JP2010129954A - Heat dissipating structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat dissipating structure which has small design burden and risk. <P>SOLUTION: The heat dissipating structure including a heat dissipating body 12 for dissipating heat from a heat source and a heat dissipating sheet 14 interposed between the heat source and heat dissipating body is provided, on the surface of the heat dissipating body which faces the heat dissipating sheet, with a projection portion 13a which comes into contact with the heat dissipating sheet by pressing a part of the surface of the heat dissipating sheet opposed to the facing sheet. Projection portions have such a shape, a size, a number, and an arrangement such that contact between the heat dissipating sheet and heat dissipating body is secured without reference to variance in thickness of the heat dissipating sheet and pressing force which is larger than predetermined is not applied to the heat source. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heat dissipation structure including a heat dissipating body for dissipating heat from a heat source and a heat dissipating sheet interposed between the heat source and the heat dissipating body.

  Conventionally, as a heat dissipation structure for dissipating heat generated by a heat source such as an integrated circuit (hereinafter referred to as “IC”), a heat dissipating sheet metal for dissipating heat from the heat source, and interposed between the heat source and the heat dissipating sheet metal The thing provided with the heat-radiation sheet | seat to perform is known. In this heat dissipation structure, fine adjustment of the gap between the heat source and the heat dissipation sheet metal is performed by drawing the heat dissipation sheet metal, and the heat dissipation sheet is sandwiched between the heat source and the heat dissipation sheet metal in the finely adjusted gap portion. I have to.

  FIG. 6 is a cross-sectional view showing an example of such a conventional heat dissipation structure. The heat radiating structure includes an IC 62 held on the substrate 61, a heat radiating metal plate 63 facing the IC 62 on the side opposite to the substrate 61, and a heat radiating sheet 64 interposed between the IC 62 and the heat radiating metal plate 63. A portion of the heat radiating metal plate 63 corresponding to the heat radiating sheet 64 is provided with a throttle portion 63a protruding toward the heat radiating sheet 64, and the IC 62, the heat radiating sheet 64, and the throttle portion 63a are closely stacked in this order. The heat generated by the IC 62 is dissipated through the heat dissipating sheet metal 63 through the heat dissipating sheet 64 and the restricting portion 63a.

  In addition, as a technique for dissipating heat generated by an IC or the like, a jet collision type heat sink is known (for example, see Patent Document 1). The heat sink includes a heat receiving plate to which a heating element is attached, and an injection unit that injects a cooling medium onto the heat receiving plate. The heat receiving plate has a jet receiving portion curved in a concave shape, and the jetting means has a jet portion curved in a convex shape. A curved channel through which the cooling refrigerant injected from the injection unit can flow is formed between the injection unit and the jet receiving unit.

JP 2007-165582 A

  However, according to the heat radiating structure of FIG. 6 described above, the heat radiating sheet 64 has elasticity and needs to be used with an optimal crushing margin, but the heat radiating sheet 64 has variations in thickness. It is difficult to form an optimal crushing allowance. Further, in order to optimize the crushing allowance, it is necessary to provide a restricting portion 63a in the heat radiating metal plate 63 and adjust a gap between the IC 62 and the IC 62.

  That is, if the thickness of the heat radiating sheet 64 is small, a gap is generated between the IC 62 and the heat radiating sheet 64 or between the heat radiating sheet 64 and the heat radiating sheet metal 63, making it difficult to radiate heat and possibly destroying the IC 62. On the contrary, if the thickness of the heat dissipation sheet 64 is large, the heat dissipation sheet 64 may not be sufficiently crushed, and the substrate 61 may be bent and the circuit pattern on the substrate 61 may be torn. Even if these problems are dealt with by fine adjustment by the diaphragm 63a, the burden required for designing the diaphragm 63a and the like is increased, and there is a large risk that heat radiation is impossible and circuit patterns are broken.

  In addition, the technology related to the jet impingement type heat sink described above is different from the above-mentioned problems related to the heat dissipation sheet because the heat dissipation method is different and the heat dissipation sheet is not used but the heat dissipation is performed via the cooling medium. It is.

  An object of the present invention is to provide a heat dissipating structure with less design burden and risk in view of the problems of the prior art.

  To achieve this object, a heat dissipating structure according to a first aspect of the present invention is a heat dissipating structure including a heat dissipating body for dissipating heat from a heat source, and a heat dissipating sheet interposed between the heat source and the heat dissipating body. Further, on the surface of the heat dissipating member facing the heat dissipating sheet, the heat dissipating member has a protrusion that presses a part of the surface of the heat dissipating sheet facing the surface and contacts the heat dissipating sheet.

  The heat dissipation structure according to a second aspect of the present invention is characterized in that, in the first aspect of the invention, the one heat dissipation sheet has two or more corresponding protrusions.

  The heat dissipation structure according to a third aspect of the present invention is the first or second aspect of the present invention, wherein the projecting portion ensures contact between the heat dissipation sheet and the heat dissipating member regardless of variations in the thickness of the heat dissipating sheet, And it has the shape, magnitude | size, number, and arrangement | positioning which do not provide the predetermined pressure or more with respect to a heat source.

  In the heat dissipation structure according to a fourth invention, in any one of the first to third inventions, the cross-sectional shape of the protruding portion is an arc shape, a V shape, a trapezoidal shape, or a shape in which a V-shaped tip is rounded. It is characterized by being.

  A heat dissipation structure according to a fifth invention is characterized in that, in any one of the first to fourth inventions, the protruding portion has a bowl-like form.

  The heat dissipation structure according to a sixth aspect of the present invention is characterized in that, in any one of the first to fifth aspects, the projecting portion has a cone, a truncated cone, or a shape obtained by rounding a tip of the cone.

  ADVANTAGE OF THE INVENTION According to this invention, a thermal radiation structure with few design burdens and risks can be provided.

  FIG. 1 is a cross-sectional view showing a heat dissipation structure according to an embodiment of the present invention. As shown in the figure, the heat radiating structure includes a heat radiating sheet metal 13 for radiating heat from the IC 12 on the substrate 11, and a heat radiating sheet 14 interposed between the IC 12 and the heat radiating metal sheet 13. On the surface of the heat radiating sheet metal 13 facing the heat radiating sheet 14, two protrusions 13 a that press a part of the surface 14 a of the heat radiating sheet 14 facing the surface and come into contact with the heat radiating sheet 14 are provided.

  FIG. 2 is an assembly view of the heat dissipation structure of FIG. As shown in the figure, the heat dissipating structure of FIG. 1 has a heat dissipating sheet 14 disposed between an IC 12 on a substrate 11 and a heat dissipating metal plate 13 so that the substrate 11 and the heat dissipating metal plate 13 face each other. 13 is brought close to a predetermined distance, and this positional relationship is fixed. In this positional relationship, the protrusion 13a has a shape that ensures contact between the heat radiating sheet metal 13 and the heat radiating sheet 14 and does not cause more than a predetermined pressure on the IC 12, regardless of variations in the thickness of the heat radiating sheet 14. It has a size, number, and arrangement. Here, two protrusions 13a having a shape obtained by cutting a part of a spherical surface with a flat surface or a dome shape and having an appropriate size are arranged at two appropriate positions.

  FIG. 3 is a cross-sectional view showing a contact state between the heat radiating sheet metal 13 and the heat radiating sheet 14. The figure (a) has shown about the case where the thermal radiation sheet 14 is thin, and the figure (b) has shown about the case where the thermal radiation sheet 14 is thick. Such a difference in thickness is caused by manufacturing variations of the heat dissipation sheet 14. When the heat radiating sheet 14 is thin, as shown in FIG. 5A, a considerable gap d is generated between the main surface 13b of the heat radiating sheet metal 13 and the surface 14a on the heat radiating sheet metal 13 side of the heat radiating sheet 14, Since the protrusion 13a has an appropriate shape, size, number, and arrangement as described above, the contact between the heat radiating sheet metal 13 and the heat radiating sheet 14 is reliably ensured. Therefore, even when the heat radiating sheet 14 is thin, the heat generated by the heat source 12 is reliably transmitted to the heat radiating sheet metal 14 via the heat radiating sheet 14 and the protruding portion 13a and is dissipated.

  On the other hand, when the heat radiating sheet 14 is thick, as shown in FIG. 4B, there is almost no gap between the main surface 13b of the heat radiating sheet metal 13 and the sheet metal side surface 14a of the heat radiating sheet 14. The crushing at 14 is only due to the protrusion 13a. For this reason, pressure that causes an adverse effect on the substrate 11 is not applied to the sheet metal side surface 14 a of the heat radiating sheet 14. That is, also in this case, the protruding portion 13a ensures contact between the heat radiating sheet metal 13 and the heat radiating sheet 14 and does not cause more than a predetermined pressure on the IC 12.

  Incidentally, in the case of FIG. 3A where the thickness of the heat radiating sheet is thin, when the conventional heat radiating metal plate 63 of FIG. 6 is used instead of the heat radiating metal plate 13, the height L of the constricted portion 63 a is the heat radiating sheet 14. It is assumed that the height is about the same as the apex of the protruding portion 13a. In this case, when the thickness of the heat radiating sheet is thick as shown in FIG. 3B due to manufacturing variation, the front surface of the heat radiating sheet is crushed by a distance L, and the corresponding pressure is applied to the substrate 11. 11 may be adversely affected.

  That is, according to the prior art of FIG. 6, the adjustment of the height L of the throttle portion 63a is more subtle than in the case of the protruding portion 13a in the present embodiment, which is difficult and causes a considerable risk. . On the other hand, according to this embodiment, since the protrusion part 13a was employ | adopted instead of the aperture | diaphragm | squeeze part 63a, this difficulty and risk are avoided.

  As described above, according to the heat dissipating structure according to the present embodiment, the heat dissipating sheet metal 14 is ensured to be in contact with the heat dissipating sheet 14 regardless of variations in the thickness of the heat dissipating sheet 13 and the heat source 12. Since the protrusion 13a having a shape, size, number, and position that does not cause excessive pressure on the substrate 11 is provided, the substrate 11 can be adversely affected reliably regardless of manufacturing variations of the heat dissipation sheet 14. In addition, the heat generated by the IC 12 can be dissipated.

  FIG. 4 is a cross-sectional view showing another example of the protruding portion 13a. In the above description, the projecting portion 13a has a circular cross-sectional shape. However, for example, the cross-sectional shape is V-shaped as shown in FIG. A trapezoidal shape such as that shown in FIG. 5 or a V-shape having a rounded tip as shown in FIG.

  FIG. 5 is a perspective view showing an example of the shape of the protruding portion 13a. As the protrusion 13a, for example, a protrusion having a bowl shape as shown in FIG. 10A or a rotating body as shown in FIG. In addition, although both the same figure (a) and (b) has shown about the case where a cross-sectional shape is V shape, also in the case of other cross-sectional shapes, the cross-sectional shape is used similarly, and the form of a bowl or a rotary body is shown. The protruding portion 13a having the above can be formed. The protrusion 13a in FIGS. 1 and 2 described above has an arc-shaped cross-sectional shape and has a form of a rotating body.

  In addition, this invention is not limited to the above-mentioned embodiment, It can deform | transform and implement suitably. For example, in the above description, an example in which the heat source is the IC 12 is shown. However, the present invention is not limited to this, and the present invention can be applied to a case where a CPU, an electronic component such as a temperature sensor, a battery, or the like is used as the heat source. Can be applied.

  In addition, although not mentioned in the above description, as the heat dissipation sheet, various materials suitable for use as a heat dissipation sheet can be used in terms of thermal conductivity, compressibility, and the like. For example, a graphite sheet can be used.

  In the above description, the heat radiating sheet metal 13 is used as the heat radiating body. However, instead of this, another heat radiating body, for example, a heat sink may be used.

It is sectional drawing which shows the thermal radiation structure which concerns on one Embodiment of this invention. It is an assembly drawing of the heat radiating structure of FIG. It is sectional drawing which shows the contact state of the heat-radiation sheet metal and heat-radiation sheet in the heat radiating structure of FIG. It is sectional drawing which shows the other example of the protrusion part in the thermal radiation structure of FIG. It is a perspective view which shows the form example of the protrusion part in the thermal radiation structure of FIG. It is sectional drawing which shows an example of the conventional heat dissipation structure.

Explanation of symbols

  11: substrate, 12: IC, 13: heat radiating sheet metal, 13a: protrusion, 14: heat radiating sheet.

Claims (6)

A radiator for dissipating heat from the heat source;
In the heat dissipation structure including the heat source and the heat dissipation sheet interposed between the heat dissipation body,
A heat dissipating structure comprising a protrusion on the surface of the heat dissipating member that faces the heat dissipating sheet and that presses a part of the surface of the heat dissipating sheet facing the surface to contact the heat dissipating sheet.   2. The heat dissipation structure according to claim 1, wherein each of the heat dissipation sheets has two or more corresponding protrusions.   The protrusion has a shape, size that ensures contact between the heat-dissipating sheet and the heat-dissipating body, and does not apply a predetermined pressing force or more against the heat source, despite variations in the thickness of the heat-dissipating sheet. The heat dissipating structure according to claim 1, wherein the heat dissipating structure has a number and an arrangement.   4. The heat dissipation structure according to claim 1, wherein a cross-sectional shape of the protruding portion is an arc shape, a V shape, a trapezoidal shape, or a shape obtained by rounding a V-shaped tip. .   The heat dissipation structure according to any one of claims 1 to 4, wherein the protrusion has a bowl shape.   6. The heat dissipation structure according to claim 1, wherein the protrusion has a cone, a truncated cone, or a shape obtained by rounding a tip of the cone.

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