JPS6235214Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a contactor, and in particular, it is an object of the present invention to provide a contactor suitable for small-sized digital code generation switches having minute contact patterns.

In electrical components such as encoder switches, rotational position/speed detection switches, channel selection switches, digital volumes, etc., in which minute conductor patterns are formed on an insulating substrate, a well-known multi-contact device is used. Contactors are frequently used.
This multi-contactor has a wide variety of metal strips arranged approximately parallel and close to each other, and generally, the various strips are formed by pressing an elastic thin plate, or the multiple strips are formed by pressing a thin elastic plate. It is formed by arranging thin metal wires close together on a plane.

Recently, however, the contact patterns of this type of electrical components have become finer and more dense, and the conventional contacts described above have the disadvantage that contact reliability sometimes deteriorates due to wear during long-term use.

For example, as shown in the first diagram, the width A of the contact pattern 2 formed on the insulating substrate 1 as a smooth conductive pattern by a transfer method incorporating a photo-etching process is 200μ, and the width A of the contact pattern 2 is 200 μm. In the switch board where the distance B is 50μ,
In order to obtain accurate signals, it is necessary to use a multi-type contactor 30 with a wire diameter C of about 80 μm or less. However, in the initial state, the area of the contact 30 that comes into elastic contact with the contact pattern 2 is relatively small, and the ON-OFF signal that appears as the contact 30 moves is at a certain point as shown by the solid line in FIG. maintains the reliability of the period, but
Due to wear of the contactor 30 due to continuous use, the contact area of the contactor 30 with the substrate 1 increases, and the second
An ON-OFF signal as shown by the dotted line in the figure begins to appear, and finally, between the contact electrode patterns 2 and 2.
There were cases where an inconvenience occurred in that the OFF signal did not appear. In addition, the contact pressure per unit area changes due to a change in the contact area, which causes noise. In order to prevent this, the wire diameter of the contact 30 can be made finer, but with the current technology, it is only possible to obtain a metal strip with sufficient elastic force as a contact at a diameter of about 50μ at most from an industrial perspective. has become a limit, and the drop in contact reliability due to the above-mentioned wear cannot be denied.

The present invention has been devised in view of the above points, and its details will be explained below with reference to an embodiment shown in FIGS. 3 and 4.

In the figure, 3 is a slider, which is formed at the bending apex of each sliding leg 4 made of a highly conductive metal strip and each sliding leg 4 whose tip is bent into a substantially dogleg shape. It is equipped with minute protrusions 5 made of precious metal plating and a base 8 made of a metal plate to which the ends of the sliding legs 4 are fixed by appropriate means such as welding, and the protrusions 5 are attached to the insulating substrate 1. It is formed as a contact portion that comes into contact with and separates from the contact pattern 2 of. In this embodiment, the sliding leg 4 is selected to have a wire diameter of about 50 to 100 microns, and is made of an appropriate material suitable for the purpose of use, such as nickel silver with spring properties.

In manufacturing the slider 3, first, as shown in FIG. Fix it to the stand 8. Next, as shown in FIG. 4b (FIGS. 4b, c, and d are cross-sectional views of important parts for convenience of illustration), after coating the tip of the sliding leg 4 with a photoresist 6, , diameter 10~20μ by well-known photo process
A circular hole 7 with a diameter of approximately
Protrusion 5 made of precious metal such as gold with a thickness of ~30μ
. . . is formed by partial plating, and then the resist 6 is removed as shown in FIG. Finally, the sliding leg 4 is gently bent,
If the protrusion 5 is positioned at the bending apex,
The contactor 4 shown in figure e is completed. In the above embodiment, the bending process is performed after the projections 5 are formed, but after the sliding leg 4 is bent in advance, the photoresist 6 is selectively etched by contact development or the like. The protrusions 5 may be formed by straining and partially plating.

According to the present invention described above, a plurality of metal strips are arranged in parallel and close to each other, and a metal strip is formed near the tip of the metal strip by partial plating and has a width smaller than the width of the metal strip. Since the contact area is a pillar-shaped projection with a diameter, the contact area is less likely to increase even if the plating layer that is the contact area gradually wears out.Therefore, errors in the ON-OFF signal of the switch are less likely to occur, and contact It is possible to provide a contact with less pressure change, noise generation, and overall precision with a long sliding life. In addition, there is no need to use noble metal for the entire contact unlike conventional wire sliders, which is advantageous in terms of cost.

In the above embodiments, the metal strip was explained using a metal wire, but instead of the wire, a thin metal piece (strip) obtained by dividing the metal strip with slits etc.
Of course, it is possible to form a protrusion smaller than the width of the strip on the strip by using the strip, and various modifications can be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

Figures 1 and 2 relate to a conventional example, Figure 1 is a sectional view of the main part, Figure 2 is an explanatory diagram showing the timing of contact ON-OFF, and Figures 3 and 4 are one implementation of the present invention. For example, Fig. 3 is a sectional view of the main part, Fig. 4 a to e
FIG. 2 is an explanatory diagram showing the manufacturing process. 1...Insulating board, 2...Contact pattern, 3...
Contactor, 4...Sliding leg, 5...Protrusion.

Claims (1)

[Scope of utility model registration request] a plurality of metal strips arranged in parallel and close to each other; and a contact portion that is a columnar protrusion formed by partial plating near the tip of the metal strip and having a diameter smaller than the width of the metal strip. A contact element characterized by comprising: