JP4426686B2 - 3D circuit board manufacturing method and 3D circuit board - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a three-dimensional circuit board such as a dielectric antenna used in a mobile communication device or a GPS device of a mobile phone, and a three-dimensional circuit substrate manufactured by the manufacturing method.
[0002]
[Prior art]
Conventionally, as a method of manufacturing a three-dimensional circuit board such as a dielectric antenna, a dielectric substrate having a predetermined shape is formed from a dielectric material, and the predetermined pattern of the surface of the dielectric substrate formed into the predetermined shape is formed. A resin mask is integrally formed on this dielectric substrate so that the surface portion where the conductive layer is to be formed is exposed and the surface portion other than this portion is covered, and metal particles are attached to the surface to be electrolessly plated. A conductive layer is formed by electroless plating on the surface of the resin mask and on the entire surface of the dielectric substrate exposed from the resin mask, and the plated dielectric substrate and the resin The resin mask is removed from the integrated product with the mask, and a conductor layer having a predetermined pattern is formed on the surface of the dielectric substrate (for example, Japanese Patent Application Laid-Open No. 11-17442).
[0003]
[Problems to be solved by the invention]
Thus, a catalyst treatment for electroless plating is necessary, and further, after the conductor layer is formed by electroless plating, that is, the entire surface of the resin mask and the dielectric substrate exposed from the resin mask. Since the resin mask is removed after the conductor layer is formed on the surface, when the resin mask is removed, the conductive layer on the surface of the resin mask and the conductor layer of the dielectric substrate that are continuous are forced. As a result of a typical peeling operation, the periphery of the conductor layer of the dielectric substrate becomes an uneven shape, that is, a zigzag state, a residue that hinders use, or a wrinkle. For this reason, the area of the dielectric antenna is not as designed, and the function as an antenna is reduced.
[0004]
Therefore, an object of the present invention is to provide a method of manufacturing a three-dimensional circuit board that can simplify the manufacturing process by eliminating the need for a catalyst treatment for electroless plating.
[0005]
Another object of the present invention is to provide a three-dimensional circuit board having a clear outline around a conductor layer of a conductor substrate and a method for manufacturing the same.
Still another object of the present invention is to provide a method of manufacturing a three-dimensional circuit board capable of easily and quickly removing a resin mask from a dielectric substrate.
[0006]
[Means for Solving the Problems]
The feature of the present invention described in claim 1 is that a first step of forming the dielectric substrate of the predetermined shape from a synthetic resin material containing a catalyst mixed with a catalyst, and the surface of the dielectric substrate, A second step of exposing a surface portion on which a conductor layer of a predetermined pattern is to be formed and forming a resin mask on the dielectric substrate so as to cover the other surface portion; and the resin mask and the resin mask. A third step of roughening the entire surface of the exposed dielectric base; a fourth step of removing the resin mask from the dielectric base; and a predetermined pattern on the surface of the dielectric base. And a fifth step of forming the conductive layer by electroless plating.
[0007]
The feature of the present invention is that the material of the conductor base formed in the first step is mixed with a catalyst for electroless, and the fifth conductive layer is formed after removing the resin mask in the fourth step. Is.
[0008]
Synthetic resin as a material for the dielectric substrate is excellent in heat resistance and strength. For example, it is molded by injecting a plating grade thermoplastic liquid crystal polymer into a cavity with the mold closed. This thermoplastic liquid crystal polymer is a thermoplastic aromatic polyester resin, and uses a plating grade C810 of “Vectra” (trade name, manufactured by Polyplastics Co., Ltd.). In addition, thermoplastic resins such as polyphenylsulfide resin, polyphenine ether resin, polyetherimide resin, polycarbonate resin, polyacetal resin, polysulfone resin, polyethersulfone resin, and polyamideimide resin as synthetic resins for the material of the dielectric substrate 1 A thermosetting resin such as a resin, an epoxy resin, a phenol resin, or an unsaturated polyester resin can be selectively applied. Therefore, a dielectric substrate, which is a cubic primary substrate of a predetermined shape, is formed by mixing a catalyst such as palladium or gold into such a synthetic resin and injection molding the synthetic resin material containing the catalyst.
[0009]
Synthetic resin as a material for the resin mask is an elastomer that can be bent easily. This elastomer has elasticity at room temperature and is appropriately selected from organic, inorganic, natural, and synthetic materials. Natural rubber elastomers include chlorinated rubber, hydrochloric acid rubber, maleated rubber, hydrogenated rubber, and the like. Synthetic rubbers that can be used as such elastomers include VDF (vinylidene fluoride) -HFP (hexafluoropropylene), VDF-CTFE (chlorotrifluoroethylene), VDF-PFVE (perfluoromethyl vinyl ether). , Fluorosilicone rubber, TFE (tetrafluoroethylene) -PFVE, PTFE-P (polytetrafluoroethylene-propylene) fluoroalkoxypolyphosphazene, and other fluororubbers, isobutylene rubber, ethylene propylene diene rubber, chlorosulfonated polyethylene Polyolefin elastomers such as rubber, styrene-isoprene-styrene block copolymer, styrene-butadiene-styrene copolymer, styrene-ethylene-butylene-styrene block Styrene elastomers such as a polymer, other polyester elastomer, isoprene rubber, urethane rubber, epichlorohydrin rubber, chloroprene rubber, silicone rubber, nylon 12, butyl rubber, and the like butadiene rubber, fluorine rubber, polynorbornene rubber.
[0010]
These elastomers may be used alone or in combination of two or more. You may mix and use a thermoplastic resin as long as the elasticity which an elastomer has is not impaired.
[0011]
In order to adjust dimensional accuracy and hardness, an inorganic filler such as talc, bentonite, mica, wollastonite, glass filler, or the like may be added to the resin material for the resin mask 2 in a composite manner. Further, an adhesion improver may be added.
[0012]
According to a second aspect of the present invention, there is provided a first step of forming the dielectric substrate having the predetermined shape from a synthetic resin material containing a catalyst mixed with a catalyst for electroless plating, and a surface of the dielectric substrate. A second step of exposing a surface portion on which the conductor layer of the predetermined pattern is to be formed and forming a resin mask on the dielectric base so as to cover the other surface portion; and the resin mask and A third step of roughening the entire surface of the dielectric substrate exposed from the resin mask; and a conductive layer on the roughened surface of the dielectric substrate and the entire surface of the resin mask. A fourth step of forming by electroless plating and a fifth step of removing the resin mask from the dielectric substrate, and the materials of the dielectric substrate and the resin mask are weakly compatible with each other. Where is A.
[0013]
This weak compatibility is an intermediate between compatibility and incompatibility. Specifically, when the interface between the dielectric substrate and the resin mask is mechanically peeled off, the surface of the dielectric substrate is hindered in use. The state which is welded at a temperature within a range in which no residue or soot remains and the etching solution in the wet process can be prevented from penetrating into the interface.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a method of manufacturing a three-dimensional circuit board according to the present invention will be described with reference to the drawings. First, the first embodiment is shown in FIGS. As shown in FIG. 1A, the first step is to form a dielectric substrate 1 that is a first molded product, and the synthetic resin of the dielectric base material is excellent in heat resistance and strength. With the mold closed, a plating grade thermoplastic liquid crystal polymer is injected into the cavity and molded. This thermoplastic liquid crystal polymer is a thermoplastic aromatic polyester resin, which uses "Vectra" (trade name, manufactured by Polyplastics Co., Ltd.), plating grade C810, which is thermoplastic while being solder-resistant. And has performance as a molded circuit component. Therefore, a dielectric substrate 1 which is a primary substrate of a cube having a predetermined shape is formed by mixing palladium in a catalyst for electroless plating into the synthetic resin and injection molding the synthetic resin material containing the catalyst.
[0015]
Next, in the second step, as shown in FIG. 1B, after the first step, a conductor layer 4 having a predetermined pattern is formed on the surface of the dielectric substrate 1 (see FIG. 1E). The resin mask 2 is formed on the dielectric substrate so that the surface portion to be exposed is exposed and the other surface portion is covered. The material of the resin mask 2 is an elastomer that can be easily bent. This elastomer has elasticity at room temperature, and is a thermoplastic polyester elastomer “trade name made by Hytrel # SB704 Toray DuPont. "It was used. When the above-mentioned vector is used as the material of the dielectric substrate 1 and Hytrel # SB704 is used as the material of the resin mask 2, the dielectric substrate 1 and the resin mask 2 are in a weakly compatible range. Therefore, the removal operation of the resin mask 2 in the fourth step described later is simplified. The molding conditions of the resin mask 2 were as follows: in a molding machine (Model: TI30G2 manufactured by Toyo Machine Metal Co., Ltd.), cylinder temperature: 230 ° C., injection pressure: 717 kg / cm ² , molding cycle: 25 seconds, mold temperature: 40 It is set to ° C.
[0016]
Next, the chemical etching step of the third step will be described with reference to FIG. 1C. This etching-treated surface 3 is the entire surface of the dielectric substrate 1 exposed from the resin mask 2 and the resin mask. Is roughened. As an example of this etching treatment, an alkaline aqueous solution in which caustic soda or caustic potash is dissolved at a predetermined concentration, for example, 45 wt% is heated to a predetermined temperature, for example, 50 to 90 ° C., and the dielectric substrate 1 of the primary molded product, The resin mask 2 is immersed for a predetermined time, for example, 30 minutes. This etching process makes the entire surface rough.
[0017]
Next, the fourth step will be described with reference to FIG. 1D. This is a step of drying the etched dielectric substrate 1 and resin mask 2 and then removing the resin mask 2 from the dielectric substrate 1. In order to facilitate this removal operation, an apparatus for removing the resin mask 2 may be used, and chemically, for example, a xylene-based organic material is used. It may be used and removed by dissolving only this resin mask. As described above, the resin mask 2 can be easily removed by selecting the resin mask 2 material and the dielectric substrate 1 material from weakly compatible synthetic resins.
[0018]
Finally, the fifth step will be described with reference to FIG. 1E. The conductive layer 4 is formed on the surface of the dielectric substrate 1 on the etching treatment surface 3 having a predetermined pattern by electroless plating.
[0019]
Next, another embodiment of the present invention will be described with reference to FIGS. 2 (A) to 2 (E). As shown in FIG. 2 (A), the first step is a first molded product. A dielectric substrate 1 is molded, and the synthetic resin of the dielectric base material is formed by injecting and molding the same liquid crystal polymer of the plating grade as in the first embodiment. As the liquid crystal polymer, a plating grade C810 of “Vectra” (trade name, manufactured by Polyplastics Co., Ltd.), which is a thermoplastic aromatic polyester resin, is used. As described above, the liquid crystal polymer is thermoplastic but has solder mounting heat resistance. Therefore, a dielectric substrate 1 which is a primary substrate of a cube having a predetermined shape is formed by mixing palladium in a catalyst for electroless plating into the synthetic resin and injection molding the synthetic resin material containing the catalyst.
[0020]
Next, in the second step, as shown in FIG. 2B, after the first step, a conductor layer 41 (see FIG. 2E) having a predetermined pattern is formed on the surface of the dielectric substrate 1. The resin mask 2 is formed on the dielectric substrate so that the surface portion to be exposed is exposed and the other surface portion is covered. The resin mask 2 is made of an easily bendable elastomer, which has elasticity at room temperature, and is a polyester-based elastomer, “Hytrel # SB704 Toray DuPont's product name”. used.
[0021]
The resin mask 2 is a thermoplastic elastomer and needs to be weakly compatible with the dielectric substrate 1. Therefore, in the state of FIG. 2B, the chemical etching solution and electroless (chemical) plating solution to be performed thereafter do not penetrate into the interface between the dielectric substrate 1 and the resin mask 2, and the resin mask. The removal of 2, i.e. mechanical peeling, can also be carried out very easily and quickly.
[0022]
Next, the chemical etching step of the third step will be described with reference to FIG. 2C. This etching processing surface 3 is the resin mask 2 and the entire surface of the dielectric substrate 1 exposed from the resin mask. Is roughened. As an example of this etching treatment, similar to the above-described embodiment, an alkaline aqueous solution in which caustic soda or caustic potash is dissolved at a predetermined concentration, for example, 45 wt%, is heated to a predetermined temperature, for example, 50 to 90 ° C. The substrate 1 and the resin mask 2 of the secondary molded product are immersed for a predetermined time, for example, 30 minutes. This etching process makes the entire surface rough.
[0023]
As described above, the first to third steps in this embodiment are substantially the same as the first to third steps in the above-described embodiment, and the same reference numerals are assigned to the same drawings. is doing. However, in the above-described embodiment, the resin mask is removed after roughening the entire surface of the resin mask 2 in the third step and the dielectric substrate 1 exposed from the resin mask. In the example, as the fourth step, the conductive layers 41 and 42 are formed by electroless plating on the etched surface 3 of the dielectric substrate 1 and the entire surface of the resin mask 2.
[0024]
Finally, in the fifth step, the resin mask 2 is removed from the dielectric substrate 1, and in this removal operation, as described above, the materials of the dielectric substrate 1 and the resin mask 2 are weakly compatible with each other. Therefore, when the interface of the resin mask is peeled in order to remove the resin mask, the peeling operation can be performed easily and promptly, and the surface of the dielectric substrate 1 is left unhindered in use. There are no checks or traps left.
[0025]
【The invention's effect】
According to the first aspect of the present invention, the catalyst application step is not required as in the prior art, and the conductor layer formed by electroless plating has an accurate contour as designed. For example, when a dielectric antenna is manufactured, According to the second aspect of the present invention, the catalyst application step is not required, and the chemical etching solution or the electroless plating solution penetrates between the dielectric substrate and the resin mask. In the case where the interface of the resin mask is peeled off, the peeling work can be easily and promptly performed, and the residue and wrinkles that hinder the use are not left on the surface of the dielectric substrate 1.
[Brief description of the drawings]
FIGS. 1A, 1B, 1C, 1D and 1E are schematic views showing step by step the respective production steps according to the first embodiment of the present invention.
FIGS. 2 (A), (B), (C), (D) and (E) are schematic views showing steps of manufacturing according to the second embodiment of the present invention in stages.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Dielectric base | substrate 2 Resin mask 3 Etching surface 4 Conductive layers 41 and 42 Conductive layer

Claims (2)

In a method for manufacturing a three-dimensional circuit board, in which a conductor layer having a predetermined pattern made of a conductive material is formed on the surface of a dielectric substrate having a predetermined shape made of a synthetic resin material,
Forming a dielectric substrate of the predetermined shape with a synthetic resin material containing a catalyst mixed with a catalyst for electroless plating;
A step of exposing a surface portion of the surface of the dielectric substrate on which the conductor layer of the predetermined pattern is to be formed and forming a resin mask on the dielectric substrate so as to cover the other surface portion;
A step of roughening the resin mask and the entire surface of the dielectric substrate exposed from the resin mask;
Forming a conductive layer by electroless plating on the roughened surface of the dielectric substrate and the entire surface of the resin mask;
And removing the resin mask from the dielectric substrate,
The material of the dielectric substrate and the resin mask der those mutually Yowasho soluble,
The method of manufacturing a three-dimensional circuit board, wherein the dielectric substrate is a thermoplastic liquid crystal polymer, and the resin mask is a thermoplastic polyester elastomer having elasticity at room temperature . A three-dimensional circuit board manufactured by the manufacturing method according to claim 1 .

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