JPS6325744Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a mounting device for a semiconductor element that generates heat when energized, such as a power transistor or a triac.

As is well known, semiconductor devices, especially power transistors and triacs, generate heat when energized, raising the temperature inside the device and having an adverse effect on other semiconductor devices and electrical components attached to it. I'm trying my best.

FIG. 1 is a longitudinal sectional view showing an example of a conventional power transistor mounting device. 1 is a cross section U made of a material with good thermal conductivity, such as aluminum.
It is a letter-shaped heat dissipating member, and a plurality of holes 3, 3a are formed through the arm portions 2, 2a facing each other at a predetermined interval. Reference numeral 4 denotes an insulating mica plate that is in contact with the outer wall of the arm portion 2 of the heat dissipation member 1, and 6 is a metal plate that is in contact with the mica plate 4, each having a hole at a position corresponding to the hole 3 of the heat dissipation member 1. 5 and 7 are provided. Reference numeral 8 denotes a power transistor, which includes a metal mounting piece 9 provided with a mounting hole 10 and a lead wire 11. 12 is a mounting bolt, 13 is a bushing, 14 is a printed board to which the heat radiating member 1 is fixed, and 15 is a cover plate made of a metal material and fixed to the upper ends of the arms 2, 2a of the heat radiating member 1. Note that the figure shows the heat dissipation member 1.
Although power transistors 8 are shown attached to the outer walls of the arm portions 2 and 2a, the attachment structure for both is the same, so only the attachment structure for one power transistor 8 will be described.

In the above-described mounting device, the power transistor 8 is mounted on the arm portion 2 of the heat dissipation member 1 via the car plate 4 and the metal plate 6, and
After being fixed with bolts 12 through
is fixed.

In such a mounting device, the heat of the power transistor 8 generated by energization is transmitted to the heat dissipation member 1 via the metal mounting piece 9, the metal plate 6, and the car board 4, and is transferred from the printed board 14 and the cover plate 15. Dissipate heat. However, since the heat dissipation member 1 has a small heat dissipation area and uses the mica board 4 as an insulator, a sufficient heat dissipation effect cannot be obtained, and the dielectric strength of the mica board 4 near the hole 5 is small. , dielectric breakdown may occur. Further, since the heat dissipating member 1 is formed in a U-shape, there are many problems such as the risk of deformation if the bolt 12 is strongly tightened.

The present invention has been made to solve the above-mentioned conventional problems, and aims to provide a semiconductor element mounting device that has a large heat dissipation effect and is free from the risk of dielectric breakdown.

In order to achieve the above-mentioned object, the semiconductor device mounting device according to the present invention includes a heat dissipating member having a diagonal-shaped cross section or a cross-sectional shape, which is formed by providing a plurality of through holes in opposing positions of both side walls, and An insulating plate with good heat conduction is provided with cylindrical protrusions corresponding to each through hole, and the cylindrical protrusions of the insulating plate are fitted into the through holes of the heat dissipation member to attach the mounting piece for the semiconductor element. abutting,
The present invention is characterized in that a bolt is inserted through a bush into the hole of the mounting piece and the cylindrical projection of the insulating plate and fixed thereto. The present invention will be explained below using the drawings.

FIG. 2 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 3 is an exploded perspective view thereof. Reference numeral 21 denotes a heat dissipating member made of, for example, aluminum and having a cross section shaped like a Japanese letter, and its side wall 2
2 and 22a are provided with through holes 23 and 23a at positions facing each other at a predetermined interval. Reference numeral 24 denotes an insulating plate with good thermal conductivity, and cylindrical projections 25 are formed at positions corresponding to the through holes 23 of the heat dissipating member 21 to fit into the through holes 23, respectively. In this embodiment, the insulating plate 24 is made of, for example, a material called Cervon (trade name), which is made of silicone rubber mixed with metal powder.

In the present invention as described above, the heat dissipation member 21
The cylindrical protrusions 25 of the insulating plate 24 are fitted into the through holes 23 of the
The power transistor 8 is fixed through the heat dissipating member 21, the lower surface of the heat dissipating member 21 is fixed to the printed board 14, and the cover plate 15 is attached to the upper surface.

In the above embodiment, a case is shown in which a heat dissipating member in the shape of a Japanese letter is used, but it may be made in the shape of an opening letter. Furthermore, although the case where the power transistors are attached to both sides of the heat dissipation member has been shown, it goes without saying that the power transistors may be attached only to one side. The shapes of other parts are not limited to the above embodiments, and can be changed as appropriate without departing from the gist of the present invention.

As is clear from the above description, according to the present invention, the following remarkable effects can be achieved.

(1) The heat dissipation member is made into a diagonal or kuji shape to increase the heat dissipation area, and its lower and upper surfaces are attached to the printed board and cover plate.Furthermore, a material with good thermal conductivity is used for the insulating board, so the heat dissipation is improved. The effect can be greatly improved.

(2) Since the insulating plate is provided with a cylindrical protrusion that fits into the through hole of the heat dissipation member, the dielectric strength is improved and there is no risk of dielectric breakdown.

(3) Since the heat dissipation member is configured in a diagonal or square shape, there is no risk of deformation even if the screws are strongly tightened.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing an example of a conventional power transistor mounting device, FIG. 2 is a vertical sectional view of an embodiment of the present invention, and FIG. 3 is an exploded perspective view thereof. 8...Power transistor, 9...Mounting piece, 1
2... Bolt, 13... Button, 14... Printed board, 15... Lid plate, 21... Heat radiation member, 24
...Insulating plate, 25...Cylindrical projection.

Claims (1)

[Scope of utility model registration request] A heat dissipating member having a cross-section with a diagonal shape or an opening shape, which is formed by providing a plurality of through holes at opposing positions on both side walls, and an insulation with good heat conduction, which has cylindrical projections corresponding to each of the through holes. The cylindrical protrusions of the insulating plate are fitted into the through holes of the heat dissipation member to abut the mounting pieces of the semiconductor element, and the holes of the mounting pieces are connected to the cylindrical shape of the insulating plate through the bushes. A mounting device for semiconductor devices that is secured by inserting bolts into protrusions.