JP5302810B2 - Manufacturing method of three-dimensional molded circuit components - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To selectively perform electrolytic plating even where there exist both portions of a portion difficult to remove by irradiation of a laser beam and a portion difficult to cover with a mask material regarding a portion which becomes a surface of a plating base and serves as a non-circuit. <P>SOLUTION: As regards those parts 22a-22d on the surface of an electroless copper plating 2 done onto an insulating substrate 1 that are easily removed by irradiation of the laser beam 3, which become non-circuits, the electroless copper plating is removed by irradiating this laser beam, and the parts not removed by irradiation of the laser beam, which will become non-circuits, are covered with a mask material 4. After the electrolytic copper platings 5 are laminated onto the parts 21 as circuits that are not removed by irradiation of the laser beam 3 and are not covered with the mask material 4, the mask material 4 is removed by being dissolved. All the electroless copper platings 2 other than the parts 21 that are covered by the electrolytic copper platings 5, which will become circuits, are removed by etching liquid. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method for manufacturing a three-dimensional molded circuit component, and more particularly to a method for manufacturing a three-dimensional molded circuit component that selectively forms electrolytic plating on the surface of a plating base made of a conductive film.

  Conventionally, the surface of an insulating substrate is covered with a mask material except for the part that becomes a circuit, and the part that is not covered with the mask material is selectively subjected to electroless plating to form a conductive circuit. A method of manufacturing a circuit component has been proposed (see, for example, Patent Document 1). In addition, after applying a plating base made of electroless plating to the entire surface of the insulating substrate, the non-circuit portion is removed by selectively irradiating the electroless plating with laser light, and the circuit that has not been removed There has been proposed a method of manufacturing a molded circuit component in which a conductive circuit is formed by laminating electrolytic plating on the portion to be (see, for example, Patent Document 2).

JP-A-11-145583 Japanese Patent No. 2965803

  However, particularly in the case of a three-dimensional molded circuit component, there may be both a portion that is difficult to cover with the mask material described above and a portion that is difficult to remove by laser light irradiation for a non-circuit portion. . For example, in the helical antenna shown in FIG. 2 and the like, the portion 121 that becomes a circuit on the surface of the insulating substrate 101 is long in a spiral shape, so that the width is narrow and the length is adjacent to the portion that becomes the circuit. In the case where the portion 122a that is a long non-circuit in a spiral shape is covered by injection molding of a mask material, the flow resistance of the resin that becomes the mask material is increased, so that it is necessary to increase the injection pressure. However, when the injection pressure is increased, problems such as deformation of the substrate occur, so that it is difficult to cover the mask material by injection molding.

  Therefore, electroless plating is performed on the entire surface of the insulating substrate 101 such as a helical antenna as a plating base, and the non-circuit portion 122a is irradiated with the laser beam 103, whereby the non-circuit portion is electroless-plated. It is conceivable to deposit electrolytic plating on the surface of the electroless plating of the portion 121 that becomes a circuit that has been removed but not removed. However, if the laser beam 103 is used, the non-circuit portion 122a having a narrow width and a spiral length can be removed. However, for example, the inside of the opening hole 122f formed in the insulating substrate is irradiated with the laser beam. Therefore, the electroless plating formed in the opening hole cannot be removed.

  Further, the irradiation region of the laser beam is circular, and the irradiation energy has a conical energy distribution in which the density increases toward the center of the circle. Therefore, it is desirable to irradiate the workpiece surface perpendicularly. When the workpiece surface is irradiated obliquely, the irradiation area spreads in an elliptical shape and the energy density in the irradiation area is dispersed. Will fall. For this reason, processing by laser light irradiation becomes difficult. However, in a workpiece having a three-dimensional shape, there are cases in which the surface to be processed extends in various ways such as a vertical surface, an inclined surface, or the inside of a cylinder. Of these, the effective laser light irradiation region is an inclined surface of less than 30 degrees from the vertical axis, and the vertical side surface, the back surface, the inside of the cylinder, and the like are difficult to process by laser light irradiation.

  For example, as shown in FIG. 3, in an insulating substrate 201 having a substantially V-shaped groove 222g at the center, a portion 221 that forms a long and narrow circuit on the upper surface on both sides sandwiching the substantially V-shaped groove. In the case of forming a conductive circuit, it is difficult to injection-mold a mask material on a portion 222a which is sandwiched between the portions to be the circuit and has a narrow width and a long non-circuit. Therefore, it is conceivable that a plating base such as electroless plating is formed on the entire surface of the insulating substrate 201, and the plating base is removed by irradiating the non-circuit portion 222a with the laser beam 203.

  However, as described above, when the angle θ of both slopes of the substantially V-shaped groove 222g is 60 degrees or more, the irradiation energy density of the laser beam 203 on both slopes is lowered, and the laser light irradiation is performed. It becomes difficult to remove the plating base. Further, in the lateral groove 222h opened on the right side surface of the insulating substrate 201, it is difficult to remove the plating base by the irradiation of the laser beam 203.

  Therefore, an object of the present invention is to selectively perform electroplating on the surface of the plating base even when there are both non-circuit portions that cannot be removed by irradiation with laser light and portions that cannot be covered with a mask material. It is an object of the present invention to provide a method for manufacturing a three-dimensional molded circuit component that can be formed into a single layer.

  In order to solve the above-described problems, the present invention is characterized in that a portion of the plating base applied to the surface of the insulating substrate that is not a circuit is easily removed by laser light irradiation. In addition to removing, a portion that becomes a non-circuit that has not been removed by irradiation with laser light is covered with a mask material. That is, the method for manufacturing a three-dimensional molded circuit component according to the present invention includes a first step of forming an insulating base, a second step of forming a conductive coating on the surface of the insulating base, and a surface of the conductive coating. In addition, a third step of removing a portion that is easily removed by laser light irradiation in a non-circuit portion is removed by the laser light irradiation.

  Further, the manufacturing method includes a fourth step of coating a portion of the surface of the conductive film that is not a circuit and is not removed by the laser light irradiation with the mask material, and a surface of the conductive film. A fifth step of laminating electrolytic plating on a portion of the circuit that is not removed by the laser light irradiation and is not covered with the mask material; a sixth step of removing the mask material; and And a seventh step of removing the conductive film in a portion where the electroplating is not laminated with an etching solution. The conductive film is preferably either electroless plating or vapor deposition plating.

  By the way, in the part which becomes the non-circuit, the part removed by the laser light irradiation and the part covered with the mask material are adjacent to each other along the outer edge of the part removed by the laser light irradiation. It is extremely difficult to accurately coat the mask material. Therefore, there is a possibility that a gap is generated between the outer edge of the portion removed by the laser light irradiation and the portion coated with the mask material. In this gap, a conductive film that is not removed by laser light irradiation and that is not covered with a mask material is exposed. Therefore, in this gap, electrolytic plating is formed in a portion that is originally non-circuited. End up.

  Therefore, in order to avoid such a problem, the portion removed by the laser light irradiation and the portion covered by the mask material are adjacent to the portion removed by the laser light irradiation. It is desirable to cover the mask material so as to overlap by a predetermined width from the adjacent portion. Further, the mask material is either hydrolyzable polyglycolic acid or polylactic acid, and the electrolytic plating is desirably performed with an acidic bath composition.

  Here, the “insulating substrate” corresponds to, for example, synthetic resin, ceramics, or glass. The synthetic resin is preferably a thermoplastic resin, but may be a thermosetting resin. Examples of such a resin include aromatic liquid crystal polymers, polyether ether ketone, polysulfone, polyether polysulfone, polyaryl sulfone, polyetherimide, Examples include polyester, acrylonitrile / butadiene / styrene copolymer resin, polyamide, modified polyphenylene oxide resin, norbornene resin, phenol resin, and epoxy resin. The shape of the “insulating base” is not limited. Not only three-dimensional but also two-dimensional. For example, a flat plate shape, a polygonal block shape, a surface having a curved surface, or a surface having an opening hole or an opening groove is applicable, and includes a case of a plurality of parts.

  “Making an insulating base” is not limited to injection molding, but includes, for example, cutting out from a block material. The “conductive film” is not particularly limited as long as it can be removed by laser light irradiation, and examples thereof include electroless plating, diffusion plating, or vapor deposition plating such as vacuum deposition, sputtering, ion plating, or chemical vapor deposition. The “mask material” means an insulating material on which electrolytic plating is not formed on the surface, and any type of resin can be used as long as the resin has good compatibility with the insulating base. For example, when the insulating substrate is an aromatic liquid crystal polymer, the same aromatic liquid crystal polymer is used as the material of the covering material 3. If the hydrolyzable polymer material polyglycolic acid or polylactic acid is used as the “mask material”, it can be easily removed by hydrolyzing the mask material with an alkaline solution in a later step. can do.

The type of “laser light” is not limited as long as it can be removed by a small amount such as scribing or trimming. For example, a YAG laser, a second harmonic laser, a CO ₂ laser, and an Ar laser are applicable. “Easy removal by laser light irradiation” means an inclined surface inclined within a range of less than 30 degrees from the laser light irradiation direction, an inside of an opening hole difficult to be irradiated with laser light, an inside of an opening groove, And the portion excluding the back surface. “Electrolytic plating” corresponds to, for example, copper, nickel, gold, silver, or an alloy thereof plated metal. Moreover, the case where the same kind of metal or a different kind of metal is electroplated is also included. The “etching” means of “removing the conductive film by etching” may be any means that can dissolve the conductive film. For example, it is immersed in an aqueous solution of sulfuric acid in which ferric chloride is dissolved or an aqueous solution of sodium persulfate. This is true.

  “Coating so that this mask material overlaps by a predetermined width from this adjacent portion” means that the portion from which the conductive film has been removed by laser light irradiation is removed from the outer edge of the removed portion. This means that the mask material is coated so as to enter a predetermined width toward the inside of the removed portion.

  Electrolytic plating is also applied to the surface of the conductive coating even when there are both non-circuit areas on the surface of the conductive coating that cannot be removed by irradiating with laser light and portions that cannot be covered with the mask material. Can be selectively formed. By employing electroless plating or vapor deposition plating as the conductive coating, a thin plating base that can be easily removed by laser light irradiation can be easily formed.

  In the part where the part removed by the laser light irradiation and the part covered with the mask material are adjacent to each other, the part removed by the laser light irradiation overlaps by a predetermined width from the adjacent part. Thus, by covering with this mask material, it becomes possible to easily and surely prevent a gap from being formed between the portion removed by laser light irradiation and the portion covered with the mask material. It is possible to prevent unintentional electrolytic plating from being laminated on a portion to be a circuit. In addition, if either hydrolyzable polymer material polyglycolic acid or polylactic acid is used for the mask material, it can be easily removed by hydrolyzing the mask material with an alkaline solution in a subsequent step. it can.

It is process drawing which shows the manufacturing method of a three-dimensional molded circuit component. It is a perspective view of a helical antenna in which it is difficult to cover with a mask material on a non-circuit portion. It is a perspective view which shows the shape where the removal of the plating foundation | substrate of the part which becomes a non-circuit by irradiation of a laser beam is difficult.

  A method for manufacturing a molded circuit component according to the present invention will be described with reference to the process chart shown in FIG. In addition, the manufacturing method of the molded circuit component by this invention is equipped with the 1st process-the 7th process (FIG. A-FIG. G). In the first step (FIG. A), a thermoplastic resin is injection-molded to form a block-shaped first insulating substrate 1. Here, as the thermoplastic resin, for example, an aromatic liquid crystal polymer (“Vectra # C820” manufactured by Polyplastics Co., Ltd.) is used. In the next second step (FIG. B), electroless copper plating 2 is applied to the entire surface of the insulating substrate 1 as a plating base. The electroless copper plating 2 uses, for example, the following known procedure.

  First, in order to improve the adhesion with the electroless copper plating 2, the entire surface of the insulating substrate 1 is roughened by etching. In this etching, an alkaline aqueous solution in which caustic soda or caustic potash is dissolved at a predetermined concentration, for example, 45% by weight, is heated to a predetermined temperature, for example, 50 to 90 ° C., and the insulating substrate 1 is immersed for a predetermined time, for example, 30 minutes. And do it. Next, a catalyst is applied to the roughened surface of the insulating substrate 1 to form nuclei for depositing electroless plating. As a procedure for applying the catalyst, for example, the insulating substrate 1 is immersed in a mixed catalyst solution of tin and palladium, and then 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.

  Next, electroless copper plating 2 is applied to the entire surface of the insulating substrate 1 provided with the catalyst. The plating solution of electroless copper plating 2 is, for example, 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 20-25 g of Rochelle salt as a complexing material. / L, and a solution having a temperature of 20 ° C. mixed with 5 to 12 g / L of sodium hydroxide as an alkaline agent is used. The electroless copper plating 2 has a thickness of about 0.2 to 2 μm so that it can be easily removed by laser light irradiation in a subsequent process.

  As a third step (FIG. C), in the electroless copper plating 2 covering the surface of the insulating substrate 1, a portion that becomes a non-circuit and can be easily removed by irradiation with the laser beam 3 is treated with the laser beam 3. Remove by irradiation. Here, the upper surface of the insulating substrate 1 corresponds to the portion that can be easily removed by irradiation with the laser beam 3. On the other hand, the side surface and the back surface of the insulating substrate 1 correspond to the portions that are difficult to be removed by irradiation with the laser beam 3. Therefore, the portion to be removed by the irradiation of the laser beam 3 is the upper surface of the insulating substrate 1, and the portions 22 a, 22 b, 22 c, and 22 d that become non-circuits adjacent to the portion 21 that becomes a narrow and long circuit, Become. In addition, since the flow resistance of the resin used as the mask material 4 increases as described above, the portions 22b and 22c that are narrow and long non-circuits sandwiched between the circuit-use portions 21 increase the injection of the mask material. It is a part that is difficult to cover by molding. The laser beam 3 is, for example, a second harmonic with an output of 6 W, and is scanned three times at a scan speed of 500 mm / second and a Q switch frequency of 30 kHz.

  As the next fourth step (D), in the electroless copper plating 2 covering the surface of the insulating substrate 1, it is a portion that becomes a non-circuit and is not removed by irradiation with the laser beam 3 described above, that is, this insulating property. The side surface and the back surface of the substrate are covered with the mask material 4. The portions 22a and 22d where the portion removed by the irradiation with the laser beam 3 and the portion covered with the mask material 4 are adjacent to each other are above the portion removed by the irradiation with the laser beam. The mask material is coated so as to overlap by a predetermined width. The mask material 4 has acid resistance and is easily hydrolyzed with an alkaline aqueous solution (“Lacia # H-100J / F” manufactured by Mitsui Chemicals) or polyglycolic acid (“# manufactured by Kureha Co., Ltd.”). One of KSK08 ").

In the next fifth step (FIG. E), on the surface 21 of the electroless copper plating 2, which is not removed by the irradiation of the laser beam 3 and becomes a circuit 21 not covered with the mask material 4, The electrolytic copper plating 5 is laminated. The electrolytic copper plating 5 is performed with an acidic bath composition or a neutral bath composition in which the pH of the electrolytic plating solution is 7 or less. As described above, the mask material 4 is hydrolyzed by the alkaline aqueous solution, but has acid resistance. The electrolytic copper plating 5 uses, for example, the following known means. That is, an acidic copper sulfate bath is used, and the bath composition is CuSO ₄ .5H ₂ O (75 g) / lH ₂ SO ₄ (190 g) / lCl (60 ppm) / additive (appropriate amount). The anode material is phosphorous copper, the bath temperature is set to 25 ° C., and the cathode current density is 2.5 A / dm 2. Instead of the electrolytic copper plating 5, an electroless nickel plating having an acidic bath composition may be laminated.

  In the next sixth step (FIG. F), the mask material 4 is removed. As described above, since the mask material 4 is easily hydrolyzed by the alkaline aqueous solution, it is about 1 to 120 minutes in a caustic alkaline (NaOH, KOH, etc.) aqueous solution having a concentration of 2 to 15% by weight and a temperature of 25 to 70 ° C., for example. The mask material is removed by dipping.

  In the final seventh step (FIG. G), the electroless plating 2 remaining on the surface of the insulating substrate 1 is removed by an etching solution, except for the portion 21 that becomes a circuit on which the electrolytic copper plating 5 is laminated. That is, the electrolytic copper plating 5 in the previous step can be easily made thicker than the electroless copper plating 2. Therefore, if the plating thickness of the electrolytic copper plating 5 is made sufficiently larger than that of the electroless copper plating 2, only the thin electroless plating can be removed by the etching solution. Here, as the etchant, for example, the insulating substrate 1 is immersed in an aqueous sodium persulfate solution for 1 minute.

  Electrolytic plating is also applied to the surface of the conductive coating even when there are both non-circuit areas on the surface of the conductive coating that cannot be removed by irradiating with laser light and portions that cannot be covered with the mask material. Can be selectively formed, and thus can be widely used in industries related to electronic devices and the like.

1, 101, 201 Insulating substrate 2 Electroless copper plating (conductive film)
21, 121, 221 Circuit parts 22a, 122a, 222a Non-circuit parts 22b, 22c, 22d Non-circuit parts 3, 103, 203 Laser light 4 Mask material 4a Overlap 5 Electrolytic copper plating (electrolytic plating)

Claims (4)

A first step of forming an insulating substrate;
A second step of forming a conductive coating on the surface of the insulating substrate;
A portion of the surface of the conductive coating that is a non-circuit, a portion that is easily removed by laser light irradiation, and is removed by laser light irradiation;
A fourth step of covering a portion of the surface of the conductive coating that is not a circuit with a mask material that is not removed by the laser light irradiation;
A fifth step of laminating electrolytic plating on a portion of the surface of the conductive film that is not removed by irradiation with the laser light and becomes a circuit not covered with the mask material;
A sixth step of removing the mask material;
And a seventh step of removing the conductive film in a portion where the electroplating is not laminated with an etching solution. A method for producing a three-dimensional molded circuit component. The method for manufacturing a three-dimensional molded circuit component according to claim 1, wherein the conductive coating is either electroless plating or vapor deposition plating. 3. The method according to claim 1, wherein the portion removed by the laser light irradiation and the portion covered with the mask material are adjacent to each other on the portion removed by the laser light irradiation. A method of manufacturing a three-dimensional molded circuit component, wherein the mask material is covered so as to overlap by a predetermined width from adjacent portions. In any one of Claim 1 or 2, the said mask material is either hydrolyzable polyglycolic acid or polylactic acid,
The method for producing a three-dimensional molded circuit component, wherein the electrolytic plating is performed with an acidic bath composition.

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