JP2014187133A - Heat radiation member and electronic circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat radiation member capable of realizing efficient heat radiation.SOLUTION: A heat radiation member is formed as a shield case 3 for radiating heat emitted from an electronic component 4 placed on a substrate 2. The shield case 3 includes a facing region facing a surface Sz of the electronic component 4 which is located at the opposite side of the substrate 2. In the shield case 3, a recessed part 31 is formed in the facing region. The recessed part 31 is formed including multiple recessed parts 310.

Description

  The present invention relates to a heat radiating member for radiating heat generated by an electronic component, and an electronic circuit including the heat radiating member.

  Conventionally, a heat radiating structure for radiating heat generated by an electronic circuit disposed on a substrate to the outside is known.

  Patent Document 1 discloses a substrate case structure as the heat dissipation structure. The board case structure is configured by housing a printed board on which electronic components are mounted in a card-like metal case. A concave portion having a depth corresponding to the height dimension of the high heat generating electronic component is formed in a region corresponding to a region where the high heat generating electronic component generating heat is mounted among the electronic components mounted on the printed circuit board. Has been. The bottom wall of the recess is in direct contact with the highly exothermic electronic component. Moreover, the heat sink fin is provided in the recessed part.

Japanese Patent Laid-Open No. 10-65385

  Since the substrate case structure of Patent Document 1 cannot efficiently dissipate heat alone, it is necessary to provide heat dissipating fins. For this reason, it is expensive to manufacture the substrate case structure.

  The present invention has been made in view of the above problems, and its purpose is to mount a heat radiating member capable of efficiently radiating heat without providing a separate heat radiating fin, and the heat radiating member and the electronic component. An object of the present invention is to provide an electronic circuit including a substrate.

  According to an aspect of the present invention, the heat dissipating member is placed on a substrate on which an electronic component is mounted, and dissipates heat generated by the electronic component. The heat radiating member is installed on the side opposite to the substrate with respect to the electronic component. The heat radiating member has a first recess formed in a region facing the surface of the electronic component opposite to the substrate. The first recess includes a plurality of second recesses.

Preferably, the first recess has a depth such that the surface of the first recess does not contact the electronic component.
Preferably, the second recesses are formed at regular intervals.

  Preferably, when n is a natural number of 4 or more, each second recess has an n-pyramidal frustum shape.

  According to another aspect of the present invention, an electronic circuit includes a substrate on which an electronic component is mounted, and a heat radiating member that is placed on the substrate and radiates heat generated by the electronic component. The heat radiating member is installed on the side opposite to the substrate with respect to the electronic component. The heat radiating member has a first recess formed in a region facing the surface of the electronic component opposite to the substrate. The first recess includes a plurality of second recesses. The electronic circuit is filled with a material for transferring heat to the heat dissipation member between the first recess and the surface of the electronic component.

Preferably, the heat dissipation member is a shield case that shields the electronic component.
Preferably, the heat dissipation member is a cover in a shield case that shields the electronic component.

Preferably, the material for transferring heat to the heat radiating member is a thermal compound.
Preferably, the second recess has a quadrangular frustum shape or a hexagonal frustum shape.

  According to the above invention, efficient heat dissipation can be realized.

It is a perspective view of the electronic circuit 1 mounted in an electronic device. It is the II-II arrow directional cross-sectional view in FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. It is a perspective view for demonstrating the back surface of a shield case. It is a figure for demonstrating arrangement | positioning of the recessed part in a structure. It is a perspective view for demonstrating the back surface of another shield case. It is a figure for demonstrating arrangement | positioning of the recessed part in another structure.

  Hereinafter, a heat radiating member according to an embodiment of the present invention and an electronic circuit including the heat radiating member will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  The heat radiating member according to the present embodiment can be configured as, for example, a shield case that shields electronic components. In addition, the heat dissipation member according to the present embodiment can be configured as a cover when the shield case is configured by a frame (frame) and a cover (lid) covering the frame. In addition, the heat radiating member does not necessarily need to have a shield function. That is, the heat dissipation member may be configured as a case that does not have a shielding function, or a cover in the case. Below, for convenience of explanation, a case where the heat dissipation member is a shield case will be described as an example.

<A. Appearance of electronic circuit>
FIG. 1 is a perspective view of an electronic circuit 1 mounted on an electronic device. Referring to FIG. 1, an electronic circuit 1 includes a substrate 2 on which electronic components are mounted, and a shield case 3. The shield case 3 is installed on the substrate 2.

  The shield case 3 prevents radiation of electromagnetic waves from the circuit and prevents adverse effects of electromagnetic waves from the outside on the circuit. Further, the shield case 3 also functions as a member for radiating heat generated by the electronic component to the outside of the shield case 3. That is, the shield case 3 has a heat dissipation (cooling) function as well as a normal shield function.

  The shield case 3 has surfaces Sa, Sb, and Sc. The surface Sa is parallel to the substrate 2 (more precisely, the main surface of the substrate 2). The surfaces Sb and Sc are side surfaces of the shield case 3.

<B. Cross section of electronic circuit>
2 is a cross-sectional view taken along line II-II in FIG. Referring to FIG. 2, the electronic circuit 1 has a structure in which a substrate 2, an electronic component 4, a thermal compound 5, and a shield case 3 are laminated in this order.

  The shield case 3 is a member for radiating heat generated by the electronic component 4 placed on the substrate 2. The shield case 3 includes an opposing region on the inner surface of the shield case 3 that faces the surface Sz of the electronic component 4 opposite to the substrate 2. Further, the shield case 3 includes a structure 30 in the facing region.

  Further, the shield case 3 has a recess 31 in the facing region. Specifically, the structure 30 has a recess 31. Further, the recess 31 has such a depth that the surface of the recess 31 does not come into contact with the electronic component 4. Specifically, the depth of the recess 31 is determined according to the height of the electronic component 4.

  The structure 30 has a shape that does not come into contact with the electronic component 4. In the shield case 3, a gap 90 is also provided between the tip 39 of the structure 30 and the electronic component 4.

  Furthermore, in the shield case 3, the recess 31 has a plurality of recesses 310. In other words, the structure 30 has concave portions hierarchically. Thereby, as for the structure 30, the surface of the recessed part 31 has uneven | corrugated shape.

  The thermal compound 5 is filled between the recess 31 and the surface Sz of the electronic component 4. The heat generated by the thermal compound 5 and the electronic component 4 is transmitted to the shield case 3. The thermal compound 5 can prevent a sudden temperature rise of the electronic component 4. Since the thermal compound 5 is mainly composed of ester-based synthetic grease, it does not adversely affect the electronic component 4 and the electronic circuit 1.

  3 is a cross-sectional view taken along line III-III in FIG. With reference to FIG. 3, as described in FIG. 2, the electronic circuit 1 includes a substrate 2, an electronic component 4, a thermal compound 5, and a shield case 3. The structure shown in FIG. 3 is substantially the same as the cross section shown in FIG. 2 except that the number of recesses 310 is larger than that in the case of FIG. 2, and therefore description thereof will not be repeated here. The details of the shield case 3 will be described later (FIGS. 4 and 5).

<C. Detailed structure of shield case>
FIG. 4 is a perspective view for explaining the back surface of the shield case 3. Referring to FIG. 4, the shield case 3 has a structure 30 on the back surface Sd. 4 shows an example in which the shield case 3 includes one structure 30, but the number of the structures 30 is not limited to one.

  As described above, the structure 30 has the recess 31. Further, the recess 31 has a plurality of recesses 310. The recess 310 has a quadrangular pyramid shape. Specifically, in consideration of ease of processing, the concave portion 310 has the surface Sa side as the upper surface side of the quadrangular pyramid and the electronic component 4 side as the bottom surface side of the quadrangular pyramid (FIGS. 2 and 3).

  FIG. 5 is a diagram for explaining the arrangement of the recesses 310 in the structure 30. Referring to FIG. 5, in structure 30 of shield case 3, recesses 310 are formed at regular intervals. Specifically, the recesses 310 are formed at regular intervals along the first direction and the second direction perpendicular to the first direction. Note that the number of the concave portions 310 in the first direction and the second direction is not particularly limited.

<D. Advantage>
By using the shield case 3, the following advantages can be obtained. Since the recess 31 includes a plurality of recesses 310, the area where the shield case 3 contacts the thermal compound 5 can be increased compared to a configuration having only one recess (for example, the recess 31). . Therefore, the shield case 3 can efficiently dissipate heat (i.e., cool) compared to a configuration having only one recess.

  In particular, since a high thermal conductivity material such as the thermal compound 5 absorbs heat efficiently, it is necessary to quickly transfer the heat to the shield case 3. In the shield case 3, as described above, since the area in which the shield case 3 contacts the thermal compound 5 can be increased, the shield case 3 is particularly useful when using a high thermal conductivity material.

  A thermal compound 5 is filled between the shield case 3 and the electronic component 4. Further, the structure 30 is not in contact with the electronic component 4. For this reason, even when an external force (for example, an impact) is applied to the surface Sa of the shield case 3, it is possible to prevent the electronic component 4 from being damaged.

  Furthermore, since the shield case 3 does not require a heat radiating fin, it can be manufactured at a lower cost than a structure having a heat radiating fin.

<E. Modification of shield case>
(1) A modification of the shield case 3 will be described. In the above, the shape of the opening part in the recessed part 31 of the structure 30 in the shield case 3 was a rectangular shape (FIG. 5). Below, the case where the shape of an opening part is circular is demonstrated.

  FIG. 6 is a perspective view for explaining the back surface of the shield case 3A. Referring to FIG. 6, shield case 3A has a structure 30A formed on back surface Sd. FIG. 6 illustrates an example in which the shield case 3A includes one structure 30A, but the number of the structures 30A is not limited to one.

  The structure 30A has a recess 31A. The recess 31A has a plurality of recesses 310A. In other words, the structure 30A has a concave portion in a hierarchical manner. Thereby, as for the structure 30A, the surface of the recessed part 31A has uneven | corrugated shape.

  Further, the recess 310A has a hexagonal frustum shape. Specifically, in consideration of ease of processing, the concave portion 310A has the surface Sa side as the upper surface side of the hexagonal frustum and the electronic component 4 side as the bottom surface side of the hexagonal frustum.

  FIG. 7 is a diagram for explaining the arrangement of the recesses 310A in the structure 30A. Referring to FIG. 7, in structure 30A of shield case 3A, recesses 310A are formed at regular intervals. Specifically, recesses 310A are formed at regular intervals in a honeycomb shape (honeycomb shape).

  The same advantage as that obtained by the shield case 3 can be obtained also by the shield case 3A. In particular, the shield case 3 </ b> A has the recess 310 </ b> A formed more densely than the recess 310 of the shield case 3, so that the heat dissipation efficiency can be increased compared to the shield case 3.

  (2) The shape of the opening in the recesses 31 and 31A is not limited to a rectangle or a circle.

  (3) The shapes of the recesses 310 and 310A arranged in succession are not limited to the quadrangular frustum and the hexagonal frustum, respectively. For example, if n is a natural number of 3 or more, it may be an n-pyramidal frustum. However, in order to perform efficient cooling, n is preferably a value of 4 or more from the viewpoint of increasing the surface area of the recess. Moreover, the shape of each recessed part 310,310A does not necessarily need to be a truncated pyramid, and may be a cone. Moreover, each recessed part 310,310A may be a rectangular parallelepiped, a cylinder, or the like.

  When the material that transmits the heat generated by the electronic component 4 to the shield cases 3 and 3A is a material having a high viscosity, the material of the cone is more likely to reach the corners.

  (4) A recess smaller than the recess 310 may be further provided between the recess 310 and the recess 310.

  (5) In the above description, the thermal compound has been described as an example of the material that transmits the heat generated by the electronic component 4 to the shield case 3, but the material is not limited to this.

  (6) In the above description, the shield case is not an example of a plate material. Of course, the shield case may be formed of a plate material by pressing or the like. In this case, although the heat capacity of the shield case itself is reduced, an uneven shape is also formed on the surface Sa of the shield cases 3 and 3A, so that the area where the surface Sa comes into contact with air increases and the heat dissipation effect is enhanced.

  The embodiment disclosed this time is an exemplification, and the present invention is not limited to the above contents. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 electronic circuit, 2 substrate, 3, 3A shield case, 4 electronic component, 5 thermal compound, 30, 30A structure, 31, 31A, 310, 310A recess, 39 tip, 90 gap.

Claims (5)

A heat dissipating member for dissipating heat generated by an electronic component placed on a substrate,
An opposing region facing the surface of the electronic component opposite to the substrate;
A first recess is formed in the facing region;
The first recess is a heat radiating member including a plurality of second recesses.   The heat dissipation member according to claim 1, wherein the first recess has a depth such that a surface of the first recess does not contact the electronic component.   The heat dissipation member according to claim 1 or 2, wherein each of the second recesses is formed at a constant interval.   The heat radiating member according to any one of claims 1 to 3, wherein each of the second recesses has a shape of an n truncated pyramid, where n is a natural number of 4 or more. An electronic circuit comprising a substrate and a heat dissipating member for dissipating heat generated by the electronic component placed on the substrate,
The heat dissipation member is
An opposing region facing the surface of the electronic component opposite to the substrate;
A first recess is formed in the facing region;
The first recess has a plurality of second recesses, and
An electronic circuit, wherein a material for transferring the heat to the heat radiating member is filled between the first recess and the surface of the electronic component.

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