JP2006310552A - Heat sink mounting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat sink mounting structure for reliably mounting and fixing a heat sink of a heat generating component to a small space. <P>SOLUTION: The heat sink mounting structure is constituted with a heat generating component 2 mounted to a printed circuit board 3, a fin 10, and a U-shape fixing tool 11 for supporting the heat generating component 2. A screw 15 is sequentially inserted into a mounting hole of a fixing tool 11 and a mounting hole of a package body 5 and is then screwed to the threaded hole of the fin 10. Accordingly, the fin 10 is tightened to the heat generating component 2 and the fin 10 is then mounted and fixed to the fixing tool 11 via the heat generating component 2. Since the fin 10 and the fixing tool 11 are individually independent of each other, the fin 10 is minimized in size as required, and the fixing tool 11 can be formed in the compact size, the fin 10 mounted to the heat generating component 2 can surely be mounted and fixed into a small space. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radiator mounting structure when a radiator is mounted on a heat generating component mounted on a substrate.

  Generally, a radiator is mounted on a heat generating component such as a semiconductor device mounted on a printed circuit board and used to dissipate heat generated by the heat generating component. FIG. 3 is a longitudinal sectional view of a main part of a conventional radiator mounting structure as viewed from the side. In the figure, a heat generating component 2 such as a diode or a transistor to which a heat sink 1 is attached is mounted on a printed circuit board 3. The heat generating component 2 includes a package main body 5 in which a mounting hole 7 is formed, and lead terminals 6 protruding from the bottom surface of the package main body 5. In addition, the heat-emitting component 2 in the same figure is what is called a single in-line package. On the other hand, the heat sink 1 is made of a metal member excellent in heat dissipation, such as aluminum. For example, as in Patent Document 1, a fin portion 10 composed of a plate-like fin bridging portion 10b in which a plurality of heat dissipation fins 10a are arranged in parallel is provided. And a fixture 11 for supporting and fixing the fin portion 10 on the printed circuit board 3. A screw hole 12 is formed in the fin bridging portion 10 b of the fin portion 10. The fixture 11 includes a connecting portion 11a that is fixed to the fin portion 10 by, for example, soldering or caulking, and a leg portion 11b that is soldered and mounted on the printed board 3.

  The heat sink 1 inserts the screw portion of the screw 15 into the mounting hole 7 from the front side of the package body 5 with the fin bridging portion 10b of the fin portion 10 in close contact with the back surface of the heat generating component 2, and the fin bridging portion 10b. By being screwed into the screw hole 12, the heat generating component 2 is attached. Then, the lead terminal 6 of the heat generating component 2 is inserted into the through hole 8 provided in the printed board 3, and the leg portion 11 b of the fixture 11 constituting the heat sink 1 is inserted into the through hole 20 provided in the printed board 3. After that, the heat sink 1 and the heat generating component 2 are fixed to the printed circuit board 3 by soldering them.

  FIG. 4 is a perspective view of a radiator mounting structure in another conventional example. In the figure, a lead terminal 6 protruding in the horizontal direction from the package body 5 of the heat generating component 2 is bent halfway in the vertical direction, and the heat generating component 2 has a back surface facing the printed circuit board 3. 2 is mounted on the printed circuit board 3 while being laid down.

The heat sink 1 is formed by bending a plate-like member such as an aluminum plate, for example, and has a function in which the fin portion 10 and the fixture 11 of the conventional example are integrated. The heat sink 1 mounts the heat generating component 2 and has a rectangular plate-shaped mounting portion 50 mounted on the printed circuit board 3, wall-shaped fin bodies 51, 51 rising from both sides of the mounting portion 50, and a fin body 51. , 51, and a holding portion 52 that rises from the side portion of the mounting portion 50 that is positioned between and 51 and is bent so as to face the mounting portion 50 in the middle. The holding portion 52 has a plate spring action, and holds the heat generating component 2 placed on the mounting portion 50 against the mounting portion 50 by its urging force. A guide portion 53 that warps upward is formed at the end portion of the holding portion 52 so that the heat generating component 2 can be easily inserted between the mounting portion 50 and the holding portion 52. The heat sink 1 is fixed to the printed board 3 by inserting a leg portion (not shown) provided on the lower surface of the mounting portion 50 into the through hole 20 provided in the printed board 3 and then soldering.
Japanese Patent Laid-Open No. 9-92993

  However, in the conventional radiator mounting structure shown in FIG. 3, since the heat sink 1 is fixed to the printed circuit board 3 by the fixing tool 11 connected to the fin part 10, the fixing tool 11 is extended from the fin part 10 to the printed circuit board 3. Therefore, the entire heat sink 1 was excessively large with respect to the necessary heat dissipation capability. When the heat sink 1 is increased in size, the space occupied by the heat sink 1 on the printed circuit board 3 is increased, which has been an obstacle to high-density mounting and thus downsizing of the device.

  Further, in another radiator mounting structure shown in FIG. 4, the heat sink 1 in which the radiator and the fixture are integrated is directly mounted on the printed circuit board 3, so that there are parts on the lower side and around the heat sink 1. It was impossible to mount, which was an obstacle to miniaturization of equipment due to high-density mounting.

  In view of the above problems, an object of the present invention is to provide a radiator mounting structure that can securely mount and fix a radiator mounted on a heat-generating component in a smaller space.

  In the radiator mounting structure according to the first aspect of the present invention, the heat generating component mounted on the substrate, the heat radiator that dissipates the heat of the heat generating component, and the heat dissipating through the heat generating component while being fixed to the substrate. And a fixture for detachably supporting the container at a predetermined height position.

  If it does in this way, a heat sink and a fixing tool become independent independently, and it can design freely in a required shape and a magnitude | size according to each function. In other words, the size of the heatsink can be reduced to the minimum necessary for the heat generation amount of the heat-generating component, and the fixture can be made compact, so the heatsink attached to the heat-generating component can be securely attached in a smaller space. , Can be fixed. Further, since the radiator is supported at a predetermined height position, components can be mounted on the lower side.

  In the radiator mounting structure according to a second aspect of the present invention, the fixing device holds the radiator in a state where the radiator is placed on the fixture via the heat generating component.

  In this way, the fixture is independent of the radiator with good heat dissipation and is attached with the radiator mounted on the fixture via a heat generating component with poor heat conductivity. As a result, a decrease in solder temperature due to the heat dissipation action of the radiator is suppressed, and the fixture can be soldered and mounted satisfactorily.

  According to claim 1 of the present invention, the radiator attached to the heat generating component can be securely attached and fixed in a smaller space.

  According to the second aspect of the present invention, the fixture can be soldered and mounted satisfactorily.

  Hereinafter, preferred embodiments of a radiator mounting structure according to the present invention will be described with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the same location as a prior art example, and since description of a common part overlaps, it abbreviate | omits as much as possible.

  FIG. 1 is a main part longitudinal sectional view of the radiator mounting structure according to the present embodiment as viewed from the side, and FIG. 2 is a main part vertical sectional view of the radiator mounting structure as viewed from the front. The radiator mounting structure in this embodiment is mainly composed of a heat generating component 2 mounted on the printed circuit board 3, a fin portion 10 as a heat radiator, and a fixture 11 that supports the heat generating component 2 and the fin portion 10. Is done.

  The heat generating component 2 and the fin portion 10 have substantially the same configuration as the conventional example. That is, the heat generating component 2 includes a package main body 5 in which the attachment hole 7 is formed, and lead terminals 6 protruding from the bottom surface of the package main body 5. However, the lead terminal 6 that protrudes in the horizontal direction from the package body 5 is bent in the vertical direction and is laid on the printed circuit board 3 so that the back surface of the heat generating component 2 faces the printed circuit board 3. Implemented in. On the other hand, the fin portion 10 includes a plate-like fin bridging portion 10b in which a plurality of heat dissipating fins 10a are arranged in parallel.

  The fixture 11 of this embodiment is formed by bending a plate-like member such as a metal plate into a U-shape, and the number of mounting holes 33 corresponding to the heat generating component 2 (two in the figure) is provided. The mounting portion 30, the leg portion 31 that hangs down from both ends of the mounting portion 30, and the soldering portion 32 that protrudes stepwise from the middle of both ends of the leg portion 31 are configured. The fixture 11 is provided to support the heat generating component 2 and the fin portion 10 placed on the placement portion 30 on the printed circuit board 3, and the height of the fin portion 10 is increased by the fixture 11. Positioning is performed. Accordingly, since the fin portion 10 is supported at a predetermined height position, components can be mounted on the lower side thereof. The position and shape of the leg portion 31 are not particularly limited, and may be suspended from the short direction of the placement portion 30 or protrude from the surface of the placement portion 30 that faces the printed circuit board 3. Also good.

  Next, the assembly procedure of the radiator mounting structure having the above configuration will be described.

  First, the screw portion of the screw 15 is inserted through the attachment hole 33 and the attachment hole 7 of the package body 5 sequentially from the opposite surface side of the fixture 11 and screwed into the screw hole 12 of the fin bridging portion 10b. Ten fin bridge portions 10b are fastened to the package body 5 of the heat generating component 2, and the fin portion 10 is mounted and attached to the mounting portion 30 of the fixture 11 via the heat generating component 2 (in a sandwiched state). Then, the lead terminal 6 of the heat generating component 2 and the soldering portion 32 of the fixture 11 are inserted into the through holes 8 and 20 provided in the printed circuit board 3, respectively, and then, for example, by flow soldering using a solder bath or the like. These are soldered together. At this time, the fixture 11 is independent from the fin portion 10 having good heat dissipation, and the fin portion 10 is attached to the fixture 11 via the heat generating component 2 having poor heat conductivity. The solder temperature drop due to the heat radiation action of the fin portion 10 is suppressed, and soldering can be performed satisfactorily. In addition, without using the screw 15 for the attachment of the fin portion 10, a locking claw or the like may be formed on the fin portion 10, and this locking claw may be locked to the side edge of the fixture 11 and attached. Good.

  Since the fixing tool 11 only needs to be large enough to support the heat generating component 2 and the fin portion 10 at a predetermined height position, the fixing tool 11 can be made more compact than before. Since the fin portion 10 is attached to the heat generating component 2 by screwing the screw 15, the fin portion 10 can be easily detached from the assembly by loosening and removing the screw 15. Accordingly, it is possible to attach the fin portion 10 having an arbitrary size and shape according to the heat generating component 2. That is, since the fin portion 10 is made the minimum necessary size with respect to the heat generation amount of the heat generating component 2 and the fixture 11 can be made compact, the fin portion 10 attached to the heat generating component 2 can be made smaller. Can be securely attached and fixed in space.

  As described above, in the radiator mounting structure of the present embodiment, the heat generating component 2 mounted on the printed circuit board 3, the fin portion 10 as a heat radiator that dissipates the heat of the heat generating component 2, and the printed circuit board 3 are fixed. And a fixture 11 that detachably holds the fin portion 10 at a predetermined height position via the heat generating component 2.

  In this way, the fin portion 10 and the fixture 11 are separately independent, and can be freely designed to have a required shape and size according to their functions. That is, since the fin portion 10 can be made the minimum necessary size with respect to the heat generation amount of the heat generating component 2 and the fixture 11 can be made compact, the fin portion 10 attached to the heat generating component 2 can be made smaller. Can be securely attached and fixed in space.

  Further, in the radiator mounting structure of the present embodiment, the fixture 11 holds the fin portion 10 placed thereon via the heat generating component 2.

  In this way, the fixture 11 is independent of the fin portion 10 having good heat dissipation, and the fin portion 10 is placed on the fixture 11 via the heat generating component 2 having poor heat conductivity. Since it is attached in a state, a decrease in solder temperature due to the heat radiation action of the fin portion 10 is suppressed, and the fixture 11 can be soldered and mounted well.

  In addition, this invention is not limited to the said Example, It can change in the range which does not deviate from the meaning of this invention. The heat generating component 2 can be applied to various package shapes, and the component type is not limited to a transistor or the like.

It is the principal part longitudinal cross-sectional view seen from the side surface direction of the radiator attachment structure in 1st Example of this invention. It is the principal part longitudinal cross-sectional view seen from the front direction of the radiator attachment structure same as the above. It is the principal part longitudinal cross-sectional view seen from the side surface direction of the radiator attachment structure in a prior art example. It is the principal part longitudinal cross-sectional view seen from the front direction of the radiator attachment structure in another prior art example.

Explanation of symbols

2 Heat-generating parts 3 Printed circuit board (board)
10 Fin section (heatsink)
11 Fixing tool

Claims (2)

A heat-generating component mounted on the substrate, a radiator that dissipates the heat of the heat-generating component, and is fixed to the substrate and detachably supports the radiator at a predetermined height position through the heat-generating component. A radiator mounting structure characterized by comprising a fixture. The radiator mounting structure according to claim 1, wherein the fixture is supported in a state where the radiator is placed via the heat generating component thereon.

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