JP2822785B2 - Radiator for electronic equipment - 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 device for cooling high heat generating elements such as ICs and semiconductor elements mounted on a printed circuit board.

[0002]

2. Description of the Related Art In recent years, as semiconductor devices have become faster and more highly integrated, the power consumption of a single semiconductor device has increased, and the reliability of the semiconductor device has often decreased. Conventionally, in order to cool an electronic device including a high heat generating element, FIG.
As shown in the figure, the cooling radiating fins 2 are mounted on the electronic component 1 and used.

As a further advanced prior art, there is, for example, a heat radiating device for electronic equipment disclosed in Japanese Utility Model Publication No. 2-5578. FIG. 6 is a front view, and FIG. 7 is an enlarged side view of a main part. In the figure, 3 is a printed board, 4 is an electronic component mounted on the printed board 3, and 5 is a shield upper cover that covers the upper part of the printed board 3. Reference numeral 7 denotes a screw type heat sink for heat radiation of the electronic components, 8 denotes a fixing plate on the upper surface, 9 denotes a heat sink fitted to the screw type heat sink 7 to release heat to the shield upper cover 5, and 6 denotes terminals of the electronic component 4. Shows lead pins, each of which has thermal conductivity. Reference numeral 10 denotes a lock screw for preventing the screw heat sink 7 from being loosened, and reference numeral 11 denotes the electronic component 4 and the screw heat sink 7.
It is a rubber with good heat conduction for increasing the contact area with the rubber.

Next, the assembling operation of the heat radiating device for electronic equipment will be described. First, the screw-type heat sink 7 is screwed into the screw portion of the heat sink 9 from the upper hole 5a of the upper shield cover 5, and the electronic component 4 is tightened. Next, the upper fixing plate 8 is placed on the shield upper cover 5, and a lock screw 10 is inserted into the hole 8a from above the upper fixing plate 8 and screwed into the female screw 7c to be fixed. In this manner, the heat generated from the electronic component 4 is radiated from above the electronic component 4 to the upper shield cover 5 by the screw type heat sink 7 and the heat sink 9. The heat sink is screwed and fixed with the lock screw 10 in order to adjust the height b between the electronic component 4 and the shield upper cover 5.

Further, as shown in FIG. 8, a conventional printed circuit board has an upper shield cover 13 and a lower shield cover 14.
The shield upper cover 13 and the shield lower cover 14 prevent electrostatic breakdown of the electronic component 15 caused by contact with the terminal lead pins 16 of the electronic component 15 on the lower side of the printed circuit board 12 and prevent the electronic component 15 from being damaged. It is installed for the purpose of blocking generated radio waves.

[0006]

Since the conventional heat radiating device for electronic equipment is constructed as described above, the following can be said. First, FIG. 9 shows a cross-sectional view of an electronic component of a multilayer ceramic package as an example of the electronic component. As can be seen from this figure, the upper part 18 of the chip 17 is sealed by vacuum and the lower part of the chip 17 is closed. 19 has an alumina body, so that the thermal resistance in the electronic
The lower portion 19 of the chip 17 is smaller than the upper portion 18 of the chip. Therefore, the conventional heat radiating device for electronic devices has a problem that the heat generated from the electronic component cannot be sufficiently radiated. Second, the thickness a of the package of the electronic component 4 shown in FIG.
Since the height differs between the electronic components 4, the height b of the electronic component 4 and the shield upper cover 5 needs to be adjusted. Therefore, the heat sink has a screw-type configuration. Adjustment is required, which increases costs. Third, since the printed circuit board is covered by the upper shield cover and the lower shield cover,
There is a problem that heat is trapped inside the shield upper cover and the shield lower cover, the temperature of the internal air rises, and malfunctions and deterioration of electronic components are promoted.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and has as its object to provide a heat radiating device for an electronic device which has an improved heat radiating effect and facilitates assembly adjustment.

[0008]

SUMMARY OF THE INVENTION A heat radiating device for electronic equipment according to the present invention is provided for radiating heat from a lower part of an electronic component having a small thermal resistance and for facilitating height adjustment of the electronic component and a heat conductive cover. Then, between the lower part of the electronic component and the printed circuit board, an expanded joining member of a heat sink with a certain thickness is interposed
Surface contact , and further, a hole is provided in a printed circuit board below the electronic component, and the heat generated from the electronic component by contacting the heat sink with the heat conductive cover covering the lower portion of the entire printed circuit board from the hole is printed board. , and was set to miss both thermally conductive cover.

[0009]

The heat radiating device for an electronic device according to the present invention is provided by enlarging a heat sink under an electronic component having a low internal thermal resistance.
By interposing the member, it is possible to dissipate more heat than the prior art from the lower part of the electronic component through this expanded joining member , and by bringing the heat sink into contact with both the printed circuit board and the heat conductive cover , The heat is dissipated not only to the cover but also to the printed circuit board, and it is possible to obtain a more effective heat dissipation effect than before. Also, the gap between the electronic component and the printed board is almost the same regardless of the electronic component,
In addition, since the printed circuit board and the heat conductive cover are constant,
A joint member with a fixed length between the electronic component and the printed circuit board and a fixed length between the printed circuit board and the heat conductive cover can be used, and the adjustment for contacting the joint member with the heat conductive cover is facilitated, and the processing cost is increased. And other cost reductions.

[0010]

[Embodiment 1] FIG. 1 is a front view showing an embodiment of the present invention. In FIG.
0 implemented Ru electronic parts, 22 a shield on the cover for covering the upper portion of the printed circuit board 20, 23 is shielded under cover for covering the lower portion of the printed circuit board 20. 24 is described in detail later miss the heat generated from the electronic part 21 heatsink,
Reference numeral 25 denotes a terminal lead pin of the electronic component 21, and 26 denotes a fixing screw for fixing the heat sink 24, each of which has thermal conductivity. FIG. 2 is an enlarged sectional view of a main part of FIG. 1, and FIG. 3 is a perspective view of the heat sink 24.

The details of the structure will be described below. First, the gap d between the printed circuit board 20 and the shield lower cover 23
A rod member 24a having a female screw 28,
The electronic component 21 and the printed circuit board 20 are connected to the
A heat sink 24 composed of the enlarged joining member 24b adjusted to the gap c of the above is prepared. And this heat sink 24
The rod member 24a of the printed circuit board 20 from above.
0a, and the electronic component 21 is mounted from above the enlarged joining member 24b . At this time, the gap c between the electronic component 21 and the printed circuit board 20 is substantially the same length regardless of the electronic component 21. Therefore, the thickness of the enlarged joining member 24b of the heat sink in contact with the electronic component 21 and the printed circuit board 20 is fixed to c. it can. Even if the gap between the electronic component 21 and the printed circuit board 20 is smaller than c, there is no problem because the length e of the terminal lead pin 25 of the electronic component 21 has a sufficient margin. Thus, the enlarged joining member 24 having a certain thickness is provided below the electronic component.
In FIG. 7 of the prior art, since the thickness of the package is different for each electronic component 4, the electronic component 4 and the heat sink 24, such as height adjustment of the shield upper cover 5, are required. The need for adjustment is eliminated.
Further, since the heat sink 24 is in contact with the lower part of the electronic component 21 having a lower internal thermal resistance than the upper part of the electronic component 21, a heat radiation effect higher than that of the related art can be expected.
At this time, in order to increase the contact surface area between the heat sink 24 and the electronic component 21 to increase the number of contact points, the electronic component 2
A heat conductive rubber 27 may be inserted between the first heat sink 24 and the heat sink 24. Further, since the heat sink 24 is brought into contact with the printed circuit board 20, the heat conduction to the printed circuit board 20 is also increased. Further, as an example of a method of fixing the heat sink 24, there is the following method. The tip of the heat sink 24 is masked so that the solder does not adhere thereto, and presses the upper part of the electronic component 21 to flow into the solder flow, and the electronic component 2
1. A method of fixing the heat sink 24 by soldering. By fixing the heat sink 24 by soldering in this way, the contact between the electronic component 21 and the printed circuit board 20 is ensured. Furthermore, when attaching the shield upper cover 22 and the shield lower cover 23, the heat sink 24 is securely contacted with the shield lower cover 23 by fixing the heat sink 24 with the fixing screw 26 from the hole 23a of the shield lower cover 23, and the shield lower cover 23 is secured. The heat conduction to the cover 23 is increased.

Embodiment 2 FIG. FIGS. 4A and 4B are perspective views showing the shield upper cover 29 and the shield lower cover 30. The shield upper cover 22 and the shield lower cover 23 shown in the first embodiment are stitched as shown in FIG. With this configuration, the air permeability inside is improved, the temperature rise in the shield cover can be suppressed, and the heat radiation effect of the electronic component can be improved.

[0013]

As described above, according to the present invention, heat can be released from the lower part of the electronic component having a lower thermal resistance than the upper part of the electronic component via the heat sink, so that the heat radiation effect can be improved. Surface on printed circuit boards
Since the enlarged joining member is provided so as to be in contact , heat can be radiated not only to the heat conductive cover but also to the printed circuit board, and a higher heat radiation effect can be obtained. In addition, the expanded joint member of the heat sink between the electronic component lower part and the printed circuit board
In the prior art,
Since the thickness of the package differs for each electronic component, there is no need to adjust the height between the electronic component and the heat conductive cover, which has the effect of reducing costs such as processing costs.

[Brief description of the drawings]

FIG. 1 is a front view showing a heat dissipation device according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a perspective view showing the heat sink of FIG. 1;

FIG. 4 is a perspective view of a shield upper cover a and a shield lower cover b according to another embodiment of the present invention.

FIG. 5 is a perspective view showing an example of a conventional heat dissipation device.

FIG. 6 is a front view showing another example of the conventional heat dissipation device.

FIG. 7 is a cross-sectional view showing a main part of the heat dissipation device of FIG.

FIG. 8 is a front view showing an example of a conventional heat dissipation device.

FIG. 9 is a cross-sectional view illustrating an example of an electronic component.

[Explanation of symbols]

Reference Signs List 20 printed circuit board, 21 electronic components, 24 heat sink, 26 fixing screw, 22, 29 upper shield cover, 23, 30 lower shield cover.

Claims (2)

(57) [Claims] And 1. A printed circuit board, an electronic component mounted on the substrate, in a semiconductor device including a thermally conductive cover covering the top and bottom of the substrate, the electronic component lower surface
Enlarged contact that makes surface contact with a certain thickness between printed circuit boards
A heat sink that has a mating member and is disposed between the electronic component and the lower heat conductive cover through a hole provided in the substrate, and that generates heat from the electronic component through the heat sink. PCB lower surface, and the heat dissipation device for an electronic device, characterized in that so as to heat radiation to the lower <br/> thermally conductive cover. 2. A heat dissipation device for an electronic device according to claim 1, wherein the thermally conductive cover configured to stitch shape covering the substrate.