JPS6214703Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mounting cover for a transistor, and more particularly to a mounting cover used when mounting a transistor on a heat sink.

Conventionally, in transistors through which large currents flow, such as power transistors, in order to dissipate the heat generated by the transistor and allow the transistor to operate normally, the transistor is placed on a heat sink with good thermal conductivity via an insulating material. It is common to install

FIG. 1 shows an example of a mounting structure for this type of transistor, and as shown in FIG. A transistor T such as a power transistor consisting of a metal mounting plate 101 as a conductive part
As shown in FIG.
A flat mounting bracket 104 is placed on the surface of the molded part 100 either through the same insulating material 103b as described above or directly, and this mounting bracket 104 is tightened with screws, nuts, etc. Accordingly, the mold part 100 is mounted on the heat radiator 102 so as to be sandwiched between the front and back sides thereof.

However, according to this structure, the transistor T is attached to the mold part 100 by the flat mounting bracket 104.
Since it is mounted with only the upper surface covered, the creepage distance from the base end of the terminal 105 of the transistor T or the mounting plate 101, which is a metal conductive part, to the upper surface and both side surfaces of the molded part 100 is The disadvantage was that the insulation was insufficient.

The present invention was proposed in view of the above points, and its purpose is to reliably sandwich and fix a transistor mounted on a heatsink with an insulating material interposed between it and the heatsink. A cover for mounting a transistor that can cover almost the entire surface of the molded part of the transistor, thereby ensuring a sufficient creepage distance between the terminal of the transistor or the mounting plate as a conductive part and the outside, and improving insulation performance. is to provide.

The present invention will be explained below with reference to the drawings.

First of all, Figures 2 to 5 show a first embodiment of the present invention, and in the figures, 1 indicates a mounting cover of the present invention which is made of flame-retardant synthetic resin and has an approximately rectangular parallelepiped shape. The inside is cut out so that the bottom side is open in a shape that can surround the molded part 100 and mounting plate 101 of the transistor T attached to the surface of the heatsink 102, and the shape of the molded part 100 is shown in the center. A recess 2 is formed to fit the . The recess 2 also includes a notch 4 formed in the one side plate 3 of the mounting cover 1 for allowing the terminal 105 of the transistor T to protrude to the outside.
It communicates with the outside through. Note that this notch 4
are formed at a height as close as possible to the base end of the terminal 105 protruding from the end surface of the molded part 100. In other words, the height of the side plate 3 facing the terminal 105 as shown in FIG. A portion extends along the end surface of the molded portion 100 to a position close to the base end of the terminal 105 .

Further, the top plate 5 of the mounting cover 1 is provided with mounting holes 6a and 6b, respectively, for mounting the transistor T housed inside the recess 2.

However, in order to attach the transistor T to the heatsink 102 using the mounting cover 1 as a lever, the heatsink 1
A sheet-like insulating material 103 made of silicone rubber or the like is placed on the surface of the mounting plate 101.
The transistor T is mounted so that the terminals 105 of the transistor T are overlapped, and the notch 4 is connected to the terminal 105 of the transistor T.
Fit the mounting cover 1 to cover the mold part 100 and the mounting plate 101, and then insert the screws 7a into the mounting holes 6a, 6b and the insulating material 1.
The molded part 10 of the transistor T is inserted through the insulating material 103 by passing through the through hole 03 and the through hole of the heat sink 102 and screwing the nut 7b.
0 and the mounting plate 101 are clamped and fixed onto the radiator 102 by the mounting cover 1 (see FIGS. 3 to 5).

Therefore, in the transistor T after being fixed, the peripheries of the molded part 100 and the mounting plate 101 are covered with the mounting cover 1, and the only exposed part of the transistor T is the molded part 100 in which the terminal 105 is implanted.
Since the end face of the terminal 105 or the mounting plate 1 is surrounded by the side plate 3 of the mounting cover 1,
The creepage distance between 01 and the outside is ensured by the side plates 3, top plate 5, etc., which is longer than in the past.

Next, FIGS. 6 to 9 show a second embodiment of the present invention. That is, as shown in FIG. 6, in this embodiment, blinds are installed near both ends of the approximately rectangular parallelepiped mold part 100', which has a metal plate (not shown) exposed on the bottom surface for heat dissipation and as a conductive part. hole 10
6' is used to mount the transistor T' which is formed by drilling a hole in the radiator 102, and the mounting cover 1' covers the bottom surface of the molded part 100' as shown in FIGS. 7 to 9. A cover body 8' is provided with a recess 2' having an opening on the bottom side so as to surround substantially the entire surface of the cover body 8', and a mounting piece connected to the lower end of one side of the cover body 8'. It consists of 9'.

On the inner surface of the top plate 10' of the cover body 8', there is a positioning plate that can be fitted into the blind hole 106' formed in the molded part 100' of the transistor T' at a position that matches the blind hole 106'. Projections 11' are provided vertically. Further, the side plate 12' of the cover body 8' located on the opposite side from the mounting piece 9' is entirely cut off to a position extremely close to the top plate 10' in the height direction. The lower edge of the terminal 105' is arranged to reach the vicinity of the base end of the terminal 105' implanted in the mold part 100' housed in the recess 2'.

Furthermore, mounting holes 13a' and 13b' are formed near both longitudinal ends of the mounting piece 9', respectively.

To use such a mounting cover 1', the molded part 100' of the transistor T' is placed on the surface of the heatsink 102 via the insulating material 103 in the same manner as described above, and then the protrusion 11' is placed on the molded part 100'. blind hole 1
06' and cover substantially the entire surface of the molded portion 100' with the mounting cover 1'. Next, screw the screw 7a into the mounting holes 13a', 13b' and the radiator 1.
02 and screw the nut 7b thereon.

In this embodiment as well, the end face of the molded part 100' in which the terminal 105' is implanted is surrounded by the side plate 12' of the mounting cover 1', etc., and the terminal 105' is connected to the outside. Sufficient creepage distance is to be ensured between.

FIG. 10 shows a third embodiment of the present invention. In this embodiment, similarly to the above, the bottom side is opened, and the lower ends of both side plates of the cover body 8'' which can surround the mold part 100' are provided. A pair of mounting pieces 9'' are provided protruding from each other so as to be located diagonally, and mounting holes 13a'' and 13b'' are formed in the mounting pieces 9'' to form a mounting cover 1''. The structure of the transistor T′ and the mounting method of the transistor T′ are explained in the second
Since this embodiment is almost the same as that of the embodiment, detailed description thereof will be omitted.

As described above, according to the present invention, the mold part of the transistor placed on the surface of the heatsink with an insulating material in between has an opening on the bottom side, and the end face where the terminals of the transistor are embedded. Since it is entirely made of synthetic resin and has a mounting hole for mounting on the heatsink, the creepage distance from the mounting plate, which serves as a terminal or conductive part of the transistor, to the outside can be reduced. The wall thickness and external surface of the mounting cover provide sufficient insulation, which has the effect of dramatically improving insulation performance, and also has the advantage of being easily manufactured by integral molding. have

[Brief explanation of the drawing]

Fig. 1 shows a conventional mounting structure of a transistor, A is a perspective view of the transistor, B is a front view showing the mounting state, and Figs. 2 to 5 are a first embodiment of the present invention. Figure 2 is a perspective view of the mounting cover and transistor, Figure 3 is a front view showing the installed state, and Figure 4 is A in Figure 3.
-A' partial sectional view, Figure 5 is a plan view showing the installed state, Figures 6 to 9 show the second embodiment of the present invention, Figure 6 is a perspective view of the transistor, Figure 7 is a plan view of the mounting cover, FIG. 8 is a bottom view, and FIG. 9A is a sectional view taken along line B-B' in FIG. 7.
FIG. 10 is a sectional view showing the installed state, and FIG. 10 is a plan view showing a third embodiment of the present invention. 1, 1', 1''...Mounting cover, 2, 2'...
Recess, 3... Side plate, 4... Notch, 5... Top plate, 6
a, 6b...Mounting hole, 7a...Screw, 7b...Nut, 8', 8"...Cover body, 9', 9"...Mounting piece, 10', 10"...Top plate, 11' ,11″...
Projection, 12'...Side plate, 13a', 13a'', 13
b', 13b''...Mounting hole, T, T'...Transistor, 100, 100'...Mold part, 101
...Mounting plate, 102...Radiator, 103...Insulating material, 105, 105'...Terminal, 106'...Blind hole.

Claims (1)

[Scope of utility model registration request] The molded part of the transistor is placed on the surface of the heatsink with an insulating material in between and has a terminal implanted in one end surface, except for the end surface where the terminal is implanted, and the terminal is attached to its base. 1. A transistor mounting cover made of synthetic resin, characterized in that the cover is configured to cover the vicinity of the end portion, and is provided with a mounting hole for mounting on the heat sink.