JPH0935850A - Circuit board using thermoplastic film and its manufacture and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate generating a step difference between a thermoplastic film and a circuit formed on this thermoplastic film. SOLUTION: In a circuit board constituted by forming a circuit 200 with a conductive material on a thermoplastic film 100, a prescribed circuit 200 is formed by a conductive material on a thermoplastic film 100. A surface of the thermoplastic film 100, formed with the circuit 200, is placed to face downward, to mount partially or total part of the formed circuit 200 of the thermoplastic film 100 on a flat mounting base 300 heated to a softening temperature or more further to a temperature less than a melting temperature, so as to pressurize at least the heated part at a pressure of the atmosphere or more by a pressure member 500. In this way, the circuit 200 is sunk into the thermoplastic film 100, to be made flush with a surface of the thermoplastic film 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board using a thermoplastic film, a method for manufacturing the same, and an apparatus for manufacturing the same.

[0002]

2. Description of the Related Art A conventional circuit board using a film has a circuit formed on the surface of the film with a conductive material.

[0003]

The circuit board using such a conventional film has the following problems. That is, as shown in FIG. 7, a step is formed between the film 600 and the circuit 610 formed thereon.
This step is formed on the circuit 610 by a contactor 620 such as a brush.
In the switch circuit in which the slider slides, the contact 620 is repeatedly
The circuit 610 may be peeled off from the film 600 due to the contact with. Further, the contact 620 may be damaged. Therefore, such a switch circuit has a problem in life.

The present invention was devised in view of the above circumstances, and a circuit board using a thermoplastic film having no step between the thermoplastic film and the circuit formed thereon, a method for manufacturing the same, and a method for manufacturing the same. It is intended to provide a manufacturing apparatus.

[0005]

A circuit board using a thermoplastic film according to the present invention is a circuit board having a circuit formed of a conductive material on a thermoplastic film, wherein the circuit is made of a thermoplastic material. It is embedded in the film and is flush with the surface of the thermoplastic film.

Further, in the method of manufacturing a circuit board using a thermoplastic film according to the present invention, the first step of forming a predetermined circuit with a conductive material on the thermoplastic film, and the thermoplastic film is formed into a circuit. With the formed surface facing downward, a part or all of the formed circuit was placed on a flat mounting table heated to a temperature not lower than the softening temperature and lower than the melting temperature of the thermoplastic film, and at least heated. A second step of pressurizing the portion at a pressure equal to or higher than atmospheric pressure for a predetermined time.

Further, in the circuit board manufacturing apparatus using the thermoplastic film according to the present invention, the thermoplastic film on which the circuit is formed of the conductive material is placed flat with the surface on which the circuit is formed adhered. A mounting table and a pressure member that covers at least a heated portion of the thermoplastic film mounted on the mounting table, and the mounting table is a thermoplastic film having a softening temperature of the thermoplastic film or more. By heating to a temperature below the melting temperature, the pressure member is configured to press at least the heated portion of the thermoplastic film at a pressure of atmospheric pressure or higher.

[0008]

1 is a schematic sectional view showing an embodiment of a circuit board using a thermoplastic film according to the present invention, and FIG. 2 is a manufacturing method of a circuit board using the thermoplastic film according to the present invention. FIG. 3 is a schematic configuration diagram showing a method and a manufacturing apparatus.
FIG. 4 is a schematic configuration diagram showing a method and a device for manufacturing a circuit board using the thermoplastic film according to the present invention, and FIG. 4 is a schematic diagram showing a method and a device for manufacturing a circuit board using the thermoplastic film according to the present invention. Fig. 5 is a schematic plan view showing an embodiment of a circuit board using the thermoplastic film according to the present invention, and Fig. 6 is another apparatus for manufacturing a circuit board using the thermoplastic film according to the present invention. It is a schematic block diagram which shows. It should be noted that the dimensional difference at each place in each drawing is exaggerated for the sake of explanation.

The circuit board using this thermoplastic film is applied to a circuit board having a contact portion 210 constituting a rotary switch, as shown in FIG. 5, for example. That is, the rotary switch has a turning member (not shown) that is rotatably supported, a contactor attached to the back surface side of the turning member, and a contact portion 210 that is conducted by the contactor. The contact portion 210 is formed of the thermoplastic film 10
It is a part of the circuit 200 formed into 0.

The contact part 210 has one common part 211 with which the common terminal of the contactor is always in contact, and a plurality of (four in the drawing) individual parts 212 formed around the common part 211. ing. The common portion 211 is formed on a circumferential line centered on the rotation center P of the rotation member.
Further, the individual portions 212 are formed on the same circumferential line centered on the rotation center P. The common part 211 and the individual part 212 have independent wiring patterns 2
13 is connected.

The common part 2 which constitutes the contact part 210
11, the individual portion 212 and the wiring pattern 213 connected to each of them, as shown in FIG.
It is flush with the surface of 00. Therefore, even when the contactor slides on the common part 211 and the individual part 212, the common part 211 and the like are not peeled off or the contactor is damaged as in the conventional case.

A circuit board using such a thermoplastic film is manufactured as follows. First, a predetermined circuit 200 is formed of a conductive material on a thermoplastic film 100 such as polyethylene terephthalate (PET), vinyl chloride, polypropylene, or polycarbonate. As the conductive material, for example, a conductive paste obtained by mixing carbon powder with phenol resin is used.

The thermoplastic film 100 on which a predetermined circuit is formed is placed on a flat table 300. On this occasion,
The thermoplastic film 100, as shown in FIG.
The surface on which 00 is formed faces downward, that is, the surface on which the circuit 200 is formed is placed in close contact with the mounting table 300.

The mounting table 300 has a predetermined suction hole 31.
0 has been established. The suction holes 310 are holes for exhausting air (indicated by dots in FIG. 3) existing between the thermoplastic film 100 and the mounting table 300 to the outside during pressurization. The suction holes 310 are provided in the circuit film 20 formed on the thermoplastic film 100 mounted on the mounting table 300.
Of 0, it is set not to be below the portion to be pressed.

A movable heating unit 400 is set on the back side of the mounting table 300. Further, when the heating unit 400 moves and comes off the back surface side of the mounting table 300, a cooling unit (not shown) for cooling the mounting table 300 moves and is set on the back surface side of the mounting table 300. .

The heating unit 400 heats the mounting table 300 to a temperature above the softening temperature of the thermoplastic film 100 but below the melting temperature.

[0017]

[Table 1]

For example, as the thermoplastic film 100, P
When ET is used, the heating unit 400 has a softening temperature of 70 ° C. and a melting temperature of 2 for PET, as shown in Table 1.
Since the temperature is 60 ° C., the temperature of the mounting table 300 is set higher than the softening temperature of 70 ° C. and lower than the melting temperature of 260 ° C.

Of the circuit 200 formed on the thermoplastic film 100, the common portion 211 forming the contact portion 210.
The cup-shaped pressing member 500 is put on the portion including the individual portion 212 (see FIG. 3). This pressurizing member 500
A packing 510 for preventing air leakage is attached to the end of the device, so that air A having a pressure equal to or higher than atmospheric pressure is supplied from a compressor (not shown).

The air A supplied to the pressure member 500, that is, the air A that pressurizes the thermoplastic film 100, is set to a temperature lower than that of the heated thermoplastic film 100.

The pressurizing member 500 has a connecting portion 520 to the compressor formed on the upper part thereof and can be moved up and down by a vertical moving mechanism (not shown). When mounting the thermoplastic film 100 on which the circuit 200 is formed on the mounting table 300, the pressing member 500 is located above the mounting table 300, and as shown in FIG. It sometimes drops and adheres to the thermoplastic film 100.

When the portion of the thermoplastic film 100 surrounded by the pressure member 500 is pressurized at a pressure higher than the atmospheric pressure in this way, the back surface of the thermoplastic film 100, that is, the surface on which the circuit is formed is placed on the mounting table. Pressed against 300. During this pressurization, the thermoplastic film 100 is heated at a temperature equal to or higher than the softening temperature of the thermoplastic film 100 and lower than the melting temperature, so that the thermoplastic film 100 becomes soft. Therefore, as the surface on which the circuit is formed is pressed against the mounting table 300, as shown in FIG.
The circuit formed in the portion surrounded by 00 is embedded in the thermoplastic film 100.

When the predetermined time has passed, the heating is stopped. Specifically, the heating unit 400 is moved from the back surface side of the mounting table 300. Then, instead of the heating unit 400, the cooling unit is set on the back surface side of the mounting table 300. The cooling table rapidly and forcibly cools the mounting table 300. With the cooling of the mounting table 300, the thermoplastic film 100 is also rapidly cooled, and the circuit 200 is solidified with the circuit 200 embedded therein.

Since the mounting table 300 is formed flat, the circuit 2 embedded in the thermoplastic film 100 is used.
00 is flush with the thermoplastic film 100.

When the thermoplastic film 100 is solidified by cooling, the pressurization is stopped and the pressing member 50 is stopped.
0 is removed from the top of the thermoplastic film 100 to prepare for the production of a circuit board using the next thermoplastic film.

For example, a film thickness of 10 μm made of PET resin
The contact portion 21 as described above on the thermoplastic film 100 of
In the case of forming 0, if the mounting table 300 is heated to 210 ° C., it is pressurized at a pressure of about 70 Pa for about 2 minutes and then cooled, and then the common portion 211 or the like has a thickness of about 7 to 10 μm. The thermoplastic film 100, and the thermoplastic film 100 is flush with the common part 211 and the like without any step.

In the embodiment of the invention described above, only the portion where the contact portion 210 is formed is pressurized, but the present invention is not limited to this. For example, the entire circuit 200 including the contact portion 210, that is, the entire thermoplastic film 100 may be pressed. In this case, not only the contact part 210 but also other parts are flush with the thermoplastic film 100.

In the embodiment of the invention described above, the heating unit 400 and the cooling unit move on the back surface side of the mounting table 300 to heat and cool the mounting table 300. It is not limited. For example, the mounting table 30
A heater and a cooler may be built in 0, and both may be operated alternately.

Further, in the above-described apparatus for manufacturing a circuit board using a thermoplastic film, air pressure is used to press the thermoplastic film 100, but as shown in FIG. 6, it has flat elasticity. Plate material, for example, silicone rubber 56
0 may be pressed by the pressing member 550 attached to the surface. With the pressing member 550, the thermoplastic film 100
When is pressed, the thermoplastic film 100 is uniformly pressed.

[0030]

The circuit board using the thermoplastic film according to the present invention is a circuit board in which a circuit is formed of a conductive material on a thermoplastic film, and the circuit is embedded in the thermoplastic film. It is flush with the surface of the thermoplastic film. That is, since there is no step between the thermoplastic film and the circuit, even if the contactor slides on the circuit, the circuit does not peel off or the contactor is damaged. Therefore, when this is used for the switch circuit, the life of the switch can be extended.

Further, in the method of manufacturing a circuit board using a thermoplastic film according to the present invention, the first step of forming a predetermined circuit with a conductive material on the thermoplastic film, and the thermoplastic film is formed into a circuit. With the formed surface facing downward, a part or all of the formed circuit was placed on a flat mounting table heated to a temperature not lower than the softening temperature and lower than the melting temperature of the thermoplastic film, and at least heated. A second step of pressurizing the portion at a pressure equal to or higher than atmospheric pressure for a predetermined time.

Therefore, the circuit can be embedded in the thermoplastic film to be flush with the surface of the thermoplastic film. For this reason, since there is no step between the thermoplastic film and the circuit, even if the contactor slides on the circuit, the circuit is not peeled off or the contactor is not damaged. Therefore, when this is used for the switch circuit, the life of the switch can be extended.

Further, when the thermoplastic film is pressurized with air pressure, the thermoplastic film can be uniformly pressed, so that the circuit of the pressed portion can be evenly embedded in the thermoplastic film. .

If the temperature of the air for pressing the thermoplastic film is lower than that of the heated thermoplastic film, the time required for the step of solidifying the thermoplastic film after heating and pressing can be shortened.

Furthermore, the method for producing a circuit board using a thermoplastic film has a third step of forcibly cooling the thermoplastic film while applying pressure after the second step.
The productivity of the circuit board using the thermoplastic film is improved. Moreover, the thermoplastic film is less likely to be deformed by cooling the thermoplastic film under pressure. That is, if the pressurization is stopped before the thermoplastic film is cooled, the thermoplastic film will be left in a state in which it is easily deformed, so that it is easily deformed even if a slight external force is applied. Such deformation does not occur if the product is cooled while being pressurized.

Further, in the circuit board using the thermoplastic film thus manufactured, it was found from the experiment that the resistance value of the portion of the circuit embedded in the thermoplastic film was halved. For example, on a thermoplastic film made of PET resin having a thickness of 70 μm, a simulated wiring pattern having a length of 50 mm and a width of 10 mm is formed of a conductive material, and the thermoplastic film is
It heated at 10 degreeC and pressurized at 70 Pa for about 2 minutes. Then, as shown in Table 2 below, the resistance value is lower when heated and pressed to be flush with the thermoplastic film than before heated and pressed.

[0037]

[Table 2]

Therefore, it can be seen that in the circuit board using the thermoplastic film manufactured by this method, the circuit has a low resistance value flush with the thermoplastic film and is particularly suitable for a switch.

On the other hand, in the circuit board manufacturing apparatus using the thermoplastic film according to the present invention, the thermoplastic film on which the circuit is formed of the conductive material is placed flat with the surface on which the circuit is formed in close contact. A mounting table and a pressure member that covers at least a heated portion of the thermoplastic film mounted on the mounting table, and the mounting table is a thermoplastic film having a softening temperature of the thermoplastic film or more. By heating to a temperature below the melting temperature, the pressure member is configured to press at least the heated portion of the thermoplastic film at a pressure of atmospheric pressure or higher.

Therefore, according to the circuit board manufacturing apparatus using this thermoplastic film, a circuit board using a thermoplastic film having a circuit flush with the thermoplastic film can be manufactured very easily. .

If the pressure member is configured to press the thermoplastic film with air pressure, the thermoplastic film can be uniformly pressed, so that the circuit can be evenly embedded in the thermoplastic film. You can

When a pressing member that presses a plate material having flat elasticity is used as a pressing member for pressing the thermoplastic film, the pressing member is applied after being adhered to the thermoplastic film as in the case of pressurizing by air pressure. Since the pressurization is completed not by the two-step process of supplying air to the pressure member but by simply pressing the pressure member against the thermoplastic film, the time required for production can be further shortened.

Table 2 above shows the experimental results when a conductive paste obtained by mixing carbon powder with a phenol resin is used as a conductive material. Further, as the conductive paste, there is one in which silver powder is mixed with epoxy resin, polyester or the like. Further, not only the silver powder but also the silver powder mixed with the carbon powder can be used.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an embodiment of a circuit board using a thermoplastic film according to the present invention.

FIG. 2 is a schematic configuration diagram showing a method and apparatus for manufacturing a circuit board using the thermoplastic film according to the present invention.

FIG. 3 is a schematic configuration diagram showing a method and an apparatus for manufacturing a circuit board using the thermoplastic film according to the present invention.

FIG. 4 is a schematic configuration diagram showing a manufacturing method and a manufacturing apparatus for a circuit board using the thermoplastic film according to the present invention.

FIG. 5 is a schematic plan view showing an embodiment of a circuit board using the thermoplastic film according to the present invention.

FIG. 6 is a schematic configuration diagram showing another manufacturing apparatus of a circuit board using the thermoplastic film according to the present invention.

FIG. 7 is a schematic cross-sectional view showing a problem of a circuit board using a conventional film.

[Explanation of symbols]

 100 thermoplastic film 200 circuit 300 mounting table 400 heating unit 500 pressure member

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[Procedure amendment]

[Submission date] August 21, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0037

[Correction method] Change

[Correction contents]

[0037]

[Table 2]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction contents]

Table 2 above shows the experimental results when a conductive paste obtained by mixing carbon powder with a phenol resin is used as a conductive material. Further, as the conductive paste, there is one in which silver powder is mixed with epoxy resin, polyester or the like. Further, not only silver powder but also carbon powder can be used.

[Procedure 3]

[Document name to be amended] Drawing

[Correction target item name] Fig. 5

[Correction method] Change

[Correction contents]

[Figure 5]

Claims (8)

[Claims] 1. A circuit board having a circuit formed of a conductive material on a thermoplastic film, wherein the circuit is embedded in the thermoplastic film so as to be flush with the surface of the thermoplastic film. A circuit board using a thermoplastic film. 2. A first step of forming a predetermined circuit with a conductive material on a thermoplastic film, and a part or all of the formed circuit, wherein the surface of the thermoplastic film on which the circuit is formed faces downward. Is placed on a flat mounting table heated to a temperature not lower than the softening temperature and lower than the melting temperature of the thermoplastic film, and at least the heated portion is pressurized at a pressure not lower than atmospheric pressure for a predetermined period of time. A method of manufacturing a circuit board using a thermoplastic film, comprising: 3. The method for manufacturing a circuit board using a thermoplastic film according to claim 2, wherein in the second step, the thermoplastic film is pressed by air pressure. 4. The method of manufacturing a circuit board using a thermoplastic film according to claim 3, wherein the air that pressurizes the thermoplastic film has a temperature lower than that of the heated thermoplastic film. 5. The thermoplastic film according to claim 2, further comprising a third step of forcibly cooling the thermoplastic film under pressure after the second step. Circuit board manufacturing method. 6. A flat mounting table on which a circuit-formed surface is closely adhered to a thermoplastic film having a circuit formed of a conductive material, and a thermoplastic film mounted on the mounting table. At least a heating member is provided to cover the heated portion, the mounting table heats the thermoplastic film to a temperature not lower than the softening temperature of the thermoplastic film and lower than the melting temperature, and the pressing member is thermoplastic. An apparatus for manufacturing a circuit board using a thermoplastic film, wherein at least a heated portion of the film is pressed at a pressure higher than atmospheric pressure. 7. The apparatus for manufacturing a circuit board using a thermoplastic film according to claim 6, wherein the pressing member presses the thermoplastic film with air pressure. 8. The apparatus for manufacturing a circuit board using a thermoplastic film according to claim 6, wherein the pressing member presses a plate material having flat elasticity.