JPH03177095A - Method of dissipating heat of electronic component - Google Patents

Abstract

PURPOSE:To make it possible to radiate the heat generated from electronic components from both sides of a printed board by mounting a first heat transfer section with a printed board so that it may be brought into contact with a package of electronic component and installing a second heat transfer section which is in thermal contact with the first heat transfer section at the position where both the heat transfer sections face each other. CONSTITUTION:A first heat transfer section 1, which is in contact with the package surface of electronic component 4, is inserted into a mounting hole of a printed board, and soldered with a conductor pattern by solder 6. In contrast, a second heat transfer section 2 is inserted into a mounting hole of the printed board 3 from the surface opposite to the surface where the electronic component 4 is mounted thereon and soldered with a conductor pattern 7 by solder 6. The generated heat of an internal chip is partially transferred to a lead 5 while it is partially conveyed to the package of the electronic component 4. This heat is transferred to the first heating element section 1. The heat is further transferred to the second heat transfer section 2 by way of the solder 6 and the conductor pattern 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat dissipation method for electronic components mounted on a printed circuit board, and a printed circuit board assembly that uses the heat dissipation method for electronic components.

[Conventional technology]

Conventionally, the heat dissipated by electronic components mounted on a printed circuit board has been reduced by reducing the mounting density of electronic components when there is sufficient mounting area, and creating more space between the printed circuit board and the casing that stores the printed circuit board. This was done using natural air cooling. Recent electronic devices are becoming smaller, and the density of electronic components mounted on printed circuit boards is also increasing.
The space between the housing and printed circuit board has become smaller, making it no longer possible to use natural air cooling. In this case, a heat sink is attached to the electronic component or forced cooling is performed using a fan. - The heat sink inside the shell is attached to the pancage surface of the electronic component, but the space on the electronic component mounting surface of the printed circuit board is
If it is restricted by other printed circuit boards, casings, etc., the heat dissipation effect of the heat sink may not be sufficiently achieved.

In such a case.

I would like to install a heat sink on the solder side of the printed circuit board to expand the heat dissipation area and obtain a sufficient heat dissipation effect. An example of this is the method described in Japanese Unexamined Patent Publication No. 128900/1983. In this method, a heat sink is attached to the lead of an electronic component protruding from the solder side of a printed circuit board, and is inserted into the lead and comes into elastic contact with the lead.

[Problem to be solved by the invention]

The above conventional technology targets electronic components such as DiP (dual in-line package) type electronic components in which leads protrude from the solder side of a printed circuit board as an electronic component to which a heat sink is attached. There was a problem that it could not be used for multi-terminal flat package type electronic components.

An object of the present invention is to provide a heat radiation method for radiating heat generated from an electronic component from both sides of a printed circuit board, regardless of the shape of the electronic component. Yet another object is to provide a printed circuit board assembly having electronic components using the heat dissipation method described above.

[Means to solve the problem]

In order to achieve the above object, a first heat transfer member is attached to the printed circuit board so as to contact the package of the electronic component from the component side of the printed circuit board as a heat sink for the electronic component, and A second heat transfer member is installed at a position facing the first heat transfer member and thermally connected to the first heat transfer member.

In addition, in order to achieve the above-mentioned other object, at least one electronic component of the printer 1 to board assembly is provided with a heat dissipation plate of the above-mentioned set.

[Effect]

This will be explained using FIG. On the surface of the printed circuit board 3,
A four-body pattern 7.7α is printed.

The leads 5 of the electronic component 4 are soldered to the conductor pattern 7o with solder 6 (l).The heat transfer member 1 is in contact with the package surface of the electronic component 4, and the printed circuit board 3 is attached through the hole. The second heat transfer member 2 is inserted into the hole and is soldered to the conductor pattern 7 with solder 6. It is pushed in and soldered to the conductor pattern 7 with solder 6.

With the above configuration, the heat generated in the internal chip is transferred to the package of the electronic component 4 by the predetermined operation of the electronic component 4. This heat is
The heat is transferred to the first heat transfer member 1, which is a good conductor of heat and is in contact with the package of the electronic component 4. Further, the heat transferred to the first heat transfer member 1 is transferred to the solder 6 and the conductor pattern 7, and is further transferred to the second heat transfer member 2 soldered to the conductor pattern 7, and finally to the second heat transfer member 2 soldered to the conductor pattern 7. Heat is dissipated into the air around the first heat transfer member 1 and the second heat transfer member 2.

Due to the above-described effects, heat generated from the electronic components can be radiated from both sides of the printed circuit board.

In FIG. 1, the first heat transfer member l and the second heat transfer member 2 are thermally connected by solder 6 and conductor pattern 7, but as shown in FIG. You can.

〔Example〕

A first embodiment of the present invention will be described below with reference to FIGS. 3 and 4. FIG. 3 shows a sectional view of this embodiment, and FIG. 4 shows a perspective view.

On the surface of the printed circuit board 3, a pattern 7° 7α is printed. Lead 5 of electronic component 4 is soldered 6α
It is soldered to the conductor pattern 7 at .

The electronic component 4 is an NMO8 type microprocessor that generates a large amount of heat. The first heat transfer member 1 is inserted into a hole for mounting a printed circuit board 3 while being in contact with the surface of a package of an electronic component 4, and is soldered to a conductor pattern with solder 6. Here, when bringing the first heat transfer member 1 into contact with the package surface of the electronic component 4, silicone grease 9 or the like may be applied in order to efficiently conduct heat. The second heat transfer member 2 is inserted into the hole for mounting the printed circuit board 3 from the side opposite to the side on which the electronic components 4 are mounted, and is soldered to the conductor pattern 7 with solder 6. In this example, the shape of the second heat transfer member 2 is wavy so that the surface area can be increased. Moreover, the first heat transfer member 1. Second heat transfer member 2
The material is preferably aluminum or the like, which has good heat conductivity.

In the above configuration, the heat generated in the internal chip is partially transferred to the leads 5 and partially to the package of the electronic component 4 due to the predetermined operation of the electronic component 4 . This heat is caused by silicone grease 9
and is transmitted to the first heat transfer member l, which is a good conductor of heat.

Further, the heat is transmitted to the solder 6 and the conductor pattern 7, and then to the second heat transfer member 2. Finally, the heat is dissipated into the surrounding air from the ↓th heat transfer member 1 and the second heat transfer member 2, and as a result, the heat generated by the electronic component 4 is effectively radiated.

Next, a second embodiment is shown in FIG. Figure 5 is.

A sectional view of this example is shown.

The difference between the first embodiment and the second embodiment described above is the difference in the method of connecting the first heat transfer member 1 and the second heat transfer member 2. In FIG. 5, the ↓th heat transfer member 1 is attached to a through hole formed from a Ji7 conductor pattern 7 in a multilayer printed circuit board 3, and is soldered with solder 6. Similarly, the second heat transfer member 2 is also attached to the through hole from the opposite side to the first heat transfer member 1 and soldered with solder 6.

In the above configuration, heat generated from the electronic component 4 is first transmitted to the first heat transfer member 1 as described in the first embodiment. After that, the inner layer conductor pattern 7 of the multilayer printed circuit board 3
The heat is transferred to the second heat transfer member 2 attached to the through hole. Therefore, the heat generated by the electronic component 4 can be effectively radiated from the first heat transfer member 1 and the second heat transfer member 2 attached to both sides of the multilayer printed circuit board 3. In this embodiment, since the heat generated by the electronic component 4 can also be released to the inner layer conductor pattern 7 of the multilayer printed circuit board, a more effective heat dissipation effect can be expected.

Finally, a third embodiment is shown in FIG.

A sectional view of this example is shown.

A conductive pattern 7° 7α is printed on the surface of the printed circuit board 3. The conductor pattern 7α is a pattern for the leads 5 of the electronic component 4. The conductor pattern 7 forms a through hole for attaching the heat transfer member 1, and is a pattern having an appropriate area.

Leads 5 of electronic component 4 are connected to conductor pattern 7 with solder 6α.
It is soldered to α. The heat transfer member 1 is pushed into the hole of the printed circuit board 3 while in contact with the package surface of the electronic component 4 via the silicone grease 9 (FIG. 6), and is soldered to the conductor pattern 7 with the solder 6. There is.

With the above configuration, the above-mentioned first. The second heat transfer member 2 used in the second example is not used. The conductor pattern 7 has the same function. As explained in the first and second embodiments, the heat generated from the electronic component 4 is first transmitted to the heat transfer member 1. The heat then passes through the through hole, is transferred to the conductor pattern 7, and is dissipated into the air. In this embodiment, heat can be radiated from both sides of the printed circuit board using one heat transfer member.

In the above three embodiments, if the conductor pattern 7 on the printed circuit board 3 is used as the ground or power supply pattern of the electronic circuit, the first heat transfer member 1 and the second heat transfer member 2 are connected to the ground or power supply level. and the electronic components 4 surrounded by these
Another possible advantage is that it is less susceptible to external noise.

〔Effect of the invention〕

According to the present invention, a package shape of an electronic component.

Since heat sinks can be attached to both sides of a printed circuit board with electronic components sandwiched between them, regardless of the number of pins, it is more common to attach a heat sink only to the 1st side of the printed circuit board, and more effective heat dissipation effects can be obtained. .

Furthermore, the present invention can provide a printed circuit board assembly having heat sinks on both sides of the printed circuit board.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of electronic components mounted to explain the operation of one embodiment of the present invention, FIG. 3 is a cross-sectional view of the embodiment of FIG. 1, and FIG. FIG. 5 is a perspective view of the second embodiment, and FIG. 5 is a sectional view of the second embodiment. FIG. 6 is a sectional view of the third embodiment. l...first heat transfer member, 2. second heat transfer member, 3...
・Printed circuit board, 4...electronic component, 5...lead of electronic component, 6,6cL...solder, 7.7 is ・conductor pattern of printed circuit board.

Claims (1)

[Claims] 1. A method for dissipating heat from electronic components mounted on a printed circuit board, the method comprising: a first heat transfer member attached to the printed circuit board so as to be in contact with a package of the electronic component; and the first heat transfer via the printed circuit board. a second heat transfer member installed at a position facing the member and thermally connected to the first heat transfer member;
1. A heat dissipation method for an electronic component, characterized in that heat generated by the electronic component is dissipated from both sides of a printed circuit board by providing a heat transfer member.