JP2584038B2 - Manufacturing method of contact board - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a contact board used for a switch or an encoder.

2. Description of the Related Art In recent years, digitalization of audio / video equipment (radio, stereo, video, etc.) and general home appliances (cooker, air conditioner, etc.) has progressed, and volume setting, frequency setting, timer setting,
Use of mode switches and encoders for temperature setting and mode setting is rapidly progressing. Further, switches and encoders used for consumer use (home appliances) are required to be less expensive as well as functional characteristics than those used for industrial use (robots, control devices, precision measuring instruments).

Hereinafter, the prior art will be described with reference to FIGS. 2a, b, c to 4a, b, c. 2A is a process drawing showing a method for manufacturing a contact substrate by a printing method, FIG. 2B is a plan view of the same contact substrate, FIG. 2C is a sectional side view thereof, and FIG. FIG. 4B is a process diagram showing a manufacturing method, b is a plan view of the contact substrate, c is a sectional side view thereof, FIG. 4A is a process diagram showing a method of manufacturing the contact substrate by a molding method, and b is the same. It is a top view of a contact board, and c is the same side sectional drawing.

The manufacturing method of the contact plate by the printing method of FIG.
This is a method for manufacturing a contact board by screen printing silver paste on 1a and baking it to form conductors 2a in a pattern. This method is inexpensive, but the viscosity of silver paste and the size of the screen mask mesh For example, the pattern is disturbed around the pattern. In addition, a step is formed between the conductor portion (layer) and the insulating substrate due to the thickness of the conductor portion (layer).

The method of manufacturing a contact substrate by the etching method shown in FIG. 3 is to apply a photosensitive resin to a copper-clad laminate having a copper foil 2b formed on the entire surface of the laminate 1b, dry the film, and bring an original having a required shape into close contact with the substrate to expose,
Develop, remove the copper foil 2b of the portion where the photosensitive resin is removed by etching, and then remove the photosensitive resin on the copper foil 2b to form a metal plating portion 2c in which the copper foil 2b is plated with another metal. In this method, a pattern faithful to the original image is obtained because the original image is produced by contacting, exposing, and developing the original image. However, the copper foil 2b is partially removed by etching, and the Since the laminate 1b of the laminate is used as an insulating portion, a step is generated between the insulating portion and the copper foil 2b and the metal plating portion 2c. The end faces of the copper foil 2b and the metal plating 2c have sharp edges.

The manufacturing method of the contact board by the molding method shown in FIG. 4 is to punch a metal foil 2d plated with another necessary metal 2e in advance into a required shape to form a pattern of the conductive portion 2f, and put this into a molding die. This is a method of manufacturing a contact board by insert molding by injecting the resin 1c.This method punches out the pattern of the conductive part 2f with a die, so that the end face of the conductive part 2f is less disturbed, and the insert molding is performed. Therefore, the step between the conductive portion and the resin 1c is small, but a gap 7 is generated at the boundary between the conductive portion 2f and the molding resin due to a difference in shrinkage ratio during molding. Also metal foil
A 2d punching die is required.

As described above, in the manufacturing method according to the above-described conventional technique, disturbance around the pattern of the conductor portion, a step between the conductor portion and the insulating portion, and a gap occur, and the contact 3 is slid on the contact board. At the time, contact points are broken due to the disturbance of the conductive part around the pattern, or due to steps or gaps, and the current flow (ON) and interruption (OFF) are not clear, causing chattering that the ON and OFF signals are disturbed. However, this causes a malfunction in the equipment used. Also, when sliding the contact, the sliding was not smooth due to the steps and gaps, and the feel was poor, and the life was short. In the molding method, a mold is still required to form the conductive part 2f, and when a contact board with a slightly different pattern of the conductive part 2f is required, a mold must be manufactured each time, and there is no versatility and high cost. Had the problem that

Means for Solving the Problems In order to solve the above problems, the present invention applies a photosensitive resin on a metal layer such as copper such as a copper-clad laminate, and then closely adheres the original of the conductive portion pattern, and performs exposure and development. By doing so, the copper foil having the conductive part pattern is exposed, and a metal layer is formed on the copper foil having the conductive pattern so as to have substantially the same thickness as the photosensitive resin layer.

Effects Therefore, according to the present invention, the original of the necessary conductive portion pattern is brought into close contact with the photosensitive resin applied on the metal layer and exposed and developed, so that a conductive portion pattern faithful to the original image can be formed. The peripheral portion of the partial pattern is linear, and there is no disturbance such as bleeding seen in the printing method, and a required pattern can be produced with high accuracy. Also, the production and modification of a new pattern to meet the needs of the user requires only the production and modification of the original image, and the investment is inexpensive and economical.

Further, since the thickness of the metal layer is made substantially equal to the thickness of the photosensitive resin, a smooth contact substrate can be easily obtained.

Embodiment An embodiment of the present invention will be described with reference to a contact board shown in FIG. FIG. 1a is a view showing a manufacturing process, b is a plan view of a contact board, and c is a side sectional view of the same.

According to FIG. 1, first, the surface of a copper-clad laminate (R6710, manufactured by Matsushita Electric Works) in which a copper foil 2 is laminated on a paper phenol laminate 1 is polished by a polishing apparatus generally used in a printed circuit board manufacturing process. After polishing and cleaning the copper foil 2, the photosensitive resin 4 having a photoresist function and a solder resist function (Provimer 52, manufactured by Nippon Ciba Geigy) is thinly applied by a spin coater or a knife coater, and then at 80 ° C. for about 30 minutes. Dried. The original image of the required conductive film (pattern) is adhered on top of it, and a metal halide lamp (power consumption 5KW) is irradiated from a distance of 1m for about 100 seconds, and a developer (Provimer developer DY90, manufactured by Nippon Ciba Geigy) To expose the necessary copper foil of the conductive portion pattern 7. Next, the photosensitive resin film 4 was cured by heating at 80 ° C. for 30 minutes and then at 150 ° C. for 60 minutes using a hot air circulation dryer. Next, after forming a nickel layer 5 of 3 μm to 5 μm by electrolytic plating, a metal layer 6 of 1 μm to 2 μm is further formed by plating to form a conductive portion pattern 7 having a plating layer having substantially the same thickness as the photosensitive resin 4. Thus, a contact substrate having excellent smoothness could be manufactured.

Note that the original image for forming the conductive portion pattern 7 can be further improved in pattern accuracy if it is manufactured by reducing an enlarged view of 5 to 10 times the original size.

 Reference numeral 3 denotes a contact that slides on the contact board.

Effect of the Invention As described above, the present invention applies the photosensitive resin on a metal layer such as copper of a copper-clad laminate, adheres the original of the conductive part pattern, and exposes and develops the conductive part pattern. Is exposed, and a metal layer is formed on the copper foil of the conductive pattern so as to have substantially the same thickness as that of the photosensitive resin layer. Therefore, the following effects can be obtained.

(1) Since the pattern is formed by close contact exposure development of the original image, there is no disturbance at the periphery of the pattern. When the contact is moved, the contact of the contact is instantly cut off at the boundary between the photosensitive resin and the metal pattern of the conductive pattern. Therefore, occurrence of chattering can be suppressed.

(2) Since there is no step between the photosensitive resin film and the conductive part pattern, when the contact is slid, there is no swelling of the contact.
Further, since there is no sharp edge in the conductive portion pattern, chattering can be prevented and the contact life can be extended, and the sliding feeling can be smooth and good.

(3) Since etching is not required, there is no additional cost such as treatment of etching waste liquid.

(4) Since a mold is not required to form the pattern of the conductor portion and only the preparation of the original image is required, it is inexpensive and versatile.

(5) It is also possible to apply a photosensitive resin to the gold layer plate itself and manufacture it.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1a is a view showing a manufacturing process of a contact board according to an embodiment of the present invention, b is a plan view of the contact board, and c is a side sectional view thereof. FIG. 2A is a process diagram showing a method for manufacturing a contact substrate by a conventional printing method, FIG. 2B is a plan view of the same contact substrate, FIG. 2C is a side sectional view thereof, and FIG. It is a process drawing showing the manufacturing method of the contact board, b is a plan view of the same contact board, c is the same side sectional view, and FIG. 4a is a process drawing showing the manufacturing method of the contact board by the same forming method. ,
b is a plan view of the contact substrate, and c is a sectional side view of the same. 2 ... copper foil, 4 ... photosensitive resin, 7 ... conductive part pattern.

Continuation of the front page (56) References JP-A-50-9072 (JP, A) JP-A-50-39818 (JP, A) JP-A-54-91781 (JP, A) JP-A-54-104563 (JP) , A) JP-A-61-231702 (JP, A) JP-A-61-234012 (JP, A) JP-A-56-130218 (JP, U)

Claims (1)

(57) [Claims] 1. After applying a photosensitive resin on at least a metal layer, a required conductive portion pattern original is brought into close contact with the photosensitive resin and exposed and developed to expose the required conductive portion pattern metal layer and to expose the metal layer. A method for manufacturing a contact board, comprising: forming a metal layer having substantially the same thickness as the photosensitive resin on the metal layer thus formed.