JPH0215700A - Printed wiring board - Google Patents

Abstract

PURPOSE:To enable the whole electronic components on a board to dissipate as much heat as possible by a method wherein a printed wiring board with a metal core and a thermal bus are jointly used, and the metal core of the printed wiring board with metal core and the thermal bus are brought into direct contact with each other. CONSTITUTION:The heat released from the lead of an electronic component 7 is conducted through a metal core 2 inside a printed wiring board 1 with a metal core, and it is dissipated to a chassis 5 conducting through a part 4 where the metal core is exposed and a joining component 6. The heat released from an electronic component 7 main body is conducted through the thermal bus 8 and transferred to the metal core 2 and dissipated from it to the chassis 5 conducting the part 4 where the thermal bus 8 and the metal core 2 are made directly contacted with each other by separating a surface insulating resin 3 from the printed wiring board 1 provided with a metal core. The thermal bus may be fitted to the chassis 5. As mentioned above, the printed wiring board 1 provided with a metal core and the thermal bus 8 are jointly employed, so that the heat released from the electronic component 7 is conducted through two heat conducting paths and consequently the printed wiring board 1 is improved in a heat dissipating property. And, as the thermal bus 8 and the metal core 2 of the printed wiring board 1 with a metal core are made directly contacted with each other near a chassis mounting part, the fitting of them to the chassis 5 can be easily made because either the printed wiring board 1 with a metal core or the thermal bus 8 may be fitted to the chassis.

Description

[Detailed description of the invention] [? I': Industrial Application Field] This invention relates to a printed wiring board that radiates heat generated from electronic components to a chassis.

[Conventional technology]

FIG. 6 is a plan view of a part of a conventional printed wiring board with a metal core attached to a chassis, and FIG. 7 is a cross-sectional view taken along the line ■--■ in FIG. In the figure, l is a printed wiring board with a metal core, 2 is a metal core therein, 3 is a surface insulating resin layer, and 4 is a part of this surface insulating resin layer 3 that is peeled off to expose the metal core 2. A portion 5 is a chassis attached to this exposed portion 4 using a connecting part 6, and 7 is an electronic component attached to the printed wiring board 1.

Figure 8 is a plan view of a conventional printed wiring board chassis installation using a board made of a material with high thermal conductivity such as FLL (hereinafter referred to as a thermal bath) that is in close contact with electronic components. , No. 9 is a front view taken along the line ■-■ in FIG. In the figure, 8 is a thermal bus, 9 is a board, and the chassis 5 is attached to one end of the thermal bus 8 by a connecting part 6.

Next, the effect will be explained. In Figures 6 and 7,
Heat generated from the electronic component 7 is transmitted from the IJ-board and the main body to the metal core 2, and then to the chassis 5 through the exposed portion 4 of the gold 4 core 2 and the connecting component 6.

Further, in FIGS. 8 and 9, heat generated from the electronic component 7 is transmitted from the main body to the thermal bus 8, and is then transferred to the chassis 5 by the thermal bus 8 and the coupling component 6.

(Problem to be solved by the invention) In the case of a conventional printed wiring board with a metal core,
When a printed wiring board with a metal core has many through holes, the metal core has holes that are larger than the through holes to maintain insulation between the circuit and the metal core, which increases the thermal resistance of the metal core and prevents the lead from the electronic component. Heat could not be dissipated sufficiently to the chassis. Also, in electronic parts! In a component such as a zero chip in which the heat source and the component lead are separated, sufficient heat dissipation performance could not be obtained because the thermal resistance between the heat source and the lead was high.

Next, when using a thermal bus, if you try to dissipate heat from a component that has many leads under the component, such as an LSI package, the thermal bus will have many holes to protect the leads, and the thermal bus will heat up. There were problems such as increased resistance and insufficient heat dissipation.

This invention was made to solve the above-mentioned problems, and its purpose is to obtain a printed wiring board that can dissipate more heat from all the electronic components on the board. .

(Means for Solving the Problems) The printed wiring board according to the present invention uses a printed wiring board with a metal core in combination with a thermal bath, and has the metal core of the printed wiring board with a metal core in direct contact with the thermal bath. be.

[Effect]

In the printed wiring board according to the present invention, heat emitted from the leads of electronic components is transmitted through the printed wiring board with a metal core, and heat emitted from the main body is transmitted through the thermal bus and connected to the metal core of the printed wiring board with a metal core. The thermal buses merge at the part where they make contact with the rfL, and heat is radiated from the wiring board with a metal core or the thermal bus connected to the chassis to the chassis.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In Fig. 2, 1 is a printed wiring board with a metal core, 2 is the metal core, 3 is a surface insulating resin layer thereon, and 4 is a printed wiring board with a part of this surface insulating resin layer peeled off to expose the metal core. part,
Reference numeral 5 denotes a chassis attached by this IM projecting external assembly part 6.

Reference numeral 8 denotes a heat dissipation thermal bus which is brought into close contact with the electronic component 7, and the end of this thermal bus 8 is also attached to the exposed portion 4 by a connecting part 9.

Next, the effect will be explained. In Figures 1 and 2,
The heat emitted from the leads of the electronic component 7 is transmitted through the metal core 2 having the width of the metal-core printed wiring board l, passes through the exposed metal core portion 4 and the connecting component 6, and is radiated to the chassis 5. be done. In addition, the heat emitted from the main body of the electronic component 7 is transmitted through the thermal bus 8, and the surface insulating resin 3 on the printed wiring board l with a metal core is peeled off, where the thermal bus 8 and the metal core 2 are in direct contact. 4 and the coupling part 9 to the metal core 2, and then radiated to the chassis 5.

In the above embodiment, the printed wiring board 1 with a metal core is attached to the chassis 5, but the thermal bath 8 may be attached to the chassis 5 as shown in the fourth diagram of FIG.

In addition, in the above embodiment, the printed wiring board 1 with a metal core and the thermal bus 8, and the printed wiring board 1 with a metal core and the chassis 5 are installed by providing cut holes in the parts, but each is installed in the 5th part. As shown in the figure, one provided with a female thread may also be used. That is, in FIG. 5, there are two metal cores 2 in the printed wiring board l with metal cores, and since the metal cores 2 and the screws that are the connecting parts 6.9 are in close contact with each other, the metal cores Compared to the case where the printed wiring board i and the thermal bus 8 and chassis 5 are installed using drilled holes, the heat transmitted through the metal core 2 on the solder side of the printed wiring board l with a mating core is transferred to the connecting parts 6.9. Since the heat is transmitted to the chassis 5 and the metal core 2 on the component side of the metal core printed wiring board 1, more heat can be radiated to the chassis 5.

In addition, in the above embodiment, the electronic component 7 and the thermal bus 8,
The thermal bath 8 and the exposed metal core part 4 and the exposed metal core part 4 and the chassis 5 are directly connected,
Depending on the surface roughness of each contact portion, a thermally conductive sheet or thermally conductive grease may be inserted.

(Effects of the Invention) As described above, according to this F44, since the printed wiring board with metal core and the thermal bus are both J)4L, there are two heat transfer paths from the electronic product, and the heat dissipation is improved. improved, and
The thermal bus and the metal core of the printed wiring board with a metal core are in direct contact near the chassis mounting section, so installation to the chassis is easy as it can be either 1MtlZ or 1MtlZ thermal bus with a metal core. be.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing parts of the chassis mounting of a J-printed wiring board according to an embodiment of the present invention, and the second factor is shown in FIG.
FIG. 3 is a Hirayama i diagram showing a part of mounting a printed wiring board on a chassis according to another example of the present invention; FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 8; FIG. is a sectional view showing another embodiment of the present invention, the sixth factor is a plan view showing a conventional heat dissipation structure using a printed wiring board with a metal core, and FIG. ■A cross-sectional view of the line, Figure 8 is a plan view showing the parts of the chassis mounting of a conventional printed wiring board when a thermal bus is used, and Figure 9 is a surface view of the ■-■ line of 8□□□. It is. In the figure, ■ is a printed wiring board with a metal core, 2 is a parallel core, and 3 i
: is the surface insulating resin layer, 4 is the part where the metal core is exposed, 5 is the part where the metal core is exposed.
is the chassis, 6.9 is the connecting part, 7 is the electronic part N81
:j It is a thermal path.

Claims (1)

[Claims] A printed wiring board with a metal core and a thermal bus in close contact with electronic components are arranged above and below to be used together, and a part of the thermal bus is brought into contact with the metal core of the printed wiring board with a metal core and combined. Printed wiring board.