JPH0143904Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a case structure for electronic components used in automobiles and the like.

[Conventional technology]

Conventionally, among the electronic components used in automobiles and other vehicles that have severe environmental resistance conditions, those that are installed in the engine compartment, which is subject to particularly harsh conditions, have been highly reliable with respect to conditions such as vibration resistance, shock resistance, and heat cycle resistance. flexibility and performance are required. As a package method that satisfies these requirements, a case structure for electronic components using a simple and inexpensive screw fastening method is adopted.

Hereinafter, a conventional example of a case structure for an electronic component as described above will be explained based on the drawings.

FIG. 3 is a side sectional view showing the case structure of a conventional electronic component, in which 1 is a thick film substrate, 2 is an electronic component 3 such as a transistor arranged on the thick film substrate 1, and an electronic component 3, such as a transistor mounted on the thick film substrate 1, A heat sink that radiates heat generated by the component 2; 4 is a frame integrally molded with the terminal 5 using thermoplastic resin; 6 is a lead wire electrically connecting the terminal 5 and the thick film substrate 1; 7 is a heat sink 3 is a screw that fastens the frame 4, 8 is a filler such as silicone gel filled inside the frame 4 to protect the internal parts of the frame 4, and 9 is a cover for the frame 4 molded from thermoplastic resin. , 10 are ultrasonic welding margins formed inside the cover 9 to have a triangular cross-section, and are formed so as to abut the entire upper circumference of the opening of the frame 4.

In the conventional example with the above configuration, the thick film substrate 1 with the electronic component 2 attached is mounted on the heat sink 3, and the heat sink 3 is mounted on the heat sink 3.
and the frame 4 are fastened together with screws 7, and after filling the frame 4 with a filler 8, the cover 9 is attached to the frame 4 by melting the ultrasonic welding margin 10 of the cover 9 by ultrasonic welding.

[Problem that the invention attempts to solve]

However, with the structure described above, the screws 7 may loosen due to vibrations, shocks, etc. during use of the case, and as a countermeasure, various methods such as applying a screw locking agent or using parts such as special washers may be used. It became necessary to take measures to prevent loosening of the
This caused the problem of high costs.

The present invention provides an inexpensive and highly reliable way to prevent the screw 7 from loosening without applying a thread locking agent or using various loosening prevention parts.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention extends a cover made of thermoplastic resin to cover the head of the screw that connects the heat sink and the frame, and extends it beyond the ultrasonic welding area between the heat sink and the frame. The means is to provide a protruding ultrasonic welding margin that comes into contact with the head of the screw.

[Effect]

According to the above-described means, one ultrasonic welding portion of the cover is ultrasonically welded to the frame, and the other ultrasonic welding portion of the cover is welded to the head of the screw connecting the frame and the heat sink. Since the cover and the screw head can be brought into close contact with each other without any play, the cover can prevent the screw from loosening.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a sectional side view of a case structure for an electronic component according to an embodiment of the present invention, and FIG. 2 is a perspective view of essential parts showing the inside of the cover.

In Figures 1 and 2, 1 is a thick film board, 2 is an electronic component, 3 is a heat sink, 4 is a frame, 5 is a terminal, 6 is a lead wire, 7 is a screw, 8 is a filler material, 9'
Reference numeral 10 indicates a cover, and 10 indicates an ultrasonic welding margin, and since these are parts common to those of the conventional example, they are also indicated by the same reference numerals.

Reference numeral 11 denotes an ultrasonic welding margin that is formed inside a cover 9' made of thermoplastic resin to cover the screw 7 and comes into contact with the screw head 7a of the screw 7, and is shaped like a cross with a triangular cross section, for example. The shape has a small contact area with the screw head 7a and allows the ultrasonic energy to concentrate easily.

According to the embodiment described above, the cover 9' can be fixed to the frame 4' by ultrasonic welding via the ultrasonic welding margin 10, and the other ultrasonic welding margin 11 of the cover 9' can be fixed to the frame 4' by ultrasonic welding. The cover 9' and the screw head 7a can be brought into close contact with each other without play by being melted by the heat generated by the sonic vibrations. Therefore, the cover 9' can fix the screw 7 and prevent it from loosening.

[Effect of idea]

As explained above, in the present invention, a cover is provided for the frame that covers the screws that fix the heat sink and the frame, and in addition to the ultrasonic welding margin that is melted by ultrasonic welding and connected to the frame, the screws are attached to the cover by ultrasonic welding. Since we have provided an ultrasonic welding margin that contacts the head, the cover is ultrasonically welded to the frame, and the ultrasonic welding margin on the screw head is melted, making the cover and screw head in close contact with no play. Since the screws can be fixed with a cover and prevented from loosening, there is no need to apply a screw locking agent or special parts to prevent screws from loosening, which is required in the past. Since the fixing state of the casing is also good, it is effective in providing a case structure for electronic components that is inexpensive and highly reliable.

In addition, since the cover completely covers the screws, the screws will not be loosened artificially, which helps prevent accidental breakdowns, and because there is no step between the cover and the screws as in the conventional case, the appearance is improved. It is also simple and has the effect of improving the external design.

[Brief explanation of drawings]

Fig. 1 is a side sectional view of a case structure for an electronic component according to an embodiment of the present invention, Fig. 2 is a perspective view of essential parts showing the inside of the cover, and Fig. 3 is a side sectional view of a conventional case structure for an electronic component. It is a diagram. 2... Electronic parts, 3... Heat sink, 4... Frame, 7... Screw, 7a... Screw head, 8... Filler, 9... Cover, 10, 11... Ultrasonic welding allowance.

Claims (1)

[Scope of utility model registration request] A frame made of thermoplastic resin containing a filler to protect the electronic components is fixed to the heat dissipation plate on which the electronic components are mounted using screws, and the cover is made of thermoplastic resin with an ultrasonic welding margin that allows ultrasonic welding. In the case structure of the electronic component that seals the frame, the side part of the cover is extended to cover the upper part of the screw, and an ultrasonic welding margin is formed on the inside of the cover to abut the head of the screw. A case structure for electronic components that is characterized by: