JP2009081157A - Heat-radiating board fitting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-radiating fitting structure capable of securely fixing a heat-radiating board to a device at a suitable position with a simple constitution. <P>SOLUTION: The heat-radiating board fitting structure includes a shield case 3 containing a printed wiring board 1 mounted with the device 11, and a plate-like member 31 which supports the heat-radiating board 2 having fins 211 by cutting a portion of the shield case 3 and bending the cut portion toward the printed wiring board and also pressing a heat absorption surface 22 of the heat-radiating board 2 against the device 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat sink mounting structure for mounting a heat sink for radiating the heat of a device mounted on a printed wiring board.

  In recent years, the degree of integration of devices such as ICs (Integrated Circuits) disposed on printed boards has increased relatively, and it has become an important issue to dissipate the heat of the devices. In order to solve the above problems, various heat sink mounting structures have been proposed.

For example, the first opening provided on one side of the case and the second opening provided on the other side facing the first opening are formed in a substantially V shape in appearance and have a required diameter. A heat dissipating plate mounting structure is disclosed in which a linear member made of spring steel is installed and a heat dissipating plate placed on the upper surface of the electronic device is urged and fixed by the linear member (see Patent Document 1).
JP 2006-310668 A

  However, in the above heat sink mounting structure, since the heat sink is urged and fixed to the electronic device side by the linear member, the acceleration of the electronic device in the left-right direction due to vibration or the like on the equipment in which the electronic device is disposed. When is added, there is a possibility that the position of the heat sink is displaced from the electronic device. That is, since the heat sink is fixed by the sliding resistance between the linear member and the heat sink, the position of the heat sink is displaced. Further, in order to increase the sliding resistance, it is necessary to increase the elastic coefficient of the linear member. However, if the elastic coefficient of the linear member is increased, the urging force of the linear member to the heat dissipation plate There is a risk that the printed wiring board or the like on which the device is disposed will be deformed, resulting in damage to the electronic device or the contact.

  The present invention has been made in view of the above problems, and an object thereof is to provide a heat sink mounting structure capable of securely fixing a heat sink to an appropriate position with respect to a device with a simple configuration. Yes.

  In order to achieve the above object, the heat sink mounting structure according to claim 1 is a heat sink mounting structure in which a heat sink for radiating heat of the device is mounted on a device mounted on a printed wiring board, It is characterized by comprising: a housing for storing a wiring board; and a plate-like member that is locked to the housing and supports the heat radiating plate and presses the heat radiating plate against the device.

  The heat sink mounting structure according to claim 2 is the heat sink mounting structure according to claim 1, wherein the heat sink abuts against a back surface that is a surface of the device that is separated from the printed wiring board. A substantially planar endothermic surface that absorbs the heat of the device; and a heat dissipating surface that is opposite to the endothermic surface and has a plurality of fins, wherein the plate-like member is the plurality of fins And a plurality of holes for supporting the heat radiating plate.

  The heat sink mounting structure according to claim 3 is the heat sink mounting structure according to claim 2, wherein the plate-like member cuts out a part of the casing, and the cut-out portion serves as the printed wiring board. It is formed by bending to the side.

  The heat sink mounting structure according to claim 4 is the heat sink mounting structure according to claim 3, wherein the notch portion of the plate-like member is absorbed by the heat sink supported by the plate-like member. The position of the surface is bent so as to be on the printed wiring board side with respect to the position of the back surface of the device disposed on the printed wiring board. The heat absorbing surface is pressed against the back surface of the device.

  The heat sink mounting structure according to claim 5 is the heat sink mounting structure according to any one of claims 2 to 4, wherein the plurality of fins are triangular or trapezoidal fins in cross section. The plurality of holes are each formed in a slit shape substantially parallel to each other in a stripe shape.

  The heat sink mounting structure according to claim 6 is the heat sink mounting structure according to any one of claims 2 to 5, wherein the plurality of holes are substantially in a height direction of the plurality of fins. It is characterized by being formed to mesh with the plurality of fins at a half position.

  The heat sink mounting structure according to claim 7 is the heat sink mounting structure according to any one of claims 1 to 6, wherein the casing is a shield case that electrostatically shields the printed wiring board. It is characterized by being.

  According to the heat sink mounting structure of claim 1, the heat sink is supported by the plate-like member locked to the housing that houses the printed wiring board, and the heat sink is pressed against the device. With a simple configuration, the heat sink can be reliably fixed at an appropriate position with respect to the device.

  That is, since the heat sink is supported by the plate-like member that is locked to the housing that stores the printed wiring board, the position of the heat sink is not shifted from the position of the device due to vibration or the like. With the configuration, the heat radiating plate can be reliably fixed at an appropriate position with respect to the device. In addition, since the heat sink is pressed against the device by the plate-like member locked to the housing, heat transfer between the heat sink and the device is improved, so that the heat sink can be properly and reliably configured with a simple configuration. It can be fixed at any position.

  According to the heat sink mounting structure according to claim 2, the heat sink is in contact with a back surface that is a surface on the side separated from the printed wiring board of the device, and a substantially planar heat absorbing surface that absorbs the heat of the device; A plurality of holes for supporting the heat dissipation plate by engaging with the plurality of fins formed on the heat dissipation plate, respectively. Since the portion is provided, the heat radiating plate can be reliably fixed at a more appropriate position with respect to the device with a simple configuration.

  That is, since the heat sink has a substantially flat heat absorbing surface that abuts against the back surface of the device that is on the side away from the printed wiring board and absorbs the heat of the device, heat transfer between the heat sink and the device Is even better. In addition, since the heat radiating plate has a heat radiating surface that is opposed to the heat absorbing surface and has a plurality of fins, heat is radiated through the plurality of fins, so that the heat radiating efficiency of the heat radiating plate can be improved. . Further, since the heat sink is supported by the plurality of holes formed in the plate-like member engaging with the plurality of fins formed in the heat sink, respectively, the heat sink can be reliably attached to the device with a simple configuration. On the other hand, it can be fixed at a more appropriate position.

  According to the heat sink mounting structure according to claim 3, the plate-like member is formed by cutting out a part of the housing and bending the cut-out portion toward the printed wiring board side. Therefore, the heat sink can be securely fixed at a more appropriate position with respect to the device with a simpler structure.

  According to the heat sink mounting structure of claim 4, the notch portion of the plate-like member positions the heat absorption surface of the heat sink supported by the plate-like member on the printed circuit board. It is formed to be bent to the printed wiring board side with respect to the position of the back surface, and since the heat absorbing surface of the heat sink is pressed against the back surface of the device by the elastic restoring force of the plate-like member, the heat absorbing surface of the heat sink Since the mechanism for pressing the device to the back surface of the device can be realized with a simple configuration, the heat sink can be reliably fixed at an appropriate position with respect to the device with a simpler configuration.

  According to the heat sink mounting structure according to claim 5, the plurality of fins are formed in a triangular shape or a trapezoidal fin in a cross-sectional view and are formed in stripes substantially parallel to each other, and the plurality of holes are Since each of them is formed in a slit shape, a plurality of fins and a plurality of holes can be realized with a simple configuration. Can be fixed.

  According to the heat sink mounting structure according to claim 6, the plurality of holes are formed so as to be engaged with the plurality of fins at substantially half positions in the height direction of the plurality of fins. Since the heat sink is surely supported at an appropriate position through the portion, the heat sink can be more reliably fixed at an appropriate position with respect to the device with a simple configuration.

  According to the heat sink mounting structure described in claim 7, since the housing is a shield case that electrostatically shields the printed wiring board, the heat sink is securely fixed at an appropriate position with respect to the device with a simpler configuration. can do.

  That is, since the printed wiring board is electrostatically shielded by the shield case and the plate-like member is locked, it is necessary to dispose a housing separate from the shield case in order to lock the plate-like member. Therefore, the heat sink can be reliably fixed at an appropriate position with respect to the device with a simpler configuration.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing an example of a configuration of a heat sink mounting structure according to the present invention. The heat sink mounting structure according to the present invention includes a printed wiring board 1, a heat sink 2, and a shield case 3. The printed wiring board 1 is, for example, a main board of a digital broadcast receiver, and is mounted with a plurality of devices such as an IC (Integrated Circuit). Here, for example, the device 11 is mounted at an appropriate position of the printed wiring board 1.

  The device 11 is a highly integrated IC such as a BGA (Ball Grid Array), for example, and is in contact with the heat sink 2 pressed on the back surface 111 which is a surface separated from the printed wiring board 1. It is what is done.

  The heat radiating plate 2 is made of aluminum (Al) or the like having good thermal conductivity, and radiates heat generated in the device 11 to the atmosphere. The heat radiating plate 2 contacts the back surface 111 of the device 11 and absorbs the heat of the device 11. A planar heat-absorbing surface 22 that faces the heat-absorbing surface 22, and a heat-dissipating surface 21 that dissipates heat absorbed from the device 11 through the heat-absorbing surface 22 into the atmosphere.

  The heat dissipating surface 21 includes a plurality of (here, six) fins 211 that dissipate heat into the atmosphere. The fins 211 are formed to stand on the heat sink 2 in a trapezoidal cross-sectional view, and the six fins 211 are formed on the heat sink 2 in stripes parallel to each other. .

  The shield case 3 (corresponding to a housing) is for electrostatically shielding the printed wiring board 1, and a part of the shield case 3 is cut out, and the cutout portion is bent toward the printed wiring board 1 to form a plate shape. The member 31 is formed, and the heat absorbing surface 22 of the heat radiating plate 2 is pressed against the back surface 111 of the device 11 by the elastic restoring force of the plate member 31.

  The plate-like member 31 supports the heat sink 2 and presses the heat absorbing surface 22 of the heat sink 2 against the back surface 111 of the device 11. That is, the plate-like member 31 has the heat absorption surface 22 of the heat dissipation plate 2 with respect to the back surface 111 of the device 11 in the state before assembling the printed wiring board 1, the heat dissipation plate 2, and the shield case 3. (= The front end side of the plate-like member 31 is bent toward the printed wiring board 1 with respect to the base end side of the plate-like member 31), the printed wiring board 1, the heat radiating plate 2, and the shield. In the state where the case 3 is assembled, the heat absorbing surface 22 of the heat radiating plate 2 is pressed against the back surface 111 of the device 11 by elastic restoring force.

  Further, the plate-like member 31 is engaged with a plurality of (here, six) fins 211 formed on the heat radiating surface 21 of the heat radiating plate 2 to support the heat radiating plate 2 respectively (six here). ) Hole 311.

  The holes 311 are each formed in an elongated rectangular shape (= slit shape) so as to mesh with a plurality of (here, six) fins 211 formed on the heat radiating surface 21 of the heat radiating plate 2. That is, a plurality of (six in this case) fins 211 formed on the heat radiating surface 21 of the heat radiating plate 2 are respectively meshed with the hole 311 so that the inner surface of the hole 311 and the side surface of the fin 211 slide. The heat sink 2 is supported by dynamic resistance.

  FIG. 2A is a side sectional view showing an example of a state in which the printed wiring board 1, the heat radiating plate 2, and the shield case 3 are assembled. The shield case 3 is fixed to the printed wiring board 1 with bolts or the like. As shown in FIG. 2, the back surface 111 of the device 11 mounted on the printed circuit board 1 is pressed by the heat absorbing surface 22 of the heat sink 2 and the elastic restoring force of the plate-like member 31 formed on the shield case 3. It is in contact with the state.

  In a state where the printed wiring board 1, the heat radiating plate 2, and the shield case 3 are assembled, heat generated in the device 11 mounted on the printed wiring board 1 passes through the back surface 111 and the heat absorbing surface 22 of the heat radiating plate 2. The heat is transmitted to the heat radiating plate 2 and radiated from the heat radiating surface 21 of the heat radiating plate 2 to the atmosphere.

  FIG.2 (b) is AA sectional drawing of Fig.2 (a). As shown in the figure, the plurality of (here, six) hole portions 311 formed in the plate-like member 31 are positioned approximately half in the height direction of the plurality of (here, six) fins 211. Thus, it is formed so as to mesh with a plurality of (here, six) fins 211. That is, the distance between the tip of the fin 211 and the center of the plate-like member 31 is formed to be half (= H / 2) with respect to the height H of the fin 211.

  In this way, the heat sink 2 is supported by the plate-like member 31 locked to the shield case 3 that houses the printed wiring board 1, and the heat sink 2 is pressed against the device 11. Thus, the heat radiating plate 2 can be securely fixed to the device 11 at an appropriate position.

  That is, since the heat sink 2 is supported by the plate-like member 31 locked to the shield case 3 that houses the printed wiring board 1, the position of the heat sink 2 is shifted from the position of the device 11 due to vibration or the like. There is no fear, and the heat radiating plate 2 can be reliably fixed at an appropriate position with respect to the device 11 with a simple configuration. Further, since the heat radiating plate 2 is pressed against the device 11 by the plate-like member 31 locked to the shield case 3, the heat transfer between the heat radiating plate 2 and the device 11 is improved, so that the configuration is simple. The heat sink 2 can be reliably fixed at an appropriate position.

  Further, the heat radiating plate 2 is in contact with the back surface 111 that is the surface of the device 11 that is separated from the printed wiring board 1, and a planar heat absorbing surface 22 that absorbs the heat of the device 11, and a surface that faces the heat absorbing surface 22 And a heat radiating surface 21 on which a plurality of (herein, six) fins 211 are formed, and the plate-like member 31 meshes with the plurality of fins 211 formed on the heat radiating plate 2 to dissipate heat. Since the plurality of holes 311 for supporting the plate 2 are provided, the heat radiating plate 2 can be reliably fixed at a more appropriate position with respect to the device 11 with a simple configuration.

  That is, since the heat sink 2 is in contact with the back surface 111 that is the surface of the device 11 on the side away from the printed wiring board 1 and includes the planar heat absorbing surface 22 that absorbs the heat of the device 11, the heat sink 2 and the device Heat transfer to and from 11 is further improved. Further, since the heat radiating plate 2 includes the heat radiating surface 21 which is the surface facing the heat absorbing surface 22 and in which the plurality of fins 211 are formed, heat is radiated through the plurality of fins 211, so the heat radiating efficiency of the heat radiating plate 2 Can be improved. Furthermore, since the plurality of holes 311 formed in the plate-like member 31 are respectively engaged with the plurality of fins 211 formed in the heat radiating plate 2, the heat radiating plate 2 is supported. The heat sink 2 can be fixed at a more appropriate position with respect to the device 11.

  Furthermore, since the plate-shaped member 31 is formed by cutting out a part of the shield case 3 and bending the cut-out portion toward the printed wiring board 1, it is necessary to lock the plate-shaped member 31 to the housing. Therefore, the heat sink 2 can be reliably fixed at a more appropriate position with respect to the device 11 with a simpler configuration.

  In addition, the cutout portion of the shield case 3 has the position of the heat absorbing surface 22 of the heat sink 2 supported by the plate-like member 31 with respect to the position of the back surface 111 of the device 11 provided on the printed wiring board 1. Since the heat absorbing surface 22 of the heat radiating plate 2 is pressed against the back surface 111 of the device 11 by the elastic restoring force of the plate-like member 31, the heat absorbing heat of the heat radiating plate 2 is formed. Since the mechanism for pressing the surface 22 against the back surface 111 of the device 11 can be realized with a simple configuration, the heat radiating plate 2 can be reliably fixed at an appropriate position with respect to the device 11 with a simpler configuration.

  Furthermore, a plurality of (here, six) fins 211 are formed by forming trapezoidal fins 211 in a cross-sectional shape in parallel with each other, and a plurality of (here, six) holes. Since 311 is formed in a slit shape, the plurality of fins 211 and the plurality of hole portions 311 can be realized with a simple configuration. Therefore, the heat radiation plate 2 can be reliably connected to the device 11 with a simpler configuration. Can be fixed at an appropriate position.

  In addition, a plurality of (here, six) hole portions 311 are formed so as to mesh with the plurality of fins 211 at approximately half the height of the plurality of (here, six) fins 211 in the height direction. Therefore, since the heat sink 2 is reliably supported at an appropriate position through the plurality of holes 311, the heat sink 2 is more securely fixed at an appropriate position with respect to the device 11 with a simple configuration. (See FIG. 2 (b)).

  Further, since the casing is the shield case 3 that electrostatically shields the printed wiring board 1, the heat radiating plate 2 can be reliably fixed at an appropriate position with respect to the device 11 with a simpler configuration.

  That is, since the printed wiring board 1 is electrostatically shielded by the shield case 3 and the plate-like member 31 is locked, a housing different from the shield case 3 is used to lock the plate-like member 31. Since it is not necessary to dispose, the heat radiating plate 2 can be reliably fixed at an appropriate position with respect to the device 11 with a simpler configuration.

The present invention can also be applied to the following forms.
(A) In the present embodiment, the case where the casing is the shield case 3 that electrostatically shields the printed wiring board 1 has been described, but the casing may be other than the shield case 3. For example, the casing may be a casing that houses a device (for example, a digital broadcast receiver) in which the printed wiring board 1 is disposed.

  (B) In the present embodiment, the plate-like member 31 is described as being formed by cutting a part of the shield case 3 and bending the cut-out portion toward the printed wiring board 1 side. The member 31 may be locked to the shield case 3 by other methods (for example, welding or the like). In this case, since it is not necessary to cut out the shield case 3, the effect of electrostatic shielding of the shield case 3 can be ensured.

  (C) In the present embodiment, the case where the fins 211 are formed to stand on the heat sink 2 in a trapezoidal view in cross section has been described. However, the fins 211 have a triangular shape in cross section on the heat sink 2. The form formed upright may be sufficient, and the form formed in other shapes (for example, truncated cone shape) may be sufficient. For example, when the fin 211 is formed in a truncated cone shape, the hole 311 of the plate member 31 needs to be formed in a circular shape.

These are exploded perspective views which show an example of a structure of the heat sink mounting structure which concerns on this invention. These are side surface sectional drawings which show an example of the state by which the printed wiring board, the heat sink, and the shield case were assembled.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printed wiring board 11 Device 111 Back surface 2 Heat sink 21 Heat sink surface 211 Fin 22 Heat sink surface 3 Shield case (housing)
31 Plate-shaped member 311 Hole

Claims (7)

A heat sink mounting structure for mounting a heat sink that dissipates the heat of the device to a device mounted on a printed wiring board,
A housing for storing the printed wiring board;
A plate-like member that is locked to the housing, supports the heat dissipation plate, and presses the heat dissipation plate against the device;
A heat sink mounting structure comprising: The heat sink is
A substantially flat endothermic surface that is in contact with a back surface that is a surface on the side away from the printed wiring board of the device and absorbs heat of the device;
A heat dissipating surface facing the heat absorbing surface and having a plurality of fins formed thereon;
With
The heat sink mounting structure according to claim 1, wherein the plate-like member includes a plurality of holes that mesh with the plurality of fins to support the heat sink.   The heat sink mounting structure according to claim 2, wherein the plate-like member is formed by cutting out a part of the housing and bending the cut-out portion toward the printed wiring board. The plate-like member is
The cutout portion should be located on the printed wiring board side with respect to the position of the back surface of the device disposed on the printed wiring board, with respect to the position of the heat absorbing surface of the heat sink supported by the plate-like member. Bent and formed,
The heat sink mounting structure according to claim 3, wherein the heat absorbing surface of the heat sink is pressed against the back surface of the device by an elastic restoring force of the plate member. The plurality of fins are formed in a triangular shape or a trapezoidal fin in a cross-sectional view and are formed in stripes substantially parallel to each other,
The heat sink mounting structure according to any one of claims 2 to 4, wherein each of the plurality of holes is formed in a slit shape.   The plurality of hole portions are formed so as to be engaged with the plurality of fins at substantially half positions in the height direction of the plurality of fins. The heat sink mounting structure described.   The heat sink mounting structure according to claim 1, wherein the casing is a shield case that electrostatically shields the printed wiring board.

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