JP2006287016A - Method of manufacturing circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate eliminating a mask and reduce a manufacturing cost by enabling to use a diffusion ray and a parallel ray of an ultraviolet ray in manufacturing a circuit board. <P>SOLUTION: In this method, a circuit patterning is performed while interrupting an ultraviolet ray L via a mask 4 on an insulating base 1 on which a conductive layer 2 is formed on the entire surface and a resist 3 is applied. The mask 4 is three-dimensionally formed in a state of adhering on the insulating base 1 by ejecting a covering material for covering the insulating base 1 with a portion to be a circuit exposed. The covering material of this mask is obtained by adding an ultraviolet absorber to a base material selected from among a biodegradabile resin, a water soluble resin, a hydrolytic resin, a decomposable resin with enzymes, and an organic acid-soluble resin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a manufacturing method capable of manufacturing a circuit board, particularly a three-dimensional circuit board.

  As shown in FIG. 2, a conventional circuit board manufacturing method forms an oxide film conductor layer 102 on the surface of an insulating substrate 101 by electroless plating, for example, electroless copper plating (A). A resist 103 made of a photosensitive material dissolved in an organic solvent is applied on the mask pattern (B). Therefore, the ultraviolet ray L is irradiated through the mask 104 positioned with a predetermined gap between the resist 103 and the ultraviolet ray is formed when diffused light is used because there is a gap between the mask 104 and the resist 103. Since the outline of the circuit pattern on the circuit board is not sharp, this diffused light cannot be used. Therefore, it becomes inevitable to process the diffused light into parallel light. By irradiating such parallel ultraviolet light L, a part of the resist 103 is exposed to the photosensitive part 103a by the parallel light ultraviolet light that has passed through the mask, and the other part becomes the unexposed part 103b (C). Therefore, the unexposed portion 103b is removed (D), and the conductor layer 102 not covered with the exposed portion 103a is removed by etching (E). Therefore, circuit patterning is performed by removing the exposed resist portion 103a.

  The problem to be solved is that it is necessary to correct the ultraviolet rays from the diffused light to the parallel light in advance with a lens, but this processing apparatus is expensive, which is a major factor that raises the manufacturing cost. .

  A first feature of the method for producing a circuit board according to the present invention is a method for patterning a circuit by forming a conductor layer on the entire surface and blocking an ultraviolet ray through an insulating insulating substrate coated with a resist through a mask. The mask is formed by three-dimensionally injecting a coating material that covers the insulating substrate in a state where a circuit portion is exposed, and in close contact with the substrate. The material is a material obtained by adding an ultraviolet absorber to a material selected from any of biodegradable resins, water-soluble resins, hydrolyzable resins, enzyme-decomposable resins, and organic acid-soluble resins. The insulating substrate may be one coated with a resist.

  The second feature of the present invention is a method of forming a conductive layer on the entire surface and patterning a circuit by blocking ultraviolet rays through a mask on an insulating substrate coated with a photoresist, and forming the insulating substrate. An etching process and a catalyst application process as plating pretreatment, a process of forming a conductor layer on the insulating base, a process of applying a photoresist to the conductive layer, and a circuit on the insulating base A step of injecting a coating material to be coated with the portion exposed and forming a mask three-dimensionally in close contact with the substrate, and the mask material includes a biodegradable resin, a water-soluble resin, An ultraviolet absorber is added to a material selected from a degradable resin, an enzyme degradable resin, and an organic acid-soluble resin, and the step of exposing the insulating substrate with ultraviolet rays and the removal of the mask The step of removing the photoresist of the photosensitive portion, the step of electrolytic plating the portion of the photosensitive portion where the photoresist has been removed, the step of removing the unexposed portion of the photoresist, and the conductor layer are removed. Including the step of performing. In addition to the ultraviolet diffused light, parallel light can also be used.

  The effect of the present invention is that mask removal can be performed easily and efficiently, and furthermore, ultraviolet light can use both diffused light and parallel light, so that it is not necessary to modify the light into parallel light in advance with a lens. The manufacturing cost can be reduced compared to the conventional example.

  The best mode for carrying out the present invention will now be described with reference to FIG. 1. A circuit board manufacturing method according to the present invention comprises an insulating substrate in which a conductor layer is formed on the entire surface and a photoresist is applied. The circuit patterning is performed by blocking ultraviolet rays through a mask. Specifically, it consists of the following steps.

  FIG. 1A shows a process of forming an insulating substrate 1, which is formed by injecting a plating grade liquid crystal polymer into a cavity with the mold closed. This liquid crystal polymer is an aromatic polyester liquid crystal polymer, for example, there is a plating grade C810 of “Vectra” (trade name, manufactured by Polyplastics Co., Ltd.).

  This is injection molded under the conditions of a cylinder temperature of 320 ° C., a mold temperature of 110 ° C., an injection pressure of 1200 kg / cm 2, and a cooling time of 20 seconds.

  Therefore, the etching treatment process and the catalyst application process as the plating pretreatment are performed. As an example of the etching treatment process, an alkaline aqueous solution in which caustic soda or caustic potash is dissolved at a predetermined concentration, for example, 45 wt% is set at a predetermined temperature, for example, 50 to 50%. It is heated to 90 ° C. and the substrate 1 is immersed for a predetermined time, for example, 30 minutes. By this etching process, the entire surface of the substrate 1 is roughened. Further, in the catalyst application step, the substrate 1 is immersed in a mixed catalyst solution of, for example, tin and palladium on the roughened surface of the substrate 1 and then activated with an acid such as hydrochloric acid or sulfuric acid to deposit palladium on the surface. Let Alternatively, a relatively strong reducing agent such as stannous chloride is adsorbed on the surface and immersed in a catalyst solution containing a noble metal ion 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.

  Thereafter, as shown in FIG. 1B, the entire surface of the insulating substrate 1 is subjected to electroless copper plating to form a conductor layer 2, that is, a base plating.

  Therefore, as shown in FIG. 1C, a photoresist 3 dissolved in an organic solvent, that is, a photosensitive material is applied on the conductor layer 2 in order to bake a pattern of a mask 4 described below. This photoresist corresponds to a photographic printing paper. In order to bring the photoresist 3 and the conductor layer 2 into close contact with each other, preliminary drying is performed at a temperature of 80 to 100 ° C. in order to evaporate the organic solvent contained in the resist. This is a so-called pre-bake process.

  Next, as shown in FIG. 1 (D), the insulating substrate 1 is exposed to a state in which a portion that becomes a circuit is exposed, that is, a coating material that covers a portion that becomes a non-circuit, and is in close contact with the substrate. The mask 4 is formed three-dimensionally in the state. This is because a cavity having a shape matching a shape having a predetermined gap on the outer periphery of the base 1 is formed on the opposing surfaces of the upper and lower molds, and a protrusion is provided in a portion that becomes a circuit. . Therefore, after injecting the coating material in a state in which the mold is closed and then taking out from the mold, a secondary molded product in which the mask 4 is formed is formed.

  The covering material of the mask 4 is obtained by adding an ultraviolet absorber to a material selected from any of biodegradable resins, water-soluble resins, hydrolyzable resins, enzyme-decomposable resins, and organic acid-soluble resins. . There is polyvinyl alcohol (PVA) as a biodegradable and water-soluble resin, poly L-lactic acid resin (PLLA) as a biodegradable and hydrolyzable resin, starch resin, polybutylene succinate lactate resin as a hydrolyzable and enzyme-degradable resin ( PBSL), and organic acid-soluble resins include copolymer nylon and polyamide (for example, JP-A-2004-59829) obtained by exchange reaction of polyamide and polyamidepoamine.

  Moreover, as a UV absorber, “Tomisorb 100” (trade name, manufactured by API Corporation), “SEESORB 706” (2- (2H-benzotriazole-2-yl) -4-mentyl-6- (3,4, 5,6-tetrahydrophthalimidylmethyl) phenol (trade name manufactured by Cypro Kasei Co., Ltd.), and this “Tomisorb 100” has the maximum absorption at the lowest wavelength among the benzotriazole UVA, especially PVC, PVDC, Useful for styrene-based, polyester-based, and acrylic polymers.

  Therefore, as shown in FIG. 1E, the insulating substrate 1 is exposed with ultraviolet diffused light. Although this embodiment is an example in which diffused light is irradiated, it is of course possible to irradiate parallel light, and the present invention is characterized in that it can be irradiated with diffused light. By exposing the substrate 1 with the ultraviolet rays, the exposed portion of the resist 3 becomes the photosensitive portion 3a, and the portion that is covered with the mask 4 and is not exposed naturally becomes the unexposed portion 3b.

  Next, as shown in FIG. 1F, the mask 4 is removed. For example, the mask 4 made of PBSL is removed by using both alkaline decomposition and enzymatic decomposition using a mixed solution of an alkaline aqueous solution and a lipase enzyme solution. In this enzymatic degradation, the mask 4 is removed by immersing the lipase enzyme in an aqueous solution of 1 to 10% by weight in an aqueous solution at a temperature of 25 to 80 ° C. for 1 to 240 minutes.

  Removal of the mask 4 made of a resin such as polylactic acid is performed by alkaline aqueous solution decomposition and hydrolysis. Specifically, caustic alkali (NaOH, having a concentration of about 2 to 15% by weight and a temperature of about 25 to 70 ° C. Immerse it in an aqueous solution for 1 to 120 minutes to remove it. The polylactic acid resin has a property of hydrolyzing with an alkaline aqueous solution and has a property of being resistant to an acidic aqueous solution, so that it can be easily decomposed with an alkaline aqueous solution.

  Thus, corresponding to the material of the resin mask 4, a method of removing by alkaline decomposition and hydrolysis with an alkaline aqueous solution, and removing the mask by using both alkaline decomposition and enzymatic decomposition with a mixed solution of alkaline aqueous solution and lipase enzyme solution. To do.

  Therefore, as shown in FIG. 1 (G), the exposed photosensitive portion 3a of the resist is removed. Then, as shown in FIG. 1 (H), electrolytic plating 5, for example, electrolytic copper plating is performed on the portion of the photosensitive portion 3 a where the resist is removed.

  Thereafter, as shown in FIG. 1I, the unexposed portion 3b of the photoresist 3 is removed.

  Finally, as shown in FIG. 1 (J), when the electroless copper plating conductor layer 2 is removed, a predetermined circuit pattern is completed. The circuit pattern is three-dimensional, but the present invention can be applied to a two-dimensional circuit pattern.

  As an application example of the invention, the electronic circuit can be made three-dimensional and can be used for developing a technology for forming an element of a built-in antenna of a mobile phone.

(A)-(J) are the end views which show each process of the manufacturing method of this invention. (A)-(F) are the end views which show each process of the manufacturing method of a prior art.

Explanation of symbols

1 Insulating substrate 2 Conductive layer (electroless plating)
3 Photoresist 3a Photoresist exposed portion 3b Photoresist unexposed portion 4 Mask 5 Electrolytic plating L UV

Claims (2)

A method of patterning a circuit by forming a conductor layer on the entire surface, blocking ultraviolet rays through a mask on an insulating substrate,
The mask is formed by three-dimensionally injecting a coating material that covers the insulating substrate in a state where a portion to be a circuit is exposed, and in close contact with the substrate,
The mask covering material is a material in which an ultraviolet absorber is added to a material selected from biodegradable resins, water-soluble resins, hydrolyzable resins, enzyme-decomposable resins, and organic acid-soluble resins. A method of manufacturing a circuit board characterized by the above. A method of patterning a circuit by forming a conductor layer on the entire surface and blocking ultraviolet rays through a mask on an insulating substrate coated with a photoresist,
Forming an insulating substrate;
Etching process and catalyst application process as plating pretreatment,
Forming a conductor layer on the insulating substrate;
Applying a photoresist to the conductor layer;
A step of injecting a coating material that covers the insulating substrate in a state in which a circuit portion is exposed, and forming a mask three-dimensionally in a state of being in close contact with the substrate;
The mask material is a material selected from any one of biodegradable resins, water-soluble resins, hydrolyzable resins, enzyme-decomposable resins, and organic acid-soluble resins, with an ultraviolet absorber added thereto,
Exposing the insulating substrate with ultraviolet rays;
Removing the mask;
Removing the photoresist of the photosensitive portion;
A step of electroplating a portion of the photosensitive portion where the photoresist is removed;
Removing the unexposed portions of the photoresist;
And a step of removing the conductor layer.

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