JPS6322683Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a mounting structure for a power transistor.

(Prior art) Conventionally, in order to attach two power transistors to the top plate of a heatsink, the power transistors are lined up on a flat top plate of the heatsink without protrusions, and the power transistors are attached to the heatsink using a holding plate from the top surface of the power transistors. It was common to be secured with screws. However, with this fixing method, as the screws are tightened, the position of the power transistor on the top surface of the heatsink may shift, and abnormal force is applied to the lead wire of the power transistor and the part where it is soldered to the printed circuit board. In some cases, there may be problems such as breakage of lead wires or peeling of soldered parts.

(Purpose of the invention) The present invention is intended to prevent malfunctions such as breakage of lead wires or peeling of soldered parts due to misalignment of the power transistor when the power transistor as described above is mounted on the upper plate of a heat sink. That is the purpose.

(Structure of the invention) The radiator is provided with a protrusion on the upper plate, the protrusion is provided with a screw hole, the retaining plate has a protrusion that engages the protrusion of the radiator by sandwiching it, and the radiator is provided with a protrusion that engages with the protrusion of the radiator. The power transistor is placed on the top plate of the heatsink, the protrusions on the heatsink engage with the protrusions on the holding plate, and the power transistor is inserted into the holding plate and the heatsink. The power transistor is fixed to the heatsink using screws.

(Example) Hereinafter, an example of the power transistor mounting structure of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an exploded perspective view of the structure of a power transistor mounting device according to the present invention. The heat sink 1 includes a strip-shaped protrusion 2 formed in the center of the upper plate. The protrusion 2 has a trapezoidal shape, and a screw hole 3 is provided near the center of the protrusion 2. The holding plate 5 is the printed circuit board 1
5, and the presser plate 5 has arc-shaped protrusions 9a, which engage with the protrusions 2 of the radiator 1 between them.
9b, an insertion hole 10 for a screw to be screwed into the screw hole 3 provided in the heat radiator 1, and a stopper 11 projecting downward at one end of the presser plate 5.
The distance between the protrusions 9a and 9b is set to be slightly smaller than the width of the base of the protrusion 2. Projection 2 of radiator 1
The upper plates 6a and 6b on both sides of the insulating film 8a,
Power transistors 7a, 7b and their temperature-compensating thermistor 12 are mounted via 8b, and the press plate 5 is brought into contact with the upper surfaces of the power transistors 7a, 7b and the temperature-compensating thermistor 12.
Then, insert the screw 13 from the screw insertion hole 10 of the holding plate 5.
is inserted and screwed into the screw hole 3 of the radiator 1. At this time, the protrusion 2 of the radiator 1 becomes wedged between the protrusions 9a and 9b of the holding plate 5 on the inclined surfaces 14 on both sides (see FIG. 1), and the protrusion 2 and the protrusion 9a , 9b engage with the power transistors 7a, 7b and the temperature compensation thermistor 1.
2 are fixed to the upper plates 6a and 6b of the heat sink 1. Further, the height of the protrusion 2 of the heatsink 1 is set to be slightly lower than the combined height of the power transistors 7a, 7b and the insulating films 8a, 8b.
A distance s is maintained between the presser plate 5 and the presser plate 5 (the second
(see figure). Further, the temperature compensating thermistor 12 is prevented from protruding laterally by a stopper 11 of the holding plate 5.

Note that the heat sink 1 and the printed circuit board 15 are fixed to a chassis or the like.

(Effect of the invention) The protrusions 2 of the radiator 1 and the protrusions 9a, 9 of the holding plate 5
b and the presser plate 5 by the screw 13.
The power transistors 7a and 7b are fixed on the upper plates 6a and 6b of the heat sink 1 by screwing them into the protrusions 2, and there is no possibility of misalignment of the presser plate or the power transistors when the presser plate is screwed together as in the conventional case. This eliminates any inconveniences such as disconnection of the power transistor lead wire or peeling of the soldered part.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a power transistor mounting structure, and FIG. 2 is a vertical sectional view showing the assembled state of the same structure. 1...Radiator, 2...Protrusion, 3...Screw hole, 5
...Press plate, 6a, 6b...Top plate, 7a, 7b...
...power transistor, 9a, 9b...arc-shaped protrusion, 10...insertion hole.

Claims (1)

[Scope of utility model registration request] The radiator has a protrusion on the upper plate, a screw hole is provided in the protrusion, and a retaining plate has a protrusion that clamps and engages the protrusion of the radiator, and a screw hole is provided in the screw hole provided on the radiator. A power transistor is placed on the upper plate of the heatsink, a retainer plate is brought into contact with the upper surface of the power transistor, and the retainer plate is fixed by applying screws to the screw holes. Mounting structure of power transistor.