Molded body and method for manufacturing the same

Abstract

The present invention provides an injection-molded circuit component (MID) capable of mounting electronic components and a method for manufacturing the same. The invention is characterized in that a skin layer 3 is at least partially removed from the surface of a synthetic resin molded body 1, and a conductive portion 8 is present on a base 4 of the molded body exposed by the removed portion 5. The invention comprises a molding step of molding the synthetic resin molded body; a skin layer removal step of removing at least a portion of the skin layer formed on the surface during the molding step by laser etching; an etching step of etching the portion from which the skin layer was removed; and a conductive portion forming step of forming the conductive portion in the etched portion.

Description

Technical Field

[0001] The present invention relates to a formed body suitable for manufacturing electronic components and a method for manufacturing the same. Background Art

[0002] In the past, in the field of electrical and electronic products, thermoplastic synthetic resins have been suitable for injection molding due to their excellent corrosion resistance and insulation properties. In addition to being used for printed circuit board installation, they are also widely used in component housings. In particular, liquid crystal polymers (LCP) have many advantages, such as excellent fluidity during molding, high heat resistance, and excellent chemical resistance. However, liquid crystal polymer (LCP) resins have the disadvantages of anisotropy of molded products and low welding strength. To improve this, methods such as filling with glass fibers are adopted. In addition, inorganic fillers such as glass microspheres and calcium pyrophosphate are also added to improve elasticity and strength.

[0003] There is a technology for manufacturing injection molded circuit components (MIDs) using laser processing. However, during the injection molding process, a structure called a skin layer exists on the surface of the molded product where liquid crystal polymer (LCP) or other synthetic resins come into contact with the mold. Its thickness is approximately 0.3 mm. Even if a circuit pattern is formed on this skin layer, the skin layer will be damaged and the conductor part will peel off from the substrate. Therefore, as shown in Patent Document 1, a technology for removing the skin layer by irradiating with laser has been proposed.

[0004] Furthermore, as disclosed in Patent Document 2, a surface roughening technique using laser etching has been proposed as an alternative to using chemical etchants to form circuit wiring. Furthermore, as disclosed in Patent Document 3, a technique for manufacturing injection molded circuit components (MIDs) using a special LDS (Laser Direct Structuring) material in which metal particles are encapsulated by an insulator is employed through laser etching and plating processes.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-318531

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2011-17069

[0009] Patent Document 3: (Japanese) Patent Publication No. 8-307038 Summary of the Invention

[0010] Technical problem to be solved by the invention

[0011] The metal films formed through laser etching and plating processes described in Patent Documents 1, 2, and 3 are practical only when forming wiring on a synthetic resin molded substrate. However, when electronic components are mounted on this substrate, the strength is insufficient and the metal film may peel off. In particular, in the case of three-dimensional injection-molded circuit components, or MIDs, there is a need for a technology that can produce injection-molded circuit components (MIDs) with the strength and adhesion required for mounting as electronic components.

[0012] Technical solutions to technical problems

[0013] The present invention is used to solve the above-mentioned technical problems. (1) A synthetic resin molded body is characterized in that there is a skin layer on the surface of the molded body that is at least partially removed, and there is a conductive part on the base of the molded body exposed by the removed part.

[0014] (2) A method for manufacturing a molded body, for manufacturing the molded body of (1) above, characterized in that it comprises: a molding step of molding a synthetic resin molded body; a skin layer removal step of removing at least a portion of the skin layer generated on the surface during the molding step by laser etching; an etching step of etching the portion from which the skin layer has been removed; and a conductive portion forming step of forming a conductive portion in the etched portion.

[0015] (3) In the manufacturing method of (2) above, the conductive portion forming step is performed by electroplating or chemical plating.

[0016] Effects of the Invention

[0017] According to the present invention, it is possible to manufacture an injection molded circuit component (MID) in which the adhesiveness between the conductive portion and the molded base is improved to such an extent that electronic components can be mounted.

[0018] Furthermore, the skin layer formed during the injection molding of the resin can be used as a masking material when forming the conductive portion of the circuit component (MID), and can be used as a surface material of the circuit component (MID) directly after the conductive portion is formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic partial cross-sectional view showing the structure of a resin molded body according to one embodiment of the present invention.

[0020] Figure 2 It is used for Figure 1Schematic partial sectional views illustrating the manufacturing process of the resin molded body according to the embodiment, (A) of the figure is a schematic partial sectional view for illustrating the first step (molding step), (B) of the figure is a schematic partial sectional view for illustrating the second step (skin layer removal step), (C) of the figure is a schematic partial sectional view for illustrating the third step (etching step), and (D) of the figure is a schematic partial sectional view for illustrating the fourth step (conductive portion forming step). DETAILED DESCRIPTION

[0021] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Figure 1 1 is a schematic partial cross-sectional view of a resin molded body according to one embodiment of the present invention. Figure 1 In the figure, the molded body 1 is formed from an LDS material used for the manufacture of injection molded circuit components (MIDs) using LDS (Laser Direct Structuring). In this example, a liquid crystal polymer (LCP) is used. It should be noted that the LDS material can be thermoplastics such as acrylonitrile-butadiene-styrene (ABS) resin, polycarbonate (PC), PC / ABS resin, PC / polyethylene terephthalate (PET), polyphthalamide (PPA), polyamide (PA) / PPA, polybutylene terephthalate (PBT), cycloolefin polymer (COP), polyphenylene ether (PPE), polyetherimide (PEI), and polyetheretherketone (PEEK), or thermosetting resins such as phenol and epoxy resin.

[0022] Furthermore, regarding the material of synthetic resin molded products other than LDS molding materials, as long as it is a synthetic resin that can firmly attach metal films such as conductive components, it can be any type of thermoplastic resin and thermosetting resin material. However, considering that the relevant molded products will be subjected to harsh treatments such as welding processing later, it is required to be a material with high heat resistance and excellent mechanical strength, and in terms of mass production, it is preferably a thermoplastic resin that can be injection molded. As examples thereof, aromatic polyesters, polyamides, polyacetals, polycarbonates, polyarylene sulfides, polysulfones, polyphenylene ethers, polyimides, polyetherketones, polyarylene esters and their compositions can be cited. In particular, from the perspectives of high melting point, high strength, high rigidity, and molding processability, liquid crystal polymers (such as liquid crystal polyesters, polyesteramides) and polyarylene sulfides are particularly suitable, but are not limited to these materials. Furthermore, in order to improve the adhesion of the metal film, suitable substances such as easily etched substances can also be mixed into this material as needed. The synthetic resin molded product is formed by injection molding or the like, but in order to improve the adhesion of the metal film, it may be further subjected to chemical etching using acid, alkali or other substances, or physical surface treatment such as corona discharge or plasma treatment.

[0023] The molded body 1 may be not only a resin molded body but also a molded body formed of ceramics or glass.

[0024] In order to improve the anisotropy of the molded product and the low welding strength, or to increase the elasticity and strength, the molded body 1 may contain glass beads, glass balls, glass powder, elements of the second main group of the periodic table and their oxides, sulfates, phosphates, silicates, carbonates, or aluminum, silicon, tin, lead, antimony, bismuth elements and their oxides, or additives such as zinc, aluminum, silicon, tin, lead, antimony, bismuth, etc.

[0025] If the material of the forming body 1 is supplied into the mold, the material moves forward from the center to the surrounding area at the front end of the mold due to the spring flow, and is rapidly cooled on the mold wall to form a skin layer 3. The inner side of the skin layer 3 is the inner core (base) 4, and the forming body 1 is formed by the skin layer 3 and the inner core 4.

[0026] like Figure 1 As shown, a formed body 1 according to one embodiment of the present invention is composed of a skinless portion 5 in which a portion of the above-mentioned skin layer 3 is removed and a skinned portion 6 in which the skin layer 3 remains. The surface of the inner core 4 exposed in the skinless portion 5 becomes a rough surface 7, and a conductive portion 8 such as Cu and Au is formed on the rough surface 7.

[0027] Figure 2 (A) to (D) are schematic partial cross-sectional views for sequentially explaining the method for producing the molded body 1 from the first step to the fourth step.

[0028] exist Figure 2 In the first step (molding step) of (A), a molded body 1 having a skin layer 3 formed on the surface of an inner core 4 is injection molded.

[0029] exist Figure 2 In the second step (skin layer removal step) of (B), the skin layer 3 is removed by irradiating a desired portion (conductive portion formation portion) on the surface of the skin layer 3 with the laser beam 2 .

[0030] Therefore, if Figure 2 As shown in (B), the skin-free portion 5 is formed, and the inner core 4 is exposed at a position where the skin layer 3 is not present.

[0031] The laser used in the present invention can be from UV laser to CO2 laser, such as UV laser with a wavelength of 355nm, green laser with a wavelength of 532nm, hybrid laser with a wavelength of 1064nm, YVO4 laser, YAG laser, fiber laser with a wavelength of 1090nm, CO2 laser with a wavelength of 10600nm, etc.

[0032] In order to remove the skin layer 3 without damaging the core 4, these lasers are used under appropriate conditions such as laser power, scanning rate, frequency, number of printing times, and printing position. For example, the energy is 0.1 W / mm 2 ~1W / mm 2 The wavelength of the laser is selected. For example, the wavelength is 0.2W to 0.5W for YAG lasers and 1.5W to 4.5W for YVO4 lasers. By changing parameters such as the scanning rate, frequency, and number of prints, the optimal surface layer can be removed and the accuracy of the processed surface, which is the accuracy of the circuit, can be improved.

[0033] The synthetic resin molded article 1 is irradiated with a laser beam directed toward the portion that will become the electrode. The laser output and laser spot diameter are appropriately adjusted to selectively remove the skin layer 3 in that portion. If the width of the removed layer is too narrow, etching the portion that will become the conductive circuit in the subsequent process will narrow the etching width, potentially causing a short circuit in the conductive circuit. Therefore, the width d of the removed skin layer is set to 100 to 500 μm, preferably 150 to 250 μm. This width prevents short circuits in the conductive circuit and reduces laser irradiation time, improving productivity.

[0034] exist Figure 2 In the third step (etching step) of step (C), when the synthetic resin molded article 1 is a liquid crystal polymer, etching is performed on the exposed surface of the inner core 4 near the skin-free portion 5 using an etching solution such as hydrochloric acid or hydrofluoric acid. The etching solution preferably has a concentration of 3 to 20 wt% and a temperature of 25 to 40°C.

[0035] By etching, the vicinity of the surface of the inner core 4 where the skinless portion 5 is exposed is etched, thereby forming a rough surface portion 7 .

[0036] The etching process of the present invention is performed by wet etching using an inorganic etching solution such as an acidic or alkaline solution, an organic etching solution such as an organic solvent, ultrasonic water, or dry etching.

[0037] By the above etching, as Figure 2 As shown in (C), the rough surface portion 7 is formed near the surface portion of the inner core 4 where the skin portion 5 is not exposed.

[0038] Then, in Figure 2 In the fourth step (conductive portion forming step) of (D), a plating catalyst such as Pd or Pt is added to the rough surface 7 of the inner core 4, and then treated with an accelerating solution such as sulfuric acid, hydrochloric acid, sodium hydroxide, or ammonium. Subsequently, electroless plating or electroplating of nickel, copper, gold, platinum, or other various metals is performed to form the conductive portion 8. Alternatively, the conductive portion 8 can be formed by dry plating such as vapor deposition or sputtering.

[0039] The conductive portion 8 is grown so that it Figure 1 As shown, the conductive portion 8 has a desired thickness.

[0040] In the present invention, in the above-mentioned etching process and the conductive portion forming process, the skin layer 3 is present at the portion where the conductive portion is not formed. Since the skin layer acts as a shielding material, it is not necessary to use the shielding material required in the conventional conductive portion forming technology, and the skin layer 3 is also Figure 1 The material remaining in the final molded product 1 of the present invention as shown directly becomes an injection molded circuit component (MID) that can be mounted as an electronic component.

[0041] [Example]

[0042] according to Figure 2 The first to fourth steps shown in (A) to (D) are as follows: Figure 1 The molded body 1 is manufactured using the liquid crystal polymer shown (aromatic polyester with the trade name "Vectra C810" manufactured by Celanese Corporation of the United States) as a material.

[0043] pass Figure 2 The molded body 1 obtained in the first step (A) was a rectangular parallelepiped of 30×30×2 mm, and the skin layer 3 thereof had an average thickness of 0.2 mm.

[0044] exist Figure 2 In the second step (B), the conductive portion of the molded article 1 is irradiated with laser light, removing the skin layer 3 by a width d (3 mm) to form a skinless portion 5, exposing the inner core 4 in the skinless portion 5. The skinless portion 5, i.e., the exposed surface of the inner core 4, has a size of 3 × 5 mm and a depth of 0.8 mm.

[0045] Here, YVO4 laser was used as the laser 2, and the skin layer was removed at three output powers of 1.5 W, 3 W, and 4.5 W. As a result, the skin layer 3 was well removed in all three cases, and the skin-free portion 5 was obtained in a good appearance.

[0046] Next, the three types of molded bodies 1 from which the skin layers were removed by the three types of lasers were subjected to Figure 2 In the third step (C), (1) the molded body 1 after the second step is immersed in a hydrochloric acid solution (an aqueous solution containing 5 wt% hydrochloric acid) maintained at 30°C for 10 minutes to perform an etching treatment. As a result, a good rough surface 7 is formed near the surface of the inner core 4 where the skinless portion 5 is exposed in all three molded bodies 1.

[0047] In addition, the above-mentioned etching conditions are set as follows: (2) the hydrochloric acid concentration of the hydrochloric acid solution is 3wt%, the temperature is 40°C, and the treatment time is 20 minutes; (3) the hydrochloric acid concentration of the hydrochloric acid solution is 20wt%, the temperature is 25°C, and the treatment time is 5 minutes; all three types of formed bodies 1 are etched, and the results show that in any case, the rough surface portion 7 is well formed near the surface portion of the inner core 4 where the epidermal portion 5 is not exposed.

[0048] Then, the three types of molded bodies 1 from which the surface layer was removed by the three types of lasers 2 were etched under the three conditions (1), (2), and (3), thereby obtaining nine types of molded bodies 1. Figure 2 In the fourth step (D), a mixed hydrochloric acid solution of stannous chloride and palladium chloride (manufactured by Ebara-Ugilite Co., Ltd., trade name "ENILEX CT-8") is added at a ratio of 20 mL / L and maintained at 30°C. The above-mentioned molded body 1 after etching is immersed in the solution for 4 minutes, washed with water, and immersed in hydrochloric acid (50 mL / L) heated to 60°C for 60 minutes to accelerate the treatment. A plating catalyst is added to the rough surface 7 near the surface of the inner core 4 exposed in the above-mentioned non-skin layer portion 5. Then, a copper plating bath of the following composition is used to perform copper chemical plating under the following plating conditions to form Figure 2 The initial plating layer 9 shown in (D) is grown to form Figure 1 The electroless plating layer 8 is shown.

[0049] Copper plating bath composition:

[0050] CuSO4·5H2O:0.04mol / L;

[0051] HCHO: 0.1 mol / L;

[0052] NaOH: 0.2 mol / L;

[0053] EDTA·4Na: 0.08mol / L;

[0054] α,α′-bipyridine: 5-10ppm;

[0055] PEG-1000: 50~100ppm.

[0056] Plating conditions:

[0057] Bath temperature: 60-70°C;

[0058] Air stirring: 0.1L / L·min.

[0059] As a result, all nine types of molded bodies 1 became Figure 1The injection molded circuit component (MID) having a good conductive portion as shown in FIG. Furthermore, in this circuit component, it was confirmed that the conductive portion 8 had improved adhesion to the molded base 4, and it could be mounted directly (ie, with the skin layer 3 ) as an electronic component.

[0060] Description of Reference Numerals

[0061] 1 formed body;

[0062] 2. Laser;

[0063] 3 epidermis;

[0064] 4. Matrix (core);

[0065] 5. No epidermis;

[0066] 6 has epidermal part;

[0067] 7 Rough face;

[0068] 8, 9 conductive parts.

Claims

1. A synthetic resin molded body having a base body containing an additive and a skin layer formed integrally therewith, wherein the base body has a skin portion where the skin layer exists on the base body surface and a skinless portion where the skin layer is removed by laser ablation, characterized in that: The surface of the substrate without the skin portion includes a rough surface that allows the additive contained in the substrate to be dissolved by etching using an etching solution, and the surface of the substrate with the skin portion is not dissolved by etching. A conductive portion formed by plating exists on the rough surface.

2. A method for manufacturing a molded body, characterized in that: have: a molding step of molding a synthetic resin molded body containing an additive; a skin layer removal step of removing at least a portion of the skin layer formed on the surface during the forming step by laser ablation; an etching step of etching the portion where the skin layer was removed to form a rough surface using an etching solution without dissolving the skin layer not removed in the skin layer removal step, thereby dissolving the additive contained in the synthetic resin molded article; The conductive portion forming step forms a conductive portion in the etched portion.

3. The method for producing a molded body according to claim 2, wherein: The conductive portion forming step is a step of injection molding a liquid crystal polymer containing an additive, and the etching solution is a hydrochloric acid solution.

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