JPH07120862B2 - Electronic circuit device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to an electronic circuit device in which electronic components are connected and held with a conductive resin material.

(Prior Art) In recent years, an electronic circuit device in which electronic components are mounted on a printed circuit board is widely used in a circuit portion of an electronic device. It is manufactured through the steps shown in the block diagram of FIG. 6, for example. That is, first, a substrate such as paper or glass cloth is impregnated with a phenolic or epoxy resin varnish to dry it into a semi-cured prepreg. To make a copper clad laminate. Then, a predetermined circuit pattern is formed on the copper foil surface of the copper clad laminate by an etching method to obtain a circuit board. Further, a hole for inserting an electronic component is opened in this circuit board, a lead of the electronic component is inserted into this hole, and the lead is fixed to the circuit from the back side of the electronic component by soldering to form a conventional electronic circuit device. .

(Problems to be Solved by the Invention) However, in the conventional electronic circuit device mounted on such a printed circuit board, since the electronic components are fixed by soldering as described above, the print as a constituent material is performed. There is a problem that the circuit board is required to have heat resistance enough to withstand the temperature of the solder bath. That is, the actual operating temperature of the electronic circuit device is around room temperature, and although heat resistance is not particularly required, it is immersed in a solder bath during the manufacturing process, so heat resistance characteristics that can withstand that temperature are required. It Therefore, it is necessary to use an expensive thermosetting resin as a substrate material, which causes a problem of increasing the cost of the electronic circuit device.

(Object of the Invention) The present invention has been made in consideration of such problems of the conventional electronic circuit device, and does not require the heat resistance property of the used material to withstand the high temperature of the solder bath. It is an object of the present invention to provide an electronic circuit device which can be easily manufactured without being dipped in a solder bath and can suppress an increase in cost.

[Configuration of Invention] (Means for Solving Problems) The present inventor has focused on a method of avoiding heating by immersion in a solder bath and not using a thermosetting resin printed circuit board in order to prevent cost increase. As a result of extensive studies, if an electronic circuit is formed by molding a conductive resin material such as thermoplastic, it is possible to simultaneously hold the electronic components together with the formation of the electronic circuit by molding once. Furthermore, they have found that the cost increase can be prevented, and have completed the present invention. That is, the present invention is to arrange a plurality of electronic components having lead terminals, a circuit portion for electrically connecting between the lead terminals of these electronic components, and a bridge portion for holding each electronic component main body, It is an electronic circuit device characterized by being formed of a conductive resin material.

(Operation) In the electronic circuit device of the present invention, since a plurality of electronic components are integrally molded by using a conductive resin material such as thermoplastic, holes for insertion of electronic components and leads are inserted as in the conventional case. It does not require a complicated process such as a heat treatment and a thermally harsh process of immersing and fixing an electronic component in a solder bath in order to fix it. Further, since an inexpensive thermoplastic resin is also used as the conductive resin material, cost increase can be prevented.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

1 and 2 are a sectional view and a bottom view showing an embodiment of an electronic circuit device of the present invention.

In FIG. 1 and FIG. 2, electronic parts 1 such as resistors, capacitors, transistors and ICs having lead terminals 1a are
Several pieces are arranged at predetermined positions, the circuit portion A electrically connects the electronic parts by molding the conductive resin material 2, and the bridge portion B holds the main bodies to each other. As the conductive resin material used here, polystyrene, ABS, polypropylene, polyphenylene oxide, copper, iron, a mixture of conductive powder or conductive fiber such as stainless steel in a thermoplastic resin such as modified polyphenylene oxide is used. To do.

This electronic circuit device can be manufactured as follows, for example, using a mold as shown in FIG. The mold of FIG. 3 has a movable side mold 4 attached to a movable side mounting plate 3.
And a fixed-side die 7 mounted on the fixed-side mounting plate 5 via a spacer 6, a spool bush 8 connectable to a nozzle of an injection molding machine, and a resin passage 9. . On the inner surface of the movable side mold 4, an electronic component fitting recess 10 capable of holding the electronic component 1 is provided, while on the other hand, on the inner surface of the fixed side mold 7, a circuit portion A and a circuit portion A formed of a conductive resin material are provided. A cavity 11 having a shape corresponding to the bridge portion B that links the bodies of the electronic component 1 to each other is formed.

Thus, first, as shown in the top view of FIG. 4 and the sectional view of FIG. 5 of the movable side die (viewed in the direction of arrows I-I in FIG. 4), the predetermined electronic component 1 is inserted into the electronic part fitting recess of the movable side die 4. 10, lead terminal
Mount so that 1a is exposed from the top surface. Then, a nozzle of an injection molding machine (not shown) is connected to the spool bush 8 of FIG. 3, the conductive resin material 2 heated and melted by the injection molding machine is filled in the cavity 11 and cooled and solidified, and The molded electronic circuit device can be taken out by opening the mold. In such an electronic circuit device, since the temperature received in the manufacturing process is lower than the solder bath temperature, it is economically advantageous that heat resistance does not need to be considered so much when selecting the constituent material of the electronic circuit device. .

Next, an example in which the present invention is embodied will be described.

After mounting 40 electronic parts such as resistors, capacitors, coils, transistors, ICs, connectors, etc. necessary for circuit formation on the inner surface of the movable side of the mold shown in FIG. 3, the mold is closed and the modified polyphenylene oxide system is used. Conductive resin material EC-3140
(Toshiba Chemical Co., Ltd., trade name) was used for injection molding to manufacture an electronic circuit device. This electronic circuit device has a self-holding function and exhibits the intended function.

In the above-mentioned embodiment, the example in which the circuit portion A and the bridge portion B are formed of only the conductive resin material has been described. However, if necessary, a metal wire or other member may be embedded in this portion so that the conductive and mechanical properties can be improved. It is also possible to improve the strength.

[Effects of the Invention] As described above, according to the electronic circuit device of the present invention, by forming the circuit portion with the conductive resin material and electrically connecting the same, it is possible to use the electronic circuit device as a constituent material in the conventional device. In addition, the heat resistance required to withstand immersion in the solder bath is no longer required, and since the electronic component bodies can be fixed to each other at the same time by molding once, the economy is extremely high.

[Brief description of drawings]

1 is a sectional view showing an embodiment of the electronic circuit device of the present invention (viewed in the direction of arrows XX in FIG. 2), FIG. 2 is a bottom view of the device shown in FIG.
3 to 5 are views for explaining the manufacturing method of the embodiment of the present invention, and FIG. 6 is a block process drawing showing the manufacturing process of the conventional electronic circuit device. 1 ... Electronic parts, 1a ... Lead terminals, 2 ... Conductive resin material, A ... Circuit part, B ... Bridge part.

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Claims (1)

[Claims] 1. A plurality of electronic parts having lead terminals are arranged, and a circuit part for electrically connecting the lead terminals of these electronic parts and a bridge part for holding each electronic part body to each other are electrically conductive. An electronic circuit device characterized by being formed from a conductive resin material.