JPS5834760Y2 - Printed circuit board mounting device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a printed circuit board mounting device, and particularly aims to efficiently dissipate heat from heat generating components mounted on a printed circuit board.

Conventionally, when dissipating heat from heat-generating components such as power amplification transistors, the heat-generating components were separated from the printed circuit board and attached to a dedicated heat sink, as seen in power amplifiers, or the metal outer case of the amplifier was used. This was done when it was installed in this case.

However, in this configuration, only the heat generating components must be assembled separately from the printed circuit board, which increases the number of man-hours and is not suitable for mass production.Therefore, conventionally, the heat generating components and their heat sinks are attached to the printed circuit board together for assembly work. Efforts are also being made to make it easier.

For example, as seen in the power amplification stage in the audio amplification circuit of a portable radio receiver or the power amplification stage in the transmission circuit of a portable transceiver, a heat radiator is fitted to the power amplification transistor itself, which is a heat generating component. structure to wear.

Alternatively, a heat sink is screwed onto a printed circuit board, and a power amplification transistor is mounted on the heat sink.

However, this structure has the drawback that the size of the heat sink cannot be increased too much due to the space on the printed circuit board, making it difficult to obtain a sufficient heat dissipation effect.

Therefore, in order to solve this drawback, the first thing that can be considered is to attach the heat sink to a separately provided relatively large metal plate, and try to dissipate the heat that does not escape from the heat sink to the outside through the metal plate. That's true.

However, when adopting such a structure, unless the heat dissipation plate and the metal plate are properly connected, a problem arises in that heat transfer is not performed well and a sufficient heat dissipation effect cannot be obtained.

The present invention solves such problems by fixing a part of the heat sink attached to the printed circuit board to a metal chassis and using the metal chassis to dissipate heat from the heat generating components. To provide a printed circuit board mounting device in which a fixed part of a metal chassis is always in close contact with a fixed part of the metal chassis, and heat conduction from a heat sink to the metal chassis is performed well.

That is, the present invention has one end of a heat sink attached to a printed circuit board protrude horizontally from one side edge of the printed circuit board,
One end of the heat sink is fixed to a metal chassis, and one side edge of the printed circuit board is attached to an elastic member for mounting a printed circuit board provided on the metal chassis and protruding horizontally from one side edge of the metal chassis. The other side edge of the printed circuit board is attached to the base.

In this way, the heat of the heat-generating components attached closely to the heat sink can be efficiently dissipated by both the heat sink and the metal chassis, and moreover, when the printed circuit board is subjected to external vibrations, etc. Since the elastic member for placing the printed circuit board always works to restore the printed circuit board to its original position, the fixed parts of the heat sink and metal chassis are less likely to be separated due to external vibrations, etc., and as a result, the printed circuit board is always in good condition. It is possible to perform a good heat conduction.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIGS. 1 and 2, a printed circuit board 2 is arranged parallel to a horizontal base 1, and on the top surface of this printed circuit board 2,
A heat generating component 3 such as an integrated circuit is attached by soldering.

Reference numeral 4 denotes a heat sink having a recess 4a that covers the heat generating component 3 in part. It is attached to the upper surface of the printed circuit board 2 with screws 5 in a horizontally protruding state.

Then, by tightening the screws 5, the inner surface of the recess 4a is brought into close contact with the surface of the heat generating component 3, so that the heat of the heat generating component 3 is transmitted to the heat radiating plate 4.

The other side edge 2b of the printed circuit board 2 is attached to the base 1 with screws 7 via spacers 6.

A metal chassis 8 is arranged horizontally on the same plane as the printed circuit board 2, and is attached to the base 1 at several points around the chassis with screws 10 via spacers 9.

One end 4b of the heat sink 4, which projects horizontally from one side edge 2a of the printed circuit board 2, is fixed to the upper surface of the metal chassis 8 by screws 11.

Reference numeral 12 denotes an elastic member for mounting a printed circuit board made of synthetic resin, and as shown in FIG.
It projects horizontally from one side edge 8a.

One side edge 2a of the printed circuit board 2 is placed on the elastic member 12 by fitting the through hole 2C provided near one side edge 2a of the printed circuit board 2 into the protrusion 12a of the elastic member 12. .

In this way, the heat of the heat-generating component 3 is transmitted to the heat sink 4 and also to the metal chassis 8 via one end 4b of the heat sink 4, and the heat is radiated from both the heat sink 4 and the metal chassis 8. be done.

Therefore, due to the space on the printed circuit board 2, the heat sink 4
Even if it is not possible to increase the heat dissipation effect, a sufficient heat dissipation effect can be obtained.

By the way, if one end 4b of the heat sink 4 is only fixed to the metal chassis 8, when the printed circuit board 2 receives external vibrations, bending force is applied to the heat sink 4 itself, causing the heat sink 4 to bend.
There is a problem in that the degree of adhesion between one end 4b of the metal chassis 8 and the fixed portion of the metal chassis 8 deteriorates, resulting in a decrease in heat conduction, and as a result, a sufficient heat dissipation effect cannot be obtained.

However, if one side edge 2a of the printed circuit board 2 is placed on the elastic member 12 as in this embodiment, even if external vibration etc. are applied to the printed circuit board 2, the elasticity of the elastic member 12 will always keep the printed circuit board 2 Since it is urged to be restored to its original position, one end 4a of the heat sink 4 and the fixed portion of the metal chassis 8 are always in close contact with each other, and as a result, a decrease in heat conduction can be suppressed.

FIG. 3 shows an example in which the present invention is applied to a record player, and parts having the same functions as those in FIGS. 1 and 2 are given the same reference numerals.

In FIG. 3, a player case 13 is constructed by connecting an upper case 14 and a lower case 15 to each other at their peripheral edges.

The base 1 is constituted by the bottom surface of the lower case 15.

On this base 1 is a power transformer 16 and a metal chassis 8.
, a printed circuit board 2, etc. are fixed.

The metal chassis 8 is securely screwed to the base 1 via spacers 9 placed at four locations on its lower surface.
On this metal chassis 8 is a turntable 17 on the left side.
A pickup base 20 that supports the pickup arm 19 is attached to the right side.
are attached to the upper and lower sides of the metal chassis 8, and large gears 21. A drive plate 22 is reciprocated by a cam groove provided on the large gear 21, and the reciprocating movement of this drive plate brings the pickup arm 19 from the pedestal position to the performance start position, and from the performance position to the pedestal position. An automatic performance mechanism consisting of a plurality of components has been assembled to restore the performance.

On the other hand, the printed circuit board 2 is screwed to the base 1 via a spacer 6 arranged on the lower surface thereof, and a heat generating component 3 is mounted on the printed circuit board 2 near one side edge 2a. A rotational speed switching switch 23 and a variable resistor 24 for finely adjusting the rotational speed are attached near the other side edge 2b.

A recess 4a of a heat sink 4 is in close contact with the outer surface of the heat generating component 3, and the heat sink 4 is fixed to the printed circuit board 2 with screws.

One end 4b of the heat sink 2 is connected to one side edge 2a of the printed circuit board 2.
It projects horizontally from the metal chassis 8 and is fixed to the metal chassis 8 with screws.

In this example, the heat sink 4 has an L-shaped arm portion 4C, and this arm portion 4C has a transistor 2 which is a heat generating component.
5 is secured with a screw.

In this way, the heat of the heat generating parts 3 and 25 is transferred to the heat sink 4.
Since the heat is conducted to the metal chassis 8 and radiated from both the heat sink 4 and the metal chassis 8, a sufficient heat radiation effect can be obtained.

In FIG. 3, the broken edges in FIGS. 1 and 2 are indicated by dashed dot lines II and II-II, respectively.

Furthermore, the present invention is not limited to record players as shown in FIG. 3, but can be applied to any electrical equipment that uses heat-generating parts.

As described above, in the present invention, one end of a heat sink attached to a printed circuit board projects horizontally from one side edge of the printed circuit board, one end of the heat sink is fixed to a metal chassis, and one end of the heat sink attached to a printed circuit board is fixed to a metal chassis. A side edge of the printed circuit board is placed on an elastic member for mounting a printed circuit board that is provided on a metal chassis and projects horizontally from one side edge of the metal chassis, and the other side edge of the printed circuit board is attached to a base. In other words, the heat of the heat generating components attached closely to the heat sink can be efficiently dissipated by both the heat sink and the metal chassis.

Furthermore, when the printed circuit board is subjected to external vibrations, etc., the elastic member for mounting the printed circuit board always acts to restore the printed circuit board to its original position, so that the fixed part of the heat sink and the metal chassis is protected against external vibrations. As a result, good heat conduction can be achieved at all times.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of the present invention, FIG. 2 is a cross-sectional view of its essential parts, and FIG. 3 is a partially cutaway top view of an applied example of the present invention. 1...Base, 2...Printed circuit board, 2
a...-side edge, 2b...other side edge, 3.
... Heat generating parts, 4 ... Heat sink, 4b ...
...One end, 8...Metal chassis, 12.
...Elastic member for mounting printed circuit boards.

Claims (1)

[Scope of utility model registration request] One end of a heat sink attached to a printed circuit board projects horizontally from one side edge of the printed circuit board, one end of the heat sink is fixed to a metal chassis, and one side edge of the printed circuit board is provided on the metal chassis. A printed circuit board mounting device in which the printed circuit board is mounted on an elastic member for mounting a printed circuit board which projects horizontally from one side edge of the metal chassis, and the other side edge of the printed circuit board is attached to a base.