JPH0425195A - Electronic circuit device - Google Patents

Abstract

PURPOSE:To dispense with a soldering process at the manufacture of an electronic circuit device by a method wherein a surface mounting electronic component is bonded onto an insulating board with a bonding agent, and the terminals of the electronic components are electrically connected to each other through a molded conductive pattern of conductive molding material. CONSTITUTION:Surface mounting electronic components 2 are bonded at a prescribed position on an insulting board 1 with a bonding agent 3. A conductive pattern 5 is molded with conductive molding material through a molding method such as an injection molding or the like and bonded to electrically connect terminals 4 of the electronic components 2. Therefore, a soldering process can be eliminated in an assembly process where the components 2 are mounted. By this setup, the insulating board 1 and the electronic component 2 can be formed of material low in heat-resistant property, and the component 2 can be prevented from deteriorating in characteristics due to a high temperature.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an electronic device in which terminals of surface-mounted electronic components are connected by a conductive circuit formed by molding a conductive molding material. Related to circuit devices.

(Prior Art) In recent years, electronic circuit devices in which various electronic components are mounted on a printed circuit board have been frequently used in the circuit portions of electronic devices.

An example of the manufacturing process is shown in FIG.

In the figure, first, multiple sheets of semi-cured prepreg made by impregnating and drying a phenolic or epoxy resin face on a base material such as paper or glass fiber are layered with copper foil, and then heated and pressed. They are integrated to form a copper clad laminate.

Next, a predetermined circuit pattern is formed on the copper foil surface by a method such as etching to obtain a circuit board. Furthermore, holes are made on this circuit board for inserting and mounting electronic component lead wires.
Lead wires (terminals) of electronic components are inserted into these holes, and these lead wires are fixed with solder from the back side to complete the electronic circuit device.

(Problem to be Solved by the Invention) However, as described above, in electronic circuit devices using such printed circuit boards, electronic components are mounted using solder, so solder is not applied to the circuit board as a constituent material. There was a problem in that it required excellent heat resistance properties that could withstand melting temperatures.

In other words, the actual operating temperature of the electronic circuit device is room temperature (=I
Although heat resistance is not particularly required, high heat resistance is required due to the manufacturing process. Therefore, it is necessary to take measures such as using an expensive thermosetting resin as the substrate material, which has been a factor in increasing costs.

In addition, in response to recent demands for equipment to be lighter, thinner, shorter, and smaller, there has been an increasing need for electronic devices using circuit boards to be thinner and smaller. A flat package type that eliminates lead wires due to warping and has metal terminals arranged flat on each of the four end faces, or a so-called surface mount type that has a leadless chip carrier type surface mount component mounted on an insulating substrate. Electronic circuit devices are becoming mainstream.

However, even in such devices, since solder is used to connect terminals of electronic components and conductive circuits, the substrate is required to have heat resistance.

The present invention was made in response to these conventional problems, and can be easily manufactured with almost no thermal stress, so there is no need for the board or the mounted electronic components to have higher heat resistance than necessary. The object of the present invention is to provide an electronic circuit device that does not have any problems, can use cheaper materials and structures, and can reduce costs.

[Structure of the Invention] (Means for Solving the Problems) That is, the electronic circuit device of the present invention has a plurality of surface-mounted electronic components bonded to predetermined positions on an insulating substrate, and a plurality of surface-mounted electronic components attached to the insulating substrate. It is characterized in that a conductive molding material is molded and bonded to the surface to form a conductive pattern that connects desired terminals of the electronic component.

Furthermore, as an insulating board, a board with holes penetrating through the front and back sides is used at predetermined positions, and surface-mounted electronic components are adhered to both the front and back sides of this board in the same manner, and a conductive molding material is used. is molded and bonded to form a conductive pattern connecting desired terminals of the electronic component, and the conductive molding material is also press-fitted into the through hole. It is an electronic circuit device.

(Function) In the electronic circuit device of the present invention, surface-mounted electronic components are bonded to predetermined positions of the insulating substrate with an adhesive or the like, and the terminals of these electronic components are electrically connected. The conductive pattern is formed by molding and adhering a conductive molding material using a method such as injection molding.

In this way, solder f is removed during manufacturing and assembly processes such as component mounting.
Since no damage is caused, it is possible to use materials with lower heat resistance than conventional materials for insulating substrates and electronic components.
Economical. Furthermore, the characteristics of electronic components do not deteriorate due to high temperatures.

Furthermore, in double-sided electronic circuit devices in which surface-mounted electronic components are mounted on both the front and back surfaces of an insulating substrate, through-holes are pre-drilled at predetermined positions on the insulating substrate, and conductive When the conductive pattern is formed by mold adhesion of the conductive molding material, the conductive molding material is also press-molded into the through hole. The conductive patterns on the front and back sides are electrically connected by this press-fit mold layer.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 and FIG. 2 are a sectional view and a top view, respectively, showing an embodiment of an electronic circuit device of the present invention.

In these figures, reference numeral 1 indicates an insulating substrate made of an insulating material such as thermoplastic resin or thermosetting resin and having a thickness of 0.1 mm to 3 mm. Electronic components 2 such as a mounting type IC, a transistor, a resistor, a capacitor, etc. are bonded with an adhesive. Reference numeral 3 indicates a layer of adhesive.

Among the electronic components 2, the electronic component 2a has terminals 4a formed on its upper and lower surfaces, and the electronic component 2b has ends T4b protruding from each of its two opposing side surfaces.

Between the terminals 4a and 4b of these electronic components 2, a conductive pattern 5 is provided by molding a conductive molding material by a method such as injection molding and adhering it onto an insulating substrate. connected. Note that the reference numeral 6 indicates a hole for positioning during molding.

Here, as the conductive molding material, ABS (acrylonitrile-butadiene-styrene copolymer) resin, modified P
A molding thermoplastic resin such as PO (polyphenylene oxide) resin mixed with powder or fiber of a conductive metal such as copper or stainless steel can be used.

Next, a method for manufacturing such an electronic circuit device will be explained based on FIG. 3.

That is, in order to manufacture the electronic circuit device of the example, first, the electronic component 2 is attached to a predetermined position of the insulating substrate 1 with an adhesive.
Glue. These operations can be performed manually or by automatic insertion devices.

Next, the insulating substrate 1 to which the electronic component 2 has been bonded in this manner is placed in an injection mold 7 shown below.

At this time, the pins 8 of the mold 7 are inserted into the positioning holes 6 formed in the insulating substrate 1 so that the positional relationship between the mold 7 and the insulating substrate is maintained accurately.

That is, the injection mold 7 includes a fixed side mold plate 11 attached to a fixed side mounting plate 9 via a spacer]0, and a spacer 13 disposed opposite thereto, and a spacer 13 on a movable side mounting plate]2.
The movable mold plate 14 is attached to the movable mold plate 14 through the movable side mold plate 14, and is configured so that a molded body having a predetermined shape can be obtained by injecting and filling a heated and melted conductive molding material into the cavity between them. ing.

The reference numeral 15 indicates a sprue bushing to which a nozzle (not shown) of an injection molding machine is connected, and the reference numeral 16 indicates a sprue and a runner, which are resin passages.

Further, reference numeral 17 indicates an ejection pin, and reference numeral 18 indicates a knock play 1.

In the cavity of the injection mold 7 having such a structure,
After mounting the insulating substrate 1 to which the electronic component 2 is adhered, the nozzle of an injection molding machine is connected to the sprue bush 15 on the upper part of the mold 7, and the heated and melted conductive molding material 19 is injected into the sprue and runner 16. The material is then press-fitted into the cavity of the mold 7 and cured by a conventional method.

By injection molding the conductive molding material 9 in a predetermined pattern on the surface of the insulating substrate 1, a conductive button 5 connecting the terminals of the electronic component 2 is formed, and an electronic circuit device with good characteristics is formed. or can be obtained.

And in such an electronic circuit device, its manufacturing, II+
Since high-temperature work such as soldering is not performed in the vertical process, it is possible to use H-moon, which has low heat resistance, improving economic efficiency.

In addition, in order to ensure the solid state (contact 5) of the conductive pattern 5 to the insulating substrate 1, a through hole 20 is provided at a predetermined position of the insulating substrate 1, as shown in FIG. In addition, the electronic component 2 may be adhered to both the front and back surfaces of this substrate in the same manner as in the embodiment described above, and the conductive pattern 5 may be molded and adhered using the conductive molding material 19.

In a double-sided electronic circuit device having such a structure, a conductive molding material 9 is also press-fitted into a through hole 20 that communicates the front and back sides of the substrate, and a conductive mold layer is formed therein. The conductive patterns 5 on the front and back sides are electrically connected by this mold layer.

Next, an example embodying the present invention will be described.

That is, a substrate made of ABS resin, which is a thermoplastic resin (50+n+n x 50n+m x 0.5mm
), apply adhesive in a predetermined pattern using silk screen in advance, and then apply the adhesive to the predetermined position on the
A total of 20 various electronic components such as IC elements, transistors, content elements, resistors, and coils were placed and bonded.

Next, the entire board with various electronic components bonded to it,
It is installed in the cavity of the injection mold shown in Fig.
-2300, ABS resin-based conductive material manufactured by Toshiba Chemical Corporation) was injected into the gap to form a circuit connecting desired terminals of various electronic components.

At this time, a piece of silicone rubber was fitted into a part of the mold to prevent damage to the electronic components when the mold was tightened, and to prevent the conductive molding material from getting around to unnecessary parts.

The electronic circuit device obtained in this way does not use materials with particularly high heat resistance, but since the manufacturing process does not involve work that is exposed to high temperatures as in the case of soldering, there is no deterioration in characteristics. It has sufficiently good characteristics.

[Effects of the Invention] As explained above, according to the electronic circuit device of the present invention, surface-mounted electronic components are bonded onto an insulating substrate with an adhesive or the like, and a conductive molding material is used between the terminals of these electronic components. Since the electrical connection is made by the conductive pattern formed by the mold, the soldering process during manufacturing becomes unnecessary.

] 1 Therefore, there is no need to use a material with particularly excellent heat resistance, and economical efficiency is improved.

[Brief explanation of the drawing]

1 and 2 are a cross-sectional view and a two-sided view showing an embodiment of the electronic circuit device of the present invention, FIG. 3 is a cross-sectional view illustrating the manufacturing method thereof, and FIG. 4 is a cross-sectional view of the electronic circuit device according to the present invention. FIG. 5 is a sectional view of a double-sided electronic circuit device which is another embodiment of the present invention, and FIG. 5 is a process diagram showing the manufacturing process of a conventional electronic circuit device. 1... Insulating substrate 2... Electronic component 3... Adhesive layer 5... Conductive Conductive pattern 7 formed by molding the molding material Injection mold 19 Conductive molding material 20
...Through hole

Claims (2)

[Claims] (1) A plurality of surface-mounted electronic components are individually bonded to predetermined positions on an insulating substrate, and a conductive molding material is molded and bonded to the surface of the insulating substrate to form desired terminals of the electronic components. An electronic circuit device characterized by forming a conductive pattern that connects between. (2) A plurality of surface-mounted electronic components are adhered to both the front and back surfaces of an insulating substrate with through holes drilled at predetermined positions,
A conductive molding material is molded and bonded to both surfaces of the insulating substrate to form a conductive pattern connecting desired terminals of the electronic component, and the conductive molding material is also applied in the through hole. An electronic circuit device characterized by being formed by press-fitting.