JP2000260608A - Variable resistor and manufacture of resistance element substrate using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a variable resistor which is used for various electronic devices, can realize a precise output voltage performance corresponding to a designing target value and hardly generate noise. SOLUTION: This device comprises an annular electric collecting part 23 made of a low resistance film 22 having an even thickness and a silver system material being provided on an insulating substrate 1 in a parallel relation in an electrically independent state, a conductive junction part 26 having a predetermined width in an electrically independent state from the annular electric collecting part 23 which is extended to an orthogonal direction to which the low resistance film 23 extends from an upper part of a predetermined part of the low resistance film 22 being provided, a resistance element substrate 21 on which a high resistance film 27 is so formed in parallel with the low resistance film 22 as a lead part 24 of the low resistance film 22. The conductive junction part 26 to be electrically junctioned is used and a sliding brush 14 is contacted by spring on the ring shape electric collecting part 23 and the high resistance art 27 to pick up an output voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable resistor used for various electronic devices and a method for manufacturing a resistor element substrate used for the variable resistor.

[0002]

2. Description of the Related Art In recent years, as various electronic devices have been improved in performance and cost, variable resistors have been used in various ways, and are often used as substitutes for switches.

Normally, the output voltage characteristic of a variable resistor used as a substitute for a switch as described above is, for example, as shown in FIG.
As shown in the figure, a portion A for keeping the output voltage constant at several places within a predetermined operation angle range is provided, and is used as a resistive element substrate for a variable resistor, which is an important component that determines its electrical characteristics. Is known as shown in FIG.

First, the resistance element substrate 10 will be described with reference to FIG. 1. A horseshoe-shaped resistance film 2 made of carbon paint is provided on the upper surface of an insulating substrate 1 made of a phenolic resin laminate and the like, A ring-shaped current collector 3 made of silver paint is concentrically printed and formed in an electrically independent state, and lead-out portions 4 (4A, 4B) and 5 are provided at both ends of the resistance film 2 and the ring-shaped current collector 3. It is formed by printing with silver paint and pulled out.
Terminals 6 (6A, 6B) and 7 are caulked to (4A, 4B) and 5, respectively.

In the output voltage characteristic diagram shown in FIG. 7, in order to obtain a portion A for keeping the output voltage constant, a conductive connecting portion 8 made of silver paint is provided below a predetermined portion of the horseshoe-shaped resistive film 2. Are formed by printing.

Next, a variable resistor using the above-described resistance element substrate 10 will be described with reference to the cross-sectional view of FIG. Is fixed by insert molding or the like, with the surface on which is formed facing the opening side.

The rotating body 12 is accommodated in the concave portion of the case 11, and a lower circular projection 12 B provided on the lower surface at the center of the flange portion 12 A is formed in the central circular hole 1 of the case 11.
1A.

On the other hand, the opening of the case 11 is
A is covered with a cover 13 held and crimped on the lower surface of the case 11, and an operation shaft 12 </ b> C protruding from the center upper surface of the flange 12 </ b> A of the rotating body 12 is provided on a bearing 13 </ b> B of the cover 13. The portion is pivotally supported so as to protrude outward and can be rotated.

A sliding brush 14 having contacts 14A and 14B which resiliently slides on the resistance film 2 and the ring-shaped current collector 3 of the resistance element substrate 10 is mounted on the flange 12A of the rotating body 12. Have been.

The variable resistor having the above-described configuration includes terminals 6A and 6B.
In the state where a constant voltage is applied during the operation, the operation shaft 12C is rotated to rotate the rotating body 12, and as shown by the arrow in FIG.
The contact portions 14A and 14B of the sliding brush 14 mounted on the flange portion 12A are resiliently slid on the resistance film 2 and the ring-shaped current collector 3, respectively, and the terminals are moved at a predetermined operation angle position of the operation shaft 12C. A voltage between 6A and 7 is taken out as an output voltage.

In a portion of the resistive element substrate 10 where the conductive connecting portion 8 is provided, a voltage change therebetween is apparently eliminated due to a difference in specific resistance between the resistive film 2 and the conductive connecting portion 8. The output voltage is kept constant within the operating angle range of the operating shaft 12C where the contact portion 14A of the sliding brush 14 elastically contacts the resistive film 2 located above the portion where the conductive connecting portion 8 is provided. It could be maintained in a state.

As described above, the conventional variable resistor includes a portion A for keeping the output voltage constant within a predetermined operation angle range.
, And in the electronic equipment used,
It is used to assign the operation angle range in which the output voltage value is constant to a predetermined function selection position.

[0013]

However, in the above-mentioned conventional variable resistor, a screen printing method is usually used as a method of forming each printed layer of the resistance element substrate.
When manufacturing the resistive element substrate 10, the conductive film 8 must be formed, and then the resistive film 2 must be formed thereon. It is difficult to form the resistive film 2 with a uniform thickness at the boundary between the ends of the conductive connection portion 8, and the actual value of the actual output voltage is slightly different from the designed Nerai value as shown by the dotted line in FIG. Therefore, it has been difficult to realize a variable resistor having highly accurate output voltage characteristics.

As a solution to the above problem, as shown in the top view of FIG. 10, a resistive film 15 is formed by printing a horseshoe-shaped resistive film 15 and then overlaying a conductive connecting portion 16 on a predetermined portion above the resistive film. There was also an element substrate 17, but in this case, since the resistance film 15 can be formed with a uniform thickness,
Although the one having the output voltage characteristic according to the designed Nerai value could be easily realized, the contact portion 14A of the sliding brush 14 which elastically slides on the resistive film 15 is connected to the resistive film 15 and the conductive connecting portion. 16 and the upper surface alternately elastically slide.
When moving from the resistive film 15 to the conductive connecting portion 16 or from the conductive connecting portion 16 to the resistive film 15, there is a problem that a change in contact resistance becomes large and noise is generated.

SUMMARY OF THE INVENTION The present invention is to solve such a conventional problem, and is capable of accurately realizing an output voltage characteristic according to a design Nerai value, and hardly generating noise and the like, and a resistance element used therefor. An object of the present invention is to provide a method for manufacturing a substrate.

[0016]

In order to solve the above-mentioned problems, a variable resistor according to the present invention comprises a current collector comprising a low-resistance film and a silver-based material having a uniform thickness in an electrically independent state and in a parallel relationship in an independent state. And a conductive connecting portion having a predetermined width in an electrically independent state with the current collector extending from a top of the predetermined portion of the low resistance film in a direction orthogonal to a direction in which the low resistance film extends. Using a resistive element substrate in which a high-resistance film is formed in parallel with the low-resistance film, so as to be electrically connected to the lead-out portion of the low-resistance film and the conductive connection portion,
A sliding brush is elastically slid on the current collector and the high-resistance film to extract an output voltage.

Accordingly, the resistance value at the position where the contact portion of the sliding brush is in elastic contact can be made dependent on the resistance value of the low-resistance film due to the difference in specific resistance between the low-resistance film and the high-resistance film. As a result, it is possible to obtain a variable resistor that can accurately obtain an output voltage characteristic according to a design Nerai value and that hardly generates noise and the like, and a method of manufacturing a resistance element substrate used for the variable resistor.

[0018]

DETAILED DESCRIPTION OF THE INVENTION According to the first aspect of the present invention, a low-resistance film having a predetermined length and a uniform thickness disposed on an insulating substrate is parallel to the low-resistance film in an electrically independent state. A current collector made of a silver-based material arranged in a relationship, and a lead portion respectively derived from both ends of the low-resistance film and the current collector,
A conductive connecting portion having a predetermined width, which extends from an upper portion of the predetermined portion of the low-resistance film in a direction orthogonal to a direction in which the low-resistance film extends, and is electrically independent from the current collecting portion; A resistance element substrate made of a high resistance film arranged in parallel with the low resistance film so as to overlap the lead-out portions at both ends of the resistance film and the conductive connection portion, and a current collector of the resistance element substrate and This is a variable resistor equipped with a sliding brush that has a contact part that slides on the high-resistivity film, and contacts the low-resistivity film and the high-resistivity film through the high-resistivity film. Since the output voltage taken out can be made to depend on the resistance value of the low-resistance film, it is possible to obtain a highly accurate output voltage characteristic according to the design Nerai value and easily realize a variable resistor that is unlikely to generate noise. Has the effect of being able to .

According to a second aspect of the present invention, in the first aspect of the present invention, a high resistance film is laminated on the low resistance film of the resistance element substrate, and the overlapping low resistance film and high resistance film are formed. Since the combined resistance changes continuously irrespective of the position of the sliding brush, a highly accurate output voltage characteristic is assured when using a variable resistor for extracting an output voltage by applying a constant current. It has the effect of being able to.

According to a third aspect of the present invention, in the first or second aspect, the low-resistance film of the resistance element substrate is formed in a horseshoe shape, and lead-out portions are provided at both ends thereof, and the low-resistance film is provided. A concentric ring-shaped current collector is formed at an interval inside the film, and has an effect that a rotary operation type variable resistor having high accuracy and excellent output voltage characteristics can be easily obtained.

According to a fourth aspect of the present invention, a low resistance film is printed on a resistance element substrate used for the variable resistor according to any one of the first to third aspects by using a low resistance paste on an insulating substrate. Forming, then, using a conductive paste, a current collector in parallel with the low-resistance film and in an electrically independent state, and a lead-out portion of each of the low-resistance film and the current collector, and the low-resistance film A conductive connecting portion electrically independent of the current collector is formed by printing so as to extend in a direction perpendicular to the direction in which the low-resistance film extends from above the predetermined portion of the predetermined portion, and then using a high-resistance paste to form the conductive connecting portion. A method of manufacturing a resistance element substrate in which a high-resistance film is printed and formed in parallel with the low-resistance film so as to overlap with the lead-out portion of the low-resistance film and the conductive connection portion. And can be formed uniformly. The current collector, lead-out, and conductive connection, which are parts that require conductivity, can be easily formed in a single printing process using the conductive paste, and the low-resistance film can be accurately formed through the high-resistance film. This has the effect that the resistance element substrate from which the resistance value can be taken out can be realized at low cost.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

The same components as those described in the section of the related art are denoted by the same reference numerals, and detailed description thereof will be omitted.

(Embodiment 1) FIG. 1 is a sectional view of a rotary operation type variable resistor according to a first embodiment of the present invention. As shown in FIG. Case 11 made of insulating resin with an upper opening fixed by
, The rotating body 12 is held by the lower circular projection 12B by the central circular hole 11A of the case 11 and the operating shaft 12C by the bearing 13B of the cover 13 fixed to the case 11 by the leg 13A. The sliding brush 14 provided with the contact portions 14A and 14B engaged with the printed layer on the upper surface of the resistance element substrate 21 is mounted on the flange portion 12A so as to be rotatable. As in the case, the configuration of the printing layer of the resistance element substrate 21 is different.

As shown in the top view of FIG. 2, the resistive element substrate 21 is a horseshoe-shaped low-resistance film of uniform thickness made of carbon paint so as to be in an electrically independent state and in a parallel relationship on the insulating substrate 1. 22 and a ring-shaped current collector 23 made of silver paint concentrically inside the low-resistance film 22. The lead-out portions 24 (24A, 24B) are provided at both ends of the low-resistance film 22 and the ring-shaped current collector 23. ) And 25 are printed out with silver paint and drawn out. Terminals 6 (6A, 24A, 24B) and 25
6B) and 7 are fixed by caulking in the same manner as in the prior art, but are printed and formed with silver paint to obtain a portion B which keeps the output voltage constant as shown in the output voltage characteristic diagram of FIG. The conductive connecting portion 26 overlaps the low-resistance film 22 and extends outward in a direction perpendicular to the direction in which the low-resistance film 22 extends, and has a predetermined width in an electrically independent state with respect to the ring-shaped current collector 23. It is arranged in three places.

Further, a high-resistivity film 27 having a higher specific resistance than the low-resistivity film 22 is concentrically formed with the low-resistivity film 22 in parallel with the low-resistivity film 22 so that a constant interval is provided in the outer peripheral portion of the low-resistivity film 22. The two ends of the high-resistance film 27 are formed so as to overlap above the lead-out portions 24A and 24B at both ends of the low-resistance film 22 and the conductive connection portion 26 is formed. Is formed so as to overlap also above.

Then, in the variable resistor having the above configuration,
The contact portions 14A and 14B of the sliding brush 14 are connected to the high-resistance film 27 and the ring-shaped current collector 2 of the resistance element substrate 21.
3 so as to be elastically slidably mounted thereon.

The operation of the variable resistor having such a configuration is performed by operating the operating shaft 12 with a constant voltage applied between the terminals 6A and 6B.
The rotating body 12 is rotated by rotating C, and the output voltage at a predetermined rotating operation position is connected to the terminal 6A as the sliding brush 14 attached to the flange portion 12A moves (see the arrow in FIG. 2). 7 is the same as the conventional case, but the variable resistor according to the present embodiment is connected to the resistance element substrate 21 via the sliding brush 14 as described above.
The output voltage is extracted from between the high-resistance film 27 and the ring-shaped current collector 23.

The output voltage is applied to the resistance element substrate 2
1 is determined by the combined resistance of the low-resistance film 22 and the high-resistance film 27 electrically connected to the same lead-out portions 24A and 24B. The resistance value of the low-resistance film 22 is preferentially dependent on the difference in specific resistance from the resistance film 27, and the low-resistance film 22 is formed directly on the insulating substrate 1 with a uniform thickness. Operation axis 12C
In the predetermined operation angle position, the output voltage characteristic depending on the low-resistance film 22 can be obtained with high accuracy according to the design Nerai value.

Further, since the contact portion 14A of the sliding brush 14 elastically slides on the high-resistance film 27 which is formed by printing over the conductive connecting portion 26, the contact portion 14A has a sharp contact resistance. There is no fluctuation and the generation of noise can be reduced.

Further, in a portion of the resistive element substrate 21 where the conductive connecting portion 26 is formed, a difference in specific resistance between the low-resistance film 22 and the high-resistance film 27 and the conductive connecting portion 26 causes a difference therebetween. The voltage change can be apparently eliminated, and the portion B shown in FIG. 3 for keeping the output voltage constant can be obtained as in the case of the conventional technique.

As described above, the variable resistor according to the present embodiment has the portion B for keeping the output voltage constant, and the output voltage characteristics can be obtained with high accuracy according to the design Nerai value, and the occurrence of noise and the like can be reduced. Therefore, when mounted on a device to be used, the operability and various characteristics of the device to be used can be easily improved.

In the above description, the resistance element substrate 21
Although the low-resistance film 22 and the high-resistance film 27 do not directly overlap with each other, as shown in the top view of FIG. 4, the high-resistance film 29 overlaps the entire circumference of the low-resistance film 28. May be configured in this case, in this case,
When using a variable resistor for extracting an output voltage by applying a constant current, it is needless to say that the output voltage can be accurately extracted.

Further, the material of the insulating substrate 1 may be a flexible insulating film made of polyethylene terephthalate other than a hard material such as a phenolic resin laminate, or the like. It is needless to say that the same effect can be obtained even if the inside and outside arrangement positions with respect to 27 are changed, and that the content of the present invention can be easily applied not only to a rotary operation type but also to a variable resistor that slides linearly. Of course.

As a variable resistor generally used, it is conceivable that the ratio of the resistance values of the high-resistance film and the low-resistance film is about 2 to 100 times. As a result of confirming a combination of a low-resistance film having a total resistance of 5 kΩ and a high-resistance film having a total resistance of 500 kΩ, a film having a stable output voltage characteristic as shown in FIG.

(Embodiment 2) The present embodiment relates to a method of manufacturing the resistance element substrate 21 described in the above-described Embodiment 1, and relates to the resistance element substrate in the in-process state shown in FIGS. This will be described below with reference to a top view.

In the manufacturing method, as a first step, a low-resistance paste is printed in a horseshoe shape on the insulating substrate 1 provided with through holes for mounting the rotating body 12 and the terminals 6 and 7 by a screen printing method. The first in-process product 30 of the resistance element substrate 21 on which the low-resistance film 22 shown in FIG. 5 is formed is manufactured by coating and baking.

Subsequently, in the second step, the lead-out portions 24 at both ends of the low-resistance film 22 and the inside of the low-resistance film 22 are concentric with the first in-process state product 30 by using a conductive paste by a screen printing method. The ring-shaped current collector 23 and its lead-out portion 25 in an electrically independent state, and the ring is superimposed on the low-resistance film 22 and extends outward in a direction perpendicular to the direction in which the low-resistance film 22 extends. The conductive connecting portion 26, which is electrically independent from the current collecting portion 23, is printed and baked with a predetermined width, and is baked. As shown in FIG. 6, the low resistance film 22 and the resistive element substrate 21 on which each conductive portion is formed are formed. The two-finished product 31 is manufactured.

Finally, in a third step, a high-resistance film 27 is formed on the second in-process state product 31 by using a high-resistance paste by a screen printing method, and concentrically outside the low-resistance film 22. Leading portions 24 at both ends of the conductive connecting portion 26 and the low resistance film 22 in a horseshoe shape
The resistive element substrate 21 is manufactured by printing and superimposing on (24A, 24B) and baking.

In the above-described method of manufacturing the resistive element substrate, the low-resistance film 22 is first formed by printing on the insulating substrate 1 by screen printing, so that the film thickness can be easily made uniform and the conductive portion can be easily formed. Ring-shaped current collector 2
3. The lead-out portions 24 and 25 and the conductive connection portion 26 can be simultaneously formed by printing using the same conductive paste in a single printing process. Further, when the lead-out portions 24 and 25 and the conductive connecting portion 26 are incorporated in the variable resistor according to the first embodiment, Since the high-resistance film 27 on which the contact portion 14A of the sliding brush 14 resiliently slides can be easily formed at the uppermost position of each printing layer, it is possible to accurately and precisely meet the design Nerai value at a predetermined operation angle position. It is possible to easily and inexpensively obtain a resistive element substrate which can realize a variable resistor having low output voltage characteristics and low noise.

[0041]

As described above, according to the variable resistor of the present invention and the method of manufacturing the resistive element substrate used in the variable resistor, the output voltage characteristic as designed can be obtained with high accuracy.
An advantageous effect is obtained that a variable resistor excellent in characteristics with little noise generation can be easily and inexpensively obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a rotary operation type variable resistor according to a first embodiment of the present invention.

FIG. 2 is a top view of a resistive element substrate which is a main part of the same.

FIG. 3 is an output voltage characteristic diagram

FIG. 4 is a top view of the resistive element substrate in the case where a low-resistance film and a high-resistance film, which are essential parts of the same, are overlaid.

FIG. 5 is a top view of a resistance element substrate in a first in-process product of the method for manufacturing a resistance element substrate according to the second embodiment of the present invention;

FIG. 6 is a top view of the resistance element substrate in the second in-process state product;

FIG. 7 is an output voltage characteristic diagram using a conventional variable resistor.

FIG. 8 is a top view of a resistance element substrate which is a main part of the variable resistor.

FIG. 9 is a sectional view of the variable resistor.

FIG. 10 is a top view of another conventional resistive element substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating board 6, 6A, 6B, 7 Terminal 11 Case 11A Central circular hole 12 Rotating body 12A Flange part 12B Lower circular protrusion 12C Operation shaft 13 Cover 13A Leg 13B Bearing part 14 Sliding brush 14A, 14B Contact part 21 Resistance Element substrate 22, 28 Low-resistance film 23 Ring-shaped current collector 24, 24A, 24B, 25 Lead-out portion 26 Conductive connecting portion 27, 29 High-resistance film 30 First in-process product 31 Second in-process product

Claims (4)

[Claims] 1. A low-resistance film having a uniform thickness and a predetermined length provided on an insulating substrate, and a current collector made of a silver-based material and arranged in parallel with the low-resistance film in an electrically independent state. A lead-out portion respectively derived from both ends of the low-resistance film and the current collecting portion, and extending from a top of a predetermined portion of the low-resistance film in a direction orthogonal to a direction in which the low-resistance film extends, And a conductive connecting portion of a predetermined width arranged in an electrically independent state, and arranged in parallel with the low-resistance film so as to overlap on the lead-out portions at both ends of the low-resistance film and the conductive connecting portion. A variable resistor comprising a resistive element substrate made of a high-resistance film, and a sliding brush having a contact portion that resiliently slides on a current collecting portion of the resistive element substrate and on the high-resistance film. 2. The variable resistor according to claim 1, wherein a high resistance film is laminated on the low resistance film on the resistance element substrate. 3. A low-resistance film of a resistance element substrate is formed in a horseshoe shape, and lead-out portions are provided at both ends thereof, and concentric ring-shaped current collectors are formed inside the low-resistance film at intervals. The variable resistor according to claim 1. 4. A resistive element substrate for use in a variable resistor according to claim 1, wherein a low-resistance film is printed on an insulating substrate by using a low-resistance paste. A current collector in a parallel relationship with the low-resistance film and in an electrically independent state, and a lead-out portion of each of the low-resistance film and the current collector; A conductive connecting portion electrically independent of the current collector is formed by printing so as to extend in a direction orthogonal to the direction in which the resistive film extends, and then a lead-out portion of the low-resistance film using a high-resistance paste and A method of manufacturing a resistive element substrate, wherein a high-resistance film is printed and formed in parallel with the low-resistance film so as to overlap the conductive connection portion.