JPS6220968Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a variable resistor, and particularly to a variable resistor having a chip-type structure.

First, a so-called chip type variable resistor will be explained with reference to FIGS. 1 and 2. As the substrate 1, an insulating material such as alumina is used. Two fixed side electrode films 2 and one variable side electrode film 3 are formed on the surface of the substrate 1 by silver printing. The hatched portions shown in FIGS. 1 and 2 represent the regions where these electrode films 2 and 3 are formed. Each electrode film 2, 3 is formed on the substrate 1 in a desired pattern.
is formed extending from one surface to the other surface.
A hatched portion shown on the other surface of the substrate 1 shown in FIG. 2 on the side opposite to the side on which the electrode films 2 and 3 are formed is the balance metal film 4. This is because when the variable resistor including the substrate 1 is electrically and mechanically connected with the other surface of the substrate 1 in contact with an appropriate circuit board (not shown), the balance metal film 4 is used to connect the variable resistor. Soldering is also performed to increase the mechanical strength of the variable resistor attachment and to improve parallelism to the circuit board. On one surface of the substrate 1 shown in FIG. 1, a resistor (not shown) is applied and formed in an arc shape. A predetermined portion of each electrode film 2, 3 and the balance metal film 4 are covered with solder, such as a solder dip. A slider (not shown) is rotatably attached using the center hole 5 of the substrate 1, and this slider is electrically connected to the variable side electrode film 3 and electrically connected to the resistor. be brought into contact with the person.

The above-mentioned conventional chip-type variable resistor requires the steps of silver printing and solder coating to form the electrode portion, and the process is complicated.
The disadvantage was that the use of silver increased costs.

Further, in the case of a component equipped with a rotating mechanism such as a variable resistor, the structure must be sufficient to withstand the external force applied when rotating the component. For example, if stress within the variable resistor that occurs during rotational operation is concentrated at a specific location, the specific location of the variable resistor may be damaged based on this stress. In addition, chip-type variable resistors are usually soldered to the appropriate circuit board using flow soldering, but temporary fixation during such flow soldering cannot be performed reliably. It is preferable that there be.

Therefore, the object of this invention is to provide a variable resistor that can eliminate the above-mentioned conventional drawbacks and satisfy the above-mentioned needs.

In summary, this invention is a variable resistor having the following configuration. That is, (1) a substrate made of a moldable resin, (2) a resistor formed in an arc shape on one surface of the substrate, and (3) a rotating member having a contact portion that slides on the resistor. (4) a slider having one end electrically connected to each end of the resistor and integrally molded with the substrate, and the other end being buried in the other surface of the substrate; (5) two fixed side lead-out conductors which are exposed so that the outer surface of the other end thereof is aligned substantially on the same plane as the other surface of the substrate, and which forms a fixed side electrode in this exposed portion; and (5) the sliding conductor. one end is electrically connected to the substrate and integrally molded with the substrate, and the other end is buried in the other surface of the substrate, so that the outer surface of the other end is connected to the other surface of the substrate. A variable resistor includes variable side lead-out conductors that are exposed so as to be lined up on substantially the same plane and form a variable side electrode in the exposed portion.

Other objects and features of this invention will become clearer from the detailed description given below with reference to the drawings.

FIG. 3 is a perspective view of an embodiment of this invention.
FIG. 4 is a perspective view of FIG. 3 with the slider removed. FIG. 5 is a perspective view of FIG. 4 with the resistor removed. FIG. 6 is a sectional view taken along the line - in FIG. 5. FIG. 7 is a sectional view taken along line - in FIG. 5.

The substrate 11 has a substantially square plate shape, for example, and is made of an insulating resin such as epoxy resin. The substrate 11 is provided with an insertion hole 12 . Two fixed-side lead-out conductors 13, 13 and one variable-side lead-out conductor 14 are fixed to the substrate 11 in a state where they are each partially embedded. The fixed side lead-out conductor 13 is the fifth
As clearly shown in the figure and FIG. 6, it has a shape in which a band-shaped metal plate made of brass, iron, etc. is bent at two points in opposite directions, and each end is exposed on one surface and the other surface of the substrate 11, respectively. Thus, the exposed portion 15 and the fixed side electrode 16 are formed. Also,
The variable side lead-out conductor 14 is made of a metal plate made of brass, iron, etc., and includes a band-shaped portion and an annular portion 17 that is continuously connected to the band-shaped portion, and the annular portion 17 is exposed from the substrate 11 and It is arranged concentrically with the insertion hole 12. The band-shaped portion of the variable-side lead-out conductor 14 is bent, and its end forms a variable-side electrode 18 exposed on the other surface of the substrate 11.

In such a manner that the exposed portion 15 and the fixed electrode 16 of the fixed-side lead-out conductor 13 are exposed or protruded, and the inner portion of the annular portion 17 and the variable-side electrode 18 of the variable-side lead-out conductor 14 are exposed or protruded, respectively. When molding the substrate 11, each lead conductor 13, 14 is insert molded in advance. As a result, for the fixed-side lead-out conductor 13, the fixed-side electrode 16 is buried in the lower surface of the substrate 11, and the lower surface of the fixed-side electrode 16 is substantially flush with the lower surface of the substrate 11. exposed to the top. Regarding the variable side lead-out conductor 14, the variable side electrode 18 is buried in the lower surface of the substrate 11, and the variable side electrode 18 is buried in the lower surface of the substrate 11.
The lower surface of the substrate 8 is exposed so as to be substantially flush with the lower surface of the substrate 11.

Fixed side drawer conductor 13 and variable side drawer conductor 14
are obtained by preparing a comb-shaped metal plate in which a plurality of pieces are successively formed, and cutting the comb-teeth part after the above-mentioned insert molding. Good too. In this case, the cutting position of the comb-teeth portion may be selected, for example, at the end surface of the substrate 11. In addition, not limited to these, the fifth
As shown by the imaginary line in the figure for the fixed side lead-out conductor 13, a portion further protruding from the end surface of the substrate 11 may be selected as the cutting position.

It is preferable that the fixed-side lead-out conductor 13 and the variable-side lead-out conductor 14 be soldered in advance to a metal plate made of brass, iron, or the like. In this way, it is extremely efficient when directly connecting the fixed side electrode 16 and the variable side electrode 18 to an appropriate circuit board (not shown).

Thereafter, the resistor 19 is formed and the slider 20 is attached by a well-known method. As a supplementary explanation, a resistor 19 is formed on one surface of the substrate 11 by an arc-shaped film made of carbon, for example. The resistor 19 is connected to each fixed side lead-out conductor 1
It is coated and baked onto the substrate 11 so as to cover each exposed portion 15 of No. 3. The slider 20 is approximately disk-shaped, and an arcuate slit 21 is formed in a portion of its periphery. The remaining portion where the arcuate slit 21 is formed is curved downward to act as a spring against the resistor 19, and a portion protruding further downward is formed, where a contact portion 22 is formed. . The entire center portion of the slider 20 is formed with a dish-shaped portion that is recessed downward, and a square hole is formed in this portion. Let each side of this square hole be one side,
Four tongue pieces 23 are formed. Each tongue piece 23 is inserted into the insertion hole 12 of the substrate 11 and is caulked so as to embrace the inner part of the annular portion 17 of the variable-side lead-out conductor 14 . As a result, the slider 20 is rotatably held relative to the substrate 11.

In this way, a so-called chip-type variable resistor integrally molded with a lead-out conductor is obtained as a finished product.

In each of the embodiments described above, the fixed side electrode 16
Although the formation positions of the variable-side electrode 18 and the variable-side electrode 18 were selected to be on opposite sides of the same plane as the other surface of the substrate 11, the present invention is not limited to this. They may also be located along the sides. Moreover, although the substrate 11 is square, it is not limited to this, and may be other square or circular shapes.

As described above, according to this invention, the fixed-side and variable-side lead-out conductors are integrally molded with the substrate, making it possible to easily form them into chips. Further, since steps such as electrode printing and solder coating can be omitted, the manufacturing process is simplified. Furthermore, since there is no need to intentionally use expensive silver as a conductive part, an inexpensive variable resistor can be provided. In addition, both the part of the fixed-side lead-out conductor that forms the fixed-side electrode and the part of the variable-side lead-out conductor that forms the variable-side electrode,
Since the variable resistor is buried in the substrate, the slider is rotated to adjust the resistance of the variable resistor while the fixed side electrode and variable side electrode are mounted on the appropriate circuit board. The stress occurring within the variable resistor can then be advantageously distributed. Therefore, for example, damage to the substrate or the like is prevented. In addition, there is almost no dimensional difference between the surfaces of the fixed side electrode and the variable side electrode facing the appropriate circuit board on which such a variable resistor is to be mounted and the surface of the board, so for example, Adhesion for temporary fixing when performing flow soldering can be reliably performed, and as a result, soldering by flow soldering can be performed reliably.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one surface side of a substrate of a conventional chip type variable resistor, and FIG. 2 is a perspective view similarly showing the other surface side. FIG. 3 is a perspective view of an embodiment of this invention. FIG. 4 is a perspective view of FIG. 3 with the slider removed. Fifth
The figure is a perspective view of FIG. 4 with the resistor removed. FIG. 6 is a sectional view taken along the line - in FIG. 5. FIG. 7 is a sectional view taken along line - in FIG. 5. In the figure, 11 is a substrate, 13 is a fixed-side lead-out conductor, 14 is a variable-side lead-out conductor, 15 is an exposed part, and 16
17 is a fixed side electrode, 17 is an annular portion, 18 is a variable side electrode, 19 is a resistor, 20 is a slider, 22 is a contact portion, and 23 is a tongue piece.

Claims (1)

[Claims for Utility Model Registration] (1) A substrate made of a moldable resin, a resistor formed in an arc shape on one surface of the substrate, and a contact portion that slides on the resistor. a rotatable slider having one end electrically connected to each end of the resistor, integrally molded with the substrate, and the other end buried in the other surface of the substrate; two fixed-side lead-out conductors that are exposed so that the outer surface of the other end thereof is aligned with the other surface of the substrate substantially on the same plane, and that forms a fixed-side electrode in the exposed portion; electrically connected at one end and integrally molded with the substrate, and the other end is buried within the other surface of the substrate so that the outer surface of the other end is substantially flush with the other surface of the substrate. A variable resistor comprising a variable side lead-out conductor that is exposed so as to line up above and forms a variable side electrode in this exposed portion. (2) The variable resistor according to claim 1, wherein the fixed side electrode and the variable side electrode are exposed within the range of the other surface of the substrate. (3) The variable resistor according to claim 1, wherein the fixed-side lead-out conductor and the variable-side lead-out conductor include portions further led out from the end surface of the substrate.