JP2009176990A - Electronic device unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that when impact and vibration are exerted on an electronic device unit, stress is liable to concentrate on joint parts of a device mounted on the electronic device unit, inhibiting improvement of joint reliability. <P>SOLUTION: The electronic device unit comprises a mounting substrate 9 having a wiring pattern, heat generating components 10, 11 mounted on the mounting substrate 9, heat-transfer elastic bodies 14, 15 whose first principal surfaces are closely contacted with ceiling surfaces 12, 13 of the heat generating components 10, 11, and a metal plate 16 closely contacted with second principal surfaces of the heat-transfer elastic bodies 14, 15, wherein the metal plate 16 is installed in a positional relation parallel with the mounting substrate 9. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electronic device unit used in various electronic devices.

  A side view of a conventional electronic device unit is shown in FIG. The conventional electronic device unit 1 shown in FIG. 5 mounts the coil component 3 or FET 4 on the printed wiring board 2 in order to dissipate the heat generated by the heat generating components such as the coil component 3 and FET 4 mounted on the printed wiring board 2. The radiating fins 6 are attached to the top surface on the opposite side to the side through the fixing medium 5.

For example, Patent Document 1 is known as prior art document information relating to the invention of this application.
JP-A-6-177320

  In the conventional electronic device unit 1, the surface area and size of the radiating fin 6 are set in accordance with the heat generation amount of the heat generation component. For example, when a small heat generation component has a large heat generation amount in comparison with the FET 4, etc. In, measures such as mounting large radiating fins 6 on small heat generating parts have been taken.

  However, when a heat radiation fin 6 that is a heavy object is attached to the top surface of a small device such as the FET 4, when vibration or impact force is applied to the electronic device unit 1, soldering of the FET 4 to the printed wiring board 2 is performed. The structure is such that stress is concentrated and easily applied to the joint 7.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce stress applied to a mounting portion of a device used for an electronic device unit.

And in order to achieve this purpose, a mounting substrate having a wiring pattern,
A heat generating component mounted on this mounting board;
A heat transfer elastic body having the first main surface in close contact with the top surface of the heat generating component;
A metal plate in close contact with the second main surface of the heat transfer elastic body,
The metal plate is provided in a positional relationship parallel to the mounting substrate.

  According to the present invention, the heat-generating component is fixed by the mounting substrate and the metal plate through the heat transfer elastic body, thereby realizing heat dissipation and making it difficult for stress to be applied to the mounting portion of the heat-generating component. It is.

(First embodiment)
Hereinafter, an electronic device unit according to a first embodiment of the present invention will be described with reference to the drawings.

  As shown in the side view of FIG. 1, the electronic device unit 8 has a heat generating component such as a coil component 10 or a semiconductor component 11 mounted on a wiring board 9 for mounting. Then, one surface of the heat transfer elastic bodies 14 and 15 is brought into close contact with the coil component top surface 12 or the semiconductor component top surface 13 which is opposite to the mounting side, and the other surface which is the back surface of the one surface. Is in close contact with the heat radiating metal plate 16. Further, the mounting wiring board 9 and the heat radiating metal plate 16 have a substantially parallel positional relationship. Further, the mounting wiring board 9 and the heat radiating metal plate 16 are supported by the fixing pins 17 in order to maintain a parallel positional relationship.

  According to the configuration of the present invention, the heat transfer elastic bodies 14 and 15 are disposed in close contact with each other between the coil component 10 or the semiconductor component 11 and the heat radiating metal plate 16, thereby mounting wiring. Even when an impact is applied to the substrate 9 or the heat radiating metal plate 16, stress due to the impact can be hardly applied to the joint portions 18 and 19 between the coil component 10 or the semiconductor component 11 and the mounting wiring substrate 9. It becomes possible to improve the joint reliability of the joint parts 18 and 19. That is, since it is the heat transfer elastic bodies 14 and 15 that are in close contact with the coil component top surface 12 and the semiconductor component top surface 13, the coil component 10 and the semiconductor component 11 and the heat transfer elastic bodies 14 and 15 generated at the time of impact are It absorbs stress due to the change in the positional relationship. Of course, the stress generated between the heat transfer elastic bodies 14 and 15 and the heat radiating metal plate 16 is also absorbed. In addition, since the heat transfer elastic bodies 14 and 15 are individually in contact with the coil component 10 and the semiconductor component 11, the force with which the heat transfer elastic bodies 14 and 15 press the coil component 10 and the semiconductor component 11 is used as the heat transfer elasticity. It is possible to adjust the thicknesses and materials of the bodies 14 and 15 to appropriate states by individually changing them as necessary. Here, the contact state between the heat transfer elastic body 14 and the coil component 10 is a state in which the contact between the heat transfer elastic body 14 and the conductor 20 is small as shown in the cross-sectional view of FIG. Even if the surface is a dotted line 21), it has functions related to heat dissipation and fixation. However, by using the heat transfer elastic body 14 having elasticity that allows one surface 22 of the heat transfer elastic body 14 to have a degree of adhesion in which about half or more of the cross section 23 of the conductor 20 is buried, greater heat dissipation is achieved. Can be obtained.

  Further, the mounting wiring board 9 and the heat radiating metal plate 16 shown in FIG. 1 have a parallel positional relationship, so that even if an impact or vibration is applied to the electronic device unit 8, the force is generally applied to each fixing pin 17. Therefore, it is possible to avoid stress concentration on a specific device even for the coil component 10 and the semiconductor component 11. Therefore, it is possible to improve the bonding reliability of the bonding portions 18 and 19 with the mounting wiring board 9. Here, the fixing pin 17 may be made of an elastic material. In this case, even if impact or vibration is applied to the electronic device unit 8 by making the elasticity of the heat transfer elastic bodies 14 and 15 larger than the elasticity of the fixing pin 17, first, the ratio of the impact in the first stage is fixed pin. After absorbing by the elasticity of 17, the stress generated between the heat transfer elastic bodies 14, 15 and the heat radiating metal plate 16 in the second stage is absorbed. This also makes it difficult for stress due to impact to be applied to the joints 18 and 19 between the coil component 10 or the semiconductor component 11 and the mounting wiring board 9, thereby improving the joint reliability of the joints 18 and 19. It becomes possible.

  Further, as shown in FIG. 3, the heat transfer elastic bodies 14 and 15 are made of a highly elastic material, so that the portions where the heat transfer elastic bodies 14 and 15 are in close contact with the coil component 10 and the semiconductor component 11 are coil components. Not only the top surface 12 and the semiconductor component top surface 13, but also the side of the coil component 10 or the semiconductor component 11 is in close contact with the top surface, so that the heat radiation efficiency can be increased.

  Further, as a method of pressing the coil component 10 and the semiconductor component 11 with substantially equal force, as shown in FIG. 4, the heat radiating metal plate 16 and the heat transfer elastic bodies 14 and 15 are interposed via the heat transfer layers 24 and 25. Are preferably arranged. That is, the upper surface side of the heat transfer elastic bodies 14 and 15 and the lower surface side of the heat transfer layers 24 and 25 are brought into close contact with each other, and the heat radiating metal plate 16 is brought into close contact with the upper surface sides of the heat transfer layers 24 and 25. Thereby, it becomes possible to make the thickness of the heat-transfer elastic bodies 14 and 15 uniform by adjusting the thickness of each of the heat-transfer layers 24 and 25.

  Therefore, since the heat transfer elastic bodies 14 and 15 press the coil component 10 and the semiconductor component 11 almost equally, the stress due to the impact or vibration applied to the electronic device unit 8 is a specific coil component 10 or semiconductor component. 11 can be avoided. Therefore, it is possible to improve the bonding reliability of the bonding portions 18 and 19 with the mounting wiring board 9.

  The electronic device unit of the present invention has an effect of reducing the transmission of vibrations and shocks as stress to the device junction, and is useful in various electronic devices.

The 1st side view of the electronic equipment unit in one embodiment of the present invention Local sectional drawing of the electronic device unit in one Embodiment of this invention The 2nd side view of the electronic equipment unit in one embodiment of the present invention The 3rd side view of the electronic equipment unit in one embodiment of the present invention Side view of a conventional electronic device unit

Explanation of symbols

8 Electronic Device Unit 10 Coil Component 11 Semiconductor Component 12 Coil Component Top Surface 13 Semiconductor Component Top Surface 14, 15 Heat Transfer Elastic Body 16 Heat Dissipation Metal Plate 17 Fixing Pin

Claims (3)

A mounting board having a wiring pattern;
A heat generating component mounted on this mounting board;
A heat transfer elastic body having the first main surface in close contact with the top surface of the heat generating component;
A metal plate in close contact with the second main surface of the heat transfer elastic body,
The metal plate is an electronic device unit provided in a positional relationship parallel to the mounting substrate. The electronic device unit according to claim 1, further comprising a heat transfer elastic body in which the first main surface is in close contact with the top surface and a part of the side surface of the heat generating component. The electronic device unit according to claim 1, wherein the heat transfer elastic body and the metal plate are arranged via a heat transfer layer.

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