JPH0555558U - Flexible heat radiator for LSI case - Google Patents

Abstract

(57) [Abstract] [Purpose] In a flexible radiator for an LSI case, the heat sink 10 itself has flexibility so that the heat sink 10 is detachable and good in thermal contact with the LSI case 2. It is wound in an O shape to improve the thermal conductivity and to have a high heat dissipation capability. [Structure] A loop is formed using one thin metal wire,
The number of turns of the loop connecting the heat receiving portion and the heat radiating portion is at least one or more, and each of the loops in the vicinity of the heat receiving portion is meandered, wound in an O shape, and is attached to one end of the heat radiating portion. For mounting on the LSI case 2, the pressing jig 12 is fixed, and the O-shaped heat dissipation portion is directly used as a heat sink.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention is a heat sink mounted directly on an LSI mounting case that requires high cooling capacity due to high-speed and high-density mounting of the system, is detachable, has flexibility, and has low contact thermal resistance. The present invention relates to a radiator having.

[0002]

[Prior Art]

 FIG. 1 shows a cross-sectional structure of a conventional LSI mounting case, where 1 is an LSI chip, 2 is an LSI case, 3 is a wire bonding portion, 4 is a power connection pin, 5 is a lid, and 6 is a printed wiring board. , 7 is a plate fin type heat sink, 8 is a fixing screw, and 9 is a flow direction of air. The above structure shows a structure in which an LSI chip 1 having high power consumption due to high speed and high density mounting is mounted on an LSI case 2 with an air-cooled heat sink (plate fin type heat sink) 7. , (A) is a cross-sectional view showing how to mount the plate fin type heat sink 7, (b) is a cross sectional view after mounting the plate fin type heat sink 7, (c) is a plate fin type heat sink 7A and 7B are plan views seen from the upper surface. In this configuration, the plate fin type heat sink 7 is made of a rigid metal such as aluminum or copper, and thus has no flexibility. Therefore, in order to realize excellent thermal contact with low contact thermal resistance between the plate fin type heat sink 7 and the LSI case 2, the back surface of the plate fin type heat sink 7 and the back surface of the LSI case 2 are polished. Then, there is no means other than reducing the surface roughness thereof or generating a large fastening force by the fastening screw 8 for tightening to reduce the contact thermal resistance. Therefore, there has been a problem that the manufacturing process (polishing / cleaning process) is increased to reduce the surface roughness, resulting in an increase in the overall cost. In addition, as a method of increasing the fastening force, it is necessary to increase the strength of the LSI case 2 in particular, so that there is a problem in that it is unavoidable to take an appropriate reinforcing structure, resulting in an increase in cost.

[0003]

[Problems to be solved by the device]

 The present invention solves the above-mentioned problems, is detachable, and has good thermal contact with the LSI case 2. Therefore, the heat sink itself has flexibility, and at the same time, the heat sink is further wound into an O shape. It is intended to provide a flexible radiator for LSI cases with improved conductivity and high heat dissipation capability.

[0004]

[Means for Solving the Problems]

 In order to solve the above problems, in claim 1, a loop is formed by using a single thin metal wire, and the number of loop turns connecting the heat receiving portion and the heat radiating portion is at least one or more. In addition, each of the loops near the heat receiving part is meandered and wound in an O-shape, and a holding jig for mounting on the LSI case is fixed to one end of the heat-dissipating part to directly attach the O-shaped heat-dissipating part. It is configured to be used as a heat sink, and in claim 3, a heat pipe structure is formed by making the inside of the small-diameter metal tubular so as to improve fin efficiency and form a heat sink with low thermal resistance.

[0005]

[Action]

 Since the present invention is configured as described above, when the flexible heatsink structure for an LSI case is applied to the cooling of the LSI case, the flexible heatsink for the LSI case has an O shape (or a structure in which an integer number of these are stacked). Since it has a shape, it has spring elasticity, and when it is fixed to the LSI case with a pressing jig, the reaction force due to the spring elasticity acts as a fastening force, and good thermal contact can be realized. Further, the flexible heat radiator for the LSI case according to the present invention has a structure in which the heat sink portion is wound in an O shape to suppress the development of the temperature boundary layer, so that the heat conduction efficiency is improved and the heat radiation ability is high. It will be possible.

[0006]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. FIG. 2 shows a first embodiment according to the present invention. Here, 1 is an LSI chip, 2 is an LSI case, 3 is a wire bonding portion, 4 is a power supply connecting pin, 5 is a lid, 6 is a printed wiring board, 8 is a fixing screw, 9 is an air flow direction, and 10 is A flexible heat sink, 11 is a heat receiving plate, and 12 is a pressing jig. This structure has a structure in which a flexible air-cooling heat sink 10 is mounted on the LSI case 2 that mounts the LSI chip 1 having high power consumption due to high-speed and high-density mounting. In the figure, (a) is a cross-sectional view showing how to mount the flexible heat sink 10, (b) is a cross-sectional view after mounting the flexible heat sink 10, and (c) is a top view from the top. The plan view seen is shown. Before the flexible heat sink 10 is mounted on the LSI case 2, the total length of the flexible heat sink 10 is made longer than the length of the pressing jig 12 in the height direction so that the spring elasticity is urged after mounting. Therefore, when the holding jig 12 is screwed to the LSI case 2 with the fixing screw 8, the reaction force due to the spring elasticity acts as a fastening force, so that good thermal contact can be realized. In addition, even if it is attached and detached several times, the spring elasticity is not lost, so it is possible to repeatedly mount it. Further, since the heat sink portion of the flexible radiator for the LSI case according to the present invention is configured by winding the thin metal wire around the O-shaped loop, the temperature boundary layer that develops along the thin metal wire is developed. Since it can be suppressed, the thermal conductivity can be remarkably improved and high heat dissipation capability can be obtained. In this embodiment, a thin metal wire is used for the heat sink member, but by forming this into a heat pipe, fin efficiency is improved, and a heat sink with lower thermal resistance can be provided.

FIG. 3 shows a second embodiment according to the present invention. The symbols given in the drawing are the same as those used in FIG. 2, 13 is a multi-chip wiring board, and 14 is a sealing cap. This structure is used when a plurality of detachable and flexible air-cooled heat sinks 10 are mounted on a multi-chip wiring board 13 on which a plurality of LSI chips 1 having high power consumption by mounting at high speed and high density are mounted. 2 is a sectional view of FIG. Similar to the embodiment of FIG. 2, the flexible heat sink 10 according to the present invention has a total length longer than the height of the pressing jig 12 in order to urge the spring elasticity after mounting. Therefore, when the holding jig 12 is screwed to the multi-chip wiring board 13 with the fixing screw 8, the reaction force due to the spring elasticity acts as a fastening force, so that good thermal contact can be realized. In addition, since the spring elasticity is not lost even if it is attached and detached several times, it can be repeatedly mounted. Further, the present invention can provide a high heat dissipation capability, as in the embodiment shown in FIG.

[0008]

[Effect of the device]

 Since the present invention is configured as described above, it has the following effects. As described in claim 1, a loop is formed using one thin metal wire, and the number of turns of the loop connecting the heat receiving portion and the heat radiating portion is at least one or more. In addition, each of the loops near the heat receiving part is meandered and wound in an O shape, and a pressing jig for mounting on the LSI case is fixed to one end of the heat dissipation part and the O shape heat dissipation part is used directly as a heat sink. The most important feature is that when the flexible radiator for LSI of the present invention is applied to the cooling of the LSI case, the flexible radiator for the LSI case has spring elasticity and is attached to the LSI case by the holding jig. When fixed, the reaction force of the spring elasticity acts as a fastening force and good thermal contact can be realized, so there is an effect that a high fastening force can be easily generated. This eliminates the need for polishing and cleaning the plate fin type heat sink and the back surface of the LSI case, resulting in a low cost radiator structure. Further, since the flexible heat sink for the LSI case according to the present invention constitutes the heat sink part with the thin metal wire, it is possible to suppress the development of the thermal boundary layer along the heat sink, and as a result, the thermal conductivity. The effect of being able to greatly improve.

[Brief description of drawings]

FIG. 1 is a structural diagram of a conventional LSI case radiator,
(A) is a cross-sectional view showing a method for mounting a plate fin type heat sink, (b) is a cross sectional view after mounting the plate fin type heat sink, and (c) is a plan view seen from above.

2A and 2B are structural views of a flexible radiator for an LSI case according to the present invention, in which FIG. 2A is a sectional view showing a mounting method of a flexible heat sink, FIG. 2B is a sectional view after mounting a flexible heat sink, and FIG.
Is a plan view from above,

FIG. 3 is a cross-sectional view showing a structure in which a plurality of heat sinks are mounted on a flexible radiator for an LSI case according to the present invention.

[Explanation of symbols]

 1 LSI Chip 2 LSI Case 3 Wire Bonding Part 4 Power Connection Pin 5 Lid 6 Printed Wiring Board 7 Plate Fin Heat Sink 8 Fixing Screw 9 Air Flow Direction 10 Flexible Heat Sink 11 Heat-Receiving Plate 12 Holding Jig 13 Multi-chip Wiring Board 14 Sealing Stop cap

Claims (4)

[Scope of utility model registration request] 1. A loop is formed by using one thin metal wire, and the number of windings of the loop connecting the heat receiving portion and the heat radiating portion is at least one or more, and the loop near the heat receiving portion is formed. Each of the loops is meandered and wound in an O shape, and a pressing jig for mounting in an LSI (Large Scale Integrated Circuit, hereinafter referred to as LSI) case is fixed to one end of the heat dissipation part to form an O shape. A flexible radiator for an LSI case, characterized in that the radiator is directly used as a heat sink. 2. An O-shaped integer number of the loops in the vicinity of the heat receiving section are connected and wound in an O-shape.
Flexible radiator for LSI case. 3. The flexible radiator for an LSI case according to claim 1, wherein the thin metal has a tubular shape to form a heat pipe structure. 4. A plurality of the loop type radiators are collectively L
A flexible radiator for an LSI case, characterized in that a holding jig for mounting the SI case is fixed.