JPH0266989A - Metal-cored printed wiring board - Google Patents

Abstract

PURPOSE:To obtain a necessary heat dissipation property by providing a heat radiating recess part wherein a core metal which connects the core metal of a metal-core printed wiring board and a heat dissipation material through a screw and the like having good heat conductivity, and providing a through hole formed in said recess part. CONSTITUTION:A heat dissipation recess part 30 which is larger than the diameter of the collor of an attaching screw 50 is formed in a metal-core printed wiring board 100. Thereafter, an inserting hole 35 for the attaching screw 50 is formed at a specified position. Then the metal-core printed wiring board 100 is cut into specified sizes by using a metal mold. An electronic part 40 is mounted. The attaching screw 50 is inserted into the screw inserting hole 35. A thread is formed at the specified position of an aluminum fin 36 of the heat dissipation material. The screw is fixed to the fin 36. The heat generated in the electronic part 40 is dissipated to, e.g., the entire supporting case of the metal-core printed wiring board. which is the heat dissipation material 36, by way of the metal-core printed wiring board 100, the heat dissipation recess part 30, and the screw 50 having the good heat conductivity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a metal core printed wiring board on which high heat generating electronic components such as power transistors are mounted by soldering or the like on the upper surface side.

[Background Art] With the recent development of electronic circuit technology, the degree of integration of electronic components such as so-called semiconductor devices has become considerably high. For this reason, various electronic devices are being installed in automobiles, industrial equipment, etc., and the operation of electronic parts is also becoming higher output. In particular, with regard to power ICs, in addition to increasing the output of the IC itself, 5 power ICs, MOS-FETs, etc. are also incorporated into hybrid ICs, and those having output circuits using electronic components are used. However, as mentioned above, high-output, highly integrated electronic components have recently been developed, and in order to provide high-load driving capability to directly drive motors, etc.
Large amounts of power are being consumed per unit area.

For this reason, printed wiring boards mounted with power IC and MOS-FET transistors are required to efficiently dissipate heat generated from electronic components. but.

Conventional printed wiring boards have not been able to fully meet these demands. For this reason, the use of a metal core printed wiring board such as an aluminum core with good thermal conductivity was considered.

However, even if a metal core printed wiring board is used, most of the heat dissipation from the metal core printed wiring board is through heat radiation from the surface and heat conduction to the support of the metal core printed wiring board, and glass-epoxy etc. It just has better thermal conductivity than printed wiring boards. Therefore, for devices that require efficient heat dissipation, it has not been possible to sufficiently meet the requirements simply by uniformly heating the metal core printed wiring board.

[Problems to be Solved by the Invention] This invention was made due to one or more reasons, and the problem to be solved is the lack of heat dissipation in the conventional technology for mounting electronic components.

In particular, if only conventional metal core printed wiring boards are used, the effect of using the core metal cannot be fully demonstrated by simply dissipating heat from the high heat generation electronic components on the component surface to the metal core printed wiring boards. The problem was that it couldn't be done.

The object of the present invention is to provide a metal core printed wiring board for high heat generation electronic components that has a simple configuration, can sufficiently utilize and develop conventional technology, and can obtain the necessary heat dissipation performance. Our goal is to provide the following.

[Means for solving the problems] The means taken by this invention to solve the above problems are as follows.
To explain with reference to FIGS. 1 and 2 corresponding to the embodiment, [In a metal core printed wiring board on which electronic components are mounted by soldering or the like on the surface, the core metal of the metal core printed wiring board and the It is characterized by having a heat dissipation recess exposed in the core metal that connects the heat dissipation material attached to the metal core printed wiring board via a screw or the like having good heat conduction, and a through hole formed in the recess. This is a metal core printed wiring board J.

Next, the present invention will be explained in detail based on the drawings.

FIG. 1 shows a metal core printed wiring board (1) according to the present invention.
00) with an electronic component (40) mounted thereon, and this metal core printed wiring board <100) is
The insulating layer (10), core metal (20), electronic component (40), heat dissipation recess (30), screw insertion hole (35), and mounting screw (50) shown in FIG. ) and a heat dissipating material (36). Figure 2(d),
(e) and (f) are partially enlarged vertical cross-sectional views of FIG. 1; Here, the installation is performed by attaching the four heat dissipating parts (30) formed by penetrating the insulating layer (10) to the heat dissipating material (36) on the screws (50).
) are in close contact and thermally connected, and the heat generated by the electronic component (40) mounted on the metal core printed wiring board (100) is absorbed by the heat dissipating material (36).For example, the metal core printed wiring board Heat is dissipated from the entire support case.

[Function] This invention has the following effects by taking the above measures.

That is, the metal core printed wiring board (1) according to the present invention
00), electronic components (40
) The heat generated in the metal core printed wiring board (100),
Heat is radiated to the entire heat radiating material (36), for example, a metal core printed wiring board support case, through the heat radiating recess (30) and the screw (50) with good heat conduction. In this way, the metal core printed wiring board (1
00) can be manufactured.

[Example] Next, the present invention will be described in detail based on an example shown in the drawings.

Example 1 A metal core printed wiring board (100N, Fig. 2 (a)) was mounted by performing counterbore processing using a cutting tool having a diameter 1 mm larger than the collar diameter of the screw (50).

A heat dissipation recess (30) is formed (FIG. 2(b)). Then, install the screw (50) into the insertion hole (
35) using a drill with a diameter of 5 mm (see Figure 2 (C)
), then this metal core printed wiring board (100) is cut into a desired size using a mold.

After mounting the electronic component (40), the screw insertion hole (3) is inserted.
5) For installation, screws (50) were inserted and the aluminum fins (36) of the heat dissipation material were threaded at predetermined positions to fix them (Fig. 2(d)).

Example 2 In FIG. 2(b), when forming the heat dissipation recess (30), a second hole was installed at a predetermined position using a drill having a diameter 1 mm larger than the diameter of the flange of the heat dissipation screw (50). The process is the same as in Example 1 except that the hole having the shape shown in Figure (e) is formed.

Implementation fM3 As shown in Fig. 2 (f>), the heat dissipation material (36) is attached to the metal core printed wiring board (100) (Fig. 2 (a)
This is the same as in Example 2 except that a heat dissipation recess (30) (FIG. 2(f)) is also provided on the back surface of the second embodiment.

When the heat dissipation characteristics of the metal core printed wiring board thus prepared were measured, Example 3 was the best, followed by Example 2. The order was that of Example 1.

[Effects of the Invention] As detailed above, the metal core printed wiring board (100) according to the present invention is as shown in the above embodiments.

"In metal core printed wiring boards that have electronic components mounted on the surface by soldering etc.

The core metal of this metal core printed wiring board and the heat radiation material attached to this metal core printed wiring board are connected through screws etc. with good heat conduction, and the four exposed heat radiation parts of the core metal are formed in the recesses. A metal core printed wiring board characterized by having a through hole. '' is characterized by its structure, which makes it possible to fully utilize and develop conventional technology with a simple structure, and also to obtain the necessary heat dissipation performance.
) can be provided.

In addition, the insulating layer needs to be made thinner in order to improve heat dissipation, but if this is done, the wiring capacity increases due to the influence of the core metal, making metal core printed wiring unsuitable for high frequency band electronic circuits. Become a board.

However, if the present invention is adopted, a metal core printed wiring board with good heat dissipation properties suitable for high frequency band electronic circuits, such as microprocessors, can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a metal core printed wiring board according to the present invention in which electronic components are mounted, and FIGS. 2(a) to (f)
) is a partially enlarged longitudinal sectional view schematically showing the structure of this metal core printed wiring board. In the figure, <10)... Insulating layer, (20)... Core metal, (30)... Heat radiation recess, (35)... Screw insertion hole, (36)... Heat radiation material. , (40)...Electronic parts, (50)...Screws for storage, (100)...
Figure 2

Claims (1)

[Claims] In a metal core printed wiring board on which electronic components are mounted by soldering or the like on the surface, the core metal of this metal core printed wiring board and the heat dissipation material attached to this metal core printed wiring board are connected by screws etc. with good heat conduction. A metal core printed wiring board characterized in that it has a heat dissipation recess exposed in the core metal and a through hole formed in the recess.