JPS5855836Y2 - Mounting structure of heat sink for heat generating parts in electrical equipment - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a structure for mounting a heat sink of a heat-generating component in an electric device, which allows the heat sink to be easily attached to a mounting plate such as a printed circuit board.

Generally, among the electrical components mounted on electrical equipment, heat generating components such as transistors that generate a large amount of heat are fixed to a heat sink to increase their heat dissipation effect, and then fixed together with the heat sink to a mounting plate such as a printed circuit board. There is.

FIGS. 1 to 4 show an example of a conventional mounting structure for such a heat sink.

That is, in FIG. 1, a heat generating component 2 such as a transistor is fixed to one side of a heat sink 1 formed in a rectangular tube shape with a mounting screw 3, and the lower end of the heat sink 1 is attached to the surface of a printed circuit board 4 with adhesive. The lead wire 5 of the heat generating component 2 is mechanically and electrically connected to a conductive layer (not shown) printed on the printed circuit board 4 by soldering.

Similarly, in FIG. 2, a substantially U-shaped heat sink 1 is fixed to the surface of a printed circuit board 4, and a heat generating component 2 is fixed to the inner surface.

However, in such a mounting structure using adhesive, high strength cannot be obtained due to poor adhesion or deterioration of the adhesive due to aging, etc., and therefore there is a risk that the heat sink 1 may fall over due to a slight external force. was there.

Furthermore, if the heat sink 1 and the printed circuit board 4 are not in close contact with each other and a gap is formed, the heat sink 1 may fall over due to vibrations during solder dipping or lead cutting operations.

On the other hand, in FIG. 3, a plurality of protrusions 6 are provided on the lower end of the heat dissipation plate 1, and these are inserted into respective engagement holes 7 drilled in the printed circuit board 4 and bent onto the back surface of the printed circuit board 4. , a heat sink 1 is fixed to a printed circuit board 4.

Further, in FIG. 4, a plurality of approximately T-shaped fixing legs 8 are provided protruding from the lower end of the heat sink 1, and these are inserted into the retaining holes 7 of the printed circuit board 4 so as to protrude from the back side of the printed circuit board 4. , and is twisted so as to intersect with the engagement hole 7 to prevent it from coming off from the hole 7.

However, in the case of a heat sink equipped with such protrusions 6 or fixing legs 8, bending (or twisting) work is required, and the life of the lead cutter may be shortened due to the contact with the lead cutter during lead cutting work. There were some inconveniences, such as making it shorter.

Therefore, insert the terminals or lead wires of electrical components such as resistors and capacitors into the printed circuit board 4, solder them in a dip tank, cut the terminals or lead wires with a lead cutter, and then remove the heat sink 1. There are methods of fixing, but all methods have the major drawback of poor workability.

This idea was made to solve the above-mentioned drawbacks of the conventional technology, and its purpose was to fix a heat-generating component on one side of a box-shaped heat sink that opens up and down, and then fix the heat-generating component on one side of the box-shaped heat sink that opens up and down, and then a substantially cross-shaped dividing groove is formed in the heat dissipation plate, and its upper and lower ends are opened to extend to the upper and lower ends of the heat sink, and a pair of retaining protrusions are provided at the lower end of the opposing surface to sandwich the dividing groove, Due to the extremely simple structure in which these pair of retaining protrusions are engaged with the holes provided in the mounting plate using the elastic force in the direction of separating from each other provided by the dividing groove, installation is easy with one touch. The present invention provides a mounting structure for a heat dissipation plate of a heat generating component in an electric device, which can be fixed easily and reliably.

This invention will be explained in detail below based on the drawings.

FIG. 5 is an exploded perspective view showing an embodiment of the heat sink mounting structure according to this invention.

In the figure, a heat dissipation plate 10 is formed by bending a plate material such as aluminum into a substantially C-shaped cross section, and is provided with rotation prevention claws 11 .

The rotation prevention claw 11 is constructed by cutting and raising a part of one side surface 10a of the heat dissipation plate 10 into a substantially U-shape and protruding toward the other side surface 10b connected to the side surface 10a. By bringing one side of the heat radiating component 2 into contact with the prevention claw 11 and fixing the heat radiating component 2 to the side surface 10b with one mounting screw 3, rotation of the heat radiating component 2 due to loosening of the mounting screw 3 is prevented. There is.

In this case, the anti-rotation claw 11 may be formed by cutting and raising a portion of the side surface 10b, to which the heat dissipating component 2 is fixed, into a substantially U-shape.

Furthermore, the side surface 10C of the heat sink 10, which is opposite to the side surface 10b on which the heat sink component 2 is attached, has upper and lower ends extending to the upper and lower ends of the heat sink 10, so that the side surface 1
0C into left and right side plates 110, 111, and a vertical groove that intersects with this vertical groove and has both ends connected to the side surface 10a.
, 10 d, and a cross-shaped dividing groove 12 is formed, which includes a horizontal groove extending approximately to the center of the groove.

Furthermore, a pair of engaging protrusions 13 and 14 are integrally provided at the lower end of the side surface 10C, sandwiching the dividing groove 12 therebetween.

Each of the engaging protrusions 13 and 14 is connected to the printed circuit board 4.
Leg portions 13 a and 14 a slightly longer than the plate thickness t of
It is constituted by substantially hook-shaped engaging portions 13b, 14b connected to these leg portions 13a, 14a, and inclined surfaces 13C, 14C provided on the outer surfaces of the engaging portions 13b, 14b.

The printed circuit board 4 has the pair of retaining protrusions 13.1.
A hole 15 is formed corresponding to 4.

This hole 15 has a groove width t 2 (t 2 > t 1) slightly larger than the plate thickness t 1 of the heat dissipation plate 10, and a groove width t 2 (t 2 > t 1) when the engaging projections 13 and 14 are elastically deformed inward as shown in FIG. The leg portion 13a is slightly longer than the width of the engaging portions 13b and 14b.
, 14a has a length L (Dl>L>D) smaller than the ID structure in its natural state.

Note that reference numeral 16 is a ventilation hole formed in the heat sink mounting portion of the printed circuit board 4, and 17 is a lead wire insertion hole through which the lead wire 5 of the heat sink component 2 is inserted.

Next, the procedure for attaching the heat sink 10 having such a configuration to the printed circuit board 4 will be explained.

First, the engagement protrusions 13 and 14 of the heat sink 10 are made to correspond to the holes 15 of the printed circuit board 4, and the lead wires 5 of the heat dissipation component 2 are inserted into the respective lead wire insertion holes 17 of the printed circuit board 4.

Next, the heat sink 10 is pressed against the printed circuit board 4, and the inclined surfaces 13C, 14C of the retaining projections 13, 14 are brought into contact with both left and right edges of the hole 15.

At this time, the engaging protrusions 13 and 14 cause the side plates 110 and 111 to elastically deform in the directions of arrows A and B, respectively, due to the dividing grooves 12 formed in the heat dissipation plate 10.
C, 14C and inserted into the hole 15.

And the engaging portions 13b, 14b of the retaining projections 13.14.
When the holes 15 project downward from the printed circuit board 4, the side plates 110, 111 elastically return in the direction of separating from each other and the legs 13a.

14 a into contact with the hole 15 and the engaging portion 13
b and 14b are engaged with the back surface of the printed circuit board 4 as shown by the chain lines in FIG. 6, thereby fixing the heat sink 10 to the printed circuit board 4.

After the heat dissipation plate 10 is fixed to the printed circuit board 4, the lead wire 5 is connected to the conductive layer printed on the back side of the printed circuit board 4 by dip soldering, and the remaining length is cut with a cutter. Ru.

In this case, since the heat dissipation plate 10 is made of aluminum, solder does not adhere to the lead cutter. If this is not the case, you can move on to the solder dip and node cutting process in this state.

Moreover, if the heat dissipation plate 10 is fixed to the printed circuit board 4 using an adhesive if necessary, it can be fixed even more reliably and wobbling can be prevented.

Although the above embodiment has been described with reference to the case where a printed circuit board is used as the mounting plate, it is of course possible to implement the case where the mounting plate is fixed to a sub-chassis or the like.

As explained above, the heat sink mounting structure for heat dissipating components in electrical equipment according to this invention has a cross-shaped dividing groove and a pair of retaining protrusions on one side of the heat sink, and these pair of protrusions are formed on the mounting plate. The heat dissipation plate can be reliably attached to the mounting plate with a single touch, and the work is extremely simple. .

In addition, since the heat sink is formed into a box shape that is open at the top and bottom, the heat sink area can be increased and the occupied volume can be reduced, so that it can be combined into a compact I.

Furthermore, the dividing groove makes it easy to elastically deform the retaining protrusion, further improving workability during installation.

Furthermore, one hole may be provided in the mounting plate corresponding to the pair of retaining protrusions.

Furthermore, it is possible to eliminate and prevent the heat sink from floating or falling due to vibrations during dips and lead cutting.
Furthermore, solder tape and lead cutting can be performed with the heat sink attached to the mounting plate.

[Brief explanation of drawings]

1 and 2 are perspective views showing an example of a conventional heat sink mounting structure, and FIGS. 3 and 4 further show a conventional heat sink mounting structure, where a is a perspective view of the heat sink, and b 5 is an exploded perspective view showing an example of a mounting structure for a heat sink of a heat-generating component in an electrical device according to this invention; FIG. 6 is an illustration of the main parts thereof. This is a diagram to help you. 2... Heat dissipation parts, 4... Printed circuit board, 5... Lead wire, 10... Heat sink,
12... Dividing groove, 13.14... Engaging protrusion, 15... Hole.

Claims (1)

[Scope of utility model registration request] A heat radiating plate formed in a box shape that is open vertically and having a heat generating component fixed to one side thereof, and a mounting plate to which the heat radiating plate is detachably fixed, the surface of the heat radiating plate to which the heat generating component is attached and A cross-shaped dividing groove whose upper and lower ends extend at least to the upper and lower ends of the heat sink is formed on opposing surfaces, and a pair of retaining protrusions each having a retaining portion is formed at the lower end of this surface, sandwiching the dividing groove. A hole is formed in the mounting plate to correspond to the pair of retaining protrusions, and the pair of retaining protrusions are attached to the retaining protrusions in the direction of separating from each other. A mounting structure for a heat dissipation plate of a heat generating component in an electric device, characterized in that the heat dissipation plate of a heat generating component is engaged by elastic force.