JPS61116718A - Condenser switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a capacitor switch applied to a signal input switch of a keyboard, etc.

<Prior art> A capacitor switch is constructed by interposing an insulating film between two opposing electrodes, and when one electrode is pressed against the other electrode through the insulating film, a capacitor is formed between the electrode pair and the insulating film. The switch is configured such that when the charge supplied between the electrode pair reaches a predetermined capacitance value or more between the electrode pair, the switch is closed.

Conventionally, in such a capacitor switch, as shown in FIG. 4, a fixed electrode is formed by etching a metal thin film deposited on one side of an insulating substrate A, and a lower surface of a movable electrode C is formed opposite to the fixed electrode. An insulating film d made of a material such as a polyethylene terephthalate film was attached to the top.

<Problems to be Solved by the Invention> By the way, when forming a circuit pattern on an insulating substrate a, generally a thin metal film is formed on one side of the insulating substrate a, and the plating resist s remains on the desired circuit pattern. , the other metal films are removed by etching, and the plating resist film is further removed. Therefore, in the conventional configuration, the formation process requires the steps of applying the plating resist film, removing it, and adhering the insulating film to the movable electrode, resulting in a large number of steps. There was a drawback.

An object of the present invention is to provide a capacitor switch that can be easily formed by eliminating the step of attaching an insulating film.

Means for Solving the Problems> The present invention provides a metal thin film formed on one side of an insulating substrate, after covering a circuit pattern portion including an electrode with a plating resist film, the metal thin film other than the circuit pattern portion is coated with a plating resist film. A circuit board on which a circuit pattern is formed by removing the plating resist film by a single plating process and leaving a plating resist film on the electrode, and a circuit board on which a circuit pattern is formed are placed facing each other at a distance from the electrodes of the circuit board and are relatively close to and separated from each other. After the etching process, the plating resist a remaining on the electrodes of the circuit board is used as an insulating film.

In the above configuration, one of the opposing electrode pairs can be placed on the fixed electrode, and the other can be placed on the movable electrode.

That is, generally speaking, the electrodes formed on the circuit board are fixed electrodes, but as shown in FIG. , the circuit pattern is also formed on the insulating substrate holding the movable electrode at the top in the figure, so it is only necessary to leave the plating resist film on either of the electrodes on the upper and lower circuit boards. It happens.

As the plating resist film,! In view of various properties such as resistance to trains and various chemicals, for example, epoxy resin is suitable.

<Example> There are two types of means shown in the flowcharts of FIGS. 1A and 1H as means for leaving the plating resist film on the required circuit pattern.

The first method is to first select a paper-phenol base material as an insulating substrate, and form copper 111ff on its surface by copper plating, pasting a copper foil sheet, etc., as shown in FIG. 1A. A predetermined circuit pattern including electrodes is silk-printed using a plating resist agent. Furthermore, the remaining portions of the copper foil on which the plating resist film is not formed are etched away using chemicals. As a result, a circuit board is formed in which a plating resist film is deposited on the upper surface of the electrode of the predetermined circuit pattern.

FIG. 1B shows a second method, in which a plating resist agent mixed with a photosensitizer is first applied to the entire surface of the thin copper film formed on the paper-phenol substrate.

The negative showing the circuit pattern is then used to expose the pattern to the plated resist layer using known development techniques.

As a result, the photosensitive plating resist portion is cured by the photosensitive agent. Therefore, the remaining plating resist that has not been exposed to light is washed away, and the underlying copper thin film portion is etched. Thus, a circuit board is formed in which a plating resist film is deposited on the upper surface of the electrodes in a predetermined circuit pattern.

FIG. 2.3 shows a sheet switch to which the capacitor switch of the present invention is applied, and the switch is optimally applied to a keyboard.

In the figure, reference numerals 1a and lb are sheet-like flexible insulating substrates made of polyester film or the like, which are opposed to each other at a constant distance above and below.

On the upper surface of the lower insulating substrate 1a, there is provided a matrix-like electrode group 2 in which fixed electrodes 3 are arranged vertically and horizontally in the left, right, front and rear. Each electrode 3 is electrically connected in the left and right direction in FIG. Further, a plating resist film 5 is formed on the electrode 3 by the above-described forming means.

Further, on the lower surface of the upper insulating substrate 1b, there is provided an electrode group 6 having the same arrangement as the electrode group 2 and having a movable electrode 7 facing the electrode 3 vertically. Each movable electrode 7 is
They are electrically connected in the front and rear directions in the figure.

Further, on the side ends of the insulating substrates 1a and 1b, electric circuit boards 11.11 are formed which face each other vertically in a bent state as shown in FIG. , 6 are connected to a large number of conductive wires 9. lO is running on its surface.

A spacer 12 is arranged between the insulating substrates 1a and lb, and a spacer 12 is arranged between the electrode pairs 3 and 7 that face each other vertically.
A through hole 13 having a larger diameter than the outer diameter of the hole 13 is formed. Furthermore, the outer diameter of the movable electrode 7 is larger than that of the fixed electrode 3,
By pressing the movable electrode 7, which will be described later, the upper surface of the fixed electrode 3 is prevented from being damaged by its periphery.

In addition, on the insulating substrate 1b, there is provided a display indicating the function of the switch constituted by the electrode pair 3.7.

By pressing the movable electrode 7 at each predetermined location on the circuit board 6, the movable electrode 7 passes through the through hole 13 and comes into pressure contact with the fixed electrode 3, which is determined by the dielectric constant, thickness, etc. of the IPJ5. When a predetermined capacitance value is exceeded, an alternating current signal flows between the electrode pair 3 and 7. Since the electrodes 3 and 7 are arranged in a matrix on the left and right, a predetermined conductive wire 9, 10 is combined and connected by joining the electrode pair 3, 7, and a predetermined signal is generated.

When the pressing operation on the fixed electrodes 3 is released, each fixed electrode 3 moves back due to the elasticity of the insulating substrate l, and the electrodes 3.
7 is released.

In the embodiment described above, the flexible insulating substrates 1a and 1b may be formed of a single plate, as shown by the two-dot chain line in FIG. They are made to face each other, with the lower part serving as the fixed circuit board 2 and the upper part serving as the movable circuit board 6.

<Effects of the Invention> As described above, the present invention uses a plating resist film, which is necessary when forming electrodes on an insulating substrate, as an insulating film, so several steps in the switch formation process can be omitted, and the formation process can be simplified. can be easily applied, there is no need to separately provide a material for forming an insulating film, and there are excellent effects such as being economical.

[Brief explanation of drawings]

1A and 1B are flowcharts showing a circuit board manufacturing means, 2 and 3 show an embodiment of the present invention, 2 is a perspective view, and 3 is a vertical side view of the main parts, Moreover, FIG. 4 is a longitudinal sectional side view showing an outline of the conventional configuration. l...Insulating substrate 3...Fixed electrode 7...Movable electrode 5...Plating resist film Agent Patent attorney Kita Matsuura 1st 1U2 A
B 20th ′! JJ30

Claims (1)

[Claims] 1) After covering the circuit pattern portion including the electrode with a plating resist film on the metal thin film formed on one side of the insulating substrate, the metal thin film other than the circuit pattern portion is removed by etching treatment. and a circuit board on which a circuit pattern is formed with a plating resist film remaining on the electrode; and an electrode that is spaced apart from and opposed to the electrode of the circuit board and that relatively approaches and separates from the electrode, A capacitor switch characterized in that the plating resist film remaining on the electrodes of the circuit board after processing is used as an insulating film.2) Of the two opposing electrodes, one is a fixed electrode and the other is movable. A capacitor switch according to claim 1), characterized in that it is an electrode.