on other devices on the mother board is prevented, and a transmission power amplifier capable of mounting high-power active elements is realized. . Further, in addition to the above configuration, if the surface of the case is provided with irregularities, the surface area of the case can be increased, and the heat dissipation efficiency can be further improved.

[Brief description of drawings]

FIG. 1 is a side view showing a first embodiment of the present invention.

FIG. 2 is a partial perspective view showing the first embodiment of the present invention.

FIG. 3 is a perspective view of an essential part showing a second embodiment of the present invention.

FIG. 4 is a side view showing a conventional example.

FIG. 5 is a partial perspective view showing a conventional example.

FIG. 6 is a side view showing an operation of a conventional example.

[Explanation of symbols]

 6 Motherboard 7 to 14 Terminals 21 PA Substrate 22 PA Built-in Device 23 First Stage FET 24 Final Stage FET 25, 27 Thermal Conductive Resin 26 Case 26a Unevenness

Claims (3)

[Claims] 1. An active element such as a transistor or FET is a P element.
In a heat dissipation structure of a transmission power amplifier mounted on a mother board, mounted on a substrate, and covered with a case on the upper surface of the active element, a heat conduction path for radiating heat from the upper surface of the active element directly to the case side. A heat dissipating structure for a transmission power amplifier, wherein: 2. The heat dissipation structure of the transmission power amplifier according to claim 1, wherein a heat conductive resin having a high heat conductivity is installed on the upper surface of the active element to provide the heat conductive path. 3. The heat dissipation structure for a transmission power amplifier according to claim 1, wherein the case surface is provided with irregularities.