JP3098236U - Heat sink mounting structure for electronic circuit elements - Google Patents

Abstract

A radiating plate mounting structure for cooling an electronic circuit element used in an electronic device is provided with a simple and reliable mounting structure by preventing rotation of the radiating plate due to a tightening torque of a mounting screw.
An attachment leg portion of a fixing bracket is fitted into a mounting hole of a printed wiring board, and further, a concave fitting of a heat sink is fitted to a rectangular flat portion and both side surfaces of the fixing bracket. With the part 42 fitted, the mounting screw 6 is inserted from above into the first through hole 71 provided in the heat sink 4, the second through hole 72 provided in the fixing member 5, and the printed wiring board 2. The screw is tightened to a screw mounting boss 74 provided on the bottom chassis 1 through the third through hole 73 provided.
[Selection diagram] Fig. 1

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a heat sink mounting structure for cooling an electronic circuit element used in an electronic device or the like.
[0002]
[Prior art]
In a heat sink mounting structure for cooling an electronic circuit element, there is a printed wiring board on which the electronic circuit element is mounted and a screw hole formed in the heat sink, and the heat sink is fixed to the printed wiring board using screws. . In such an attachment structure, it is required that the radiator plate be reliably and easily attached to the printed wiring board while being thermally coupled to the electronic circuit element.
However, in the conventional mounting structure in which the screws are fixed from the back surface of the printed wiring board, it is necessary to turn the printed wiring board upside down and fasten the screws, resulting in poor work efficiency and a jig for positioning.
On the other hand, by attaching a spring or the like to the screw, a heat radiator or the like that allows a heat sink or the like to be securely attached to the printed wiring board in a state of being thermally coupled to the electronic circuit element (for example, see Patent Document 1), There is an attachment structure in which the influence of the warpage of the printed wiring board that occurs when soldering is devised by devising the attachment position and the like. (For example, see Patent Document 2). In addition, there is one in which a nut portion is provided on a printed wiring board, and a heat sink is attached to the nut portion from above using a screw (for example, see Patent Document 3).
[0003]
[Patent Document 1]
JP 2001-237579 A [Patent Document 2]
Japanese Patent Application Laid-Open No. 9-232778 [Patent Document 3]
JP-A-6-112676
[Problems to be solved by the invention]
However, in any of the inventions described in Patent Documents 1 to 3, when the heat radiating plate is attached to the printed wiring board with screws, rotation of the heat radiating plate due to the screw tightening torque cannot be prevented, and the heat radiation is not achieved. The rotation of the plate may damage peripheral parts. In recent years, the density of printed wiring boards has been increasing more and more, and in order to prevent damage to peripheral parts due to rotation of the heat sink, it was necessary to go through a procedure of temporarily tightening the screws once and then fully tightening them. If the rotation of the heat radiating plate due to the tightening torque of the screws can be prevented, the final tightening can be performed without going through the temporary tightening procedure, and the work procedure can be simplified.
[0005]
The present invention has been made in order to solve the above-described problems, and it is an object of the present invention to provide a heat sink mounting structure that can easily and reliably mount a heat sink for cooling an electronic circuit element to a printed wiring board. Aim.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 is to provide a printed circuit board having a surface mounted electronic circuit element mounted on a bottom chassis, thermally coupled to the electronic circuit element, and cooling the element. In the heat sink mounting structure in which the heat sink is attached to the printed wiring board using mounting screws, the heat sink is interposed between the printed wiring board and the heat sink to fix the heat sink to the printed wiring board. The printed wiring board is provided with a mounting hole for mounting the fixing bracket, and the fixing bracket is bent vertically downward from a rectangular flat portion and a pair of parallel edges of the flat portion. And a mounting leg portion formed by projecting from a lower end of the both side surface portions and being partially fitted to the mounting hole, wherein the heat sink is formed by extrusion molding, and the electronic circuit element is formed. A fin portion for releasing the heat generated therefrom, and a concave fitting portion fitted to the rectangular flat portion and both side portions of the fixing bracket, wherein the fixing bracket is provided in a mounting hole of the printed wiring board. The mounting screws are fitted to the radiator plate from above with the concave fitting portions of the radiator plate fitted to the rectangular flat portions and both side surfaces of the fixture. Through the first through hole provided, the second through hole provided in the fixing member, and the third through hole provided in the printed wiring board, a screw is attached to the screw mounting boss provided in the bottom chassis. When the screw is tightened, a fixing bracket is interposed to prevent the heat sink from rotating.
[0007]
In this configuration, the heat radiating plate for cooling the surface-mounted electronic circuit element is fixed to the printed wiring board by mounting screws via a fixing metal fixed to the printed wiring board. Since the fixing bracket for fixing the heat sink is fitted and attached to the mounting hole provided in the printed wiring board, it does not rotate due to the tightening torque of the screw. In addition, the fixing fittings also serve as a mounting guide that fits into the fitting portion of the heat sink to facilitate positioning of the through holes and the like and facilitates operation when fixing the mounting screws.
[0008]
Further, the heat sink has a concave fitting portion that fits with the rectangular flat portion and both side portions of the fixing bracket, and is attached to the printed wiring board in a state where the fitting portion is fitted with the fixing bracket. It does not rotate due to the tightening torque of. The heat sink is made by extruding a metal having high thermal conductivity. By using the extrusion molding method, a heat sink having a plurality of fins having a large heat dissipation area in the extrusion direction can be easily and continuously manufactured.
[0009]
The mounting screw was provided on the bottom chassis through the first through hole provided in the heat sink, the second through hole provided in the fixing member, and the third through hole provided in the printed wiring board from above. Attached to the screw boss. Since the mounting screws are fixed from above, there is no need to turn the printed wiring board over and no jig for positioning is required. Further, since the heat sink and the printed wiring board, and the printed wiring board and the bottom chassis can be fixed using the same mounting screw, the members for fixing the printed wiring board to the bottom chassis can be simplified.
[0010]
According to a second aspect of the present invention, an electronic circuit element is mounted on a printed wiring board, and the electronic circuit element is thermally coupled to the electronic circuit element, and a heat sink for cooling the element is mounted on the printed wiring board using mounting screws. In the heat sink mounting structure to be attached, a fixing member is provided between the printed wiring board and the heat sink to fix the heat sink to the printed wiring board. A mounting hole for mounting a member is provided, and the fixing member is fitted with a mounting guide portion for preventing rotation of the heat radiating plate in a state fitted with the heat radiating plate, and is fitted with a mounting hole of the printed wiring board. A mounting leg for preventing rotation of the fixing member, wherein the radiator plate has a fin portion for releasing heat generated from the electronic circuit element and a fitting portion for fitting to a mounting guide portion of the fixing member. And a part, The mounting leg of the fixing member is fitted into the mounting hole of the lint wiring board, and the mounting screw of the heat sink is fitted onto the mounting guide of the fixing member. A screw is fastened to the printed wiring board through a first through hole provided in the heat sink and a second through hole provided in the fixing member. It is a detent.
[0011]
In this configuration, a heat radiating plate for cooling the electronic circuit element is fixed to the printed wiring board by a fixing screw via a fixing member fixed to the printed wiring board. Since the heat radiating plate is fitted and attached to the fixing member attached to the printed wiring board, it does not rotate due to the tightening torque of the screw. Here, the mounting guide portion of the fixing member may be fitted with the fitting portion of the heat radiating plate to prevent rotation of the heat radiating plate due to screw tightening torque, and the shape is not particularly limited. In addition, the mounting leg may be fitted with a mounting hole provided in the printed wiring board so as to prevent rotation of the mounting member, and the number and shape of the legs are not particularly limited.
[0012]
According to a third aspect of the present invention, in the heat radiating plate mounting structure according to the second aspect, the heat radiating plate is formed by extrusion molding. In this configuration, by forming the heat sink by extrusion molding, a heat sink having a plurality of fins can be easily and continuously manufactured.
[0013]
[Embodiment of the invention]
A heat sink mounting structure according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a heat sink mounting structure mounted in a housing of an electronic device. The heat radiating plate mounting structure is for radiating heat generated from the bottom chassis 1, the printed wiring board 2 mounted on the bottom chassis 1, the electronic circuit element 3 surface-mounted on the printed wiring board 2, and the electric circuit element 3. The heat radiating plate 4 includes a fixing member (fixing member) 5 for fixing the heat radiating plate 4 to the printed wiring board 2 and mounting screws 6.
[0014]
FIG. 2 is a perspective view of the fixing fitting 5. The fixing bracket 5 includes a rectangular flat portion 51, both side portions 52 bent vertically downward from a pair of parallel edges 51a of the flat portion, and mounting legs 53 formed to project from lower ends of the both side portions 52. ing. The rectangular flat portion 51 has a second through hole 72 through which the mounting screw 6 passes.
[0015]
FIG. 3A is a perspective view of the heat sink 4, and FIG. 3B is a front view thereof. The radiator plate 4 is composed of a fin portion 41 for releasing heat generated from the electronic circuit element 3, and a concave fitting portion 42 for fitting with the rectangular flat portion 51 and the both side portions 52 of the fixture 5. A first through hole 71 through which the screw 6 passes is provided. The heat sink 4 is made by an extruder having an extrusion die outlet having the same shape as the front view of the heat sink 4 shown in FIG. By using the extrusion molding method as the method of manufacturing the heat sink 4, the heat sink 4 having a plurality of fins having a large heat dissipation area in the extrusion direction can be easily and continuously manufactured, and the heat sink 4 having a sufficient heat dissipation area can be manufactured. Can be created. In addition, in the extrusion molding method, since the heat sink 4 can be manufactured continuously, the manufacturing cost can be reduced. The first through hole 71 is provided after the heat sink 4 is extruded.
[0016]
Next, an operation for attaching the heat sink 4 to the printed wiring board 3 will be described with reference to FIGS. FIG. 4 is a cross-sectional view of the heatsink mounting structure on a line connecting the mounting screws 6. Since the fixing bracket 5 is attached by fitting the attachment leg 53 to the attachment hole 21 provided in the printed wiring board 2, it does not rotate due to the tightening torque of the screw.
[0017]
Next, the heat sink 4 is set on the upper surface of the electronic circuit element 3. At this time, a heat radiating sheet 31 made of, for example, silicon rubber is attached between the electronic circuit element 3 and the heat radiating plate 4 in order to efficiently transmit the heat of the electronic circuit element 3 to the heat radiating plate 4. The radiator plate 4 is attached by fitting the fitting portion 42 to the fixture 5. Then, the heat sink 4, the fixture 5, the through holes 71, 72, 73 of the printed wiring board 2 and the screw mounting boss 74 are aligned, and the mounting screws 6 are screwed through the through holes 71, 72, 73. To the boss 74 for use. By screwing the mounting screw 6, the heat radiating plate 4 is fixed to the printed wiring board 2 while being thermally coupled to the electronic circuit element 3 via the heat radiating sheet 31.
[0018]
By fitting the fitting 5 to the fitting portion 42 of the heat sink 4, the heat sink 4 is not rotated by the screw tightening torque. Therefore, when attaching the heat sink 4 to the printed wiring board 2 by using the mounting screws 6, the heat sink 4 does not rotate and does not damage the surrounding parts, and it is not necessary to temporarily tighten the work procedure. can do. The fixing metal fitting 5 is fitted to the fitting part 42 of the heat radiating plate 4 to facilitate alignment of the through holes 71, 72, 73 and the like, and to facilitate the operation for fixing the mounting screw 6. Also serves as a guide.
[0019]
The present invention can be variously modified without being limited to the configuration of the above-described embodiment. For example, the fixing bracket (fixing member) 5 does not need to be a metal fitting, and may be made of, for example, resin. Good. Further, the shapes of the fixing fitting 5 and the fitting portion 42 of the heat radiating plate 4 fitted thereto are not limited to the shapes of the above-described embodiment, and the shape of the fitting can prevent rotation of the heat radiating plate 4 due to screw tightening torque. Should be fine. The number and shape of the mounting legs 53 of the fixing bracket 5, and the numbers and positions of the mounting screws 6 and the corresponding through holes 71, 72, 73 and the screw mounting bosses 74 are not limited to the above-described embodiment. Further, the heat sink 4 and the printed wiring board 2, and the printed wiring board 2 and the bottom chassis 1 do not need to be mounted using the same mounting screws 6, but may be mounted using different mounting screws.
[0020]
[Effect of the invention]
As described above, according to the first aspect of the present invention, since the heat radiating plate is fitted with the fixing bracket attached to the printed wiring board, the heat radiating plate is not rotated by the tightening torque of the screw. Therefore, when attaching the heat sink to the printed wiring board using the mounting screws, the heat sink does not rotate and does not damage the surrounding parts, and it is not necessary to temporarily fasten, so that the work procedure can be simplified. . In addition, the fixing fittings also serve as a mounting guide that fits into the fitting portion of the heat sink to facilitate positioning of the through holes and the like and facilitates operation when fixing the mounting screws.
[0021]
By using the extrusion molding method as a method of manufacturing the heat sink, a heat sink having a plurality of fins having a large heat dissipation area in the extrusion direction can be easily formed, and a sufficient heat dissipation area can be obtained. In addition, in the extrusion molding method, since the heat sink can be manufactured continuously, the manufacturing cost can be reduced.
[0022]
Since the mounting screws are mounted from above the printed wiring board, there is no need to turn the printed wiring board over, and the mounting operation is facilitated. Further, since the heat sink and the printed wiring board, and the printed wiring board and the bottom chassis can be fixed using the same mounting screw, the members for fixing the printed wiring board to the bottom chassis can be simplified.
[0023]
According to the second aspect of the present invention, since the heat radiating plate is fitted and attached to the fixing member attached to the printed wiring board, it does not rotate due to the tightening torque of the screw. Therefore, when the screw is tightened, the heat radiating plate does not rotate to damage surrounding parts, and it is not necessary to temporarily tighten the screw, so that the operation procedure can be simplified.
[0024]
According to the third aspect of the present invention, by using the extrusion molding method as the method of manufacturing the heat sink, a heat sink having a sufficient heat dissipation area can be easily formed. In addition, in the extrusion molding method, since the heat sink can be manufactured continuously, the manufacturing cost can be reduced.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view illustrating a heat sink mounting structure according to an embodiment of the present invention.
FIG. 2 is a perspective view of a fixture having the same mounting structure.
3A and 3B are a perspective view and a front view of a heat sink having the same mounting structure.
FIG. 4 is a sectional view of the mounting structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Bottom chassis 2 Printed wiring board 3 Electronic circuit element 4 Heat sink 5 Fixing bracket (fixing member)
6 mounting screw 21 mounting hole 41 radiation fin 42 fitting part 51 rectangular flat part (mounting guide part)
52 Both sides (Mounting guide)
53 Mounting leg 71 First through hole 72 Second through hole 73 Third through hole 74 Boss for screw mounting

Claims (3)

A printed wiring board having an electronic circuit element surface-mounted on the bottom chassis is attached, thermally coupled to the electronic circuit element, and a radiator for cooling the element is mounted on the printed wiring board using mounting screws. In the heat sink mounting structure that is mounted by
A fixing bracket interposed between the printed wiring board and the heat sink, for fixing the heat sink to the printed wiring board,
The printed wiring board is provided with a mounting hole for mounting the fixing bracket,
The fixing bracket has a rectangular flat portion, both side portions bent vertically downward from a pair of parallel edges of the flat portion, and portions projecting from lower ends of the both side portions, and are fitted with the mounting holes. And a mounting leg,
The radiator plate is formed by extrusion molding, and has a fin portion for releasing heat generated from an electronic circuit element, and a concave fitting portion fitted to the rectangular flat portion and both side portions of the fixing bracket. ,
The mounting legs of the fixing bracket are fitted in the mounting holes of the printed wiring board, and the concave fitting portions of the heat sink are fitted in the rectangular flat portions and both side surfaces of the fixing bracket. Passing the mounting screw from above through a first through hole provided in the heat sink, a second through hole provided in the fixing member, and a third through hole provided in the printed wiring board. A heat sink mounting structure, wherein a screw is fastened to a screw mounting boss provided on a bottom chassis, and a fixing bracket is interposed at the time of screw tightening to prevent the heat sink from rotating. An electronic circuit element is mounted on a printed wiring board, and a heat radiation board for thermally coupling the electronic circuit element and cooling the element is mounted on the printed wiring board using mounting screws. In structure
A fixing member interposed between the printed wiring board and the heat sink, for fixing the heat sink to the printed wiring board,
The printed wiring board is provided with a mounting hole for mounting the fixing member,
The fixing member includes a mounting guide portion for preventing rotation of the heat radiating plate when fitted to the heat radiating plate, and a mounting leg portion for fitting to a mounting hole of the printed wiring board to prevent rotation of the fixing member. And having
The radiator plate has a fin portion for releasing heat generated from the electronic circuit element, and a fitting portion fitted with a mounting guide portion of the fixing member,
The mounting leg of the fixing member is fitted in the mounting hole of the printed wiring board, and the mounting screw of the heat sink is fitted in the mounting guide of the fixing member. From the first through hole provided in the heat sink and the second through hole provided in the fixing member, screws are fastened to the printed wiring board. Heat sink mounting structure characterized by a rotation stop. The heat sink mounting structure according to claim 2, wherein the heat sink is formed by extrusion molding.

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