JPH07235781A - Printed substrate mount device - Google Patents

Abstract

PURPOSE:To provide a printed substrate mount device which can commonly use a fixing metal part for fixing a printed substrate to a chassis as a heat sink of a semiconductor element regarding a printed substrate mount device used for various electronic devices. CONSTITUTION:A power transistor 16 is screwed to a side surface 21B of a U-shaped fixing metal part 21 and the fixing metal part 21 is mounted to a printed substrate. A printed substrate is mounted to a chassis at a specified interval by screwing a machine screw inserted to a hole of a chassis to a screw hole 29 of the fixing metal part 21. Heat generated in the power transistor 16 is dissipated by the fixing metal part 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board mounting device for use in electronic equipment such as a car audio system.

[0002]

2. Description of the Related Art FIG. 3 shows a part of a conventional vehicle audio system. In FIG. 3, reference numeral 1 denotes a chassis that constitutes a part of a box-shaped chassis of an in-vehicle audio device, and the chassis 1 is formed by bending a metal plate. 2 and 3 are connector holes formed in the chassis 1, and 4 and 5 are small screw holes formed at the edges of the connector holes 2 and 3. Reference numeral 6 is a printed circuit board, and various electronic components (not shown) are soldered to the surface 7 of the printed circuit board 6. Reference numeral 8 denotes a printed board, which is attached to the lower end of the printed board 6 via a connector (not shown). Reference numerals 9 and 10 denote connectors fixed to the printed circuit board 8. Reference numeral 11 denotes a fixing metal member formed by bending a metal plate into a substantially U-shape. The fixing metal members 11 are provided at the lower ends of the side surfaces 12A and 12B. As shown in FIG. 4, the protrusions 13A and 13B are integrally formed. Reference numeral 14 denotes a screw hole formed in the upper surface portion 12C of the fixing metal fitting 11. The fixing bracket 11 has a protrusion 1
3A and 13B are inserted into the small holes 15A and 15B of the printed circuit board 6, and then the projections 13A and 13B are bent and soldered on the back surface of the printed circuit board 6 to be fixed to the printed circuit board 6. Reference numeral 16 is a power transistor, and the terminal of this power transistor 16 is soldered to the printed board 6. Reference numeral 17 denotes a radiator plate attached near the power transistor 16 on the printed circuit board 6, and the power transistor 16 is screwed to the radiator plate 17. The heat generated in the power transistor 16 is transferred to the heat dissipation plate 17 and dissipated.

As shown in FIG. 3, when the printed circuit board 6 on which the fixing metal fitting 11, the power transistor 16, the heat sink 17, and other electronic parts are mounted is fixed to the chassis 1, the upper surface of the fixing metal fitting 11 is fixed. 12C is brought close to the back surface of the chassis 1 and the screw 19 inserted into the small hole 18 of the chassis 1 is screwed into the screw hole 14 of the fixing metal fitting 11 and further inserted into the small hole of the printed circuit board 6. 20
A and 20B are fixed by being screwed into screw holes of a cut and raised piece (not shown) formed on the back surface of the chassis 1. In this way, by using the fixing metal fitting 11, the printed circuit board 6 can be fixed by being separated from the chassis 1 by a certain distance so that the electronic components mounted on the printed circuit board 6 do not come into contact with the chassis 1.

[0004]

As described above, the above-mentioned conventional printed circuit board mounting device has the power transistor 1
In order to dissipate the heat generated at 6, the heat dissipation plate 17 must be attached to the printed circuit board 6, resulting in an increase in the number of parts and an increase in the number of assembly steps.

The present invention eliminates the above-mentioned conventional problems, and provides a printed circuit board mounting device which has a small number of parts and is easy to assemble.

[0006]

The first invention of the present invention is as follows:
In order to achieve the above-mentioned object, it is provided with a fixing metal fitting which is bent into a U shape and whose end is attached to a printed circuit board, and a semiconductor element which is attached to a side surface of the fixing metal fitting.
The printed circuit board is fixed to the chassis by screwing the upper surface of the fixing metal member to the chassis.

A second aspect of the present invention is that the opposing pieces on the side surfaces of the fixing fitting are bent outward to form a bent piece, and the semiconductor element is positioned by this bent piece. It is a feature.

[0008]

In accordance with the first aspect of the present invention, the upper surface of the fixing metal fitting fixed to the printed circuit board is screwed to the chassis to fix the printed circuit board to the chassis. Can be fixed at a predetermined distance from, and the fixing metal fitting can also serve as a heat dissipation plate of the semiconductor element.

According to the second aspect of the present invention, the position of the semiconductor element fixed to the side surface of the fixing metal fitting can be regulated by the bent piece formed on the side surface of the fixing metal fitting.
This has an advantage that the semiconductor element can be easily and surely attached.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be explained together. FIG. 1 shows a printed circuit board mounting device of the present invention, and FIG. 2 shows a fixing metal fitting used in the device. 1 and 2, the same parts as those in the conventional example shown in FIGS. 3 and 4 are designated by the same reference numerals. Figure 1,
In FIG. 2, reference numeral 21 denotes a fixing metal member formed by bending a metal plate into a substantially U-shape. At the lower ends of the side surfaces 21A and 21B of the fixing metal member 21, as shown in FIG.
2A and 22B are integrally formed. 23A, 23B
Is a bent piece formed by bending both side pieces of the side surface 21B of the fixing metal fitting 21 outward, and 24 is a screw hole formed in the side surface 21B. Reference numeral 16 is a power transistor having a rectangular shape, and the power transistor 16 is attached to the side surface 21B of the fixing metal fitting 21 with a screw 25. The bent piece 2
Since the distance between 3A and 23B is slightly wider than the width of the power transistor 16, the power transistor 1
When 6 is screwed to the side surface 21B of the fixing metal fitting 21,
The power transistor 16 does not rotate,
The power transistor 16 is a side surface 21B of the fixing bracket 21.
Has the advantage of being positioned at.

When the fixing metal fitting 21 having the power transistor 16 fixed to the side surface 21B is attached to the printed circuit board 6, the protrusions 22A and 22B of the fixing metal fitting 21 are inserted into the small holes 26A and 26B of the printed circuit board 6 and fixed. The terminals 27 of the power transistor 16 attached to the side surface 21B of the metal fitting 21 are inserted into the small holes 28 of the printed circuit board 6, and the projections 22A, 22 protruding on the back surface of the printed circuit board 6 are inserted.
After B is bent, the protrusions 22A and 22B are soldered to the land formed on the back surface of the printed circuit board 6, and the terminals 27 of the power transistor 16 and the land formed on the back surface of the printed circuit board 6 are also soldered. To do.

When the printed circuit board 6 to which the fixing metal fittings 21 are attached is attached to the chassis 1 as described above,
Bring the printed circuit board 6 close to the chassis 1
1 and the screw hole 29 formed in the upper surface portion 21C of the chassis 1
The screw 19 inserted into the hole 18 is screwed into the screw hole 29 of the fixing member 21.

As described above, in the above embodiment, the power transistor 16 is fixed to the side surface 21B of the fixing metal fitting 21, and the fixing metal fitting 21 is also used as the heat dissipation plate of the power transistor 16. Since there is no need to attach a separate heat dissipation plate 17 to the printed circuit board 6 separately, the number of parts can be reduced and the number of assembling steps can be reduced. Although the fixing metal fitting 21 is used as the heat dissipation plate of the power transistor 16 in the above-described embodiment, the fixing metal fitting 21 is not limited to the power transistor and may radiate heat from a semiconductor element that requires heat radiation. If so, the present invention is useful.

[0014]

The present invention has the above-mentioned structure. According to the present invention, the fixing metal fitting for fixing the printed circuit board to the chassis can also be used as the heat radiating plate of the semiconductor element. Since it is not necessary to attach the plate to the printed board, the number of parts can be reduced and the number of assembling steps can be reduced. Further, according to the second aspect of the present invention, since the bent piece is formed on the side surface of the fixing metal piece, there is an advantage that the semiconductor element mounted on the side surface of the fixing metal piece can be positioned by the bent piece. Is.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a printed circuit board mounting device according to an embodiment of the present invention.

FIG. 2 is a perspective view of a fixing bracket in the same embodiment.

FIG. 3 is an exploded perspective view of a conventional printed circuit board mounting device.

FIG. 4 is a perspective view of a fixing bracket of the conventional example.

[Explanation of symbols]

 1 Chassis 6 Printed Circuit Board 16 Power Transistor 21 Fixing Hardware 21A, 21B Side 21C Upper Surface 22A, 22B Protrusion 23A, 23B Bending Piece 24 Screw Hole 29 Screw Hole

Claims (2)

[Claims] 1. An upper surface of the fixing metal fitting, comprising: a fixing metal fitting bent at a U-shape and having an end attached to a printed circuit board; and a semiconductor element mounted on a side surface of the fixing metal fitting. A printed circuit board mounting device in which the above-mentioned printed circuit board is fixed to the chassis by screwing a part to the chassis. 2. The printed circuit board mounting device according to claim 1, wherein the opposing pieces on the side surfaces of the fixing member are bent outward to form a bent piece, and the semiconductor element is positioned by the bent piece.