JPH06232514A - Assembling method for heat dissipation printed substrate - Google Patents

Abstract

PURPOSE:To provide an assembling method for a heat dissipation printed substrate with which a soldering operation can be conducted on a circuit part similar to the ordinary type printed substrate. CONSTITUTION:After a circuit part 5 has been mounted on the surface of a printed substrate main body 1 on which prescribed conductive pattern 3 is formed, an aluminum plate 7 is laminated and bonded to the back side of the printed substrate 1 through the intermediary of heat conductive bonding agent 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for assembling a heat radiation type printed circuit board.

[0002]

2. Description of the Related Art A heat dissipation type printed circuit board is generally constructed by laminating and adhering a metal plate having good thermal conductivity such as an aluminum plate on the back surface of the printed circuit board body, and mounted on the surface of the printed circuit board body. Parts such as resistors and DC / D
The Joule heat generated from an electronic circuit that tends to generate a relatively large amount of heat such as a C converter is radiated through the metal plate to prevent overheating of the printed circuit board body,
It protects the circuit.

This heat radiation type printed circuit board is supplied to a mounting site as a semi-finished product in which a substrate body and a metal plate are integrated in advance, and various circuit components are mounted on a circuit pattern formed on the surface of the substrate body. It

[0004]

However, when a circuit component is mounted on such a heat radiation type printed circuit board by soldering, good heat radiation is a problem. That is, since the heat for melting the solder, which is supplied from the soldering iron, is radiated from the metal plate, the solder cannot be melted easily, the soldering work is complicated, and the soldering failure is caused. It was easy to occur.

Further, as a means for preventing such a problem, conventionally, the printed circuit board itself has been heated to about 150 ° C. and soldered in a state in which heat is not easily dissipated. There is a fear that the substrate will be warped due to the heat stress caused, and since it is heated at a high temperature, it was not always a rational work method in terms of work and handling.

The present invention solves the above problems, and an object thereof is a method of assembling a heat dissipation type printed circuit board, which enables the soldering work of circuit components to be carried out in the same manner as in the case of a normal printed circuit board. Is provided.

[0007]

In order to achieve the above-mentioned object, a method of assembling a heat dissipation type printed circuit board according to the present invention is characterized in that after a circuit component is mounted on the surface of a printed circuit board body on which a predetermined conductive pattern is formed by soldering. A metal plate having good thermal conductivity is laminated and adhered to the back surface of the printed circuit board body via a heat conductive adhesive. Further, in the present invention, the printed circuit board body may be a flexible printed circuit board.

[0008]

In the assembling method of the present invention having the above-described structure, when the circuit component is soldered on the printed circuit board body by soldering, the metal plate as the heat radiating means is not yet attached, so that heat generated through this metal plate is not applied. Circuit parts can be soldered by the normal working method without escape. After the metal plates are laminated and bonded, they function as a heat dissipation type printed circuit board having high heat dissipation and rigidity.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. First, in FIG. 1 (a), a printed circuit board body 1 cut into a predetermined outer shape has an appropriate conductive pattern 3 made of copper foil or the like formed on the surface of a substrate 2 made of an insulating material such as glass epoxy resin. The entire surface of the conductive pattern 3 except for the connection part 3a of the circuit component is covered with an insulating solder resist layer (or film) 4.

As shown in FIG. 1 (b), various circuit parts 5 are installed on the surface of the substrate main body 1 according to designation.
The terminal portion 5a is fixed to the conductive pattern 3 with the solder 6 in a state where the terminal portion 5a is in contact with the connection portion 3a. This soldering work can be performed by the same method as the component mounting work on a general printed circuit board that is usually performed.

After the connection of all the connection points 3a with the solder 6 is completed, as shown in FIG. 1C, an aluminum plate 7 having the same outer shape and the required thickness is formed on the back surface of the substrate body 1. Laminated and bonded. The aluminum plate 7 has a function as a heat radiating plate that transfers heat generated from the substrate body 1 and dissipates the heat from a surface equal to the area of the substrate body 1 corresponding to the B side of the substrate body 1, and the substrate body 1 It also functions as a reinforcing plate to give rigidity to the.

The adhesive 8 used for bonding is uniformly applied to the entire bonding surface of the aluminum plate 7 in advance, and the substrate body 1 on which the circuit components are mounted is installed on the upper surface of the aluminum plate 7 and pressed and held on the aluminum plate 7. The curing of the adhesive 8 completes the bonding operation. As the adhesive 8, a heat conductive adhesive such as a silicone adhesive is used, and the heat generated from the circuit component 4 is sufficiently transmitted and radiated to the aluminum plate 7 side.

Although not shown, in the bonding work, the substrate body 1 and the aluminum plate 7 may be clamped and fixed using a crimping jig at a position where they do not interfere with the circuit component 5.

The heat-dissipating printed circuit board according to the present invention, which has been assembled, has exactly the same function as that of the conventional heat-dissipating printed circuit board. Resist layer 4 through pattern 3
Since it is transmitted to the substrate 2 and further to the aluminum plate 7 through the adhesive 8, the entire non-bonded surface of the aluminum plate 7 serves as a heat dissipation surface, and most of the generated heat is dissipated to the outside, Prevents overheating of the main body 1 and circuit parts 4
Protect.

In the above embodiments, a printed circuit board made of glass epoxy resin or the like is used as the substrate 2, but if a flexible printed circuit board made of an insulating film or an insulating sheet is used instead, the printed circuit board is Since the thermal deformation of itself is small, it is possible to further reduce the thermal stress that acts on the component during the component mounting work, and since the substrate itself is thin, the heat transfer to the aluminum plate 7 is efficiently performed, which is more preferable.

[0016]

As described above in detail with reference to the embodiments, in the method of assembling the heat dissipation type printed circuit board according to the present invention, the circuit component is soldered to the surface of the printed circuit board body on which the predetermined conductive pattern is formed. After mounting, the metal plate with good thermal conductivity is laminated and adhered to the back surface of the printed circuit board body via the heat conductive adhesive, so the solder melts when the circuit parts are mounted on the printed circuit board body by soldering. The heat to dissipate is not dissipated, and good soldering can be performed.Because high heat dissipation and rigidity can be obtained after the metal plates are laminated and bonded, the heat dissipation metal plate is provided in advance before mounting the circuit components. There is no complicated work or soldering failure such as when mounting circuit components on a conventional heat dissipation type printed circuit board by soldering, and the heat stress caused by overheating the board itself Ku problem can be avoided.

[Brief description of drawings]

1A to 1C are explanatory sectional views showing an assembling procedure according to the method of the present invention.

[Explanation of symbols]

 1 Printed Circuit Board Body (Flexible Printed Circuit Board) 3 Conductive Pattern 5 Circuit Parts 6 Solder 7 Aluminum Plate (Metal Plate with Good Thermal Conductivity) 8 Adhesive

Claims (2)

[Claims] 1. A metal plate having good thermal conductivity after a circuit component is mounted on the front surface of a printed circuit board body on which a predetermined conductive pattern is formed by soldering, and a heat conductive adhesive is applied to the back surface of the printed circuit board body. A method for assembling a heat dissipation type printed circuit board, which comprises laminating and adhering the two. 2. The method for assembling a heat dissipation type printed circuit board according to claim 1, wherein the printed circuit board body is a flexible printed circuit board.