JPH11254485A - Method for forming circuit wiring of conductive plastic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming circuit wiring in which a conductive resin composition prepared from a special conductive plastic which gives no undesirable influence to environment when discarded is not peeled from a frame of a different resin. SOLUTION: A resin frame 3 having grooves for forming circuit wiring with special constitution transferred is molded by male and female molds of special constitution, and a conductive plastic consisting of a conductive resin composition containing a thermoplastic resin, lead-free solder, and dispersion media is injected into the special grooves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for circuit-wiring conductive plastic on a substrate and a frame serving as a three-dimensional component.

[0002]

2. Description of the Related Art Conventionally, when circuit wiring is made of a conductive plastic on a resin frame to be used as a substrate or a three-dimensional component, the circuit wiring is not separated from the resin frame on the assumption that the circuit is used in a severe environment. As described above, the resin material of the resin frame serving as the substrate and the resin material of the conductive plastic are made the same, or both resins are made of non-crystalline resin to improve the adhesion between them. However, conductive plastics are being made of a special composition in order to increase conductivity or eliminate adverse effects on the environment in the case of waste. Therefore, the resin frame as the substrate and the conductive plastic cannot be made of the same resin material, and a new problem arises in that the circuit wiring is easily peeled off from the resin frame as the substrate.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been developed by using a special conductive plastic made of a composition that does not adversely affect the environment when it is made into waste. It is an object of the present invention to provide a method for constructing a circuit wiring which does not peel off even with a resin frame of such a material.

[0004]

In order to achieve the above-mentioned object, a first method for performing circuit wiring of a conductive plastic according to the present invention is to provide a method of forming a circuit wiring groove in a resin frame. Forming a male mold in which the surface of the mold projection is processed into a fine uneven surface by projecting a hard granular material at high speed against the mold projection, and a recess for forming the outer surface of the resin frame. Molding a resin frame having a circuit wiring working groove in which a resin is injected into a cavity defined by mold-forming the female mold and transferring a fine uneven surface to the surface; A lead-free solder in which a thermoplastic resin, a melting point of which is adjusted to an alloying component within a temperature range in which the thermoplastic resin is thermoplasticized, and a lead-free solder. Helps to finely disperse in the thermoplastic resin And injecting and injecting a conductive plastic composed of a conductive resin composition containing a dispersion medium. A cavity defined by molding a male mold having a protruding projection for forming a concave portion and a female mold having a recess for forming an outer surface of the resin frame. The resin frame is formed by injecting a resin into the groove for forming the circuit wiring of the resin frame into a dovetail groove or an undercut groove; A thermoplastic resin, a lead-free solder having an alloying component adjusted within a temperature range in which the melting point of the thermoplastic resin is plasticized, and assisting fine dispersion of the lead-free solder in the thermoplastic resin. With distributed media Be injection injecting conductive plastic comprising a conductive resin composition comprising; is characterized in.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION (Production Example 1 of Conductive Plastic) 40% by volume of ABS resin (manufactured by Toray) as a thermoplastic resin, copper powder (Fukuda Metal Foil & Powder Industry: FCC-115) 15 as a dispersion medium After lightly mixing the volume%, the mixture was put into a pressure kneader (manufactured by Moriyama), and the rotation speed was 2 for 5 minutes.
Copper powder was dispersed in the resin in a state where the resin was thermoplasticized by kneading at 0 to 50 rpm to obtain a kneaded body. Next, lead-free solder (Fukuda Metal Foil Industry: Sn-Cu-Ni) was added to this kneaded body.
-AT-150), and the mixture was kneaded for 10 minutes at a rotation speed of 20 to 50 rpm, whereby the resin was thermoplasticized and the lead-free solder became a semi-molten state and was dispersed in the resin.

As a result, a thermoplastic resin, a lead-free solder whose melting point is adjusted to an alloy component within a temperature range where the thermoplastic resin is plasticized, and finely dispersing the lead-free solder in the thermoplastic resin. Distributed media to assist
The conductive resin composition containing was obtained. The obtained conductive resin composition was extruded into a linear shape by extrusion molding, and cut into granules (pellets) suitable for injection molding. Observation of the cross section of the pellet with an optical microscope showed that lead-free solder was uniformly dispersed in the resin to a size of 5 μm, and the semi-molten solder was continuously bonded with lead-free solder throughout. Had become. In addition, an injection molded product was prepared using the pellets, and the volume resistivity was measured.
The order of ↑-↑ 5Ω · cm was shown.

(Production Example 2 of Conductive Plastic) 40% by volume of PBT resin (made by Toray) which is a thermoplastic resin, and copper powder (Fukuda Metal Foil & Powder Industry: FCC-
115) After 15% by volume is lightly mixed, the mixture is put into a pressure kneader (manufactured by Moriyama), and the number of rotations is 20 to 50 rpm for 5 minutes.
In a state where the resin was thermoplasticized by kneading with m, the copper powder was dispersed in the resin to obtain a kneaded body. Next, lead-free solder (Fukuda Metal Foil Industry: Sn-Cu-Ni-AT-15) was added to this kneaded body.
0) 45% by volume is charged and the rotation speed is 20 to 50r for 10 minutes.
pm, the resin becomes thermoplastic and lead-free
The solder became a semi-molten state and was dispersed in the resin.

As a result, a conductive resin composition similar to that of Production Example 1 was obtained. The conductive resin composition was extruded into a linear shape by extrusion, cut and cut into granules (pellets) suitable for injection molding. And In this pellet, as in the case of Production Example 1, lead-free solder was uniformly dispersed in a resin to a size of 5 μm, and semi-molten solder was continuously joined to lead-free solder throughout. Had become. An injection-molded article was prepared using the pellets, and the result of measurement of the volume resistivity thereof was also on the order of 10 °-↑ 5Ω · cm.

In the above Production Examples 1 and 2, copper powder having the best wettability was used as a dispersion medium. In addition to copper, graphite, plated graphite, iron, tungsten, tungsten carbon, ceramic, conductive Any powder having good wettability, such as ceramic (aluminum nitride), can be used. Further, in Production Examples 1 and 2, a tin-based alloy (Sn-Cu-N) was used as lead-free solder.
Although i) was used, tin alone may be used.

(Example 1 of Circuit Wiring) FIG.
A resin frame 3 serving as a substrate is injection-molded in a cavity defined by matching the mold with a female mold 2. The male mold 1 is a mold having a mold projection 1A for forming a circuit wiring construction groove 3A (see FIG. 3) of the resin frame 3. As shown in FIG. 1, hard particles such as metal particles and sand particles are projected and collided at high speed, and the surface of the mold projection 1A is processed into a fine uneven surface.
In addition, at the time of high-speed projection of the hard granular material, the portions other than the mold projection 1A of the male mold 1 are masked. The female mold 2 has a recess 2A for forming the outer surface of the resin frame 3. Therefore, the resin frame 3 which has been injection-molded has the fine uneven surface 3B transferred to the surface of the circuit wiring construction groove 3A of the resin frame 3 when separated from the male mold 1, as shown in FIG. To be.

The resin frame 3 thus formed is
Is held in the female mold 2 as it is, or is taken out from the female mold 2 and set in another set mold, and another holding mold having no protrusion on the upper part thereof for filling the groove 3A for circuit wiring construction. 4, and the conductive plastic 5 obtained in the conductive plastic production example 1 or 2 is injected and injected into the circuit wiring construction groove 3A of the resin frame 3 to form the resin as shown in FIG. A conductive plastic 5 is applied to the frame 3 as circuit wiring. At this time, since the conductive plastic 5 is injected into the circuit wiring construction groove 3A having the fine uneven surface 3B, the anchoring effect works on this interface, and the adhesion between the two is enhanced, so that the peeling does not occur. Have been.

(Example 2 of Circuit Wiring) As in the case of Example 1, the resin frame 3 serving as a substrate is injected into a cavity defined by matching the male mold 1 and the female mold 2 together. It is formed into the state shown in FIG. The male mold 1 is provided with a divergent projection 1B for forming a circuit wiring construction groove of the resin frame 3 in the dovetail groove 3C (see FIG. 6). Therefore, in order to pull out the male mold 1 from the resin frame 3 in the state of FIG. 5, an operation of pulling out the protruding projection 1B in a state of flexibility before the resin frame 3 is solidified (die cutting). Need to be done. Thereafter, the conductive plastic 5 obtained in the production of the conductive plastic 1 or 2 is injected and injected into the dovetail groove 3C, which is a groove for circuit wiring, in the same manner as in the case of the working example 1 to obtain the state shown in FIG. The conductive plastic 5 is applied to the resin frame 3 as circuit wiring. At this time, since the conductive plastic 5 is injected and injected into the dovetail groove 3C, the conductive plastic 5 is in a state in which the conductive plastic 5 does not come off so as not to come out. Similar effects can be obtained even if the circuit wiring construction groove is formed in the undercut groove 3D as shown in FIGS. 7, 8, and 9 in addition to the dovetail groove 3C.

[0013]

As is apparent from the above description, the present invention provides a resin frame having a circuit wiring construction groove in which a special structure is transferred by a specially configured male mold and female mold. Molded and injected into this special circuit wiring groove, a conductive plastic consisting of a conductive resin composition containing thermoplastic resin, lead-free solder, and dispersion media. The conductive resin composition which does not give the resin can be applied as a circuit wiring which does not peel off even to a resin substrate made of a different material.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a processing state of a mold projection of a male mold.

FIG. 2 is a conceptual diagram showing a molding state of a resin frame serving as a substrate.

FIG. 3 is an explanatory view in which the surface of a groove for circuit wiring of a resin frame is exaggerated and enlarged.

FIG. 4 is a conceptual diagram showing a situation in which conductive plastic is used for circuit wiring.

FIG. 5 is a conceptual diagram illustrating another molding state of a resin frame serving as a substrate.

FIG. 6 is a conceptual diagram showing another situation in which conductive plastic is used for circuit wiring.

FIG. 7 is an explanatory view showing an example of an undercut groove.

FIG. 8 is an explanatory view showing another example of the undercut groove.

FIG. 9 is an explanatory view showing still another example of the undercut groove.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Male mold 1A Mold projection 1B Converging projection 2 Female mold 2A recess 3 Resin frame 3A Circuit wiring construction groove 3B Fine uneven surface 3C Dove groove 3D Undercut groove 4 Holding mold 5 Conductive mold Plastic

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeo Nakagawa 223-4-416, Notobotsu, Nakahara-ku, Kawasaki City, Kanagawa Prefecture (72) Inventor Hiroyuki Noguchi 1-170-2-306, Yayoimachi, Inage-ku, Chiba-shi, Chiba

Claims (2)

[Claims] A male member obtained by subjecting a hard granular material to high-speed projection collision with a mold projection for forming a groove for forming a circuit wiring of a resin frame to treat the surface of the mold projection into a fine uneven surface. A resin is injected into a cavity defined by molding a mold and a female mold having a concave portion for forming an outer surface of the resin frame, and a fine irregular surface is formed on the surface. Forming a resin frame having a circuit wiring construction groove onto which the pattern has been transferred;
A lead-free solder in which a thermoplastic resin and an alloy component whose melting point is adjusted within a temperature range in which the thermoplastic resin is thermoplasticized with respect to a circuit wiring construction groove of the molded resin frame;
And a dispersion medium for assisting fine dispersion of the lead-free solder in the thermoplastic resin. A conductive plastic circuit comprising a conductive resin composition comprising: Wiring construction method. 2. A male mold having a protruding projection for forming a circuit wiring construction groove of a resin frame, and a female formed with a recess for forming an outer surface of the resin frame. Resin is injected into a cavity defined by matching the mold with the mold to form a resin frame having a dovetail groove or an undercut groove in which a circuit wiring construction groove of the resin frame is formed; A lead-free solder having a thermoplastic resin, an alloy component adjusted to have a melting point within a temperature range in which the thermoplastic resin is plasticized, and a lead-free solder for the circuit wiring groove in the molded resin frame; And injecting and injecting a conductive plastic made of a conductive resin composition containing a dispersion medium for assisting fine dispersion of the solder in the thermoplastic resin.