JP2010238724A - Method of manufacturing molded circuit component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deformation of a substrate by an injection pressure of coating material in partially coating the plate-like substrate with the coating material. <P>SOLUTION: Projections 62, 62 arranged on a lower mold 6 are abutted on a part which is a rear surface 12 of the substrate 1 and serves as a conductive circuit by plating, and the coating material 4 is injected into a first cavity 51 which covers a front surface 11 of the substrate 1. A tip end of a projection 64 for a dummy conductive circuit is abutted on midpoints of the projections 62, 62 so as to prevent deformation of the substrate 1 by the injection pressure of the coating material 4. Right and left end parts of the substrate 1 are restrained by a stepped portion 65 arranged on an inner circumferential wall of the lower mold 6 to prevent deformation of the end parts. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method of manufacturing a molded circuit component, and more particularly to a method of manufacturing a molded circuit component in which a surface is partially covered with a coating material and a conductive circuit is formed by plating on a portion not covered with the coating material.

  Conventionally, a method of manufacturing a molded circuit component, wherein a surface of a base made of an insulating material is partially covered with a covering material, and a conductive circuit made of a plating layer is selectively formed on a portion not covered with the covering material. Have been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 01-207989

  By the way, in Patent Document 1, when the surface of a base is partially covered with a coating material, the base is placed in a mold, and the coating material is injection-formed in a cavity provided between the base and the mold. . Here, in the case where both the front and back surfaces of the base are partially covered with a covering material, cavities are provided between the front and back surfaces of the base body and the mold, respectively, and the covering materials are placed in these cavities. Injection molding.

  However, when the coating material is injection-molded separately for each of the cavities covering the front and back surfaces of the base body, it is necessary to provide separate runners in the mold, and the manufacturing cost of the mold and the injection of the coating material are required. The working cost of forming increases. In order to avoid this increase in cost and the like, a runner is provided only in the cavity covering the surface of the base, and the coating material injected into the cavity covering the surface of the base is passed through the cavity covering the end face of the base, The method of injecting into the cavity which covers the back surface of this base | substrate is employ | adopted.

However, in the case where the substrate is made of a thin flat plate, when the coating material is injected into the cavity covering the surface of the substrate, the injected coating material is in a period until it enters the cavity covering the back surface of the substrate. When pressed by the injection pressure of the covering material, the end portion or the central portion of the base body may be deformed toward the cavity that covers the back surface of the base body. The conductive circuit formed on the molded circuit component is extremely small and dense, so if the shape of the substrate is deformed, the conductive circuit is not formed accurately, making it difficult to assemble other electronic circuits or electronic components. become.

  The injection pressure of the coating material varies depending on the flow characteristics of the coating material, and the degree of deformation of the substrate varies depending on the material of the substrate, the thickness, the shape of the cavity, and the like. Therefore, it is very difficult to prevent the deformation of the substrate by appropriately combining these elements.

  Accordingly, an object of the present invention is to partially coat the surface of a substrate made of an insulating material with a coating material and selectively form a conductive circuit made of a plating layer on a portion not covered with the coating material. Another object of the present invention is to propose a method of manufacturing a molded circuit component that prevents the base body from being deformed by the injection pressure of the covering material.

  A feature of the method of manufacturing a molded circuit component according to the present invention is that the base body is deformed by the injection pressure of the covering material, and the base body is not deformed by providing a dummy conductive circuit in a portion contacting the inner wall of the cavity of the mold. There is in doing so. In other words, the method for producing a molded circuit component according to the present invention comprises forming a molded circuit by injection-molding a coating material on the surface of a substrate made of an insulating material, leaving a portion that becomes a conductive circuit, and plating the portion that becomes the conductive circuit. A method of manufacturing a component, wherein the substrate is plate-shaped and has a first surface, a second surface, and a third surface that form an end surface of the substrate. . A mold for injection-molding the covering material includes a first cavity, a second cavity, and a first cavity for covering the first surface, the second surface, and the third surface with the covering material, respectively. And a third cavity. The first cavity and the second cavity are in communication with each other via the third cavity.

  The covering material is injected into the first cavity from the outside of the mold, and the covering material injected into the first cavity is injected into the second cavity through the third cavity. The second surface is provided with conductive circuits in at least two places at a predetermined interval, and is either in the middle of the conductive circuits adjacent to each other or at the end of the base body. In other words, a dummy conductive circuit is formed.

  When the predetermined interval is at least three times the thickness of the substrate, it is desirable to provide a dummy conductive circuit in the middle of the interval.

  When the distance between the end face of the base and the conductive circuit closest to the end face is at least twice the plate thickness of the base, it is desirable to provide a dummy conductive circuit at the end of the base.

  It is desirable that the base be provided with an opening hole that allows the first cavity and the second cavity to communicate with each other.

  Here, the “substrate made of an insulating material” is not limited to the case where the substrate itself is made of an insulating material, but includes a substrate in which the surface of a conductive member is covered with an insulating material. “Plating” of “plating on a portion to be a conductive circuit” includes not only electroless plating but also a case where electroplating is laminated on the surface of electroless plating. “Plate” means a shape having two front and back surfaces and a thickness smaller than the surface area, but the shape is not limited. Moreover, not only a flat plate shape but also a curved surface shape and a three-dimensional shape bent partially. “Cavity” of “first cavity”, “second cavity”, and “third cavity” is a recess provided on the inner surface of the mold, and the base is placed in this mold In addition, it means a space formed between the surface of the substrate and the mold. That is, when a coating material is injection-molded in this “cavity”, the surface of the substrate is covered with this coating material.

  The “conductive circuit” in “the conductive circuit is provided in at least two places” may be of any shape. In addition to a linear shape, a bent shape, an arc shape, a ring shape, or a spot shape is also included. The “end of the substrate” means a peripheral portion of the plate-shaped substrate, but includes not only the entire circumference of the peripheral portion but also a portion of the entire periphery. The “dummy conductive circuit” means a portion of the molded circuit component that is not actually energized, and is formed by plating in the same manner as the conductive circuit. Moreover, the shape and number are not ask | required. The shape of the “open hole” is not limited. Not only circular holes but also elliptical holes or polygonal holes are included. Moreover, it is not limited to a single case but includes a case where a plurality are arranged.

  A conductive circuit is formed by plating on the surface of the substrate, which becomes a conductive circuit. Accordingly, the inner wall surface of the mold is brought into contact with the portion to be the conductive circuit so as not to be covered with the covering material. That is, the inner wall surface of the mold is provided with a protrusion having the same shape as that of the portion that becomes the conductive circuit, and this protrusion is brought into contact with the surface of the base so as not to be covered with the covering material. On the other hand, the portion that does not contact the surface of the base is a cavity formed in the mold, and the periphery of the portion that becomes the conductive circuit is covered with the coating material by injection molding the coating material in the cavity.

  Therefore, when the coating material is injected only from the outside of the mold into only the first cavity provided on the first surface of the flat substrate, the second surface that opposes the first surface due to the injection pressure of the coating material. The base body is deformed toward the second cavity provided on the surface. Here, when the second surface is provided with two or more portions to be conductive circuits, that is, two or more projection surfaces of the mold that abuts on the second surface, the projections adjacent to each other are provided. In the meantime, the substrate is deformed. Further, between the end portion of the base and the portion serving as the conductive circuit, the portion serving as the conductive circuit is used as a support portion to be in a cantilever state, so that the cantilever portion is deformed. Therefore, by providing a protrusion of a mold for forming a dummy conductive circuit at the middle of the conductive circuit adjacent to each other or at the edge of the substrate, the edge of the conductive circuit adjacent to each other or the edge of the substrate is formed. The deformation of the part can be prevented.

  When the interval between the conductive circuits adjacent to each other is 3 times or more the plate thickness of the substrate, or the interval between the end surface of the substrate and the conductive circuit closest to the end surface is twice or more the plate thickness of the substrate. Further, the influence of the deformation of the base body on the function of the molded circuit component is increased. Therefore, in such a case, the substrate can be effectively prevented from being deformed by providing the dummy conductive circuit described above at the end of the substrate.

  By providing the substrate with an opening hole that allows the first cavity and the second cavity to communicate with each other, the coating material injected into the first cavity enters the second cavity through the opening hole. It becomes easy and a base | substrate becomes difficult to deform | transform.

It is a front view of the flat molded circuit component by a prior art example. It is a top view of the flat-shaped molded circuit component by a prior art example. It is sectional drawing of the flat base body installed in the metal mold | die by a prior art example. It is a top view of the flat base | substrate provided in the metal mold | die by a prior art example. It is sectional drawing when a coating | coated material is injection-molded to the flat base body installed in the metal mold | die by a prior art example. FIG. 12 is another cross-sectional view when a coating material is injection-molded on a flat substrate placed in a mold according to a conventional example. FIG. 12 is another cross-sectional view when a coating material is injection-molded on a flat substrate placed in a mold according to a conventional example. It is sectional drawing of the deformed flat plate-shaped molded circuit component by a prior art example. It is sectional drawing of the flat base body installed in the metal mold | die by this invention. It is a top view of the flat base | substrate provided in the metal mold | die by this invention. It is sectional drawing when a coating | covering material is injection-molded to the flat base body installed in the metal mold | die by this invention. FIG. 5 is another cross-sectional view when a coating material is injection-molded on a flat substrate placed in a mold according to the present invention. FIG. 5 is another cross-sectional view when a coating material is injection-molded on a flat substrate placed in a mold according to the present invention. It is sectional drawing of the flat molded circuit component by this invention. It is a top view of the flat molded circuit component by this invention. It is a perspective view of the U-shaped molded circuit component by a prior art example. It is sectional drawing of the U-shaped base | substrate installed in the metal mold | die by a prior art example. It is a horizontal sectional view of a U-shaped base installed in a mold according to a conventional example. It is sectional drawing when a coating | covering material is injection-molded to the U-shaped base | substrate installed in the metal mold | die by a prior art example. FIG. 10 is another cross-sectional view when a coating material is injection-molded on a U-shaped base installed in a mold according to a conventional example. FIG. 10 is another cross-sectional view when a coating material is injection-molded on a U-shaped base installed in a mold according to a conventional example. It is sectional drawing of the deformed U-shaped molded circuit component by a prior art example. It is sectional drawing of the U-shaped base | substrate installed in the metal mold | die by this invention. It is a horizontal sectional view of the U-shaped base installed in the mold according to the present invention. It is sectional drawing when a coating | coated material is injection-molded to the U-shaped base | substrate installed in the metal mold | die by this invention. FIG. 5 is another cross-sectional view when a coating material is injection-molded on a U-shaped base placed in a mold according to the present invention. FIG. 5 is another cross-sectional view when a coating material is injection-molded on a U-shaped base placed in a mold according to the present invention. It is sectional drawing of the U-shaped molded circuit component by this invention. It is sectional drawing of the other U-shaped base | substrate installed in the metal mold | die by this invention.

  In order to facilitate understanding of a method for manufacturing a molded circuit component according to the present invention, first, a manufacturing method according to the prior art will be described with reference to FIGS. 1 and 2 show molded circuit components in which conductive circuits 202 and 203 are provided on the front and back surfaces of a flat substrate 201, respectively. That is, the flat substrate 201 has a horizontally long rectangular shape as shown in FIG. 2, and is manufactured by injection molding an insulating thermoplastic resin. Two conductive circuits 202 and 203 are formed on the front surface 211 and the back surface 212 of the flat substrate 201 at a predetermined interval, respectively. The conductive circuits 202 and 203 are formed by performing electroless plating on the surface 211 and the back surface 212 of the base body 201 that are not covered with the coating material 204, respectively. The molded circuit components shown in FIG. 1 and FIG. 2 are designed in shape, and the flat substrate 201 is deformed as described later in the conventional manufacturing method.

  FIG. 3 shows a case where the base body is accommodated between the upper mold 205 and the lower mold 206 in order to injection-mold the coating material 204 on the front surface 211, the end surface 213, and the back surface 212 of the base body 201. ing. The portions of the front surface 211, the back surface 212, and the end surface 213 of the base body 201 that are covered with the coating material 204 are the first cavity 251 and the second cavity on the inner surfaces of the upper mold 205 and the lower mold 206, respectively. 261 and a third cavity 263 are provided. Further, the portions where the conductive circuits 202 and 203 are formed by electroless plating in the subsequent process, which are not covered with the coating material 204, are provided with protrusions 252 and 262 on the inner wall surfaces of the upper mold 205 and the lower mold 206, respectively. The tips of the protrusions are in contact with the front surface 211 and the back surface 212 of the base body 201, respectively. The upper mold 205 is provided with a runner 253 for injecting the coating material 204 into the first cavity 251.

  4 to 7 show that when the coating material 204 is injected from the runner 253 to the first cavity 251, the coating material is applied to the first cavity, the second cavity 261, and the third cavity 263. , Shows a state of gradually spreading. As shown in FIG. 4, the coating material 204 injected from the runner 253 of the upper mold 205 into the first cavity 251 that covers the surface 211 of the base 201 is along the surface of the base as indicated by an arrow. spread. FIG. 5 shows the state shown in FIG. 4 in a cross section including the center line of the base 201. That is, the coating material 204 injected into the first cavity 251 that covers the surface 211 of the base body 201 covers the back surface 212 of the base body that has not yet penetrated and is hollow due to the injection pressure. The base body is deformed toward the second cavity 261. Similarly, the covering material 204 spreading to the left and right first cavities 251 deforms the left and right end portions of the base body 201 toward the left and right second cavities 263 by the injection pressure.

  As shown in FIG. 6, when the injection amount of the covering material 204 further increases, the covering material enters the second cavity 261 through the third cavity 263 covering the end surface 213 of the base body 201. Until the second cavity is filled, the central portion and the left and right end portions of the base body are further deformed, and finally come into contact with the inner wall surface of the second cavity. FIG. 7 shows a state in which the covering material 204 is filled in the first cavity 251, the second cavity 261, and the third cavity 263, and the injection of the covering material is completed.

  FIG. 8 shows a molded circuit component according to the prior art described above. That is, the base body 201 is deformed at the center portion and the left and right end portions thereof and abuts against the inner wall surface of the second cavity 261, so that this portion is not covered with the covering material 204. For this reason, the conductive circuit 207 by electroless plating is formed in the center part and both ends of the base | substrate 201 which are not covered with the coating | covering material 204. FIG. That is, the conductive circuit 207 is also formed in portions other than the conductive circuits 202 and 203 that were designed for the purpose as shown in FIGS.

  The present invention prevents the conductive circuit from being formed in portions other than the design purpose and deformation of the base 201 in the prior art described above. Hereinafter, a method for manufacturing a molded circuit component according to the present invention will be described in detail with reference to FIGS. The molded circuit parts manufactured according to the present invention are as shown in FIGS. First, the flat substrate 1 constituting the molded circuit component is injection molded using a synthetic resin. The synthetic resin is preferably a thermoplastic resin, but may be a thermosetting resin. Examples of the synthetic resin include aromatic liquid crystal polymer, polysulfone, polyether polysulfone, polyarylsulfone, polyetherimide, polyester, acrylonitrile / butadiene / styrene copolymer resin, polyamide, modified polyphenylene oxide resin, norbornene resin, and phenol resin. Epoxy resin is applicable. In addition, you may mix an inorganic filler etc. with the synthetic resin which carries out the injection molding of the base | substrate 1 as needed.

  Next, the surface of the substrate 1 is roughened. This is because small irregularities are formed on the surface of the substrate 1 to improve the adhesion of the electroless plating in the subsequent process and impart hydrophilicity by the anchor effect. Specifically, the substrate 1 is first degreased with a solvent such as trichloroethylene or an aqueous alkali solution such as sodium hydroxide. Next, for example, an aqueous solution of an alkali metal hydroxide such as NaOH or KOH, an aqueous solution of an alkali metal alcoholate such as alcoholic sodium or alcoholic potassium, or an organic solvent such as dimethylformamide is used to remove these liquids from the substrate 1. The surface is etched by coating the surface of the substrate or immersing the substrate in these liquids.

  As the next step, the roughened surface of the substrate 1 is coated with the coating material 4. Specifically, as shown in FIG. 9, a base 1 having a roughened surface is accommodated between an upper mold 5 and a lower mold 6, and a first cavity 51 covering the surface 11 of the base The covering material 4 is injection-molded into the second cavity 61 that covers the back surface 12 of the substrate. Here, the upper mold 5 and the lower mold 6 are formed so that the portions where the conductive circuits 2 and 3 shown in FIG. In addition, the tips of the two protrusions 52 and 62 provided respectively are in contact with each other. The distance between the two protrusions 52 and 52 and the protrusions 62 and 62 is three times or more the plate thickness of the base 1. Further, the distance between the two protrusions 62 and 62 and the left and right end portions of the base body 1 is twice or more the plate thickness of the base body 1.

  In addition, the projection 64 for the dummy conductive circuit is provided at the center of the projections 62 and 62 provided on the lower mold 6 so that the above-described deformation does not occur at the center of the base body due to the injection pressure of the covering material 4. It is provided. Further, both the left and right ends of the base are in close contact with the stepped portion 65 provided on the inner peripheral wall of the lower mold 6 and the lower surface of the upper mold 5 so that the above-described deformation does not occur at the end of the base. It is inserted.

  FIG. 10 shows a state in which the coating material 4 is injected from the runner 53 provided in the upper mold 5 into the first cavity 51 covering the surface 11 of the base 1. The covering material 4 spreads in the first cavity 51 that covers the surface 11 of the substrate 1 as indicated by an arrow. 11 to 13 show a second cavity in which the coating material 4 injected into the first cavity 51 travels around the third cavity 63 covering the upper and lower end surfaces 13 of the substrate 1 and covers the back surface 12 of the substrate. 61 shows a state of sequentially entering. As the covering material 4, a water-soluble polyvinyl alcohol resin is used. This is because the covering material can be easily removed in a process described later. As the covering material 4, polyglycolic acid, which is a polymer material that can be easily hydrolyzed with an aqueous alkaline solution, a simple substance of polylactic acid, or a mixture or copolymer of polylactic acid and aliphatic polyester may be used. .

  Here, as shown in FIG. 12, when the coating material 4 is injected into the first cavity 51, the substrate is pressed downward by the injection pressure until the coating material sufficiently enters the second cavity 61. However, since the tip of the projection 64 for the dummy conductive circuit is in contact with the back surface 12 of the base body at the center of the second cavities 61, 61, the base body is deformed downward. It is prevented. Further, when the covering material 4 spreads in the left and right first cavities 51 covering the surface 11 of the base body 1, the left and right end portions of the base body are pressed downward. Since the stepped portion 65 provided on the inner peripheral wall of the upper mold 5 and the lower surface of the upper mold 5 are closely inserted, it is possible to prevent the both end portions from being deformed downward.

  Now, as shown in FIG. 13, after covering the front surface 11, the back surface 12, and both ends of the substrate 1 with the covering material 4, leaving portions that become conductive circuits, the portions not covered with the covering material. The catalyst which becomes the nucleus which electroless plating precipitates is provided. The catalyst is applied by a known method. For example, after immersing the substrate 1 in a mixed catalyst solution of tin and palladium, the substrate 1 is activated with an acid such as hydrochloric acid or sulfuric acid to deposit palladium on the surface. Alternatively, a relatively strong reducing agent such as stannous chloride is adsorbed on the surface and immersed in a catalyst solution containing noble metal ions such as gold to deposit gold on the surface. What is necessary is just to immerse the temperature of a liquid at 15-23 degreeC for 5 minutes.

  In the next step, the covering material 4 injection-molded on the surface of the substrate 1 is removed. As described above, since the covering material 4 is water-soluble, the covering material is eluted and removed by being immersed in hot water at 80 ° C. for about 10 minutes.

  In the next step, electroless plating is performed on the surface of the substrate 1. The portion from which the covering material 4 has been removed by elution is covered with this covering material in the previous step, so that no catalyst is applied, and electroless plating is not formed. On the other hand, the portion not covered with the covering material 4 is provided with a catalyst, so that electroless plating is formed. As shown in FIGS. 14 and 15, two conductive circuits 2 and 2 are formed on the front surface 11 of the substrate 1 and two conductive circuits 3 and 3 are formed on the back surface 12 by electroless plating. A dummy conductive circuit 8 is formed between the two conductive circuits on the back surface of the substrate. Dummy conductive circuits 8 are also formed at the left and right end portions 13 of the base 1.

  For electroless plating, known means can be used. For example, in the case of electroless copper plating, 5-15 g / l of copper sulfate as a metal salt, 8-12 ml / l of a 37% by volume solution of formalin as a reducing agent, and Rochelle salt as a complexing material. A solution having a temperature of 20 ° C. mixed with 20 to 25 g / l and 5 to 12 g / l of sodium hydroxide as an alkaline agent can be used. Electroless nickel plating can be performed instead of electroless copper plating. It is also possible to easily perform electroless plating of other metals or electrolytic plating on the electroless plating.

  Further, when using the above-mentioned polyglycolic acid hydrolyzed with an alkaline aqueous solution, a simple substance of polylactic acid, or a mixture or copolymer of polylactic acid and aliphatic polyester, the coating material is removed. Electroless plating may be performed before the electroless plating, and the coating material may be removed after the electroless plating. As a means for removing the covering material 4, it is immersed in an alkaline aqueous solution (concentration 2 to 15 wt%) at a temperature of 25 to 70 ° C. for about 1 to 120 minutes. Since these polyglycolic acids have acid resistance, electroless plating is performed with bath plasticity being acidic or neutral.

  16 to 28 show another embodiment, which shows a method for manufacturing a molded circuit component having a U-shaped cross-sectional shape. 16 to 22 show a manufacturing method according to the prior art, and FIGS. 23 to 28 show a manufacturing method according to the present invention. For convenience of reference, etc., in FIG. 16 to FIG. 28, parts and parts equivalent to those shown in FIG. 1 to FIG. Yes. Hereinafter, a description will be given centering on portions that differ from FIGS. As shown in FIG. 16, the molded circuit component to be manufactured by the conventional technique has a horizontally long flat plate formed on the back surface 312 of the base body 301 bent in a U shape, and strip-shaped conductive circuits 303 and 303 are 2 They are arranged in parallel. Note that a conductive circuit is not provided on the surfaces 311, 311, and 311 of the base body 301. The distance between the conductive circuits 303 and 303 is at least twice the plate thickness of the base 301, and the distance between the conductive circuit and the end surface 313 of the base is at least three times the plate thickness of the base. It has become.

  In FIG. 17, the base material is covered with an upper mold 305 and a lower mold 306 in order to cover the front surface 311 and the back surface 312 of the base body 301 with the covering material 304, leaving portions that become the conductive circuits 303 and 303. It shows the case where it is housed inside. That is, the front surface 311, 311, 311, the back surface 312, and the left and right and upper and lower end surfaces 313, 313, 313, and 313 of the base body 301 are respectively defined by the first cavity 351, the second cavity 361, and the third cavity 363. Covered. However, the tips of the protrusions 362 and 362 provided on the lower mold 306 are in contact with the back surface 312 of the base 301 and the portions that become the conductive circuits 303 and 303.

  18 to 21 show a third cavity in which the coating material 304 injected from the runner 353 provided in the upper mold 305 to the first cavity 351 covering the surface 311 of the base body 301 covers the end surface 313 of the base body. A state is shown in which the second cavity 361 covering the back surface 312 of the base body sequentially enters via the H.363. That is, as shown in FIG. 20 and the like, until the covering material 304 sufficiently enters the second cavity 361 covering the back surface 312 of the base body 301, this base body is caused by the injection pressure of the covering material in the first cavity 351. Then, it deforms between the protrusions 362 and 362 and at both the left and right ends, and finally comes into contact with the inner wall surface of the second cavity 361 as shown in FIG.

  For this reason, as shown in FIG. 22, the molded circuit component is deformed at the central portion of the base 301 and the left and right end portions, and the central portion and the left and right end portions of the base body are not electrically conductive. A circuit 307 is formed.

  Next, an injection molding method for the covering material 104 according to the present invention will be described with reference to FIGS. The other manufacturing processes and equipment are the same as those described with reference to FIGS. As shown in FIG. 23, in the injection molding of the covering material 104 according to the present invention, the projection for the dummy conductive circuit is provided at the center between the two rows of projections 162, 162 provided on the lower mold 106. 164 is provided, and the tip thereof is brought into contact with the back surface 112 of the base 101. Further, the left and right end portions of the base 101 are closely inserted into grooves 165 and 165 provided in the lower mold 106, respectively.

  24 to 27, the covering material 104 injected from the runner 153 provided in the upper mold 105 into the first cavity 151 covering the surface 111 of the base 101 covers the upper and lower end surfaces 113, 113 of the base. A state is shown in which the second cavity 161 that sequentially covers the back surface 112 of the base body sequentially enters via the third cavity 163. Here, as shown in FIG. 26 and the like, when the covering material 104 is injected into the first cavity 151, the base 101 is moved downward by the injection pressure until the covering material sufficiently enters the second cavity 161. However, since the protrusion 164 for the dummy conductive circuit is provided at the center of the second cavity and the tip is in contact with the back surface 112 of the base, the base is moved downward. Deformation is prevented. Further, when the covering material 104 spreads left and right in the first cavity 151 covering the surface 111 of the base 101, the left and right ends of the base are pressed inwardly. Since it is closely inserted in the groove 165 provided in 106, this end portion is prevented from being deformed inward.

  FIG. 28 shows a molded circuit component manufactured according to the present invention, and two electroconductive circuits 103 and 103 are formed on the back surface 112 of the base 101 by electroless plating. A dummy conductive circuit 108 is formed between the circuits. Dummy conductive circuits 108 are also formed on the left and right ends of the substrate 101, respectively.

  In the embodiment shown in FIG. 29, the above-mentioned base having a U-shaped cross section is provided with an opening hole for communicating the front surface and the back surface thereof. That is, in the base 401, circular opening holes 409 that connect the front surface and the back surface of the base body are formed at both sides of the dummy conductive circuit projection 464. In addition, on both the left and right sides of the base body 401 that are bent, circular opening holes 409 that connect the front surface and the back surface of the base body are opened.

  Therefore, in the state shown in FIG. 29, when the coating material is injected from the runner 453 provided in the upper mold 405 into the first cavity 451, the coating material covers the third cavity 463 that covers the upper and lower end surfaces of the base body. In addition to entering the second cavity 461 through the opening holes 409, 409, 409, and 409, respectively, the deformation of the center portion and the left and right end portions of the base body can be prevented more reliably. Become.

  When the surface of the substrate is partially covered with a coating material, the substrate can be prevented from being deformed by the injection pressure of the coating material, and thus can be widely used in industries related to electronic devices and the like.

1, 101-401 Base 11, 111-411 Surface (first surface)
12, 112-412 Back surface (second surface)
13, 113 to 413 End face (third surface)
2, 102-302 Conductive circuit 3, 103-403 Conductive circuit 4, 104-304 Coating material 5, 105-405 Upper mold 51, 151-451 First cavity 52, 252 Protrusion 53, 153-453 Runway 6, 106-406 Lower mold 61, 161-461 Second cavity 62, 162-462 Protrusion 64, 164, 464 Protrusion 65,165 Stepped portion, groove 207,307 for dummy conductive circuit Circuit 8, 108 Dummy conductive circuit 409 Opening hole

Claims (4)

A method of manufacturing a molded circuit component by injection molding a coating material leaving a portion to be a conductive circuit on the surface of a base made of an insulating material, and plating the portion to be a conductive circuit,
The base body is plate-shaped, and has a first surface, a second surface, and a third surface forming an end face of the base body, facing each other,
A mold for injection-molding the covering material includes a first cavity, a second cavity, and a first cavity for covering the first surface, the second surface, and the third surface with the covering material, respectively. And a third cavity,
The first cavity and the second cavity communicate with each other via the third cavity,
The covering material is injected into the first cavity from the outside of the mold,
The coating material injected into the first cavity is injected into the second cavity through the third cavity,
The second surface is provided with the conductive circuit in at least two places at a predetermined interval,
A method of manufacturing a molded circuit component, wherein a dummy conductive circuit is formed either in the middle of the conductive circuits adjacent to each other or at an end of the base. 2. The method of manufacturing a molded circuit component according to claim 1, wherein the predetermined interval is at least three times the plate thickness of the base body. 2. The method of manufacturing a molded circuit component according to claim 1, wherein the distance between the end face of the base and the conductive circuit closest to the end face is at least twice the plate thickness of the base. The method of manufacturing a molded circuit component according to any one of claims 1 to 3, wherein the base body is provided with an opening for communicating the first cavity and the second cavity with each other. .

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