JPS6097603A - Chip type 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 The present invention relates to a chip type variable resistor that can be directly attached to a printed circuit board or the like.

Conventionally, this type of variable resistor has been provided with a collector electrode that makes electrical contact with a slider that slides on the resistor, and the collector electrode and both ends of the resistor are connected to the back surface through one side of the resistor substrate. It is known that the extended portions are arranged in a line on one end of the back surface of the substrate to form a predetermined terminal portion.

However, in a variable resistor having such a terminal structure, the distance between the variable side terminal part and the fixed side terminal part becomes narrow, and when the variable resistor is attached to a printed circuit board, there is a risk that the terminals may be short-circuited. Various ideas have been proposed to solve these problems, but new troubles such as solder adhering to the screws that engage the slider and the variable side terminals, preventing them from rotating, may occur. At present, satisfactory results have not been obtained in terms of shape and dimensions, mass productivity, and cost.

The present invention has been made in view of the above-mentioned circumstances regarding conventional chip-type variable resistors.The purpose of the present invention is to prevent short circuits between terminals when soldering occurs, and prevent screws from rotating. It is an object of the present invention to provide a chip type variable resistor that can eliminate such troubles, has a simple structure, and is easy to manufacture.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1, 1 is a resistor board, 2 is a slider, 3 is a screw, and 4 is a variable side terminal plate made of a material to which solder does not easily adhere, such as stainless steel.

The resistance substrate 1 is made of an insulating material such as ceramic, and has a hole 1a provided approximately in the center thereof for attaching the slider 2 with a screw 3. As shown in FIG. 2(a), a ring-shaped collector electrode 5 is formed on the surface of the resistor substrate 1 around the hole 1a, and a lead electrode 5a is formed approximately in the center of one end of the substrate surface. It's being pulled out. An arc-shaped cermet resistor 6 is formed on the outer periphery of the collector electrode 5, and both ends of the resistor 6 are extended to the back surface through conductive films 7 and 8 through one end side surface 1b of the resistor substrate 1.
A fixed side terminal portion 9.10 (see FIG. 2) is formed near the one end.

As shown in FIGS. 2(b) and 2(C), on the back surface of the resistance board 1, there is a hole 1a in the board 1 between the fixed side terminal parts 9 and 1o.
A groove 1d passing through is formed. The variable-side terminal plate 4 is fitted into this groove 1d, and the connection part 4a formed at one end, which is narrower than the other part, is pulled out onto the extraction electrode 5a through the small hole 1f provided in the resistor board 1, and this connection is made. The portion 4a is soldered to the extraction electrode 5a. Other end 4C of variable side terminal plate 4
is bent at a right angle and placed in a groove 1e provided on the other end side face 1C of the resistance board 1, which is continuous with the groove 1d. A round hole 4b is provided in the variable side terminal plate 4 so as to be concentric with the hole 1a of the resistance board 1 when the terminal plate 4 is attached to the resistance board 1 as described above.

The variable side terminal board 4 is plated with a material to which solder easily adheres, such as solder or tin, on the back side of the resistor board 1 near the other end side surface 1C and a part of the other end side surface 1C side. A layer 4d is formed and serves as a variable side terminal portion.

Referring again to FIG. 1, the screw 3 is made of a material such as copper, and has a large diameter head 3a equipped with an adjustment driver (not shown).
It has a driver i3b for fitting.

A slider 2 made of a metal material with spring properties is placed on the surface of the resistance board 1, and screws 3 are inserted into the hole 2a of the slider 2, the hole 1a of the resistance board 1, and the round hole 4b of the terminal board 4. One end of the slider 2 is plastically deformed outward and caulked, and the slider 2 is rotatably attached to the resistance board 1.

At this time, the cross-sectional shape of the lower part of the head 3a of the screw 3 is made into a rectangular shape, for example, and the hole 2a of the slider 2 into which this lower part is fitted is also shaped to match the shape, and the slider 2 is connected to the screw 3. Co-rotate. Therefore, when the screw 3 is rotated, the slider 2 also rotates, and the contacts 2b formed on the slider 2 slide on the resistor 6.

With the above configuration, the slider 2 has a collector electrode 5,
The variable side terminal portion 4d, which is electrically connected to the extraction electrode 5a and the terminal plate 4 but allows soldering of the terminal plate 4, is connected to (l!) of the resistor board 1.
! It is formed on the end side surface 1C side, and as is clear from FIG.
d, 9.10 are placed at the vertices of the triangle. Therefore, when attaching the variable resistor having the above configuration to a printed circuit board, etc., the distance between the variable side terminal section 4d and the fixed side terminal section 9.10 of the terminal board 4 is large, so that short-circuiting between them due to soldering is prevented. . Also, the tip of screw 3 is
Since the terminal plate 4 is caulked and fixed to the terminal plate 4 to which solder does not easily adhere, there will be no problem of solder adhering to that part and making it impossible for the screw 3 to rotate.

Furthermore, the variable side terminal portion 4d of the terminal board 4 is as described above.
It is away from the fixed side terminal parts 9 and 10, and the caulked part of the screw 3 does not protrude from the back surface of the resistance board 1 because of the groove 1d provided in the resistance board 1. The pattern of the printed circuit board can be passed between the parts of the circuit board to which the variable side terminal section 4d and the fixed side terminal sections 9 and 10 are soldered, thereby increasing the density of the circuit pattern on the printed circuit board. I can do it.

FIG. 3 shows another embodiment, and FIG. 2(b) of the above embodiment
FIG. In this example,
The variable side terminal plate 14 is made by plating the entire one side of a metal plate made of a material to which solder does not adhere, such as stainless steel, with a metal to which solder adheres, such as tin, for example, to form a layer 14.
A is used. This terminal board 14 is attached to the groove 1d of the resistor board 1 so that the conductive layer 14a faces the back side of the resistor board 1, and the other end 14c of the terminal board 14 is bent to form a two-layer structure with the conductive layer 14a on the outside. This portion is exposed as the variable side terminal portion 14d.

In this embodiment, the same effects as those of the above-mentioned embodiments can be obtained, and also the effect that the plating treatment of the layer 14a to which solder does not adhere can be more easily performed.

In each of the above embodiments, the screw 3 is used, but according to the present invention, it is not necessary to use the screw 3 or eyelet, which are separate parts. That is, a cylindrical part is formed in the center of the variable-side terminal plate 4 by drawing, and this cylindrical part is inserted into the hole 1a of the resistance board 1 and the contact 2a of the slider 2, and the tip of the cylindrical part is The slider 2 may be configured to be caulked onto the slider 2 so that the slider 2 can rotate.

[Brief explanation of drawings]

The figures show an embodiment of a variable resistor according to the present invention, and FIG. 1 (a) is a plan view, FIG. 2(a) is a top view of the resistor board, FIG. 2(b) is a sectional view taken along the If-It line in FIG. 2(a), FIG. 2(c) is a bottom view, and FIG. 1 is a cross-sectional view of the resistance board of the embodiment. 1 is the resistance board, 2 is the slider, 4 is the variable side terminal plate, 4d is the variable side terminal section, 6 is the resistor, and 9.10 is the fixed side terminal section. Patent applicant Murata Manufacturing Co., Ltd.) Figure 2 0) and C)

Claims (1)

[Claims] In a chip type variable resistor comprising a resistor formed on the surface of a resistor substrate and a slider that slides on the resistor,
The variable side terminal that conducts to the slider is made of a metal plate made of a material that does not easily adhere to solder, and is placed on the back side of the resistor board, and a layer that does not easily adhere to solder is formed on a part of the metal plate. A chip type variable resistor characterized in that a variable side terminal section is provided on the back surface of a resistor substrate, and a fixed side terminal section that is electrically connected to an end of a resistor body is provided.