JPH06163758A - Heat-dissipating structure by ic socket using spring made of shape memory alloy - Google Patents

Abstract

PURPOSE:To achieve that heat generated by an LSI as a CPU or the like and an IC is dissipated by bringing the LSI and the IC into contact with a heat sink plate installed at the upper part of a printed-circuit board. CONSTITUTION:The fundamental structure of an IC socket 1 provided with a spring made of a shape memorizing alloy is formed in such a way that IC sockets are stacked as two stages and that the spring 8 made of the shape memorizing alloy is sandwiched in between. When a power supply is turned on and an LSI 12 generates heat and reaches a prescribed temperature, the spring 8 made of the shape memorizing alloy is expanded, it pushes up the LSI 12 together with an upper-part IC socket 2, it presses the LSI 12 to a heat sink plate 14 at the upper part, it brings the LSI 12 into contact with the heat sink plate and heat is dissipated. The heat sink plate 14 is fixed to a board frame so as to have a heat-conducting route, and the board frame is cooled by water cooling or air cooling. When the power supply is turned off and the LSI becomes the prescribed temperature or lower, the spring 8 made of the shape memorizing alloy shrinks and the LSI 12 is lowered together with the upper-part IC socket 2 and the spring is returned to its original state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for high heat-generating components on a printed circuit board in electronic equipment such as computers.
Heat dissipation structure by C socket.

[0002]

2. Description of the Related Art A conventional LSI 12 on a printed circuit board 13
The heat dissipation structure of the uniform heat generating component was as shown in FIG.

(A) shows a structure in which a heat sink film 18 is provided on the surface or an intermediate layer of the printed board 13 and a heat conductive sheet 19 is sandwiched under the LSI 12 to radiate heat.

(B) shows the LSI 12 on the printed circuit board 13.
The liquid heat sink package 20 is sandwiched between the surface of the above and the upper heat sink plate 14 to radiate heat.

(C) shows the case of air cooling, in which air cooling fins 21 are provided on the surface of the LSI 12 to radiate heat.

[0006]

The conventional heat dissipation of heat-generating components on a printed circuit board has the following problems. Provide a heat sink film on the surface of the printed circuit board or on the intermediate layer,
The method of sandwiching a heat conductive sheet under the heat generating component to radiate heat by heat transfer requires a heat conductive sheet for each component, and it was also necessary to adjust the thickness of the heat conductive sheet. Also, the thickness of the heat sink film cannot be increased depending on the length of the component lead, which is disadvantageous to thermal conductivity.

When a liquid heat sink package is used, it is necessary to consider the arrangement of parts and the like due to the shape limitation due to the packaging technology. Further, since the liquid heat sink package is sandwiched between the heat sink plate and the heat generating component, it is necessary to completely fix the printed circuit board and the heat sink plate. Also, an increase in the mass of the device is unavoidable.

When air cooling fins are used on the heat generating component,
In order to increase the heat dissipation efficiency, it is necessary to increase the height of the fins, which widens the pitch between the printed boards, which is disadvantageous in terms of high-density mounting.

Therefore, the present invention can improve the drawbacks of the above-mentioned conventional techniques, facilitate the maintenance of the printed circuit boards, and can prevent the pitches and the masses of the printed circuit boards from being greatly increased. It is intended to obtain a highly efficient heat dissipation structure.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention deals with the heat generation of LSI such as CPU and IC, and when a specified temperature is reached in order to radiate heat by contact with a heat sink plate above a printed circuit board. A heat dissipation structure using an IC socket using a stretchable shape memory alloy spring and a heat dissipation structure of a board rack for mounting the IC socket on a printed board are adopted.

[0011]

Embodiments of the present invention will be described with reference to the drawings.

First, an embodiment of the invention described in claim 1 will be described.

FIG. 1 is a sectional view of an IC socket 1 with a spring made of shape memory alloy of the present invention in which an LSI 12 is mounted. The basic structure is such that the IC sockets are stacked in two stages, and the shape memory alloy spring 8 is provided between them. There is a metal plate 9 in the center of the upper IC socket 2, and the LSI 12 is inserted into the upper contact 4 and held in contact with the upper inner contact 5 up to a position where the metal plate 9 comes into contact with the belly. The upper contact 4 is inserted into the lower contact 6 of the lower socket 3. The lower contact 6 is a printed circuit board 13
Solder to. That is, in the IC socket 1 with a shape memory alloy spring, the lower socket 3 is a fixed portion to the printed circuit board 13, and the upper IC socket 2 is a movable portion. The movable range of the upper IC socket 2 is the lead portion of the upper contact 4 and the lower inner contact 7 in the lower contact 6.
Since the gap between the surface of the LSI 12 and the upper heat sink plate 14 is set to the movable range or less, it is important to give the upper contact 4 a sufficient lead length. On the other hand, a shape memory alloy spring 8 serving as a drive unit is fixed at its upper and lower ends to a metal plate 9 at the center of the upper IC socket 2 and a plate spring 10 at the center of the lower socket 3 by fasteners 11, rivets or an adhesive. . The metal plate 9 transmits the temperature of the LSI 12 to the shape memory alloy spring 8, and the plate spring 10 extends when the shape memory alloy spring 8 extends and the LSI 12 tries to extend even when the LSI 12 contacts the heat sink plate 14. It has the function of relieving overload stress.

Next, an embodiment of the invention described in claim 2 will be described.

FIG. 2 shows a spring IC made of shape memory alloy according to the present invention.
An example of mounting the printed circuit board 13 on the board rack 16 using the socket 1 is shown. The heat sink plate 14 is fixed to the board rack 16 with a heat transfer path. Printed circuit board 13
Is inserted along the board guide 17 with the component mounting surface on the heat sink plate 14 side, and is joined to the mother board 15. When the power is turned on and the LSI 12 reaches the specified temperature, the IC socket 1 with the shape memory alloy spring is extended, and the LSI 12 contacts the heat sink plate 14 to radiate heat. The heat transferred to the heat sink plate 14 is the frame of the substrate.
In order to be transmitted to 16, the substrate rack (frame) 16 is cooled by water cooling or air cooling using the water cooling pipe 22 and the air cooling fins 21. (In particular, this method is effective in the case of water cooling.) When the power is cut off and the LSI 12 cools, the shape memory alloy spring IC socket 1 contracts, and the LSI 12 and the heat sink plate 14 are brought into non-contact state. Since it returns, the printed circuit board 13 can be pulled out.

[0016]

As described above, according to the first aspect of the present invention, by providing the shape memory alloy spring in the IC socket to which the heat generating component is attached, the heat generating component comes into contact with the heat sink plate when the heat is generated, and heat is dissipated. When it gets cold, the heat sink plate and the parts are in a non-contact state,
It is possible to provide an IC socket capable of maintaining a printed circuit board.

By providing a heat sink plate on the printed board and the board rack on which the IC socket with a shape memory alloy according to the second aspect of the present invention is mounted, the printed board can be inserted into and removed from the board rack without any special work. Further, as compared with the other methods, the effect of enabling an efficient heat dissipation structure can be achieved without significantly increasing the pitch between printed circuit boards or increasing the mass. Further, since this heat sink plate for heat dissipation is made of metal, it also plays a role of an electromagnetic shield between the printed circuit boards and also has an effect of reducing noise in the circuit.

[Brief description of drawings]

FIG. 1 is a sectional view of an IC socket according to an embodiment of the present invention.

FIG. 2 is a mounting example of the board rack according to the second aspect of the present invention.

FIG. 3 is a conventional heat dissipation structure, (A) is a heat dissipation structure using a printed board with a heat sink film, (B) is a heat dissipation structure using a liquid heat sink package, and (C) is a heat dissipation structure using air-cooled fins.

[Explanation of symbols]

 1 Shape memory alloy IC socket with spring 2 Upper IC socket 3 Lower socket 4 Upper contact 5 Upper inner contact 6 Lower contact 7 Lower inner contact 8 Shape memory alloy spring 9 Metal plate 10 Leaf spring 11 Fastener 12 LSI (heating element) 13 Printed Circuit Board 14 Heat Sink Plate 15 Motherboard 16 Board Rack (Frame) 17 Board Guide 18 Heat Sink Film 19 Thermal Conductive Sheet 20 Liquid Heat Sink Package 21 Air Cooling Fin 22 Water Cooling Pipe

Claims (2)

[Claims] 1. A heat dissipation structure using an IC socket using a shape memory alloy spring that expands and contracts when a prescribed temperature is reached in order to cope with heat generation of LSI such as CPU and IC and heat dissipation by contact with a heat sink plate above a printed circuit board. 2. An IC socket using a shape memory alloy spring that expands and contracts when a specified temperature is reached in order to cope with heat generation of LSI such as CPU and IC and to radiate heat by contacting with a heat sink plate above the printed board. The heat dissipation structure of the board frame to be mounted.