JPS6167997A - Shielding cover with heat sink mechanism - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shield cover with a heat dissipation mechanism for a printed board.

Printed boards on which digital signal circuits and the like are formed are generally equipped with a shield cover on the pattern-forming surface in order to prevent electromagnetic waves from entering from the outside and to prevent electromagnetic interference with other printed boards.

In addition, as electronic devices become smaller, it is becoming more common to mount components at a high density in order to reduce the number of printed circuit boards. For this reason, among the mounted components, it is recommended to install a special heat dissipation mechanism for heat generating components that generate a particularly large amount of heat (for example, power transistors, etc.).
This is necessary for maintaining the characteristics of other mounted parts.

When such a heat dissipation mechanism for heat generating components is provided, it is required that this heat dissipation mechanism does not hinder high-density mounting of the components.

[Conventional technology]

FIG. 4 is a partially cutaway side view of a conventional printed board equipped with a heat dissipation mechanism.

In FIG. 4, the shield cover 5 is made of a metal plate (for example, a thin steel plate), and has a shallow box shape whose planar shape is approximately the same as the shape of the printed board 1.

The shield cover 5 is fixed to the printed board 1 with set screws 6 at its four corners so that the four peripheral frame surfaces are in close contact with the edges of the pattern-formed surface IB of the print temporary 1, and shields the pattern-formed surface IB. are doing.

In addition, on the printed board 10 component mounting surface IA, heat generating components 2
is installed. The heat generating component 2 is in close contact with the component mounting surface 1^ via a heat dissipating sheet 4A whose bottom surface is made of a metal plate (for example, aluminum), and is fixed to the printed board l by fixing screws 3.

The heat dissipation sheet 4A is stretched toward one end surface of the heat generating component 2, and heat dissipating pieces 4 are formed in parallel to the main body of the heat generating component 2.

Therefore, most of the heat of the heat generating component 2 is transmitted to the heat radiating piece 4 via the heat radiating sheet 4A, and is radiated from the portion of the heat radiating piece 4 having a large heat radiating area.

[Problem that the invention seeks to solve]

However, the conventional heat dissipation mechanism described above has a problem in that high-density mounting of components is inhibited because a heat dissipation piece with a large heat dissipation area is provided on the component mounting surface.

[Means for solving the problem] The problem with the conventional method is that the shallow box-shaped shield cover is attached to the pattern forming surface side of the printed board, and the heat generated by the component mounting surface of the printed board is This problem is solved by the shield cover with a heat dissipation mechanism of the present invention, which is configured such that a recess is provided in a portion corresponding to the component, and the bottom plate of the recess is in close contact with the pattern forming surface via an insulating sheet.

[Effect]

According to the above means of the present invention, the bottom plate portion of the concave portion of the shield cover is brought into close contact with the pattern forming surface of the printed board corresponding to the position where the heat generating component is mounted, and the heat of the heat generating component is dissipated via the bottom plate portion. The heat is transmitted to the shield cover, which has a large heat dissipation area equivalent to a flat slope, and is radiated. Therefore, there is no need to mount a special heat dissipation piece or the like on the component mounting surface side, and it is possible to mount components at high density.

〔Example〕

The gist of the present invention will be specifically explained below with reference to illustrated examples. Note that the same reference numerals indicate the same objects throughout the figures.

FIG. 1 is a partially cutaway side view of one embodiment of the present invention, FIG. 2 is a top view of the main part, and FIG. 3 is a back plan view of the main part.

1 to 3, heat generating components 2 are mounted in parallel (three in the illustrated example) on the component mounting surface IA of the printed board 1, and a shield cover 10 is attached to the pattern forming surface IB. .

The shield cover 10 is made of a metal plate (for example, a thin steel plate, an aluminum plate, etc.), and has a shallow box shape whose planar shape is approximately the same as the shape of the printed board 1.

This shield cover 10 has at least four corners fixed to the printed board 1 with setscrews 6 so that the four peripheral frame surfaces are in close contact with the edges of the pattern forming surface IB of the printed board 1, and the pattern forming surface Shields IB. Also,
The portions corresponding to the heat generating components 2 arranged in parallel are drawn and recessed toward the pattern forming surface side, and recessed portions 11 are provided.

The size of the bottom plate portion 12 of this recessed portion 11 is formed to be approximately equal to the area occupied by the heat generating components 2 on the component mounting surface IA in which the heat generating components 2 are arranged in parallel. Between the bottom plate part 12 and the pattern forming surface IB,
An insulating sheet (for example, a mica sheet) 7 is inserted, and the fixing screws 3 that attach the heat generating component 2 to the printed board 1 are used to bring the bottom plate portion 12 into close contact with the pattern forming surface IB.

In this way, the insulating sheet 7 is inserted between the bottom plate part 12 and the notation forming surface IB, so that the pattern formed on the pattern forming surface IB is not short-circuited by the bottom plate part 12.

Since the present invention is configured as described above, the heat of the heat generating component 2 is passed through the bottom plate part 12 of the recessed part 11 to the shield cover 1 which has a large heat dissipation area equal to that of the printed board 1.
0 and the heat is radiated. Therefore, on the component mounting surface IA,
There is no need to mount a special heat dissipation piece, etc., and components can be mounted at high density.

Furthermore, since the shield cover 10 also serves as a heat dissipation mechanism, no other heat dissipation mechanism is particularly required, resulting in low cost.

〔Effect of the invention〕

As explained above, the present invention has a shield cover equipped with a heat dissipation mechanism, and there is no need to mount a special heat dissipation piece on the component mounting surface of the printed board, and components can be mounted at high density. It has excellent practical effects, such as being possible and low cost.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway side view of one embodiment of the present invention, Fig. 2 is a surface plan view of the main part, Fig. 3 is a rear plan view of the main part, and Fig. 4 is a conventional one equipped with a heat dissipation mechanism. FIG. 3 is a partially cutaway side view of the printed board. In the figure, l is the printed board, IA is the component mounting surface, IB pattern forming surface, 2 is the heat generating component, 3 is the fixing screw,
4 is a heat sink, 5.10 is a shield cover, 6 is a set screw, 7 is an insulating sheet, 11 is a recess, 12
indicates the bottom plate portion. Figure 1 Figure 2

Claims (1)

[Claims] The shallow box-shaped shield cover is attached to the pattern forming surface side of the printed board, and has a recessed portion in a portion corresponding to the heat generating component mounted on the component mounting surface of the printed board, and the bottom plate portion of the recessed portion is attached to the pattern forming surface side of the printed board. A shield cover with a heat dissipation mechanism, characterized in that the shield cover is configured to be in close contact with the pattern forming surface via an insulating sheet.