JPS60192391A - Electronic circuit component - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to unit electronic circuit components used in electronic equipment such as video tape recorders.

Conventional configurations and their problems In recent years, with the aim of reducing the size and weight of electronic devices and streamlining their assembly, circuits have been made into units of 21... and the unit circuits have been constructed on small printed wiring boards. A mounting method of configuring an electronic circuit by mounting this on a mother printed wiring board is used in many electronic devices.

The unit circuit electronic components used in this mounting method are mounted on an insulating substrate 1 made of phenolic resin, etc., as shown in Figure 1.
A plurality of circuit elements 3a necessary for constructing a desired unit circuit on a small printed wiring board provided with a circuit conductor layer 2,
3b, and these circuit elements 3a and 3b are electrically connected to the wiring circuit conductor layer 2 made of copper foil of the printed wiring board by solder 4, and the external connection for connecting to the mother printed wiring board is made. A lead terminal 5 for use is attached. As shown in FIG. 2, such electronic components are attached to the mother printed wiring board by inserting external lead wires 5 into through holes 7 of the mother printed wiring board 6 and using solder 8.

However, such electronic circuit components are made by soldering external lead terminals to a conductor layer for connection provided at one end of a small printed wiring board that constitutes a unit circuit, and connecting them in a plane using a 3'-shield reflow method. Therefore, the solder joint strength between the lead terminal and the conductor layer is not necessarily sufficient.

Therefore, the scale of the unit circuit is expanded, the dimensions are large,
When configuring a unit circuit electronic circuit component that is also large in weight, when mounting it on a mother printed wiring board,
If the external lead wires come off during the soldering process, or if the lead terminals are bent and the unit circuit is laid down while mounted, stress tends to concentrate on the solder joints of the lead terminals, making the solder joints more likely to break. Furthermore, if a vibration test or drop test was performed while the device was mounted on a mother printed wiring board, the solder joints of the lead terminals would become unstable, making the circuit more likely to malfunction.

OBJECTS OF THE INVENTION An object of the present invention is to strengthen the solder joints between a small printed wiring board that constitutes a unit circuit and an external lead terminal, and to protect it from mechanical shock when it is attached to a mother printed wiring board.
It is an object of the present invention to provide an electronic circuit component that can ensure the reliability of solder joints of external lead terminals of the unit electronic circuit component.

Structure of the Invention The electronic circuit component of the present invention is an electronic circuit device in which a unit circuit is constructed by mounting a plurality of various circuit elements on a printed wiring board and electrically connecting them. A through hole for attaching a lead wire for external connection is provided along the end face of the through hole, a conductive layer that can be soldered is formed on the inner wall of this through hole, and a lead wire for external connection is inserted into the conductor layer. Some have a structure in which the through-holes are filled with solder, which makes it possible to realize a unit electronic circuit component to which external lead terminals are firmly soldered.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

5 Vane In Figures 3 and 4, 9 is an insulating substrate, 10 is a circuit conductor layer formed of copper foil, 11 is a through hole, 11a is a through hole for attaching an external lead terminal wire, and 12 is a through hole. Conductor layer (through-hole conductor layer) formed on the inner wall surface, 1
3a and 13b are circuit elements, 14 is solder, and 16 is a lead terminal for external connection.

The details of the electronic circuit component of this embodiment configured as described above will be described below.

As shown in FIGS. 3 and 4, the electronic circuit component according to the present invention is manufactured by etching a copper foil on the main surface of an insulating substrate 9 made of a synthetic resin such as paper phenol or glass epoxy, thereby forming a circuit conductor layer 1o. Various circuit elements 13a and 13b such as resistors, capacitors, and semiconductor ICs necessary for constructing a unit circuit are mounted on a small-sized printed wiring board with lead connection terminals provided on the small-sized printed wiring board. Hole 11
A desired unit circuit was constructed by electrically connecting to the circuit conductor layer 10 through the solder 14. Then, an external connection lead terminal 16 for attaching this unist electronic circuit to the mother printed circuit board 6 and the vane wire plate is inserted into the through hole 11a provided along one end surface of the small printed circuit board. By soldering, a unit circuit with leads, that is, an electronic circuit component was constructed.

In this case, a conductive layer 12 that can be soldered is formed on the inner wall of the through hole 11a into which the external connection lead terminal 15 is inserted by a method such as through-hole plating or applying a conductive paste. A lead terminal 16 for external connection is inserted into the through hole 11a, and the circuit element 13a,
At the same time as 13b, soldering is performed by a solder dipping method to fill the through holes 11a with solder, thereby firmly fixing the lead terminals.

Then, as shown in FIG. 5, the external lead terminals 15 of the unit electronic circuit components are inserted into the through holes 17 provided in the mother printed wiring board 16. 7 Although circuit elements with lead wires are used as the circuit elements 13a and 13b to be vaned, in the present invention, there are no restrictions on these circuit elements. For example, various leadless type circuit elements are used to A unit circuit may be constructed by directly mounting on a circuit conductor surface.

Effects of the Invention As is clear from the above description, the present invention provides a method of forming a conductive layer on the inner wall surface of a through hole for attaching an external connection lead terminal formed along the end surface of a small printed wiring board constituting a unit circuit. By inserting a lead terminal for external connection into this through hole and performing soldering, a structure is created in which the through hole is filled with solder and the lead terminal for external connection is fixed, so that the external lead terminal is connected to the unit. It is firmly fixed to the printed wiring board that made up the circuit, and therefore can withstand various mechanical shocks when the mother printing board is attached.
Reliability of solder joints of external lead terminals

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an electronic circuit component to explain a conventional example, Fig. 2 is a sectional view of a main part of an electronic circuit component according to a conventional example attached to a mother printed wiring board, and Fig. 3 is a cross-sectional view of an electronic circuit component according to the present invention. FIG. 4 is a perspective view of the electronic circuit component for explaining the embodiment, and FIG. 6 is a sectional view of the main part of the electronic circuit component according to the present invention attached to a mother printed wiring board. 9...Insulating substrate, 1o...Circuit conductor layer, 1
1...Through hole for inserting circuit element, 11a...
...Through hole for external +7- terminal insertion, 12...Through hole conductor layer, 13a, 13b...Circuit element, 14.18...Solder, 15 ...
...External lead terminal, 16...Mother printed wiring board, 17...Mother printed wiring board through hole. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3

Claims (1)

[Claims] A unit circuit is constructed by mounting a plurality of various circuit elements on a printed wiring board and electrically connecting them, and a through hole for attaching a lead wire for external connection along at least one end surface of the printed wiring board. An electronic circuit component having a structure in which a hole is provided, a solderable conductor layer is formed on the inner wall of the through hole, a lead wire for external connection is inserted into the through hole, and solder is filled.