JP2793568B2 - Heat dissipation structure of electronic components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat radiating structure for an electronic component, and more particularly to a heat radiating structure having a shield for a flat electronic component such as an LSI mounted on a multilayer wiring board.

[0002]

2. Description of the Related Art Conventionally, the heat dissipation structure of this kind of electronic component has
As shown in the perspective view of FIG. 3, a radiator 11 having a large number of radiating fins is mounted on the surface of an electronic component 12 by mounting hooks 13. Heat generated by the electronic component 12 is radiated from the fins of the radiator 11 to the space.

[0003]

As described above, the conventional radiator radiates the heat generated from the electronic components. However, a large number of fins of the radiator are susceptible to electromagnetic noise generated from the electronic components due to the structure thereof. There is a problem that it plays a role of an antenna and emits electromagnetic noise into space.

[0004]

According to the present invention, there is provided a heat dissipation structure for an electronic component, wherein a lower flat plate is closely attached to an upper surface of a flat electronic component mounted on a wiring board, and is fixed to the lower flat plate. It is composed of a plurality of columnar fins and an upper flat plate fixed to the upper surface of the fins.

In addition, a ground pattern surrounding the periphery of the wiring pattern extending from the terminal of the electronic component on the wiring board in a quadrilateral, and the wiring pattern sandwiched between the electronic component and the lower flat plate are covered. Further, a box-shaped shield cover in which the lower edge of the side plate is in contact with the ground pattern in a spring structure may be provided.

[0006]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which (a) is a perspective view of a radiator, and (b) is a partial perspective view of a multilayer substrate. In FIG. 1A, a radiator includes a metal radiator main body 1 having a high thermal conductivity in which a plurality of radiating fins 11 are provided on a lower flat plate 12, and a heat radiator having a thermal conductivity attached to an end of the radiator main body 1. A box-shaped shield case 2 provided with an upper cover 4 made of a high metal, a spring contact portion 21 at a lower edge of each side plate, and a hook 22 for attaching to an electronic component, and the shield case 2 indicated by a dotted line are attached to the main body. Metal base part 3 for
It is composed of The base portion 3 is provided with a projection for press-fitting, and the projection is press-fitted into a hole of the heat radiating portion main body 1 to integrate the shield case 2 and the main body.

In FIG. 1B, an electronic component 6 such as an LSI which generates heat is mounted on a multilayer substrate 5, and a ground pattern 8 is provided so as to surround a signal pattern 7 wired to the electronic component 6. I have. The radiator of FIG. 1A is mounted on the upper surface of the electronic component 6 by a mounting hook 22 so that the spring contact portion 21 comes into contact with the ground pattern 8.

FIG. 2 is a sectional view showing a state in which the radiator of FIG. 1A is attached to the electronic component 6 of FIG. 1B. The heat radiating portion main body 1 is fixed to the electronic component 6 by a mounting hook 22. As a result, the ground pattern 8 comes into contact with the spring contact portion 21 of the shield case 2, and the shield case 2 is connected to the ground of the multilayer board.

Next, the operation will be described with reference to FIG. The heat generated from the electronic component 6 is transmitted to the base portion 3 having high thermal conductivity, and is released to the space from a large number of fins of the shield case 2 which also functions as a heat radiating plate and the heat radiating portion main body 1 having high heat radiating efficiency. Although the heat radiation effect of the heat radiating portion main body 1 due to the attachment of the upper cover portion 4 is slightly reduced as compared with the conventional heat radiator, the heat radiating effect of the shield case 2 is larger than that of the conventional heat radiator. Has the effect of suppressing the rise in temperature of the electronic component 6 and maintaining the performance of the electronic component 6.

Electromagnetic noise emitted into the space from the electronic component 6 and the signal pattern 7 is suppressed from being emitted to the outside by the shield effect of the shield case 2. Also, regarding the electromagnetic noise transmitted from the electronic component 6 to the heat radiating portion main body 1, in the conventional heat radiating device, the heat radiating fin becomes an antenna and emits the electromagnetic noise to the space.
In this radiator, the upper cover part 4 is attached to the tip of the heat radiation fin, and plays a role of preventing the heat radiation fin from being used as an antenna.

[0012]

As described above, the heat radiating structure for an electronic component according to the present invention is provided with the upper cover at the upper end of the fin and the shield cover covering the signal pattern surface, thereby suppressing electromagnetic wave noise in addition to the heat radiating effect. effective.

[Brief description of the drawings]

FIGS. 1A and 1B are a perspective view of a heating device and a partial perspective view of a multilayer substrate, respectively, showing a structure according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state where the radiator in FIG. 1 is attached to an electronic component on a multilayer substrate.

FIG. 3 is a perspective view showing a conventional structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat radiating part main body 2 Shield case 3 Base part 4 Upper cover 5 Multilayer board 6 Electronic component 7 Signal pattern 8 Ground pattern 21 Spring contact part 22 Mounting hook

Claims (1)

(57) [Claims] 1. A lower flat plate closely attached to an upper surface of a flat electronic component mounted on a wiring board, a plurality of columnar fins fixed to the lower flat plate, and an upper portion fixed to the upper surface of the fin. Heat radiating part of electronic parts composed of flat plate and front
A wiring pattern extending from the terminal of the electronic component on the wiring board;
A ground pattern surrounding the outer periphery of the
The top plate is sandwiched between the product and the lower plate.
Cover the wiring pattern and apply the spring
With a box-shaped shield cover where the lower edge of the side plate contacts
A heat dissipation structure for an electronic component, comprising: