JPH0543200B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a self-retaining electronic circuit device in which electronic components are held together using a conductive molding material.

[Technical Background of the Invention and Problems Therewith] In recent years, electronic circuit devices in which electronic components are mounted on printed circuit boards have been frequently used in the circuit portions of electronic devices.

For example, as shown in FIG. 6, it is manufactured through the following steps.

That is, first, multiple sheets of semi-hardened prepreg, which is made by impregnating and drying a base material such as paper or glass fiber with phenolic or epoxy resin varnish, are layered with copper foil, and then integrated by heating and pressing. to form a copper-clad laminate. Next, a predetermined circuit pattern is formed on the surface of the copper foil by etching to form a circuit board. Further, holes for inserting electronic components are made in this circuit board, electronic components are inserted into these holes, and these electronic components are fixed with solder from the back side to complete an electronic circuit device.

However, as mentioned above, in electronic circuit devices using printed circuit boards, electronic components are mounted using solder, so the printed circuit board as a constituent material does not have enough heat resistance to withstand the temperature of the solder bath. The problem is that it is required.

In other words, although the actual operating temperature of electronic circuit devices is around room temperature and there is no particular requirement for heat resistance, they are immersed in a solder bath during the manufacturing process, so they do not have enough heat resistance to withstand that temperature. Therefore, it is necessary to take measures such as using an expensive thermosetting resin as a substrate material, which is a factor in increasing costs.

Furthermore, since the solder of the electronic circuit device manufactured in this manner has poor moisture resistance, there is a problem in that the electrical characteristics of the electronic circuit device are impaired when used in a humid atmosphere.

[Object of the Invention] The present invention has been made in response to these conventional problems, and can be easily manufactured without immersion in a solder bath. It is an object of the present invention to provide a self-retaining electronic circuit device that is not required to have heat resistance characteristics sufficient to withstand temperatures and has improved moisture resistance.

[Summary of the invention] That is, the self-retaining electric circuit device of the present invention has the following features:
A plurality of electronic components having lead terminals are arranged at predetermined positions on the same plane, and a predetermined connection pattern is formed between each lead terminal on these electronic components,
Furthermore, by molding a conductive molding material so that each electronic component is mutually held, heating by a solder bath is avoided and moisture resistance is also improved.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 are a side view and a bottom view showing an embodiment of the self-retaining electronic circuit device of the present invention.

In these figures, numeral 1 indicates lead terminal 1
a resistor, capacitor, transistor,
The figure shows electronic components such as ICs, which are arranged at predetermined positions on the same plane, and are molded with a conductive molding material 2 to form a predetermined connection pattern, and are mutually held. is being done.

In the figure, A indicates a connection pattern formed by molding the conductive molding material 2, and B indicates a bridge portion for mutually holding electronic components by the connection pattern A.

The above-mentioned conductive molding material is a synthetic resin such as polystyrene, ABS resin, polypropylene, polyphenylene oxide, modified polyphenylene oxide, etc., mixed with conductive powder such as copper, iron, stainless steel, or conductive fiber. things can be used.

Such a self-retaining electronic circuit device can be manufactured in the following manner using, for example, a mold as shown in FIG.

In Fig. 3, this mold is attached to the movable side mounting plate 3.
For normal injection molding, it consists of a movable mold plate 4 attached to a fixed side mounting plate 5, a fixed side template 7 attached to a fixed side mounting plate 5 via a spacer 6, and a sprue bush 8 to which an injection molding machine nozzle can be connected. In the mold, 9
indicates a resin passage.

An electronic component fitting recess 10 capable of holding the electronic component 1 is provided on the inner surface of the movable side template 4, and a connection pattern to be molded with a conductive molding material is provided on the inner surface of the fixed side template 7. A cavity 11 is formed in a shape corresponding to the bridge portion B that connects the electronic component A and the main body of the electronic component 1 to each other.

First, as shown in the top view of FIG. 4 and the cross-sectional view of FIG. Wear it so that it is more exposed. Next, the nozzle of an injection molding machine (not shown) is connected to the sprue bush 8, and the conductive molding material 2 heated and melted by the injection molding machine is poured into the cavity 11.
After filling the mold and cooling and solidifying it, the mold is opened to complete the electronic circuit device of the above embodiment.

Since such an electronic circuit device is subjected to a lower temperature during its manufacturing process than a solder bath, there is no need to take heat resistance into consideration when selecting constituent materials, etc., thereby improving economic efficiency. Furthermore, unlike conventional solder, which has poor moisture resistance, it does not use solder, so even if it is used in a humid place, reliability is unlikely to deteriorate.

Next, a concrete example of the present invention will be described.

Using a mold with a predetermined connection pattern formed in the cavity shown in Figure 3, the resistors, capacitors, coils necessary for circuit formation are placed on the inner surface of the movable mold plate.
Various electronic components such as transistors, ICs, connectors, etc.
After installing 40 pieces, the mold was closed and a modified polyphenylene oxide based conductive molding material (product name: EC
-3140 manufactured by Toshiba Chemical Co., Ltd.) to produce a self-retaining electronic circuit device.

This electronic circuit was self-retaining and exhibited the intended function.

In the above embodiment, an example was explained in which the connection pattern A and the bridge part B were formed only from conductive molding material, but if necessary, metal wires or other members may be embedded in these parts to make conductive and It is also possible to improve mechanical strength.

[Effects of the Invention] As explained above, according to the self-retaining electronic circuit device of the present invention, electronic components are arranged on the same plane, a predetermined connection pattern is formed between these electronic components, and mutual retention is achieved. Since the conductive molding material is molded in such a way that the conductive molding material is formed, it is no longer necessary to have heat resistance characteristics sufficient to withstand a solder bath, thereby improving economical efficiency. Also, since no solder is used, moisture resistance is improved.

[Brief explanation of the drawing]

FIG. 1 is a side view showing one embodiment of the self-holding electronic circuit device of the present invention, FIG. 2 is a bottom view thereof, and FIG.
5 to 5 are diagrams explaining the manufacturing method of this embodiment, and FIG. 6 is a process diagram showing the manufacturing process of a conventional electronic circuit device. 1...Electronic component, 1a...Lead terminal, 2...
Conductive molding material, A... Connection pattern, B... Bridge portion.

Claims (1)

[Claims] 1 A plurality of electronic components having lead terminals are arranged at predetermined positions on the same plane, and a predetermined connection pattern is formed between each lead terminal on these electronic components, and each electronic component is held together. A self-retaining electronic circuit device, characterized in that it is formed by molding a conductive molding material onto the wafer.