JPH10283875A - Flexible board and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible board of simple configuration, which is easily manufacturable, enables cost reduction, and ensures a high reliability. SOLUTION: A circuit pattern 12 consisting of conductor and stationary contacts 14a and 14b are provided on a flexible base film 10 of insulative resin. The conductors in the part of stationary contacts 14a and 14b are subjected to solder plating, and a movable contact 18 in connection with the stationary contacts 14a and 14b is formed from a metal plate of phosphor bronze, etc., subjected to solder plating. A membrane sheet 20 having slit 22 is affixed to the surface of the movable contact 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible substrate having an electric contact such as a push switch and a circuit pattern.

[0002]

2. Description of the Related Art For example, in a conventional contact structure of a push switch portion formed on a flexible substrate, a circuit pattern and fixed contacts made of copper foil are formed on a surface of a base film such as polyimide, and a circuit other than the base film and the fixed contacts is formed. The pattern was covered with a cover film such as polyimide, and the surface of the fixed contact was gold-plated. A movable contact that opens and closes the contact is in contact with the fixed contact so that the movable contact can be separated from and connected to the fixed contact. The movable contact was formed on a circular dome with a silver material. And the movable contact is PE
Partially connected to the fixed contact and fixed by a membrane sheet such as T. When attaching the membrane sheet, the membrane sheet and the separator laminated on the carrier tape were used, the separator was peeled off, and the membrane sheet was attached together with the movable contact at a predetermined position on the flexible substrate, and the carrier tape was peeled off.

[0003]

In the case of the above prior art, gold-plated or silver movable contacts at the contact portion hinder cost reduction. If the contacts are formed without using these materials, the reliability and durability of the contacts are increased. There was a problem that the sex fell. In addition, in the pasting of the membrane sheet, since the management and the pasting work of the membrane sheet is performed using the carrier tape, the separator and the carrier tape are discharged as useless garbage, which takes a lot of man-hours,
It was also a cause of cost increase.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has a simple structure, is easy to manufacture, can reduce costs, and has high reliability. It is intended to provide a manufacturing method.

[0005]

According to the present invention, a circuit pattern and a fixed contact made of a conductor are formed on a flexible insulating resin base film, and the conductor at the fixed contact portion is subjected to solder plating. The movable contact connected to the contact is a flexible substrate in which a metal plate such as phosphor bronze is subjected to solder plating, and a membrane sheet having a slit is attached to the movable contact.

[0006] The movable contact is a circular dome-shaped metal plate made of phosphor bronze, and this metal plate is plated with solder. The movable contact is connected to one of the fixed contacts and the other is a polyimide sheet. They face each other via an insulating layer. Further, the portion of the flexible substrate provided with the respective contacts is fixed to a resin holding member.

In addition, the present invention forms a circuit pattern and a fixed contact by a conductor on a flexible insulating resin base film, applies a solder plating to the conductor at the fixed contact portion, and forms a slit when attaching the movable contact. The separator of the attaching sheet comprising the membrane sheet and the separator was peeled off, the movable contact was attached to the slit portion, the movable contact was opposed to the fixed contact portion, and the membrane sheet was placed on the base film. This is a method for manufacturing a flexible substrate to be attached to a substrate.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. The flexible substrate of this embodiment is made of a base film 10 such as polyimide.
A circuit pattern 12 and a pair of fixed contacts 14a, 1 made of a conductive paint such as copper foil, silver, copper, carbon, etc.
4b. Then, the circuit pattern 12 other than the surface of the base film 10 and the fixed contacts 14a and 14b is provided.
Are covered with a cover film 16 such as polyimide. A movable contact 18 for opening and closing the fixed contacts 14a and 14b is located so as to be able to be separated from and connected to the fixed contacts 14a and 14b.

The movable contact 18 is formed of a phosphor bronze thin plate and has a circular dome shape. I have. In addition, fixed contact 1
The surfaces of the movable contacts 4a and 14b and the movable contact 18 are plated with solder. The movable contact 18 is fixed on the fixed contacts 14a and 14b by a membrane sheet 20 made of a resin film such as PET and having an adhesive layer formed on the back surface. Two parallel slits 22 are formed in a portion of the membrane sheet 20 located on the surface of the fixed contact 18.

A holding member 26 made of ABS resin or the like that supports the contact forming portion is fixed on the back surface of the base film 10 to the portion of the flexible substrate on which the fixed contacts 14a and 14b are provided. The holding member 26 is inserted into through holes (not shown) formed in the base film 10, the cover film 16, and the membrane sheet 20.
Then, the distal end portion of the welding convex portion 28 integrated with the above is fitted, and the distal end portion is melted and fixed on the surface of the membrane sheet 20 side.

In the method of manufacturing a flexible substrate according to this embodiment, first, a circuit pattern 12 and fixed contacts 14a and 14b are formed on a base film 10. This forming method is the same as the conventional method for forming a circuit pattern on a printed circuit board. The fixed contacts 14a, 14a
The cover film 16 is attached so that b and other predetermined portions are exposed. Next, the sticking sheet provided with the membrane sheet 20 has no carrier tape as shown in FIG. 4, and two parallel slits 22 are formed at predetermined movable contact positions of the membrane sheet 20. It is formed in advance. The separator 24 is peeled off from the membrane sheet 20, and the movable contact 18 is attached to a portion of the adhesive surface where the slit 22 is formed. Thereafter, the movable sheet 18 is positioned on the fixed contacts 14a and 14b, and the membrane sheet 20 is attached to the base film 10.

A holding member 26 made of ABS resin is attached to the back surface of the portion of the flexible substrate on which the fixed contacts 14a and 14b are formed, to which the membrane sheet 20 is attached, and the welding convex portion 28 is inserted into the fixing hole. Insert and melt the tip to fix both.

The flexible substrate of this embodiment is obtained by plating the fixed contacts 14a and 14b and the movable contact 18 made of phosphor bronze with solder. Since the cheap material is plated with inexpensive solder, the manufacturing cost is reduced. It can be greatly reduced. Moreover, solder plating is durable,
The reliability as a contact is also good. Furthermore, the separator sheet 24 can be peeled off and attached as it is without providing a carrier tape on the membrane sheet 20, so that the cost of parts, the number of manufacturing steps, and the cost can be reduced.

In the flexible substrate and the method of manufacturing the same according to the present invention, the circuit pattern, the material of the contact, the shape of the movable contact, and the like can be changed as appropriate, and the membrane sheet can be selected as appropriate. Further, the material of the movable contact can be appropriately selected, and the shape may be other than the dome shape.

[0015]

According to the flexible substrate and the method of manufacturing the same of the present invention, the fixed contact constituting the contact and the contact can be made of an inexpensive and highly reliable material, thereby achieving both cost reduction and maintenance of reliability. Is what you can do. In addition, it can be easily manufactured, and the number of manufacturing steps and cost can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a flexible substrate according to an embodiment of the present invention.

FIG. 2 is an enlarged plan view of a contact portion of the flexible substrate according to the embodiment.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view of a membrane sheet and a separator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Base film 12 Circuit pattern 14a, 14b Fixed contact 16 Cover film 18 Movable contact 20 Membrane sheet 22 Slit 24 Separator

Claims (4)

[Claims] 1. A circuit pattern and a fixed contact made of a conductor are formed on a base film of a flexible insulating resin, and a conductor of the fixed contact portion is plated with solder, and a movable contact connected to the fixed contact comprises: A flexible substrate in which a metal plate is subjected to solder plating, and a membrane sheet having slits is attached to the movable contact. 2. The movable contact is a circular dome-shaped metal plate made of phosphor bronze, which is plated with solder, is connected to one of the fixed contacts and is insulated from the other fixed contact. The flexible substrate according to claim 1, which faces through a layer. 3. The flexible substrate according to claim 1, wherein the portion of the flexible substrate provided with the fixed contact and the movable contact is fixed to a resin holding member. 4. A circuit having conductors and fixed contacts formed on a base film of a flexible insulating resin, and the conductors at the fixed contact portions are subjected to solder plating. When the movable contacts are fixed, a membrane having a slit is provided. Production of a flexible substrate in which the separator of the attaching sheet comprising the sheet and the separator is peeled, the movable contact is attached, the movable contact faces the fixed contact portion, and the membrane sheet is attached on the base film. Method.