JP2007012930A - Electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cool a plurality of heating elements efficiently in a space. <P>SOLUTION: Electronic equipment has a first circuit board (a main board 27), a first heating element (an electronic board 29) mounted on the first circuit board, a second circuit board (a sub-board 28) oppositely arranged to the first circuit board, and a second heating element (the electronic board 30) mounted on the side opposed to the first circuit board of the second circuit board. The electronic equipment further has a heat receiver (a heat-receiving block 31) thermally connected to the first heating element and the second heating element, heat-dissipating means (a heat exchanging section 24 and a heat pipe 47) for dissipating the heat of the heat receiver, and a pushing means (a spring 35) for pushing the first and second heating elements against the heat receiver. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device such as a personal computer provided with a heat receiving portion and a heat radiating means for cooling a heat generating member such as an electronic substrate having heat generation, and more specifically, an electronic device capable of cooling a plurality of heat generating members in a space efficient manner It is about.

In this type of electronic equipment, a technique is disclosed in which a plurality of heating elements such as an exothermic electronic substrate are fixed to one heat receiving block, and a heat sink is connected to the heat receiving block to dissipate the heat of the heating element from the heat sink. 1 is disclosed.
Japanese Patent Laid-Open No. 7-176661

  When providing a plurality of heating elements in one heat receiving block as described above, the heat receiving block is fixed inside the casing of the electronic device, and the heating element is fixed to the vertical surface thereof. In a laptop personal computer with a small thickness, it was difficult to arrange in space.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an electronic device capable of cooling a plurality of heating elements in a space-efficient manner.

  In order to achieve the above object, an electronic device according to the present invention is arranged to face a first circuit board, a first heating element mounted on the first circuit board, and the first circuit board. A second circuit board to be mounted, a second heating element mounted on a side of the second circuit board facing the first circuit board, the first heating element and the second heating element A heat receiving portion thermally connected to the heat receiving portion, a heat radiating means for radiating heat of the heat receiving portion, and a pressing means for pressing the first and second heat generating members against the heat receiving portion. .

  According to the electronic apparatus according to the present invention, it is possible to cool a plurality of heating elements with high space efficiency.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view of a notebook personal computer showing an example of an electronic apparatus to which an embodiment of the present invention is applied. In the personal computer 1, a display unit 3 is connected to a main body 2 via a hinge unit 4 so as to be opened and closed. A keyboard 5 and a cursor operation unit 6 are provided on the upper surface of the main body 2. A liquid crystal display panel (LCD) 7 is provided inside the display unit 3.

  The main body 2 has a main body housing 9 made of resin, and the display unit 3 has a display unit housing 10 made of resin. The display housing 10 has an exposure opening 11 for exposing the built-in liquid crystal display panel 7.

  A heat exhaust port 14 is provided on one side surface of the main body housing 9, and the fan unit 15 is built in the main body housing 9 so as to be located inside the heat exhaust port. In addition, a heat generating portion 16 is incorporated so as to be located on the front side of the fan unit 15.

[First Embodiment]
2 to 5 show a first embodiment of the present invention. As shown in FIGS. 2 and 3, the fan unit 15 includes a fan 20 that is rotationally driven by an electric motor 19 inside a fan case 18, and an air inlet 21 is opened on the upper surface of the fan case 18. An exhaust duct 22 provided on one side surface of the case 18 faces the heat exhaust port 14 inside the main body housing 9. Inside the exhaust duct 22 is incorporated a heat exchanging section 24 (heat dissipating means) configured by connecting cooling fins.

  On the other hand, as shown in FIG. 2 to FIG. 4, the heat generating portion 16 has one sub-board 28 (second circuit board) disposed in parallel and facing above the main board 27 (first circuit board). ), An electronic substrate 29 (first heating element) such as two heat-generating BGA substrates, and an electronic substrate 30 (second heating element), and a good heat conductive material such as an aluminum material, A heat receiving block 31 (heat receiving portion) formed on the substrate, a back plate 32 formed of an insulating material, four stud bosses 33 erected from the main board 27, four stepped screws 34, and a spring 35 ( Pressing means).

  The sub-board 28 and the back plate 32 have a rectangular shape with the same size, and screw holes 36 are formed at the four corners. The position of each screw hole 36 matches the position of the stud boss 33.

  The two electronic substrates 29 and 30 have a rectangular shape smaller than the sub substrate 28 and the back plate 32. The lower electronic substrate 29 is on the upper surface of the main substrate 27 and the upper electronic substrate 30 is on the lower surface of the sub substrate 28. , Each is mounted and electrically connected. Heat conducting portions 38 and 39 are respectively provided in the central portions of the facing surfaces of the electronic substrates 29 and 30, and these heat conducting portions 38 and 39 are in surface contact with two opposite surfaces (upper and lower surfaces here) of the heat receiving block 31. .

  As shown in an enlarged cross section in FIG. 5, the stepped screw 34 includes a screw portion 41 and a cylindrical portion 42 having an outer diameter larger than that of the screw portion 41, and a washer-like flange 44 is provided on the head portion 43. It is integrally formed.

  The four stepped screws 34 are inserted from above into the screw holes 36 of the sub board 28 and the back plate 32 with the springs 35 around the respective cylindrical parts 42, and the screw parts 41 are connected to the main board 27. The stud boss 33 is screwed and tightened until the cylindrical portion 42 abuts against the stud boss 33.

  Since the inner diameter of the screw hole 36 is slightly larger than the outer diameter of the cylindrical portion 42, the sub-board 28 and the back plate 32 can slide smoothly along the axial direction of the cylindrical portion 42, and the urging force of the four springs 35 It is pressed toward the main board 27 side. Therefore, the sub board 28 is mounted on the main board 27 side by the urging force of the spring 35.

  At this time, the height of the stud boss 33 is set so that a small gap C is generated between the upper end of the stud boss 33 and the sub-board 28 as shown in FIG. For this reason, the heat conducting portions 38 and 39 of the upper and lower electronic substrates 29 and 30 are pressed against the upper and lower surfaces of the heat receiving block 31 by a predetermined surface pressure by the four springs 35 and are thermally connected.

  A heat pipe 47 (heat dissipating means) extends from one side of the heat receiving block 31, and the heat pipe 47 is bent by 90 °, for example, and passes through an opening 48 formed on the side of the exhaust duct 22 of the fan unit 15. Connected to the exchange unit 24. The heat pipe 47 has a known configuration in which a working fluid such as water or chlorofluorocarbon is sealed together with air inside a metal tube such as an aluminum tube closed at both ends.

  In this embodiment, the heat radiating means (the heat exchanging unit 24 and the heat pipe 47) is single for the plurality of heating elements (electronic substrates 29 and 30).

  Heat generated during operation of the electronic boards 29 and 30 is received by the heat receiving block 31 through the heat conducting sections 38 and 39 and is transmitted to the heat exchanging section 24 through the heat pipe 47. When the electric motor 19 of the fan unit 15 is activated and the fan 20 is rotated, outside air is drawn from the air inlet 21 of the fan case 18 and blown to the exhaust duct 22, and is discharged to the outside from the heat exhaust port 14 of the main body housing 9. Is done. At that time, heat of the heat exchanging part 24 installed in the exhaust duct 22 is taken away and exhausted from the exhaust heat port 14, and the heat of the electronic boards 29 and 30 is radiated.

  According to the personal computer 1 configured as described above, since the electronic boards 29 and 30 can be brought into contact (thermally connected) with the upper and lower surfaces of the heat receiving block 31 to be cooled, these three members 29, 30, 31 can be stacked with a relatively small height dimension, and even in the case of an electronic device having a thin casing main body 9 like the personal computer 1, a plurality of heat-generating electronic boards can be very space-efficient. Can be cooled.

  Further, since the heat dissipating means (the heat exchanging unit 24 and the heat pipe 47) is single for the plurality of heating elements (electronic substrates 29 and 30), the internal space efficiency of the personal computer 1 can be further enhanced.

  By the way, the heat exchanging part 24 is fixed only to the heat receiving block 31 through the heat pipe 47, and the sub board 28 is urged toward the main board 27 by the urging force of the spring 35 as described above. Since the heat receiving block 31 is mounted and is positioned between the main board 27, the sub board 28, and the electronic boards 29 and 30 by being pressed by the spring 35, the heat receiving block 31 is positioned inside the exhaust duct 22. 24 is held inside the exhaust duct 22 so as to be floatable, and can be somewhat displaced.

  Since the heat exchanging part 24 is held so as to float inside the exhaust duct 22 in this way, stress due to the displacement of the heat exchanging part 24 during assembly does not act on the heat receiving block 31 side. 29 and 30 can be brought into close contact with the heat receiving block 31 to obtain good cooling performance. Further, the heat exchange part 24 and the heat pipe 47 can be prevented from being damaged by an external impact.

  FIG. 6 shows a modification of the heat generating portion 16 shown in FIG. Here, step portions 52 that are one step lower are formed at the four corners of the back plate 51 with a step size H, and screw holes 53 are formed in the step portions 52 and stepped screws 34 are inserted. The height of the stud boss 54 is lowered by the step size H of the step portion 52, and a gap C is provided between the step portion 52 and the stud boss 54. Since the configuration of the stepped screw 34 and other parts is the same as that of the first embodiment (FIG. 4), the same reference numerals are given and description thereof is omitted.

  With this configuration, the height of the head portion of the stepped screw 34 can be made the same level as the upper surface of the back plate 51, so that the overall height of the heat generating portion 16 can be further reduced and the electronic device 1 can be made compact. it can.

[Second Embodiment]
7 to 9 show a second embodiment of the present invention. Here, electronic substrates 63 and 64 (heating elements) respectively disposed on the upper surface of the main substrate 61 and the lower surface of the sub substrate 62 are disposed offset in the horizontal direction. A back plate 65 is overlaid on the sub-substrate 62.

  Then, electronic substrates 63 and 64 are arranged offset to the two opposite surfaces (upper and lower surfaces) of the heat receiving block 66 (heat receiving portion) formed in a rectangular parallelepiped shape, and are thermally connected (contacted) and pressed. . That is, the electronic substrate 63 is in surface contact with the lower surface of one end of the heat receiving block 66, and the electronic substrate 64 is in surface contact with the upper surface of the other end of the heat receiving block 66. In addition, since the member configurations such as the stud boss 33, the stepped screw 34, and the spring 35 that are members for pressing the electronic substrates 63 and 64 against the heat receiving block 66 are the same as those in the first embodiment, the same reference numerals are given. Description is omitted.

  For example, two heat pipes 67 and 68 extend from the heat receiving block 66 and are bent by 90 ° and connected to a heat exchanging unit 69 built in the fan unit 15. The configuration of the fan unit 15 is the same as that of the first embodiment. The heat of the electronic boards 63 and 64 is received by the heat receiving block 66 and is transmitted to the heat exchanging unit 69 through the heat pipes 67 and 68 to be radiated.

  According to this configuration, the upper and lower electronic substrates 63 and 64 that are offset in the horizontal direction can be cooled by being pressed against both surfaces of the single heat receiving block 66, so that it is possible to cope with a more complicated electronic substrate layout, The internal space efficiency and component layout of electronic equipment can be greatly improved.

  In the second embodiment, the two heat pipes 67 and 68 penetrate the heat receiving block 66 in the short side direction. For example, one heat pipe penetrates in the long side direction of the heat receiving block 66. It may be.

  Incidentally, in both cases of the first embodiment and the second embodiment, the electronic substrates 29, 30, 63, and 64 are in surface contact with the upper and lower surfaces of the heat receiving blocks 31 and 66, respectively. More electronic substrates may be brought into surface contact with the heat receiving blocks 31 and 66. Furthermore, the heating element that receives heat by the heat receiving blocks 31 and 66 does not necessarily have to be an electronic substrate, and may be an electronic component, a mechanical component, or the like having other types of heat generation.

  Further, the heat radiating means is not necessarily limited to the heat exchanging portion and the heat pipe, and may be a heat sink, a liquid cooling type cooling device, or the like.

  Furthermore, the pressing means does not necessarily have to be a coil spring, and the elasticity of a plate-like spring, elastic material such as rubber, soft resin, foaming resin, or the elasticity of the back plate is used. May be.

  Note that the present invention can be widely applied not only to notebook personal computers but also to many other electronic devices such as desktop personal computers, word processors, acoustic devices, and communication telephone devices.

FIG. 11 is a perspective view of a notebook personal computer showing an example of an electronic apparatus according to the invention. The disassembled perspective view which shows a heat-emitting part and a fan unit. The top view which shows a heat-emitting part and a fan unit. The side view which shows 1st Embodiment of this invention by the IV-IV arrow of FIG. FIG. 5 is a longitudinal sectional view taken along line V-V in FIG. 3. The side view which shows the modification of this invention. The top view which shows 2nd Embodiment of this invention. The side view by the VIII-VIII arrow of FIG. The side view by the IX-IX arrow of FIG.

Explanation of symbols

1 Personal computer (electronic equipment)
15 Fan unit 24 Heat exchange part (heat dissipation means)
27 Main board 28 Sub board 29, 30 Electronic board (heating element)
31 Heat receiving block (heat receiving part)
47 Heat pipe (heat dissipation means)
33 Stud boss 35 Spring (Pressing means)

Claims (4)

A first circuit board;
A first heating element mounted on the first circuit board;
A second circuit board disposed opposite to the first circuit board;
A second heating element mounted on a side of the second circuit board facing the first circuit board;
A heat receiving portion thermally connected to the first heating element and the second heating element;
A heat radiating means for radiating the heat of the heat receiving portion;
Pressing means for pressing the first and second heating elements against the heat receiving portion;
An electronic apparatus comprising: 2. The electronic apparatus according to claim 1, wherein the first heat generating element and the second heat generating element are arranged offset. The electronic device according to claim 1, wherein the heat radiating means includes a heat pipe extending from the heat receiving portion and a heat exchanging portion provided at the other end of the heat pipe. 4. The electronic apparatus according to claim 3, wherein the second circuit board is mounted on the first circuit board via a pressing unit that biases the second circuit board in the direction of the first circuit board.

Images