JPH07336009A - Radiation structure of semiconductor element - Google Patents

Abstract

PURPOSE:To obtain a radiation structure which is provided with a radiation spacer for making radiation of heat of a semiconductor element more excellent and transfers the heat to a chassis through the spacer. CONSTITUTION:A semiconductor element (transistor or the like) 1 is set on a printed board 3, and a ground pattern 4 formed on the surface of the printed board and a heat radiating face 2 are soldered. A radiation spacer is set at the fore end of a projection 7 provided on a chassis 6 and the printed board is set at a prescribed position on the upper surface of the chassis, while a hole provided in the printed board is fitted on the projection. As the result, a heat radiating from a heat sink of the semiconductor element is transferred to the projection of the chassis through the radiation spacer and further conducted to the whole of the chassis. Meanwhile, a heat radiating from the heat radiating face of the semiconductor element is conducted to the chassis through the ground pattern formed on the surface of the printed board and further through the printed board.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for radiating heat generated by a semiconductor element to a chassis.

[0002]

2. Description of the Related Art Conventionally, when an electronic component having a large heat generation amount, for example, a component such as a transistor, a diode or an IC is mounted on a printed circuit board, the transistor 30 is mounted on the printed circuit board 31 as shown in FIG. Board 31
Is placed on top of the chassis 32, and the transistor 30 is attached to the side of the chassis 32 (or radiator) with screws 33.
The heat generated from the transistor 30 was conducted to the chassis 32 through the heat radiating plate on the side of the transistor 30.

Recently, in order to reduce the size of equipment, surface mount components such as transistors are used, and as shown in FIG.
The ground pattern 35 is formed on both surfaces of the printed board 34, the transistor 36 is placed on the printed board 34, and the heat sink 37 of the transistor 36 is soldered to the ground pattern 35. Then, the printed circuit board 34 is fixed to the chassis 38 (or radiator). On the other hand, the upper and lower patterns of the printed circuit board 34 are connected by through holes 39, and the heat generated from the transistor 36 is conducted to the pattern on the lower surface through the ground pattern 35 and the through holes 39 and radiated to the chassis 38.

According to these methods, the heat radiation plate of a semiconductor component such as a heat generating transistor cannot be directly contacted with the chassis 38, so that the heat radiation efficiency is poor, and when the substrate has a single-sided pattern, the through hole enhances the heat radiation effect. Three
Since 9 could not be formed, there was a problem that the heat dissipation effect was reduced accordingly. In addition, in the above mounting structure, the problem that heat dissipation becomes insufficient as the amount of heat generated by components such as transistors that generate heat increases, and in order to solve this problem, an auxiliary heat radiator for improving heat dissipation is used for transistors, etc. Therefore, there is a problem in that a load is applied to the lead joint portion of the transistor, which causes damage due to stress.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art. A heat dissipation structure is provided to dissipate heat from a semiconductor element and the heat dissipation structure dissipates heat to a chassis through the spacer. The purpose is to provide.

[0006]

In order to solve the above-mentioned problems, according to the present invention, a rectangular or circular arbitrary hole is provided and a printed board having a ground pattern formed on the upper surface thereof, and the hole is inserted into the hole. A chassis with a protrusion,
A semiconductor element having a heat dissipation surface on the bottom surface, the semiconductor element is mounted on the printed circuit board with the heat dissipation surface of the semiconductor element facing downward, and the heat dissipation surface and a ground pattern are soldered to each other, A heat dissipation structure for a semiconductor device, characterized in that the printed circuit board is placed on the upper surface, and silicon grease is applied to the protrusions of the chassis to insert the holes of the printed circuit board into the protrusions.

[0007]

According to the above construction, the semiconductor element (transistor or the like) is placed on the printed board, and the ground pattern formed on the printed board surface and the heat radiation surface of the semiconductor element are soldered. Then, silicon grease is applied to the tips of the protrusions provided on the chassis, the printed board is placed at a predetermined position on the upper surface of the chassis, and the holes provided in the printed board are inserted into the protrusions. As a result, the heat generated from the heat dissipation surface of the semiconductor element is transmitted to the protrusion of the chassis and further conducted to the entire chassis. On the other hand, the heat generated from the heat dissipation surface of the semiconductor element is conducted to the chassis via the ground pattern formed on the printed board surface and the printed board.

[0008]

Embodiments of the present invention will be described in detail with reference to the accompanying drawings. As shown in FIG. 1, reference numeral 1 denotes a semiconductor element such as a transistor, a diode, an IC, etc., and a heat radiation surface 2 for radiating heat generated from the element is mounted on the back surface. Reference numeral 3 is a printed circuit board. A circuit pattern and a ground pattern 4 for heat dissipation are formed on the printed circuit board 3 and arbitrary square or circular holes 5 are provided. 6 is a chassis or heat dissipation material, and is a printed circuit board 3
Inserted into the hole 5 formed in the hole, the projection 7 for conducting heat
Are formed. Reference numeral 8 denotes a heat radiating spacer, which is a square or circular plate material having a high thermal conductivity, which is matched with the outer shape of the hole 5, and is inserted into the hole 5 after silicone grease is applied to both surfaces of the heat radiating spacer 8.

Next, the above-mentioned components are assembled as follows. First, the semiconductor element 1 is placed on the ground pattern 4 of the printed board 3, and the heat radiation surface 2 provided on the back surface of the semiconductor element 1 and the ground pattern 4 are soldered so that the heat from the heat radiation surface 2 is effective. Ground pattern 4
To be transmitted to. Next, on the upper portion of the protrusion 7 of the chassis 6, a heat dissipation spacer 8 coated with silicon grease on both surfaces
After mounting, the printed circuit board 3 is mounted on the chassis 6 at a predetermined position. At this time, the heat dissipation spacer 8 is first inserted into the hole 5 of the printed circuit board 3, and the projection 7 of the chassis 6 is further inserted into the hole 5. The printed circuit board 3 and the chassis 6 are not shown.
To fix.

In the above structure, the heat generated from the heat radiating surface 2 of the semiconductor element 1 is transmitted to the projection 7 of the chassis 6 through the heat radiating spacer 8, and then conducted to the entire chassis and radiated. On the other hand, the heat generated from the heat radiation surface 2 of the semiconductor element 1 is conducted to the entire chassis 6 via the ground pattern 4 formed on the upper surface of the printed board 3 and the printed board 3 and is radiated. In another embodiment, the ground patterns 4 are formed on both sides of the printed circuit board 3, and the through holes 9 are formed in the holes 5 of the printed circuit board 3. As a result, the heat generated from the heat dissipation surface 2 of the semiconductor element 1 described above is transmitted to the through hole 9 and the ground pattern 4 on the lower surface of the board 3 via the ground pattern 4 formed on the upper surface of the printed board 3, and then the chassis 6 as a whole. Is conducted to and is dissipated.

[0011]

As described above, in the present invention, the heat from the semiconductor element can be directly radiated to the chassis through the heat radiation surface, the heat radiation spacer, etc., so that the heat radiation efficiency is improved as compared with the conventional heat radiation method.

[Brief description of drawings]

FIG. 1 is an external view showing an embodiment of a heat dissipation structure for a semiconductor device of the present invention, in which A is a front view and B is a side sectional view.

FIG. 2 is a side sectional view showing another embodiment of the heat dissipation structure of the semiconductor element of the present invention.

3A and 3B are external views showing an example of a conventional heat dissipation structure for a semiconductor element, wherein A is a partial front sectional view and B is a side sectional view.

FIG. 4 is an external view showing another embodiment of a conventional heat dissipation structure for a semiconductor element, wherein A is a front view and B is a side sectional view.

[Explanation of symbols]

 1 semiconductor element 2 heat dissipation surface 3 printed circuit board 4 ground pattern 5 hole 6 chassis 7 protrusion 8 heat dissipation spacer 9 through hole

Claims (3)

[Claims] 1. A printed circuit board having an arbitrary square or circular hole and a ground pattern formed on the upper surface thereof, and a chassis having a protrusion for insertion into the hole.
A semiconductor element having a heat dissipation surface on the bottom surface, the semiconductor element is mounted on the printed circuit board with the heat dissipation surface of the semiconductor element facing downward, and the heat dissipation surface and a ground pattern are soldered to each other, A heat dissipation structure for a semiconductor device, characterized in that the printed circuit board is placed on the upper surface, and silicon grease is applied to the protrusions of the chassis to insert the holes of the printed circuit board into the protrusions. 2. A semiconductor element characterized in that a heat radiating spacer is placed on the tip of the protrusion, silicon grease is applied to both surfaces of the heat radiating spacer, and the printed circuit board is placed on the upper surface of the chassis. Heat dissipation structure. 3. The heat dissipation structure for a semiconductor element according to claim 1, wherein ground patterns are formed on both surfaces of the printed circuit board, through holes are formed in the holes, and the upper and lower ground patterns are connected.