JP4288740B2 - Resin molded product having conductive portion and method for producing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin molded product having a conductive part and a manufacturing method thereof, and more particularly to a resin molded product having a conductive part having a three-dimensional shape inside and a manufacturing method thereof.
[0002]
[Prior art]
Conventionally, resin molded products having a conductive portion include those disclosed in, for example, Japanese Patent Application Laid-Open Nos. 10-9893 and 10-12995. The resin molded product disclosed in the former publication, for example, integrally has a conductive part obtained by press-molding a metal plate, and FIG. 11 shows a method for producing a resin molded product having a conductive part having a three-dimensional shape. . In FIG. 11, first, a metal plate serving as a conductive portion is cut into a predetermined shape by press dies A and B. After that, bending is performed several times by the bending dies A, B and C, D so as to obtain a three-dimensional predetermined shape, the die is opened, and the conductive part is bent into a predetermined shape. Removed from the mold. On the other hand, a resin molded product is formed by creating a cavity space with two concave and convex molds and injecting resin from the injection device into the cavity space. Then, after setting the press-molded conductive part on the injection-molded resin molded product, the attachment site is subjected to heat caulking with a hot press die, and the resin molded product and the conductive part are integrated.
[0003]
Moreover, in the resin molded product disclosed in the latter publication, a resin molded product having a conductive portion is manufactured by performing metal plating on the surface of the resin molded product.
[0004]
[Problems to be solved by the present invention]
However, in the former resin molded product, since the conductive portion is formed by press molding, there is a problem that the pattern shape of the conductive portion is restricted and material loss occurs due to press working. Furthermore, if the pattern of the conductive part is to be complicated in three dimensions, the more complicated the pattern becomes, the more the bending process of the pattern of the conductive part becomes necessary, which increases the manufacturing cost. It was.
[0005]
In addition, in the latter case, in order to obtain a resin molded product having a conductive portion by plating, it is possible to form a conductive portion having a three-dimensional shape, but this increases the number of plating steps, Increases manufacturing costs.
[0006]
Then, this invention is made | formed in view of said problem, and provides the resin molded product which has a three-dimensional-shaped electroconductive part which can be manufactured without causing the increase in manufacturing cost, and its manufacturing method. Technical issue.
[0007]
[Means for Solving the Problems]
The technical means taken in order to solve the above problems is to mix an alloy that melts the conductive part in a thermoplastic resin at the time of injection molding in a conductive resin molded product having a conductive part formed by injection molding. The connector terminal and the conductive portion are provided with conductivity by providing a metal connector terminal having a through hole, and covering one end side portion of the connector terminal including the through hole with a conductive resin. This is a conductive resin molded product having a conductive portion characterized by electrically connecting the two .
[0008]
According to this means, the conductive part having a three-dimensional shape can be easily formed by the fluidity of the conductive resin, and the manufacturing cost of the resin molded product can be reduced.
[0009]
In the above-described means, if a conductive resin can be formed at the time of resin molding and a low melting point alloy containing no lead and containing tin as a main component is kneaded with a thermoplastic resin or a thermosetting resin, resin molding is performed. Sometimes, the alloy melts, and a conductive resin having a conductive portion through which electricity easily flows can be formed.
[0010]
Preferably, if the resin molded product has a connector terminal made of a conductive resin, a connector terminal having good electrical connection with the conductive portion when the conductive portion is formed of the conductive resin on the resin molded product. It can be provided integrally. For this reason, it is not necessary to use a lead wire for connecting the connector terminal and the conductive portion, and to solder the lead wire, so that the number of parts is reduced.
[0011]
In addition, when the resin molded product has a metal connector terminal, a through hole is formed in the connector terminal, and one end side portion of the connector terminal including the through hole is covered with a conductive resin, thereby reducing the number of parts. It is possible to obtain a good electrical connection between the conductive portion and the metal connector terminal.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
1 to 3 show a first embodiment of a resin molded product having a conductive portion according to the present invention. In the first embodiment, an example in which the present invention is applied to a lamp unit that blinks or lights a brake lamp or a blinker of a vehicle is shown.
[0014]
In this lamp unit, a lamp 6 to be lit or blinked is attached to a circuit board 1 which is a resin molded product formed of resin, and lamp sockets 5 having two cylindrical shapes 5a are provided on both sides of the circuit board 1. I have. From the lamp socket 5, wiring patterns (conductor portions) 2, 3, 4 extend from the plus terminals 3 b, 4 c and the minus terminals 2 b, 2 c of the two lamp sockets 5 to the connector portion 7. The positive terminal 6a and the negative terminal 6b of the lamp 6 are fitted into the lamp 6 and come into contact with the positive terminals 3b and 4c and the negative terminals 2b and 2c on the circuit board. Therefore, if a predetermined voltage is applied to the terminals 2a and 3a of the connector section 7 from the outside, the lamp 6 is turned on or blinks. Similarly, if a predetermined voltage is applied to the terminals 2a and 4a, the lamp 6 is turned on. Or blink.
[0015]
Therefore, in the above configuration, a conductive resin is used for the wiring patterns 2, 3, and 4 that are conductive portions. There are two types of this conductive resin, one of which uses a mixture of thermoplastic fibers in a thermoplastic resin, and the conductive fibers are physically bonded. Some are joined by low melting point solder. The conductive metal fibers, the volume resistivity of 10 ^- about ⁴ Omega · cm, for example, copper, nickel, can be used as such iron-based, a range to reduce the electrical resistance in a thermoplastic resin Mix in (up to 80% by weight). In this case, it is preferable to use conductive fibers having an aspect ratio of 1 to 1000.
[0016]
In addition, the thermoplastic resin blended with the conductive fiber includes 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 acrylonitrile / butadiene / styrene resin and polybutylene terephthalate resin. For example, it has a high viscosity at high temperatures and mixes well with low melting point alloys. In this case, a polymer blend with another resin may be used.
[0017]
Further, the low melting point alloy only needs to have a melting point of 100 ° C. or higher, and an alloy that melts at the time of injection molding is used. As its components, Sn-Pb, Sn-Ag-Pb, Sn-Bi, Sn-Bi-In, Bi-Pb, Bi-Sn, Sn-Cu, Sn-Cu-Ni-P Sn-Ag, Sn-Bi-Pb, and Sn-In can be used, and if a Sn-CU-Ni-P system having a melting point of about 200 ° C is used, a thermoplastic resin may be used during molding. It becomes easy to become familiar with.
[0018]
As another example, if a low melting point alloy of 10% by weight or more is mixed in a thermoplastic resin, the low melting point alloy is melted at the time of forming and connected to a network to improve conductivity. Can do. In this case, the same low melting point alloy and thermoplastic resin as those described above are used. According to one conductive resin mixed with this low melting point alloy, the resistance is small and the conductive portion can be made thin or thin as compared with the other mixed metal fiber.
[0019]
Next, a method for manufacturing the circuit board 1 having a conductive portion will be described. There are two types of this manufacturing method. One method is to use only the above-described conductive resin for the terminals 2a, 3a, 4a and the wiring patterns 2, 3, 4 (A), and to connect the connector terminals 2aa, 3aa, 4aa as shown in FIG. In the case of metal (B), the manufacturing method in these cases will be described.
[0020]
(A) When conductive resin is used for the terminals 2a, 2b, 2c, 3a, 3b, 4a, 4c and the wiring patterns 2, 3, 4 to be conductive parts, as shown in FIG. The molds 21 and 22 are overlapped to form a cavity space 12 between the two molds 21 and 22, and an insulating resin is applied to the place where the cavity space 12 is formed from an resin injection port 22a by an external resin extrusion device (not shown). The resin is injected into the cavity space 12 to make a primary molded product. In this state, the circuit board 1 is not yet provided with a conductive portion. Next, one mold 22 is changed to another mold 23 to create a cavity space 23b in which the superimposed conductive resin is molded, and the resin is injected from the resin injection port 23a in the same manner. This time, the conductive resin having conductivity is injected to fill the cavity space 23b with the resin. As a result, the circuit board 1 in which the conductive resin is provided on the wiring patterns 2, 3, 4 having the portions of the terminals 2 a, 2 b, 2 c, 3 a, 3 b, 4 a, 4 c to be conductive portions is made by secondary molding. Can do.
[0021]
In this case, the order may be reversed, and the conductive portion may be made of a conductive resin to make a primary molded product, the primary molded product may be set in a mold, and the insulating portion may be made of a secondary molded product.
[0022]
(B) When the connector terminals 2aa, 3aa, 4aa of the connector part 7 are metal, the connector terminals 2aa, 3aa, After 4aa is set in advance, the conductive portion is molded with a conductive resin. Thereafter, a method can be used in which the conductive resin is set in another mold, the insulating resin is injection-molded, and the molded product is taken out from the resin mold.
[0023]
In this case, as shown in FIGS. 4 and 5, through holes 2aa1, 3aa1, 4aa1 are provided in one end side portions of the connector terminals 2aa, 3aa, 4aa, and the entire circumference of the one end side portion of the connector terminal including these through holes is provided. Cover with conductive resin, and fill the through holes 2aa1, 3aa1, 4aa1 with conductive resin. Accordingly, the connector terminals 2aa, 3aa, 4aa and the conductive portion are not peeled off due to the difference in coefficient of linear expansion between the metal and the conductive resin (metal: 1 × 10 ⁻⁵ , conductive resin: 3 × 10 ⁻⁵ ) The reliability of the thermal shock resistance of the electrical connection between the conductive portion and the connector terminal can be ensured. If the conductive resin is Sn-based as described above, Sn plating is applied to the connector terminals 2aa, 3aa, 4aa, so that Sn of the same system is fused together at the time of injection molding, so that the conductive portion and the connector terminal The reliability of the electrical connection between them can be further improved.
[0024]
6 and 7 show a second embodiment of the present invention. The second embodiment shows an example in which the present invention is applied to a resin delivery pipe 100 that distributes fuel to each cylinder of an internal combustion engine. The delivery pipe 100 has a fuel passage 101 connected to a fuel pipe (not shown), and a fuel injection valve mounting hole 102 (not shown) is opened in the fuel passage 101. The delivery pipe 100 is formed with a connector housing portion 103 extending to the side where the mounting hole 102 opens, and the fuel injection valve is mounted in the connector housing portion 103 when a fuel injection valve (not shown) is attached to the mounting hole 102. The metal connector terminals 104 and 105 that are electrically connected to each other are accommodated. On the side opposite to the side where the mounting hole 102 of the delivery pipe 100 is opened, a connector portion 110 is formed which accommodates a metal connector terminal 111 that is electrically connected to a control device for an internal combustion engine (not shown). The terminal 111 and the connector terminals 104 and 105 are electrically connected by conductive portions 106 and 107 each having a three-dimensional shape made of a conductive resin. Note that the connection portions between the connector terminals 104, 105, and 111 and the conductive portions 104 and 105 have the same configuration as that shown in FIGS. 4 and 5, so that a good electrical connection can be maintained.
[0025]
FIG. 8 shows a third embodiment of the present invention. In the third embodiment, an example in which the present invention is applied to a resin-made timing belt cover 200 of an internal combustion engine is shown. The timing belt cover 200 has connector portions 204 and 205 formed in spaced apart portions on one side surface thereof, and the portions between the connector portions 204 and 205 are electrically connected by conductive portions 201 to 203 each having a three-dimensional shape made of conductive resin. Connected. In FIG. 8, the conductive portions 201 to 203 are embedded in, for example, the timing belt cover 200, bent upward in the drawing in the vicinity of the connector portions 204 and 205, and extend to the connector portions 204 and 205. 9 and 10 show a fourth embodiment in which the present invention is applied to a flat plate 300 constituting a base of a vehicle door module. The flat plate 300 serves as a base of a door module that is attached to an inner panel of a vehicle door (not shown). The flat plate 300 has connector portions 301 and 302 at a central portion and one end portion in the longitudinal direction, respectively. Each is electrically connected by a conductive portion 303 having a three-dimensional shape made of resin. In the fourth embodiment and the third embodiment described above, the connector terminal is formed of a conductive resin, but the connector terminal is made of metal so that the connection form with the conductive portion shown in FIGS. 4 and 5 is taken. Also good. In the second to fourth embodiments described above, any one of two types of conductive resins can be used as in the first embodiment.
[0026]
Although the example which applied this invention to various resin molded products was demonstrated in above-described embodiment, this invention is not limited to these.
[0027]
【The invention's effect】
As described above, according to the present invention, since the conductive portion is formed of the conductive resin, it is possible to easily form even a three-dimensional complicated conductive portion due to the fluidity of the conductive resin. The manufacturing cost of the resin molded product can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a first embodiment of a resin molded product having a conductive portion according to the present invention.
2 is a perspective view showing a connection portion between a metallic connector terminal and a conductive portion of the resin molded product according to the first embodiment shown in FIG. 1; FIG.
FIG. 3 is an explanatory view showing a manufacturing process of a resin molded product having a conductive portion in the first embodiment shown in FIG. 1;
4 is an enlarged view of the connecting portion shown in FIG.
5 is a cross-sectional view taken along the line AA in FIG.
FIG. 6 is a top view showing a second embodiment of a resin molded product having a conductive portion according to the present invention.
FIG. 7 is a bottom view showing a second embodiment of a resin molded product having a conductive portion according to the present invention.
FIG. 8 is a plan view showing a third embodiment of a resin molded product having a conductive portion according to the present invention.
FIG. 9 is a perspective view showing a fourth embodiment of a resin molded product having a conductive portion according to the present invention.
FIG. 10 is a perspective view showing a fourth embodiment of a resin molded product having a conductive portion according to the present invention.
FIG. 11 is an explanatory view showing a manufacturing process of a resin molded product having a conventional conductive part.
[Explanation of symbols]
1 Circuit board (resin molded product)
2, 3, 4 Wiring pattern (conductive part)
2b, 2c Negative terminal (conductive part)
3b, 4c Positive terminal (conductive part)
6 lamps

Claims (2)

In a conductive resin molded product having a conductive part formed by injection molding,
Forming the conductive part by blending an alloy that melts during injection molding in a thermoplastic resin,
Imparts conductivity,
Furthermore, it has a metal connector terminal in which a through hole is formed,
A conductive resin molded article having a conductive portion, wherein one end side portion of the connector terminal including the through hole is covered with the conductive resin, and the connector terminal and the conductive portion are electrically connected.   The conductive resin can be molded at the time of resin molding, and is produced by kneading a low melting point alloy containing no lead and containing tin as a main component with a thermoplastic resin or a thermosetting resin, and injecting the conductive resin. The conductive resin molded article having a conductive portion according to claim 1, wherein the conductive portion is formed by molding.

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