JPH01122112A - Manufacture of pattern coil - Google Patents

Abstract

PURPOSE:To manufacture a pattern coil having different patterns on front and rear faces by catalyst-treating both side faces of an insulating substrate to be electrolessly plated, coating it with photosensitive resin, then simultaneously exposing the patterns on both side faces, and developing them. CONSTITUTION:An insulating substrate having optical shielding property against an ultraviolet ray is prepared, and both side faces are catalyst-treated to be electrolessly plated. Then, both the faces of the substrate thus catalyst-treated are coated with photosensitive resin, and then simultaneously exposed independently at the patterns. Further, after they are developed with solution responsive to the resin, and a conductor circuit is formed by an electroless plating or both electroless plating and electric plating. Thus, a pattern coil having different patterns on both the front and rear faces can be manufactured accurately in high density with high productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a patterned coil that is thin and compact, has conductor thickness greater than the spacing between conductors, and has high reliability.

[Prior Art] Conventionally, a wire winding method has been frequently used as a method for manufacturing coils. However, since the occupancy rate of the conductor is low in the coil manufactured by this method, it is difficult to make the coil smaller and thinner, and in addition, there is a problem in assembly accuracy. Therefore, there was a limit to increasing the rotation accuracy of motors manufactured using this coil.

In addition, using copper foil as a raw material, using the photoetching method,
Methods of manufacturing patterned coils are also known. However, according to this method, the spacing between the conductors of the coil is generally more than twice the conductor thickness of the coil, and there is still a limit to the production of a dense coil with a high occupancy rate of the conductors.

As a manufacturing method applying the photoelectroforming method, an insulating film is used, and after the surface is treated with a catalyst,
A method has also been proposed in which a desired circuit is obtained using a photosensitive dry film, and then a high-density pattern coil is obtained by electroless plating or a combination of electroplating (JP-A-5
No. 9-204215).

[Problems to be Solved by the Invention] However, the insulating film used in this method does not have the ability to block ultraviolet light when exposing the photosensitive dry film, so the circuit shape to be manufactured may have two sides. In different cases, circuits cannot be formed on both sides at the same time, or even if they can be formed, they can only provide extremely unreliable products in terms of quality, ie, productivity and high precision are extremely low.

The present invention was made to solve the above-mentioned drawbacks, and its purpose is to create a patterned coil with different patterns on the front and back sides, while utilizing the photoelectroforming method.
It is an object of the present invention to provide a manufacturing method through a double-sided simultaneous exposure process.

[Means for Solving the Problems] The present invention achieves the above object by using an insulating substrate that blocks ultraviolet rays to enable simultaneous exposure of both sides. That is, the present invention includes a step of subjecting both sides of the substrate to a catalyst treatment for electroless plating, a step of coating both sides with a photosensitive resin, and then performing simultaneous pattern exposure and development on both sides. This method of manufacturing a patterned coil includes the step of forming a conductor layer by electroless plating or a combination of electroless plating and electroplating.

Hereinafter, the basic aspects of the present invention will be explained in detail along the steps thereof.

First, an insulating substrate having a light-shielding property against ultraviolet rays is prepared, and both surfaces thereof are treated with a catalyst for electroless wipes.

A typical example of the insulating substrate used here that has a UV-blocking property is an insulating base in which an ultraviolet-blocking material is mixed. The insulating substrate may be thermoplastic resin such as acrylic, polyamide, polyester, phenol, epoxy, etc.
Examples include films or plates made of thermosetting resins such as polyimide.

Various organic and inorganic pigments and dyes can be used as the ultraviolet light blocking material mixed into such an insulating substrate.
Inorganic pigments such as carbon black, zinc white, and Hansa yellow are good in terms of their UV blocking efficiency and economic efficiency.

A known method may be used for the catalyst treatment for electroless plating. Prior to this catalyst treatment, it is desirable to carry out an appropriate treatment in order to ensure the adhesion of the plating to the insulating substrate. There are various methods for this, such as treatment with caustic soda, a mixture of chromic acid and sulfuric acid, an organic solvent, or honing treatment.

Next, a photosensitive resin is coated on both sides of the catalytically treated insulating substrate having a light shielding property against ultraviolet rays, and then independent pattern exposure is simultaneously performed on both sides.

For coating the photosensitive resin, an ordinary dry film or liquid resist made of a photosensitive resin may be used, and the thickness of the coating layer is appropriately selected depending on the required circuit density and circuit conductor thickness.

Pattern exposure can typically be performed using a glass mask or a film mask.

Next, after developing with a solution suitable for the photosensitive resin, a conductor circuit is formed by electroless plating or a combination of electroless plating and electroplating. By the above method, a high-density, high-precision patterned coil can be manufactured with good productivity.

[Examples] Hereinafter, the present invention will be described in more detail according to Examples.

Example 1 PE with a thickness of 50p containing and dispersing 3% by weight of carbon black as an insulating substrate having a light-shielding property against ultraviolet rays.
Prepare T (polyethylene terephthalate) film,
A hole of 0.8 mmφ was made at a predetermined position using an NC lathe, and treated with 50 g/j of caustic soda at 60° C. for 5 minutes.

Then 30 g/j CrO2, 100 g/f H2
After treating with an SO4 mixture at 50°C for 5 minutes, catalytic treatment was performed with an electroless plating catalyst (trade name H5-101B, manufactured by Hitachi Chemical Co., Ltd.), and a photosensitive dry film (trade name T1020, manufactured by DuPont) was used for 20 minutes. A thick photosensitive layer was formed.

Next, after simultaneous exposure on both sides at an exposure dose of 200 mJ/cn+2, triethane development was performed to obtain a desired pattern.

The amount of transmitted and incident ultraviolet rays of 365 nm in the film used were as shown in FIG. 1, and no influence on opposite surfaces was observed during exposure.

Next, after one scale of electroless copper was deposited, 25- was deposited by electrolytic copper plating, and a sheet coil was formed.

Example 2 50-thick PET with 5% by weight of zinc white mixed and dispersed
Prepare a film and place it in a predetermined position using an NC lathe.
After drilling holes of 8111 mφ and roughening the surface by third blasting, catalyst treatment, photosensitive layer formation, exposure, and development were performed in the same manner as in Example 1 to obtain a desired pattern.

The transmitted amount and incident amount of ultraviolet rays at 385 nm in the film used are as shown in FIG. 2, and no influence of opposite surfaces was observed during exposure. Thereafter, a patterned coil was obtained in the same manner as in Example 1.

[Effects of the Invention] By the method for manufacturing a patterned coil of the present invention described in detail above, patterned coils with different patterns on the front and back sides can be manufactured with high productivity, high density, and high precision.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are diagrams showing the transmitted amount and incident amount of 365 nm ultraviolet rays in Examples, respectively.

Claims (1)

[Claims] 1) An insulating substrate having a light-shielding property against ultraviolet rays is prepared,
A step of subjecting both surfaces to a catalyst treatment for electroless plating, a step of coating both surfaces with a photosensitive resin, and then performing simultaneous pattern exposure and development on both sides, and an electroless plating or electroless plating step. A method for manufacturing a patterned coil, comprising the steps of: and forming a conductor layer by a combination of electroplating.