JPH04342190A - Front-back connection of double-side substrate - Google Patents

Abstract

PURPOSE:To connect an upper face electrode and a lower face electrode are connected by making the use of thermal conduction of a spray dip using cream solder and lead of a part. CONSTITUTION:An upper face electrode 2 of a printed circuit board 1 is coated with cream solder 6 and a component 4 such as an electrolytic condensoer is mounted on the coated cream solder 6. After it is mounted, spray dip is performed from a lower face electrode 3 to connect the upper face electrode 2 and the lower face electrode 3 by making the use of thermal conduction of the spray dip.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to television receivers, V
This invention relates to a method for connecting the front and back sides of double-sided printed circuit boards used in TRs, radios, tape recorders, etc.

0002

2. Description of the Related Art In a printed circuit board having patterns formed on both sides, it is sometimes necessary to connect pattern electrodes on both sides.

Conventionally, in such cases, pattern electrodes were formed around or in part of the openings on both sides of the through-hole provided in the double-sided printed circuit board, and leads of electronic components that could withstand solder were connected to one side of the board. The leads are inserted into the through holes and passed through the other side of the board, and soldered from the general parts mounting side of the board to connect the leads to the pattern electrodes on the general parts mounting side. Soldering is performed from the general soldering side along with other general parts as necessary. (Unexamined Japanese Patent Publication No. 57-120
(Refer to Publication No. 393)

0004

[Problem to be Solved by the Invention] However, the conventional method requires two soldering steps when connecting double-sided pattern electrodes.
It is not rational because it takes a long process, and it is difficult to apply unless the electronic component is highly heat resistant.Furthermore, there is a problem that heat is applied to the printed circuit board, weakening it, and the soldering process is two steps. However, there were problems in that the working time was longer and the cost was higher.

The present invention aims to eliminate the above-mentioned drawbacks of the conventional method and to provide a connection method that allows connection of front and back pattern electrodes in a single dip soldering process.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention connects pattern electrodes on both sides of a double-sided printed wiring board using leads of insertion type components. At this time, the method of connecting the electrodes on the upper surface and the electrodes on the lower surface is to apply cream solder to the upper surface and solder the lower surface by jet dip.

The cream solder on the top surface is melted by the heat of the substrate when the bottom surface is jet-dipped and soldered to establish electrical connection between the front and back electrode patterns.

[0008]

[Operation] According to the present invention, since the upper and lower electrodes of the printed wiring board are connected by the leads of the insertion type component, it is equivalent to forming a through hole by electrolytic plating or electroless plating, and the soldering process is unnecessary. It only takes one step. Further, the component body is not directly immersed in the soldering device, and heat resistance is not required so much.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the embodiment shown in FIG. 1, 1 is a printed circuit board (phenol resin, glass epoxy resin, etc.);
2 is a top electrode, 3 is a bottom electrode, 4 is an electrolytic capacitor,
5 is the lead of the electrolytic capacitor, 6 is the cream solder applied to the top electrode 2, and 7 is the bottom electrode 3 by jet dip.
This is the solder that connects the wire and the lead.

Next, the process of connecting the front and back pattern electrodes will be explained. ■Print and apply cream solder 6 on printed wiring board 1. ■Mount parts 4 such as electrolytic capacitors on the board 1 coated with cream solder 6. ■Solder the mounted printed wiring board 1 using a jet dip process. By performing jet dipping in this manner, heat is conducted to the printed circuit board 1, and the cream solder 6 applied to the upper surface electrode 2 is melted to fix the lead 5 of the electrolytic capacitor 4.

[0011] In this front-back connection method, the soldering process is completed in one step, and the components are less likely to be damaged by heat.

0012

[Effects of the Invention] As described above, according to the present invention, cream solder is applied on the upper electrode of the component lead insertion hole of the printed circuit board, the component lead is inserted from above, and the jet dip is performed from the lower electrode surface. This makes it possible to solder the top electrode and lead, and the bottom electrode and lead, making it possible to connect both sides in one step. Furthermore, the parts may also be of low heat resistance.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view for explaining a method for connecting the front and back sides of a double-sided board in an embodiment of the present invention.

[Explanation of symbols]

1 Printed wiring board 2 Top electrode 3 Bottom electrode 4 Electrolytic capacitor 5. Electrolytic capacitor lead 6 Cream solder 7 Jet dip soldering

Claims (1)

[Claims] Claim 1: Pattern electrodes are formed around or part of the opening on both sides of a through hole provided in a double-sided printed circuit board, and cream solder is printed on one of the pattern electrodes. The lead of the electronic component is inserted into the through hole from one side of the board, passed through the other side of the board, and dip soldered on the other side. A method for connecting the front and back sides of a double-sided board, characterized in that the cream solder is melted and the patterned electrodes on the front and back sides are connected through the leads.