JPH0714694U - Heat dissipation structure for electronic devices - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a heat dissipation structure for electronic devices, which is small in size, has a sufficient heat dissipation area, and is inexpensive to manufacture. [Electronics for cooling a strip-shaped heat dissipation plate 1 made of a metal plate having a high thermal conductivity on a fixed substrate such as a printed circuit board C, and contacting a power device 4 with the surface of the heat dissipation plate 1 for cooling In a heat dissipation structure of equipment or the like, the heat dissipation plate 1 is formed by bending at least one end portion in the lateral direction of the heat dissipation plate 1 into a "U" shape.
A heat dissipation structure for an electronic device or the like in which the power device 4 is sandwiched between the surface of the general portion 1c and the folded portion 1d.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cooling structure for a power device incorporated in an electronic device, and more particularly to a heat dissipation structure for a power device for a thin device mounted on a fixed substrate such as a printed substrate.

[0002]

[Prior art]

Generally, electronic devices have built-in power devices such as power transistors, FET devices, and diodes, but these power devices are usually mounted on a printed circuit board together with various circuit devices. Therefore, conventionally, heat dissipation plates A ₁ and A ₂ as shown in FIG. 5 or 6 are used to prevent the temperature rise of the power devices B ₁ and B ₂ . That is, in FIG. 5, a strip-shaped heat sink A ₁ is installed facing the power device B ₁ mounted on the printed circuit board C, and a fixing screw D is attached to the surface of the heat sink A ₁ made of a metal plate having good thermal conductivity. _The power device B ₁ is brought into close contact with the spring material restraining tool E fixed at ₁ , and the anchor a which is integrally formed with the heat dissipation plate A ₁ is fixed to the ground conductor (not shown) of the printed circuit board C. . Also, FIG. 6 is directly fixed to the heat radiating tip b of the power device B ₂ in the same manner on the surface of the heat radiating plate A ₂ using the fixing screws D _2, grounding conductor of the anchor a for the heat radiating plate A ₂ PCB C It is an example of being fixed and connected to (not shown).

[0003]

[Problems to be solved by the device]

However, since the retainer E and the fixing screws D ₁ and D ₂ do not contribute to the cooling of the power devices B ₁ and B ₂ , the heat dissipation area of these conventional heat dissipation structures is substantially the same as that of the heat dissipation plates A ₁ and A ₂ . Since the surface area is too small, the power devices B ₁ and B ₂ cannot be sufficiently cooled by the small heat sinks A ₁ and A ₂ , and the temperature of the power devices B ₁ and B ₂ rises above the rating, which may easily cause a failure. is there. Of course, in order to avoid such a problem, it is sufficient to use large heat sinks A ₁ and A ₂ having a large surface area, but if the large heat sinks A ₁ and A ₂ are installed on the printed circuit board C, The installation of the heat sinks A ₁ and A ₂ obstructs the mounting space of other circuit elements on the surface of the printed circuit board C.

Further, in the above-described two heat dissipation structures, a tool such as a screw driver must be inserted from a direction parallel to the surface of the printed circuit board C to tighten the fixing screws D ₁ and D _2. There is also a problem that the mounting density of the circuit elements on the surface of the printed circuit board C is reduced by securing the insertion space for the driver and the like.

Further, in both heat dissipation structures, the number of parts is increased by using the fixing screws D ₁ and D ₂ and the holding metal fittings E, and the manufacturing cost required for heat dissipation measures tends to be relatively high. Further, in the heat dissipation structure of FIG. In some cases, the height of the heat dissipation plate A ₂ on the printed circuit board C becomes unnecessarily high, which makes it difficult to secure a space for incorporating the printed circuit board C inside the electronic device.

In view of the problems of the conventional heat dissipation structure as described above, an object of the present invention is to obtain a heat dissipation structure for an electronic device or the like which is small in size, has a sufficient heat dissipation area, and is inexpensive to manufacture. .

[0007]

[Means for Solving the Problems]

 In order to achieve this object, the present invention installs a strip-shaped heat sink made of a metal plate with good thermal conductivity on a fixed substrate such as a printed circuit board, and contacts the surface of the heat sink with a power device. In a heat dissipation structure of an electronic device or the like for cooling, at least one end portion in the lateral direction of the heat dissipation plate is bent into a "U" shape so that the power device is sandwiched between the general surface of the heat dissipation plate and the folded part. Is proposed.

[0008]

【Example】

 1 to 4, the details of the embodiment of the present invention will be described below. 1 and 2 show a heat dissipation structure according to a first embodiment of the present invention. In this embodiment, a brass plate, a phosphor bronze plate, or a sandwich steel plate in which a copper plate is laminated on the surface of an iron plate is sufficiently heat-treated. The heat dissipation plate 1 made of a metal plate having a high conductivity (thickness is about 0.6 mm to 2.0 mm) is used.

That is, a pair of anchors 1 a soldered to a ground conductor foil (not shown) of the printed circuit board C on which the heat sink 1 is installed are attached to the lower edges of the heat sink 1 formed in a strip shape. , 1b are integrally formed, and in order to prevent excessive heat conduction during soldering, a choke hole 2 is formed in the general portion 1c of the heat dissipation plate 1 facing these anchors 1a, 1b. One end of the heat sink 1 in the lateral direction is folded back in a "U" shape to form a folded part 1d, and a heat is provided between the elastically folded back part 1d and the general part 1c of the heat sink 1. The power device 4, which is prevented from being scratched by the protective tube 3 having good conductivity, is elastically clamped, and the power device 4 is closely attached to the surface of the general portion 1c of the heat dissipation plate 1 by this clamping.

In addition, a pair of burring protrusions 1e vertically aligned are formed on the general portion 1c of the heat dissipation plate 1 toward the folded-back portion 1d. Therefore, when the heat dissipation plate 1 is fitted to the power device 4, The burring protrusions 1e of the above function as a stopper for obtaining the positional relationship between the heat dissipation plate 1 and the power device 4.

Since the heat dissipation structure according to the first embodiment has the above-described structure, any tool can be used only by sandwiching the power device 4 between the general part 1c and the folded part 1d of the heat dissipation plate 1. Since the installation can be completed without the need for a heat dissipating structure that uses conventional metal fittings and fixing screws, the manufacturing cost is lower and no tools need to be used. Therefore, the mounting density on the surface of the printed circuit board C can be reduced. Becomes higher. The amount of heat of the power device 4 transmitted to the heat sink 1 is surely conducted not only to the general portion 1c but also to the folded portion 1d. Therefore, the substantial heat dissipation area of the heat sink 1 is equal to that of the general portion 1c. Since the surface area is the same as that of the folded-back portion 1d, the structure is small and has a sufficient heat radiation area. In the first embodiment, the above-mentioned heat dissipation plate 1 is made of a brass plate or a sandwich steel plate in which a copper plate is laminated on the surface of an iron plate. It was choked with a good soldering result. This means that, according to the structure of the first embodiment, the heat dissipation area of the heat dissipation plate 1 can be increased and the solderability of the anchors 1a and 1b of the heat dissipation plate 1 to the printed circuit board C can be supported.

FIG. 3 is a plan view of a heat dissipation structure according to a second embodiment of the present invention, which corresponds to FIG. 2. In this embodiment, both end portions in the lateral direction of the general portion 1c of the heat sink 1A are directed to the opposite side. The device is folded back in a U-shape, and the power devices 4A 1 and 4B 2 are sandwiched between the folded portions 1d and the general portion 1c. Since two pairs of burring protrusions 1e are formed on the general portion 1c of the heat radiating plate 1A so as to protrude toward the folded portions 1d, the power devices 4A and 4B closely attached to both surfaces of the general portion 1c are Positioning can be performed by abutting against each pair of burring protrusions 1e.

Since the second embodiment has such a structure, one heat dissipation plate 1A is used for heat dissipation of the two power devices 4A and 4B. Therefore, as compared with the case of the first embodiment. The manufacturing cost can be further reduced. Also in terms of the heat radiation area of each power device 4C, since the general portion 1c and the folded portion 1d of the heat radiation plate 1A are integrated, a sufficient heat radiation area can be secured.

FIG. 4 shows a heat dissipation structure according to a third embodiment of the present invention in which the heat dissipation area is enlarged, and the same structural parts as those in FIG. 1 are designated by the same reference numerals. That is, one end in the horizontal direction of the general portion 1c of the heat sink 1B is bent into a "U" shape as the folded portion 1d as in the case of the first embodiment, but on the opposite side of this folded portion 1d. A heat radiation extension portion 1f bent at a right angle is integrally formed with an end portion of the horizontal general portion 1c.

Therefore, according to the heat dissipation structure of the third embodiment, in order to dissipate the heat of the power device 4C, not only the surfaces of the general part 1c and the folded part 1d of the heat dissipation plate 1B but also the surface of the heat dissipation extension part 1f are exposed. Since it can be used, it is possible to secure a sufficient heat dissipation area and obtain a relatively small heat dissipation structure.

[0016]

[Effect of device]

 As is apparent from the above description, according to the heat dissipation structure of the present invention, the power device is sandwiched between the general part and the folded part in which at least one lateral end of the heat sink is folded back in a "U" shape. Therefore, it is possible to obtain a heat-dissipating structure which can be mounted without using any tools and which is inexpensive to manufacture. Further, since this heat dissipation structure is a small size with a sufficient heat dissipation area, it has a small installation area on the printed circuit board, can sufficiently cool the power device, and can improve the mounting density of the printed circuit board.

[Brief description of drawings]

FIG. 1 is a perspective view of a heat dissipation structure according to a first embodiment of the present invention.

FIG. 2 is a plan view of the heat dissipation structure.

FIG. 3 is a plan view of a heat dissipation structure according to a second embodiment of the present invention.

FIG. 4 is a perspective view of a heat dissipation structure according to a third embodiment of the present invention.

FIG. 5 is a perspective view of a conventional heat dissipation structure.

FIG. 6 is a perspective view of another conventional heat dissipation structure.

[Explanation of symbols]

 C Printed circuit board 1, 1A, 1B Heat sink 1c General part 1d Folding part 1e Burring protrusion 4, 4A-4C Power device

Claims (1)

[Scope of utility model registration request] 1. An electronic device or the like in which a strip-shaped heat dissipation plate made of a metal plate having good thermal conductivity is installed on a fixed substrate such as a printed circuit board, and a power device is brought into contact with the surface of the heat dissipation plate for cooling. In the above heat dissipation structure, at least one end portion in the lateral direction of the heat dissipation plate is bent into a "U" shape so that the power device is sandwiched between the surface of the general part of the heat dissipation plate and the folded portion. Heat dissipation structure.