JP3928243B2 - Circuit component and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circuit component having a sliding portion and a manufacturing method thereof, and more particularly to a structure of a conductive portion and an insulating portion of a circuit component and a manufacturing method thereof.
[0002]
[Prior art]
Conventionally, in a circuit component having a position detection function or a switching function, a wiring pattern is provided on a substrate by etching or the like, and a brush is formed on a conductive portion where the wiring pattern is formed and an insulating portion where the wiring pattern is not formed. Such a circuit component is used in a vehicle, such as a throttle sensor, a vehicle height sensor, or a lock / unlock switch mechanism provided in a door lock device.
[0003]
[Problems to be solved by the present invention]
However, when the brush slides between the conductive part and the insulating part on the substrate, the sliding part that moves while the terminal of the brush contacts during wear is worn due to aging. Or an insulating oxide is formed by the influence of temperature, humidity, etc., and poor conduction occurs at the sliding portion. In order to prevent this, the material used for the conductive portion on which the brush or the wiring pattern is formed may be gold or silver, but it becomes expensive.
[0004]
Therefore, the present invention has been made in view of the above-described problems, and it is a technical problem to prevent conduction failure by an inexpensive method without generating wear powder on the sliding portion.
[0005]
[Means for solving the problems]
According to the technical means of claim 1 taken in order to solve the above problem, the conductive part and the insulating part are formed by injection molding of a resin, and the conductive part has a melting point of 200 ° C. or more as a conductive substance. The lower layer made of a resin containing only a low melting point alloy connected in a network form and the sliding portion on the substrate are made of an upper layer made of a resin containing carbon.
[0006]
In this case, since a conductive layer containing carbon is formed on the sliding portion on the substrate on which the contact member slides in the substrate on which the conductive portion and the insulating portion are formed by resin injection molding, the sliding portion is protected by carbon. Therefore, the slidability is improved, and no wear powder is generated during sliding. In addition, since no oxide is formed due to the influence of temperature, humidity, or the like, conduction failure does not occur due to an inexpensive configuration. The conductive material for a low-melting alloy, conductivity is rather good, because a melting point of 200 ° C. or higher, the conductive portion is familiar easily with the molten thermoplastic resin during injection molding.
According to the technical means described in claim 2, crystalline or amorphous carbon is used for the upper layer formed of a resin containing carbon.
[0007]
In this case, if crystalline carbon is used for the carbon-containing conductive layer, the conductivity is improved. Further, if amorphous carbon is used, the adhesion to the resin is improved and the wear resistance is improved.
[0008]
According to the technical means of claim 3 , the contact member slides on the substrate having the conductive portion and the insulating portion inside, and the contact state between the conductive portion and the insulating portion is determined by the contact member. In the method of manufacturing a circuit component to be detected, a first step of forming an insulating resin molded product (primary molded product) by injection molding, and a melting point of 200 ° C. or more as a conductive substance on the primary molded product , A second step of injection-molding a resin containing only a low-melting-point alloy connected in a mesh shape to produce a conductive substance-containing resin molded product (secondary molded product) provided with the insulating portion and the conductive portion; It is characterized by comprising a third step in which a carbon-containing conductive layer is formed at a sliding portion on which the contact member on the next molded product slides.
In this case, it is easy to form a carbon-containing conductive layer that has good slidability, does not generate wear powder when the contact member slides, and does not cause poor conduction because the conductive material is joined with a low melting point alloy. It becomes possible to do. Further, since the melting point of the low melting point alloy is 200 ° C. or higher, the conductive part is easily compatible with the thermoplastic resin melted during the injection molding .
[0009]
According to the technical means described in claim 4 , since the carbon-containing conductive layer is formed by injection molding and can be performed by the same injection molding as the substrate, productivity is improved.
[0010]
According to the technical means of the fifth aspect , since the carbon-containing conductive layer is formed on the secondary molded product by transfer, it is possible to easily provide a simple conductive layer by transfer. .
[0011]
According to the technical means of claim 6 , since the carbon-containing conductive layer is formed on the secondary molded product by screen printing, even a conductive layer having a complicated shape can be easily provided by screen printing. become.
[0012]
According to the technical means described in claim 7 , the carbon-containing conductive layer is formed of a thermoplastic resin, a thermosetting resin, or a photocurable resin. When thermoplastic resin is used, productivity is good and suitable for mass production, when thermosetting resin is used, the equipment is inexpensive and suitable for small-scale production, and when photocurable resin is used, it is conductive. Useful when heat is not applied to the layer.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 is an explanatory diagram showing a relationship when a brush (contact member) 2 slides on a substrate which is a circuit component. In (a), the conductor part 3 connected to the insulating part 6 and the connector 4 is provided on the substrate, and one terminal 2b of the brush 2 slides along the conductive part 3b in the sliding part 5 as shown in (b). It is shown that the other terminal 2a has a switching function by being in contact with the conductor portion 3a or the insulating portion. In this case, the conductive portion 3 has a hierarchical structure shown in (c), and a conductive resin is formed on the insulating layer, and a carbon-containing conductive layer is formed thereon, whereby the sliding portion. 5 is protected.
[0015]
The conductive portion 3 Ru der those made of a conductive resin. Conductive material contained in Ru are bonded by low melting point alloy. In this case, the conductive substance is a mixture of up to 80% by weight in a thermoplastic resin, and copper-based, nickel-based, and iron-based materials can be used. Moreover, the aspect ratio can use the thing of 1-1000.
[0016]
At this time, if a low melting point alloy having a melting point of 100 ° C. or higher is used, the low melting point alloy melts at the time of injection molding, so that the conductive alloy is melted and connected in a chain, thereby improving the conductivity. The components of the low melting point alloy include Sn—Pb, Sn—Ag—Pb, Sn—Bi, Sn—Bi—In, Bi—Pb, Bi—Sn, Sn—Cu, Sn—Cu. -Ni-P system, Sn-Ag system, Sn-Bi-Pb system, Sn-In system can be used, especially if Sn-Cu-Ni-P system having a melting point of about 200 ° C is used. It becomes easy to become familiar with resin.
[0017]
Examples of the thermoplastic resin include propylene, polyethylene, polystyrene, acrylonitrile / butadiene / styrene resin, modified polyphenylene oxide resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin, aromatic polyamide resin, polyphenylene sulfide resin, liquid crystal polymer, Polyetherimide, polybenzimidazole, polyetheretherketone, polyethersulfone, and other resins can be used. Especially when acrylonitrile / butadiene / styrene resin or polybutylene terephthalate resin is used, the viscosity at high temperature is a low melting point alloy. And mixes well at about 200 ° C. In this case, it is also possible to use a polymer blended with another resin.
[0018]
Furthermore, as another example of the conductive resin, a mixture of the above-described thermoplastic resin with 10% by weight or more of a low melting point alloy may be used. In this case, if the low melting point alloy is continuously connected in a network, and the low melting point alloy and the thermoplastic resin are the same as those described above, conductivity is ensured.
[0019]
In the carbon-containing conductive layer formed on the conductive resin of the sliding part 5, carbon can be carbon black (acetylene black, furnace black, thermal black, etc.) and graphite, and a thermoplastic resin, A thermosetting resin or a photocurable resin is used as a binder and cured.
[0020]
Next, a hierarchical structure of circuit components having a conductive portion and an insulating portion will be described with reference to FIG. This manufacturing method is roughly classified into three types. (1) As shown in FIG. 2, a carbon-containing conductive layer is formed by injection molding on a brush sliding portion on a resin molded product 22 obtained by molding. A method, (2) a method other than injection molding, for example, a method of forming the carbon-containing conductive layer 23 by, for example, stamp-type transfer, or (3) a method of forming the carbon-containing conductive layer 23 by screen printing. The manufacturing method will be described below.
[0021]
(1) Method of forming a carbon-containing conductive layer after forming a conductor (see FIG. 2)
The molds 10, 11, and 12 are closed (step 1), and the molds 10, 11, and 12 are closed, and the insulating resin is supplied from the external resin extrusion device to the cavity space 31 having a shape suitable for the product shape. Injecting and injecting from the resin injection port 11a, an insulating primary molded product is obtained by injection molding (step 2). Thereafter, the molds 11 and 12 are replaced with the molds 13 and 14, and then the molds are clamped to form a cavity space 32 as a conductive portion on one side surface of the primary molded product 21 (step 3). The conductive resin is injected into the cavity space 32 from the resin injection port 13a of the mold 13 and injection molding is performed, whereby a wiring pattern is formed on the primary molded product 21 by secondary molding. The formed conductive resin is formed (step 4). Thereafter, one mold 13 is opened, the mold 13 is replaced with the mold 15, and then the mold is clamped to form a cavity space 33 in the sliding portion 5 of the brush 2 at the conductive portion. The conductive resin resin containing carbon described above is injected from the resin injection port 15a of the mold 15 into the cavity space 33, the resin containing carbon is injected into the cavity space 33, and injection molding is performed. The carbon-containing conductive layer 23 is formed by the next molding.
[0022]
Thereafter, the clamped molds 10, 14, and 15 are opened, and a resin molded product having the conductive portion 3 and the insulating portion 6 and having an insulating layer, a conductive layer, and a carbon-containing conductive layer is formed as the mold 10. The final product can be obtained by taking it out of
[0023]
Therefore, if this method is employed, a resin molded product can be obtained by performing only injection molding several times. Therefore, the cycle time during molding is short, and it is suitable for mass production.
[0024]
(2) Method for forming carbon-containing conductive layer 23 by stamp transfer (see FIG. 3)
This method is the same as the method described above until the step of obtaining the secondary molded product (step 3 in FIG. 2). In this method, a carbon-containing thermoplastic resin is formed on the surface of the conductive resin 22 of the sliding portion 5. Is transferred by a transfer jig 17 made of rubber or the like. That is, a method of transferring a carbon-containing resin by applying a carbon-containing conductive resin to the transfer jig 17 and pressing the transfer jig 17 against the conductive resin 22 is employed.
[0025]
After the transfer, the binder resin is cured by heat or ultraviolet rays at a temperature of 120 to 150 ° C. for about 1 hour to form the carbon-containing conductive layer 23. If this method is adopted, the carbon-containing conductive layer 23 can be easily provided at the brush sliding portion of the conductive portion 3, and the equipment is simple and inexpensive.
[0026]
(3) Method of forming carbon-containing conductive layer 23 by screen printing (see FIG. 4)
In this method, a carbon-containing conductive film is formed by printing on a film 24 having a film thickness of 50 to 200 μm, such as polyester or polyethylene coated with a release agent, at the position of the conductive portion 3 of the brush sliding portion, and cured. Let On the other hand, after forming a primary molded product through step 2 in FIG. 2, the film 24 cured in the mold 16 is set inside the mold 16 and clamped. In this state, a cavity space is provided at a position where the conductive resin is formed, and the conductive resin is injected from the resin injection port 16a of the mold 16 into the cavity space to perform injection molding. After that, after the mold 16 is opened, since the release agent is applied to the film 24, only the film 24 can be easily peeled off, and after the film transfer, the resin molded product is taken out from the molds 10, 14. Thus, a resin molded product can be obtained.
[0027]
In this case, it is also possible to change the order of forming the insulating portion 6, the conductive portion 3, and the carbon-containing conductive layer 23 in the manufacturing method described above. Another method for providing the carbon-containing conductive layer 23 on the conductive layer may be a spray method or a roll coat.
[0028]
【effect】
According to the present invention, the conductive portion and the insulating portion of the substrate are formed by resin injection molding, and the carbon-containing conductive layer is formed on the sliding portion on the substrate on which the contact member slides. Since a conductive layer containing carbon is formed on the sliding portion on the substrate on which the contact member slides, the sliding portion is protected by carbon. And wear powder is not generated when sliding. In addition, oxides are not formed under the influence of temperature, humidity, and the like , and the conductive material is joined by a low melting point alloy, so that poor conduction can be prevented.
When a low-melting-point alloy having a melting point of 100 ° C. or higher is used, the low-melting-point alloy melts at the time of injection molding, so that the conductive alloys are connected in a chain and the conductivity can be improved.
When a low melting point alloy having a melting point of 200 ° C. or higher is used, it is easy to become familiar with the molten thermoplastic resin at the time of injection molding.
[0029]
If crystalline carbon is used for the carbon-containing conductive layer, the conductivity is improved. Further, if amorphous carbon is used, the adhesion to the resin is improved and the wear resistance is improved.
[0030]
Also, a step of making a primary molded product by injection molding, a step of making a secondary molded product provided with a conductive portion including a conductive material joined by an insulating portion and a low melting point alloy by injection molding on the primary molded product If it is composed of a process in which a carbon-containing conductive layer is formed in the sliding part where the contact member slides in the secondary molded product, it has good slidability, no abrasion powder is generated during sliding, and low melting point Since the conductive material is joined with the alloy, a carbon-containing conductive layer that does not cause poor conduction can be formed inexpensively and easily.
[0031]
In this case, if the carbon-containing conductive layer is formed by injection molding, productivity can be improved because it can be performed by the same injection molding as the substrate.
[0032]
Further, if the carbon-containing conductive layer is formed on the secondary molded product by transfer, even a simple shape can be easily provided by transfer.
[0033]
Furthermore, if the carbon-containing conductive layer is formed on the secondary molded product by screen printing, even a complicated shape can be easily provided by screen printing.
[0034]
Furthermore, if the carbon-containing conductive layer is formed of a thermoplastic resin, a thermosetting resin, or a photo-curing resin, the productivity is good when the thermoplastic resin is used, and suitable for mass production. Thus, when a thermosetting resin is used, the equipment is inexpensive and suitable for small-scale production, and when a photocurable resin is used, it is effective when heat cannot be applied to the conductive layer.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a relationship when a contact member slides on a substrate in a circuit component according to an embodiment of the present invention.
FIG. 2 is a first manufacturing process of a circuit component according to an embodiment of the present invention.
FIG. 3 is a second manufacturing process of the circuit component according to the embodiment of the present invention.
FIG. 4 is a third manufacturing process of the circuit component according to the embodiment of the present invention.
[Explanation of symbols]
1 Board (circuit parts)
2 Brush (contact member)
3, 3a, 3b Conductive part 4 Connector 5 Sliding part 6 Insulating part 21 Insulating resin molded product (primary molded product)
22 Conductive resin molded products (secondary molded products)
23 Carbon-containing conductive layer (tertiary molded product)

Claims (7)

A circuit component in which a contact member slides on a substrate having a conductive portion and an insulating portion inside, and the contact state between the conductive portion and the insulating portion or the contact state between the conductive portions is detected by the contact member. In
The conductive portion and the insulating portion are formed by resin injection molding,
The conductive part has a melting point of 200 ° C. or more as a conductive substance, and a lower layer formed of a resin containing only a low-melting point alloy connected in a network ,
A circuit component, wherein the sliding portion on the substrate is composed of an upper layer formed of a resin containing carbon.   2. The circuit component according to claim 1, wherein the upper layer formed of the resin containing carbon uses crystalline or amorphous carbon. In the circuit component manufacturing method, the contact member slides on the substrate having the conductive portion and the insulating portion inside, and the contact state between the conductive portion and the insulating portion is detected by the contact member.
A first step of molding an insulating resin molded product (primary molded product) by injection molding;
A conductive material containing the insulating part and the conductive part is formed by injection-molding a resin containing only a low-melting point alloy having a melting point of 200 ° C. or more as a conductive substance on the primary molded product. A second step of making a resin molded product (secondary molded product);
A circuit component manufacturing method comprising a third step in which a carbon-containing conductive layer is formed on a sliding portion on which the contact member slides on the secondary molded product. The circuit component manufacturing method according to claim 3 , wherein the carbon-containing conductive layer is formed by injection molding. The circuit component manufacturing method according to claim 3 , wherein the carbon-containing conductive layer is formed on the secondary molded product by transfer. The method for manufacturing a circuit component according to claim 3 , wherein the carbon-containing conductive layer is formed on the secondary molded product by screen printing. The circuit component manufacturing method according to claim 3 , wherein the carbon-containing conductive layer is formed of a thermoplastic resin, a thermosetting resin, or a photocurable resin.

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