JPS6153788A - Electronic circuit part - 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 electronic circuit components used in a wide range of electronic equipment such as television receivers and magnetic recording/reproducing devices.

Conventional configurations and their problems In recent years, as the demand for smaller, lighter, thinner, and more sophisticated electronic devices has increased, it has become extremely important to increase the density and reliability of the circuits in these electronic devices. It has become a challenge.

Under these circumstances, efforts are being made in recent years to develop various mounting technologies aimed at increasing the density and reliability of electronic circuits, and one of the methods is mounting technology that incorporates the concept of circuit functional blocks. It is implemented in many fields of electronic equipment.

This mounting method divides an electronic circuit into several functional blocks, and integrates each of the divided functional blocks into 11"11" circuit elements with high density on a small circuit board. h11+S is formed, a lead wire serving as an external connection terminal is attached to this, and it is mounted on a mother printed wiring board to form an electronic circuit.

Here, the above-mentioned circuit block body is a small-scale electronic circuit created by integrating multiple small circuit elements, and is also called an electronic circuit component, but its shapes and configurations vary widely. is used.

The most commonly used electronic circuit components today are
Chip resistors, tape-shaped multilayer capacitors, mini-molded transistors,
Diode, IC.

It is constructed by high-density soldering of planar connection type small circuit elements such as LSI.

These electronic circuit components are constructed by inserting their lead wires into through holes drilled in the mother printed wiring board and soldering them together with other circuit elements. Electronic circuit components having wires are generally easy to attach to the mother printed wiring board, and have the advantage of being able to be reliably soldered to the mother printed wiring board, but it is difficult to solder the lead wires to the circuit block body. When soldering is required, the higher the density of the circuit block, the more space is required for soldering, the more complicated the work, and the more difficult it is to obtain sufficient solder connection strength. When soldering is done, the lead wires tend to come loose from the circuit block body due to the heat of the solder, and furthermore, if the circuit block body is subjected to mechanical fullness while mounted on the mother printed wiring board, the leads may be easily separated from the circuit block body. There were inconveniences such as the wires becoming easy to peel off.

Therefore, electronic circuit components having various shapes are used as a method to solve this problem.

A typical form of electronic circuit components is shown in FIG.

This is a flexible wiring board in which a circuit core layer 2 is formed on the main surface of a flexible insulating substrate 1, and small circuit elements 3 necessary for constructing a functional circuit block are connected by 1 solder 4. , its external connection terminal 5
is made of the same metal foil as the circuit core layer 2 of the flexible wiring board, and is drawn out in the shape of a finger from the end of the flexible wiring board. The metal foil of the external connection terminal 6 is partially plated thicker than the circuit conductor layer 2 to make it as hard as a normal lead wire.

As shown in FIG. 2, such electronic circuit components are manufactured by inserting lead terminals 5 into through holes provided on the mother printed wiring board and soldering them using the solder dipping method to form circuit conductor layers 8 on the mother printed wiring board. and connected by solder 9,
It constitutes an electronic circuit.

However, this electronic circuit component has lead terminals and circuit 101.
Since the two circuit conductor layers are made of the same type of metal regardless of the solder connection, there is no risk of poor connection, but thick plating is applied in some areas to give appropriate hardness to the lead terminals. However, the work is complicated and uneconomical.Furthermore, the conductive metal layer obtained by high-speed plating is hard and brittle, so the lead terminals are easily broken, especially when mounted on a mother printed wiring board. If mechanical fullness is applied to electronic circuit components in such a state, there are problems such as lead terminal parts breaking and disconnection defects, and there is a strong demand for an improvement in this problem.

Purpose of the Invention The purpose of the present invention is to improve the mechanical strength of external connection terminals, to ensure the connection between the circuit block and the mother printed wiring board, and to ensure high H resistance when mounted on the mother printed wiring board. The present invention provides electronic circuit components with excellent performance.

Structure of the Invention The electronic circuit component according to the present invention has cutouts at regular intervals between the conductor layers forming external connection terminals formed along the end face of a flexible wiring board, and small circuit elements are electrically connected to the flexible wiring board. This is a high-density, highly reliable electronic circuit component that is connected to form a functional circuit block, which allows the external connection terminals to become independent, allowing for reliable connection to the mother printed wiring board. This is something that can be achieved.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 3 is a perspective view of an electronic circuit component in one embodiment of the present invention.

3 and 4, 10 is a flexible insulating substrate, 11 is a circuit conductor layer, 12 is an external connection terminal, 13 is a notch, 1
4 is a small circuit element, and 15 is a solder.

The method for configuring the electronic circuit component of this embodiment configured as described above will be explained in detail below.

As shown in FIGS. 3 and 4, the electronic circuit component according to this embodiment is a flexible insulating substrate 1Q of about 76 to 200 μm thick, such as polyimide insulation notebook or glass epoxy/insulation notebook, and 35 μm of electrolytic copper. A desired circuit conductor layer 11 is formed by a known method such as photoetching using a so-called copper-clad insulating notebook to which metal foil such as foil or rolled copper foil is bonded.
At the same time, in order to ensure a more reliable solder connection to the circuit conductor layer 11 and the printed wiring board, the circuit conductor layer 11 is formed not only on one side of the flexible insulating substrate 10 but also on the other side. did. In this example, a copper-clad board is used, in which electrolytic copper foil of 35μ is adhered to both the front and back sides of a glass epoxy board 10 with a thickness of 100μ, and a circuit conductor layer 11 is added to one side of the glass epoxy board by a photoetching method. A flexible wiring board was prepared which included a conductor layer serving as external connection terminals 12 having constant intervals between the two sides. Next, a mold is used to create cutouts 13 at regular intervals between the conductor layers, which will become the external connection terminals 12 of this flexible wiring board.
and circuit conductor layer 1 of this flexible wiring board.
1. The small circuit elements 14 necessary to configure the functional block circuit include a square chip resistor, a dress type multilayer ceramic capacitor, a step coil, and a mini-mold type transistor 7-8 diode 10. LSI
.

An electronic circuit component was manufactured by mounting planar connection type small circuit elements such as the following, and connecting these small circuit elements 14 to the circuit conductor layer 11 with solder 15 using a solder reflow method.

Then, this electronic circuit component is mounted on a mother printed wiring board 16 as shown in FIG.
1-, but the mounting method is to insert the notch 1 of the electronic circuit component into the through hole 17 provided in the mother printed wiring board 16.
The external connection terminals 12 provided with 3 are inserted and soldered by the solder dipping method, and the circuit conductor layer 18 of the mother printed wiring board 16 and the external connection terminals 12 are connected by the solder 19.

Here, the external connection terminal 12 of the electronic circuit component is connected to the notch 13.
By providing a lead wire, it becomes an independent connection terminal like a normal lead wire, but the soldering part is slightly exposed from the side by the thickness of the flexible insulating board 10, so it cannot be connected to the mother printed wiring board. When the external connection terminal 12 is inserted into the through hole 17 of the mother printed wiring board 16 and soldered, there is a slight problem in the solder connection with the circuit conductor layer 18 of the mother printed wiring board 16 due to the exposed flexible insulating board. Therefore, in this example, electroless plating technology was applied to the side surface of the flexible insulating substrate 10 exposed at a part of the tip of the external connection terminal 12 provided with the notch 13 of the electronic circuit component. The problem was solved by depositing a conductive metal layer.

Effects of the Invention As is clear from the above explanation, the electronic circuit component according to the present invention is formed on a flexible wiring board, with cutouts provided between conductor layers that serve as external connection terminals, and small circuit elements mounted on this flexible wiring board. They are connected to form a functional circuit block.

Therefore, in the electronic circuit component according to the present invention, the external connection terminal has an independent shape due to the notch, and the processing method thereof is extremely simple, and the circuit block body and the external connection terminal are continuously integrated. Moreover, the external connection terminals do not need to be particularly thick with plating, etc., and the conductor layers formed on both sides of the flexible wiring board have sufficient hardness and flexibility. The mounting on the printed wiring board can be easily carried out, and the solder connection can be made reliably.

Furthermore, the electronic circuit component according to the present invention has the effect that the reliability of the solder joint can be sufficiently ensured against heat and mechanical shock when mounted on a mother printed wiring board.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an electronic circuit component according to 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 sectional view of an electronic circuit component according to an embodiment of the present invention. 4 is a sectional view of FIG. 3, and FIG. 6 is a sectional view of a main part of an electronic circuit component obtained in an embodiment of the present invention attached to a mother printed wiring board. It is a diagram. 10...Flexible insulating substrate, 11...Circuit conductor layer, 12...External connection terminal, 13...
・Notch part, 14...Small circuit element, 15.19
... Solder, 16 ... Mother printed wiring board, 17 ... Pore hole, 18 ... Circuit conductor layer of mother printed wiring board. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) A functional circuit block is constructed by providing a notch between the conductor layers that serve as external connection terminals formed along the end surface of the flexible wiring board, and connecting small circuit elements to the circuit conductor layer surface of the flexible wiring board. Electronic circuit components featuring: (2) The electronic circuit component according to claim 1, wherein the external connection terminal is provided with a conductive metal layer on both the front and back surfaces of the flexible insulating substrate. (3) The electronic circuit according to claim 1, wherein a part of the tip of the external connection terminal is provided with a conductive metal layer on both the front and back surfaces of the flexible insulating substrate and on the side walls. parts.