JPH06310309A - Chip-type variable resistor - Google Patents

Abstract

PURPOSE:To regulate a resistance value fine and precisely by a method wherein an arc-shaped resistance film is formed as a two-layer structure by a first resistance film both ends of which are connected electrically to both electrode terminals for connection and by a second resistance film both ends of which are not connected electrically to both electrode terminals for connection. CONSTITUTION:An arc-shaped resistance film 12 is formed as a two-layer structure by a first resistance film 12a both ends of which are connected electrically to surface electrodes 13a, 14a for connection and by a second resistance film 12b both ends of which are separated by proper sizes L1, L2 from, and are not connected electrically to, the surface electrodes 13a, 14a at both electrode terminals 13, 14 for connection. A resistance value per unit length in the part of the two-layer structure can be made small. In addition, a resistance value in parts of the lengths T1, L2 which are not included in the two-layer structure can be made large. Thereby, the resistance value can be regulated precisely and fine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a chip type variable resistor constructed so that its resistance value can be adjusted arbitrarily.

[0002]

2. Description of the Related Art Generally, a chip type variable resistor of this type is described in, for example, Japanese Utility Model Laid-Open No. 58-44805.
In addition, as shown in FIGS. 11 and 12, an arc-shaped resistance film 2 is provided on the upper surface of the insulating substrate 1, and both ends of the resistance film 2 have a pair of connection electrode terminals 3 on one side surface of the insulating substrate 1.
4 is formed so as to be electrically connected to the arc-shaped resistance film 2, and a slider 5 rotatably pivotally attached to the insulating substrate 1 is slidably contacted with the arc-shaped resistance film 2 so that the slider 5 is slidable. Pendulum 5
By rotating within the range of the appropriate rotation angle θ ′ in FIG. 1, the resistance between one of the connection electrode terminals 3 and 4 and the intermediate terminal 6 electrically connected to the slider 5 is increased. The values are arranged to be adjusted over the range r1 'to r2'.

[0003]

However, in this conventional chip-type variable resistor, both connection electrode terminals 3 and 4 are used.
Since the width dimension and the thickness dimension of the arc-shaped resistance film 2 between the two are configured to be substantially uniform over the entire length of the resistance film 2 in the length direction, the both connection electrode terminals 3, 3.
13, the variable characteristic of the resistance value between one of the electrode terminals and the intermediate terminal 6 is, as shown in FIG. 13, the point of zero resistance value and the nominal value between the two connection electrode terminals 3 and 4. That is, a straight line with a large inclination angle connecting the total resistance value R is formed.

That is, as shown in FIG. 13, the variable characteristic of the resistance value in the conventional chip-type variable resistor is a substantially straight line that is relatively inclined, so that the resistance by the unit rotation angle δθ of the slider 5 is increased. Since the change value δr ′ of the value is large, in other words, the change rate of the resistance value with respect to the rotation angle of the slider 5 is large, the both connecting electrode terminals 3,
There is a problem that the resistance value between one of the electrode terminals of No. 4 and the intermediate terminal 6 cannot be finely and precisely adjusted.

The present invention solves this problem and reduces the resistance value to
It is a technical object to provide a variable resistor that can be finely and precisely adjusted.

[0006]

In order to achieve this technical object, the present invention provides an insulating substrate with arc-shaped resistance films at both ends of the resistance film on both connection electrode terminals provided on the insulation substrate. In a chip type variable resistor formed so as to be electrically connected and rotatably mounted so that a slider electrically connected to an intermediate terminal is slidably in contact with the resistance film. , A first resistance film whose both ends are electrically connected to both the connecting electrode terminals, and both ends are not electrically connected to the both connecting electrode terminals A two-layer structure with the second resistance film thus formed is adopted.

[0007]

[Operation] In this way, the arc-shaped resistance film is configured so that both ends thereof are electrically connected to both connection electrode terminals.
By using a two-layer structure of a resistance film of No. 2 and a second resistance film of which both ends are not electrically connected to both connection electrode terminals, While the resistance value can be reduced, the first
It is possible to increase the resistance value of the portion of the resistance film of No. 2 which does not have a two-layer structure with the second resistance film.

As a result, the slope of the variable characteristic of the resistance value between one of the connecting electrode terminals and the intermediate terminal is made gentle, in other words, the change of the resistance value with respect to the rotation angle of the slider. Although the ratio can be reduced, the resistance value between the two connection electrode terminals is determined by the resistance value in a portion of the first resistance film that does not have a two-layer structure to have a predetermined nominal total resistance value. It can be

[0009]

Therefore, according to the present invention, the resistance value of the chip type variable resistor can be finely adjusted with high accuracy while keeping the nominal total resistance value of the chip type variable resistor at a predetermined value. It has the effect that In particular, by providing the insulating substrate with auxiliary conductor patterns that are electrically connected to both ends of the resistance film in the two-layer structure portion, the resistance value in the two-layer structure portion and The resistance value of a portion of the resistance film that does not form a two-layer structure with the second resistance film is brought into contact with both auxiliary conductor patterns and both connection electrode terminals by a probe for resistance value measurement, Since each can be measured easily and surely, during the manufacturing process of the chip type variable resistor, it is extremely easy to inspect whether or not each of the resistance values is within the predetermined value for each. It can be done.

[0010]

Embodiments of the present invention will be described below with reference to the drawings of FIGS. 1 to 3 show the first embodiment, in which reference numeral 11 denotes a ceramic insulating substrate formed in a chip type.
A resistance film 12 is formed on the upper surface of the insulating substrate 11 in an arc shape centered on a through hole 11a formed substantially in the center of the insulation substrate 11, and on one side surface of the insulation substrate, the arc resistance film 12 is formed. Electrode terminals 13 and 14 for connection to both ends of 12
Are formed.

The electrode terminals 13 and 14 for both connections are
Is the upper surface electrodes 13a, 14a and the lower surface electrodes 13b, 14
b and side electrodes 13c and 14c. Reference numeral 16 denotes an intermediate terminal made of a metal plate arranged on the lower surface side of the insulating substrate 11. The intermediate terminal 16 is integrally formed with a hollow shaft 16a fitted in the through hole 11a of the insulating substrate 11. It is shaped.

Further, reference numeral 15 indicates a slider made of a metal plate, which is disposed on the upper surface side of the insulating substrate 11, and this slider 1
5 is rotatably fitted to the upper end of the hollow shaft 16a, and then caulked the upper end of the hollow shaft 16a to rotatably attach it to the insulating substrate 11. The circular resistive film 12 is formed on the child 15.
There is provided a sliding contact 15a that slidably contacts with.

The arc-shaped resistance film 12 is formed on both ends of the upper surface electrode 13 of the connecting electrode terminals 13 and 14.
The first resistance film 12a that is electrically connected to a and 14a and both ends of the upper surface electrodes 13a and 14a of both connection electrode terminals 13 and 14 are appropriately dimensioned L1.
A two-layer structure is formed with the second resistance film 12b so as not to be electrically connected by separating only L2.

When the arc-shaped resistance film 12 has a two-layer structure of the first resistance film 12a and the second resistance film 12b, first, the first resistance is formed on the upper surface of the insulating substrate 11. Membrane 1
2a, both ends of which are appropriately dimensioned L1 and L2 with respect to the upper surface electrodes 13a and 14a of the connecting electrode terminals 13 and 14, respectively.
Formed so that they are not electrically connected to each other, and then the second resistance film 12a is formed on the upper surface of the first resistance film 12a.
The resistance film 12b of the both ends of the connecting electrode terminal 13,
It may be formed and configured so as to be electrically connected to the upper surface electrodes 13a and 14a in 14.

In this structure, both connection electrode terminals 1
It is possible to adjust the resistance value between one of the electrode terminals 13 and 3 and the intermediate terminal 16 in the range of r1 to r2 by rotating the slider 15 within a range of an appropriate rotation angle θ. You can do it. In this case, the arc-shaped resistance film 12 is provided on both ends of the connecting electrode terminal 1
The first resistance film 12a electrically connected to the upper surface electrodes 13a and 14a of the electrodes 3 and 14, and the upper surface electrodes 13a of both connection electrode terminals 13 and 14 at both ends.
14a has a two-layer structure with the second resistance film 12b which is appropriately separated from each other by the dimensions L1 and L2 so that the resistance per unit length in the two-layer structure is reduced. While the value can be reduced, the second resistance film 1 of the first resistance film 12a is
It is possible to increase the resistance value in the portions of lengths L1 and L2 that do not form a two-layer structure with 2b.

As a result, the resistance characteristic becomes as shown in FIG. 4, and the inclination of the variable characteristic of the resistance value between one of the connecting electrode terminals 13 and 14 and the intermediate terminal 16 is expressed by Slowly, in other words, the rate of change δr of the resistance value with respect to the unit rotation angle δθ of the slider 15 can be reduced, while the resistance value between the connection electrode terminals 13 and 14 is set to the first resistance. A predetermined nominal total resistance value R can be obtained by the resistance values of the portions of the lengths L1 and L2 of the film 12a that do not form the two-layer structure.

By the way, as described above, the arc-shaped resistance film 12 has its both ends electrically connected to the upper surface electrodes 13a and 14a of the connection electrode terminals 13 and 14, respectively. 12a and a second resistance film 12b of which both ends are not electrically connected to the upper surface electrodes 13a and 14a of the connection electrode terminals 13 and 14, the two-layer structure of this two-layer structure is used. The resistance value in the portion and the second resistance film 1 of the first resistance film 12a.
The resistance values at the portions of the lengths L1 and L2 that do not form a two-layer structure with 2b will vary due to the deviation between the first resistance film 12a and the second resistance film 12b. .

Therefore, by providing auxiliary conductor patterns 17 and 18 on the upper surface of the insulating substrate 11 to electrically connect to both ends of the resistance film 12 in the two-layer structure portion, the two-layer structure is formed. And the resistance value in the portion of lengths L1 and L2 of the first resistance film that does not form a two-layer structure with the second resistance film. Connection electrode terminal 1
By contacting the probes for measuring the resistance value to the electrodes 3 and 14, it is possible to easily and surely measure them, respectively. Therefore, during the manufacturing process of the chip type variable resistor,
The inspection as to whether or not each of the resistance values is within the predetermined value can be performed extremely easily.

The length L not having the double-layered structure
One of the lengths L1 and L2 is made longer than the other length L2 as in the second embodiment shown in FIG. 9, so that the slider 15 is rotated. The adjustable resistance value can be shifted to the higher side as shown by the solid line in FIG. 10, and sliding can be achieved by making the other length L2 portion longer than the one length L1 portion. As shown in FIG. 10, the resistance value that can be adjusted by the rotation of the child 15 can be shifted to the lower side, as shown by the chain double-dashed line. The length can be arbitrarily set by adjusting the lengths of the portions L1 and L2.

Furthermore, with respect to the insulating substrate 11 shown in FIG. 5, an arcuate resistance film 12, both connection electrode terminals 13 and 14,
When forming both auxiliary conductor patterns 17 and 18, first, as shown in FIG. 6, the lower surface electrodes 13 of both connection electrode terminals 13 and 14 are formed on the lower surface of the insulating substrate 11.
After forming b and 14b, the upper surface electrodes 13a and 1 of both connection electrode terminals 13 and 14 are formed on the upper surface of the insulating substrate 11.
4a and both auxiliary conductor patterns 17 and 18 are formed, and then the first resistance film 1 is formed on the upper surface of the insulating substrate 11.
2a, as shown in FIG.
After being formed so as to partially overlap 3a and 14a, the second resistance film 12b is formed on the upper surface of the first resistance film 12a.
As shown in FIG. 8, both ends of the upper surface electrodes 13a, 1a
4a is formed so as not to be electrically connected to each other by appropriately separating the dimensions L1 and L2 from each other (in this case, the first resistance film 12a is formed on the upper surface of the insulating substrate 11 and both ends thereof are for both connections). After being formed so as not to be electrically connected to the upper surface electrodes 13a and 14a of the electrode terminals 13 and 14 by appropriate distances L1 and L2, the second resistance is formed on the upper surface of the first resistance film 12a. Membrane 1
2b may be formed such that both ends thereof are electrically connected to the upper surface electrodes 13a and 14a of the connecting electrode terminals 13 and 14, respectively.

Then, on one side surface of the insulating substrate 11, the side surface electrode 13 of each of the connecting electrode terminals 13 and 14 is formed.
c and 14c are formed. Of course, the insulating substrate 1
1, lower surface electrodes 13b and 14b, upper surface electrode 13a,
14a, auxiliary conductor patterns 17 and 18, first resistance film 1
The formation of the second resistance film 12a and the second resistance film 12b is performed, for example, in a patent application previously proposed by the present inventor (Japanese Patent Application No. 63-292096).
As in the case of Japanese Patent Laid-Open No. 2-137201), a raw material plate obtained by arranging a plurality of the insulating substrates 11 vertically and horizontally and integrating them is used for each insulating substrate 11 in the raw material plate. Next, the material plate is divided into rods, and in this rod-like state, side electrodes 13c,
After forming 14c, each insulating substrate 11 is divided.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a chip type variable resistor according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway plan view of FIG.

FIG. 3 is a perspective view of the insulating substrate in FIG.

FIG. 4 is a diagram showing a variable characteristic of a resistance value in the first embodiment.

FIG. 5 is a perspective view of an insulating substrate.

6 is a perspective view showing a state where a lower surface electrode, an upper surface electrode and an auxiliary conductor pattern are formed on the insulating substrate of FIG.

7 is a perspective view showing a state in which a first resistance film is formed on the insulating substrate of FIG.

8 is a perspective view showing a state in which a second resistance film is formed on the insulating substrate of FIG.

FIG. 9 is a perspective view of an insulating substrate according to a second embodiment.

FIG. 10 is a diagram showing variable characteristics of resistance values in the second embodiment.

FIG. 11 is a vertical sectional front view of a conventional chip type variable resistor.

12 is a partially cutaway plan view of FIG. 11. FIG.

FIG. 13 is a diagram showing variable characteristics of a conventional chip variable resistor.

[Explanation of symbols]

 11 Insulating Substrate 12 Arc Resistive Film 12a First Resistive Film 12b Second Resistive Film 13,14 Connection Electrode Terminal 15 Slider 16 Intermediate Terminal 17,18 Auxiliary Conductor Pattern

Claims (2)

[Claims] 1. An insulating substrate is provided with arc-shaped resistive films such that both ends of the resistive film are electrically connected to both connection electrode terminals provided on the insulating substrate, and an intermediate terminal is electrically connected. In a chip type variable resistor, which is rotatably mounted so as to be slidably contacted with the resistance film, the arc-shaped resistance film is provided with both ends of the connecting electrode terminals. A two-layer structure of a first resistance film electrically connected to the first resistance film and a second resistance film both ends of which are not electrically connected to the connection electrode terminals. Chip type variable resistor characterized by. 2. An arc-shaped resistive film is formed on an insulating substrate such that both ends of the resistive film are electrically connected to both connecting electrode terminals provided on the insulating substrate, and an electrical resistance is provided on an intermediate terminal. In a chip type variable resistor, which is rotatably mounted so as to be slidably contacted with the resistance film, the arc-shaped resistance film is provided with both ends of the connecting electrode terminals. A first resistance film electrically connected to the first resistance film and a second resistance film having both ends not electrically connected to the connection electrode terminals. A chip-type variable resistor, wherein the insulating substrate is provided with auxiliary conductor patterns electrically connected to both ends of a two-layer structure portion of the resistance film.