JPS60235409A - Small-sized variable resistor - 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 FIELD OF INDUSTRIAL APPLICATION The present invention relates to a variable resistor used for circuit adjustment of electronic equipment.

Conventional configuration and considerations In recent years, with the trend toward miniaturization of electronic devices and automation of assembly, variable resistors VC are mounted and soldered onto printed circuit boards of electronic devices (a high-density mounting, automatic mounting, automatic soldering). In particular, support for automatic soldering is required for other miniaturized parts (e.g. chip resistors, chip capacitors, etc.).
There is a demand for support for solder dip method soldering, which allows soldering of mini-mold parts) and lead wires of parts with lead wires at the same time.

A conventional small variable resistor will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view of a conventional small variable resistor.

FIG. 2 shows the A--A' cross section shown in FIG. 1. In FIGS. 1 and 2, 1 is a shaft that holds each component. 2 is a slider that slides on the surface of the resistor to change the resistance value. 3
The seat plate makes stable contact with the inner terminal printed on the slider 2 and the resistor, and generates torque. 4 is a resistor, and a resistor and electrode material are printed and formed on a ceramic substrate.

Reference numeral 5 denotes an intermediate terminal formed on the resistor 4 with a mark 9; the resistance value taken out from the slider 2 is transmitted through the seat plate to the electrode. 6 is a resistive film, and 7 is an electrode which is soldered to the wiring part of the printed circuit board.

However, when trying to solder a variable resistor with the above configuration using the solder dip method, shaft 1. If the brush and seat plate 3 are made of a solderable material such as brass, copper, or nickel silver, the VC has the disadvantage that solder will adhere to it, and even if a non-solderable material such as stainless steel is used, there will be resistance. Surface of body 4, slider 2. 3 seats, 3 seats. There was a problem in that the flux adhering between the resistors 4 had to be completely removed. Also, some variable resistors are designed to prevent flux.

To cope with the cleaning process, an O-ring is interposed between the resistor 4 and the knob to create a pressure-contact state, resulting in a sealed structure, but when used in a small variable resistor, it is difficult to process the parts.

There was a drawback that it was not easy to handle during assembly work.

OBJECTS OF THE INVENTION In view of the above-mentioned drawbacks, it is an object of the present invention to provide a small variable resistor that can be soldered using a solder dip method regardless of whether or not a cleaning step is performed after soldering.

Structure of the Invention In order to achieve the above object, the small variable resistor of the present invention includes a resistor substrate made of an insulating material having a hole in the center, and a resistor substrate formed on the entire surface of the resistor substrate surrounding the hole. a resistor, a lead-out terminal disposed on the other main surface side of the substrate and having a protrusion, a seat plate provided on the resistor, and a sliding member made of a metal material and sliding in contact with the resistor. A mover, a heat-resistant elastic ring provided on the resistor at the outer periphery of the hole, and a knob provided on the ring and serving as a caulking portion of the protrusion of the lead-out terminal.

and a heat-resistant film provided on the upper surface of the knob.

This configuration provides a small variable resistor that can be soldered using the solder dip method, regardless of whether or not a cleaning process is performed after soldering.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is an exploded perspective view of a variable resistor according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along the line A-A' shown in FIG.

In FIGS. 3 and 4, reference numeral 2' denotes a slider made of spring metal and has a cut-and-raised portion 2a formed in its center. 3 is an insulating seat plate made of a heat-resistant resin film, 4 is a resistor with a resistive film 6 formed on an alumina substrate, and a heat-resistant elastic ring 10 has adhesive properties to the resistor. And 10 & is formed on the back side. 7 is an electrode that is soldered to the printed circuit board.

8 is a heat-resistant film, and 9 is a knob made of a heat-resistant, non-solder adhesive material. 11 is a pull-out terminal with slider 2 and cut-and-raise 2
% after connecting resistor 4 and knob 9, maintaining contact and continuity with a
At the same time, the knob 9 and the ring 1o formed on the resistor 4 and the lead-out terminal 11 and the ring ioa are held in pressure contact with each other.

As described above, according to this embodiment, in the small variable resistor, the parts other than the electrode 7 and the lead terminal 11 are made of heat-resistant resin and an alumina substrate, so there is no adhesion of solder even when solder dipping is performed. Further, the contact portions between the knob 9 and the resistor 4 and the lead-out terminal 11 and the resistor 4 are pressed together by the rings 1o and 10&.

In addition, a heat-resistant film 1711 is pasted on the top surface of knob 9 to create a sealed structure, so Franks and solder can be used.

Can prevent infiltration of cleaning solvent. Furthermore, ring 10.
Since 10 & can be formed by a printing method, it is possible to provide a small variable resistor compatible with solder dip method soldering with a method excellent in mass production. Note that the heat-resistant film on the top surface of the knob is easily broken by inserting an operating screwdriver, so there is no problem in using it after soldering and mounting.

Effects of the Invention As described above, the present invention includes a resistor substrate made of an insulating material having a hole in the center, a resistor formed on the whole surface of the resistor substrate surrounding the hole, and other parts of the substrate. A lead-out terminal arranged on the main surface side and having a protrusion, a seat plate provided on the resistor, a slider made of a metal material and sliding in contact on the resistor, and a slider on the resistor. A heat-resistant elastic ring provided on the outer periphery of the hole, a knob provided on the ring and serving as a caulking portion of the protrusion of the pull-out terminal, and a heat-resistant film provided on the top surface of the knob. Since it is a small variable resistor with
Since solder does not adhere to anything other than the electrodes, it has the effect that soldering by the solder dip method is possible regardless of the cleaning process after soldering.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a conventional small variable resistor. 2 is a sectional view taken along line AA' in FIG. 1, and FIG. 3 is an exploded perspective view of a small variable resistor according to an embodiment of the present invention. FIG. 4 is a sectional view taken along line AA' in FIG. 3. 2'...-Slider, 3... Seat plate, 4...
...Resistor, 6...Resistance film, 8...Heat-resistant film, 9...Knob, 1o...Ring, 11...Output terminal. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] a resistor substrate made of an insulating material and having a hole in the center; a resistor formed on one principal surface of the resistor substrate surrounding the hole; and a protruding portion disposed on the other principal surface of the substrate. a seat plate provided on the resistor, a slider made of a metal material and sliding in contact with the resistor, and a slider provided on the outer periphery of the hole on the resistor. A small variable resistor comprising: a heat-resistant elastic body ring; a knob provided on the ring and serving as a caulking part for a protrusion of the pull-out terminal; and a heat-resistant film provided on the upper surface of the knob.