JP2008283209A - Resistor substrate, method of manufacturing the same, and variable resistor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resistor substrate for variable resistor which has high reliability, high durability, and high precision, its manufacturing method, and a variable resistor. <P>SOLUTION: This resistor substrate comprises a metal plate 7 provided with a plurality of strip-shaped input/output terminal sections used as external lead terminals, an insulating coat layer 8 formed on the entire front and rear surfaces including the input/output terminal sections and sides of the metal plate 7, a conductor pattern 2 of a predetermined shape and a resistor pattern 1 of a predetermined shape elongated to the input/output terminal sections formed on the surfaces of the insulating coat layer 8, and a conductive paste layer or a conductive plated layer 9 which is formed on insulating coat layer 8 in the plurality of strip-shaped input/output terminal sections used as the external lead terminals, and conductively connects to the conductor pattern 2 and the resistor pattern 1, respectively. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technical field of a variable resistor widely used as a component of an electronic device, and more particularly to a resistor substrate on which a resistor pattern is formed in a variable resistor.

  Conventionally, as shown in a perspective view of FIG. 4 or a longitudinal sectional view of FIG. 5, a predetermined resistor pattern 1 and a conductor pattern 2 are formed on an insulating surface and a plurality of small holes 3a, 3b, 3c. Are drilled in the input / output terminal portion 4, and a plurality of external lead terminals 5a, 5b, 5c are caulked in the small holes 3a, 3b, 3c by means of attachment tools 6 (metal eyelets, metal rivets, etc.) through the through holes, respectively. A paper phenol laminate or a glass epoxy substrate is widely used as the resistor substrate (element) 20 for the variable resistor that is fixed.

  In [Patent Document 1] below, as shown in the perspective view of FIG. 6 or the longitudinal cross-sectional view of FIG. 7, a metallic substrate 30 is provided for the circuit board of the variable resistor (synonymous with the resistor substrate). The conductive path 22 (synonymous with the conductor pattern 2) is attached and fixed thereto via the insulating layer 21, and provided to the output from the conductive path 22 or the input electrode part 23 (synonymous with the input / output terminal part 4). An insulating retaining rod 24 is inserted into the through holes provided in the small holes 3a, 3b, 3c and the external lead terminals 5a, 5b, 5c and caulked to output the external lead terminals 5a, 5b, 5c to the output or A circuit board having a structure fixedly connected to the input electrode portion 23 is disclosed.

JP 63-98102 A

  There is a strong demand from the electronics manufacturing industry for highly reliable variable resistors with excellent durability.

  In this respect, small holes 3a, 3b, 3c are formed in the insulating substrate on which the horseshoe-shaped resistor pattern 1 or the linear resistor pattern as shown in FIG. 4 is formed, and external lead terminals 5a, 5b, A rotary volume having a basic structure in which a resistor board 20 in which 5c is caulked and fixed by a conductive fitting 6 such as a metal eyelet and a rivet, and a rotor or slider provided with a slider (also referred to as a conductive brush) are combined. In addition, it is difficult to improve reliability with a rotary encoder or a slide volume.

  That is, although a phenolic resin substrate such as a paper phenol laminate is low in cost, (a) the resistance value is increased by about 10% in the rainy season due to humidity and (b) when the resistor pattern 1 is printed and baked. Needs to be baked 4 to 5 times at a high temperature of 200 ° C. to 220 ° C. However, the paper phenol laminate has a high shrinkage ratio and a large shift of the printed pattern, which makes it difficult to obtain a highly accurate resistor pattern. As mentioned.

  On the other hand, the glass epoxy substrate has a material cost that is about 4 times higher than that of the paper phenol laminate. It is gradually switching from.

  However, (c) this glass epoxy substrate also has a linearity error because the shrinkage rate of the glass epoxy substrate is 0.05% when the printed resistor pattern is baked at a high temperature of 200 ° C. to 220 ° C. The yield of high-precision resistors with a resistance of 3% or less is not good, (d) the shrinkage of epoxy occurs due to the above-mentioned baking, and the glass fiber rises on the surface, causing an increase in sliding noise, (E) Glass fiber broken powder adheres to the surface when printing, punching, and punching due to glass fiber and is printed, causing sliding noise. (F) The glass fiber powder continues to be crushed and spattered from the substrate even after washing, and this acts as an abrasive to significantly increase the rotational life of the resistor pattern. Shrink That has become a factor, furthermore, be mentioned as a drawback such as a point is not easy disposal of the remaining scrap after (g) the substrate stamping.

  In this regard, in [Patent Document 1], in view of the point that the thermal shrinkage rate of the phenol resin substrate is large and the impact resistance of the ceramic substrate is weak, the highly reliable variable as shown in FIGS. Examples of the variable resistor using the metal substrate 30 as a substrate to replace the insulating substrate such as the paper phenol laminate and the ceramic substrate having the disadvantage as the resistor are shown, but the external lead terminal 5a, As an attachment 6 for fixing 5b and 5c to the substrate, an “insulating stopper 24” (insulating rivet) is an essential component. The conductive stopper rods such as metal eyelets that have been used in the past are all electrically connected to the external lead terminals 5a, 5b, and 5c through the back surface of the metallic substrate 30 and the inner surfaces of the small holes 3a, 3b, and 3c. It cannot be used. In the above-mentioned [Patent Document 1], there is no disclosure about the specific material of the “insulating retaining rod 24”, but it is considered that it is probably made of resin. However, this is not common as a retaining rod, lacks versatility, and is clearly inferior in cost and handling. In addition, the resin-made insulating retaining rod 24 is problematic in that it has a risk of softening at the soldering temperature and loosening the caulking, and lacks reliability.

  The present invention has been made in view of the above circumstances, and provides a resistor substrate having a new structure that meets the demand for a highly reliable variable resistor having excellent durability, a manufacturing method thereof, and a variable resistor using the same. To do.

In order to achieve the above object, the present invention
(1) A resistor substrate 19 for a variable resistor, in which a plurality of strip-like input / output terminal portions 17a, 17b, and 17c serving as external lead terminals are formed, and the insertion of the metal plate 7 The insulating film layer 8 formed on the entire front and back and side surfaces including the output terminal portions 17a, 17b, and 17c, and the input / output terminal portions 17a, 17b, and 17c formed on the surface of the insulating film layer 8 The conductor pattern 2 having a predetermined shape and the resistor pattern 1 having a predetermined shape, and the insulating film layer 8 formed on the plurality of strip-like input / output terminal portions 17a, 17b, and 17c serving as the external lead terminals. Provided is a resistor substrate 19 comprising a conductor pattern 2 and a conductive paste layer or a conductive plating layer 9 that are conductively connected to the conductor pattern 2 and the resistor pattern 1, respectively.
(2) A step of forming a plurality of strip-like input / output terminal portions 17a, 17b, 17c serving as external lead terminals on the metal plate 7, and a front and back including the input / output terminal portions 17a, 17b, 17c of the metal plate 7 A step of forming the insulating film layer 8 on the entire surface and side surfaces, and a conductive material that can be soldered onto the insulating film layer 8 in the plurality of strip-like input / output terminal portions 17a, 17b, and 17c serving as the external lead terminals. A step of forming a paste layer or conductive plating layer 9, and conductive connection of the conductive paste layer or conductive plating layer 9 of the input / output terminal portions 17a, 17b and 17c on the surface of the insulating coating layer 8 of the metal plate 7; A step of printing and baking the conductor pattern 2 having a predetermined shape and the resistor pattern 1 having a predetermined shape, and a step of stamping and forming the metal plate 7 into a predetermined outer shape; Method for manufacturing a resistor substrate according to (1), characterized in that it has to provide.
(3) The resistor substrate 19 according to (1) above, a slider that slides on the resistor pattern 1 of the resistor substrate 19, a knob mechanism that holds and moves the slider, A variable resistor is provided.

Since the resistor substrate for a variable resistor according to the present invention, the manufacturing method thereof, and the variable resistor are configured as described above, they have the following effects.
(1) There is almost no expansion / contraction of the substrate due to humidity, and since there is almost no contraction even when baking at high temperature, a highly accurate resistor pattern can be obtained. As a result, a highly accurate variable resistor can be obtained.
(2) Since there is no influence of the powder that scatters when the substrate is cut, perforated or punched, the trouble of removing dust can be saved.
(3) The surface of the resistor pattern formed on the surface of the insulating film layer of the smooth metal plate is smooth and has low sliding noise, and durability such as slide life is remarkably improved and high reliability. The variable resistor is realized.
(4) Since the heat dissipation of the resistor substrate is good, the wattage as a variable resistor can be set high.
(5) Since the resistor substrate has high heat resistance, polyimide resin (high wear resistance) that requires baking at high temperatures can be applied as a varnish for resistor inks, so that the variable resistance is further excellent in wear resistance. The vessel is realized.
(6) Since the external lead terminal of the input / output terminal portion formed integrally with the metal plate is provided, and the step of separately caulking and fixing the external lead terminal is omitted, the manufacturing process can be automated.
(7) Since there is no possibility of loosening of the external lead terminal, a highly reliable variable resistor can be obtained.

  Embodiments of a resistor substrate and a manufacturing method thereof according to the present invention will be described with reference to the drawings.

  FIG. 1 is a plan view of a resistor substrate according to the present invention. FIG. 2 is a longitudinal sectional view of the input / output terminal portion of the resistor substrate according to the present invention. FIG. 3 is a manufacturing process flow diagram of the resistor substrate according to the present invention.

  Next, the resistor substrate according to the present invention has a plurality of strip-like input / output terminal portions 17a and 17b that serve as external lead terminals, as in the slide / volume resistor substrate 19 shown in FIGS. , 17c and a metal plate 7 having a thickness of about 0.4 mm (for example, the aluminum thin plate 14 or the tin plate 11), and the entire front and back surfaces of the metal plate 7 including the input / output terminal portions 17a, 17b, and 17c. Insulating film layer 8 formed on the side surface (for example, aluminum oxide film or epoxy resin film formed by alumite treatment) and the input / output terminal formed on the surface of insulating film layer 8 The conductor pattern 2 having a predetermined shape and the resistor pattern 1 having a predetermined shape reaching the portions 17a, 17b, and 17c, and a plurality of strip-shaped input / outputs serving as the external lead terminals A conductive paste layer or a conductive plating layer 9 that is conductively connected to the conductor pattern 2 and the resistor pattern 1 formed on the insulating film layer 8 in the terminal portions 17a, 17b, and 17c, respectively. .

  The resistor pattern 1 and the conductor pattern 2 are printed with conventional resistance ink (resistor ink mixed with carbon powder using a polyimide resin that requires baking at a high temperature as a varnish) or silver ink. It is formed by baking and hardening.

  The alumite treatment (trade name when invented at RIKEN, circa Taisho 12) is an electrolysis using sulfuric acid, oxalic acid, etc. as an electrolytic solution, and an anodizing process to form a corrosion-resistant insulating film on the surface of aluminum. It is a process to form.

  As shown in FIG. 3, the manufacturing method includes (m) a step of forming a plurality of strip-like input / output terminal portions 17a, 17b, 17c serving as external lead terminals on the metal plate 7, and (n) the metal A step of forming an insulating film layer 8 on the entire front and back and side surfaces including the input / output terminal portions 17a, 17b, and 17c of the plate 7, and (p) a plurality of strip-shaped input / output terminal portions 17a serving as the external lead terminals. 17b, 17c, forming a solderable conductive paste layer or conductive plating layer 9 on the insulating coating layer 8, and (q) on the surface of the insulating coating layer 8 of the metal plate 7. Printing and baking a conductor pattern 2 having a predetermined shape that is conductively connected to the conductive paste layer or the conductive plating layer 9 of the input / output terminal portions 17a, 17b, and 17c; and (r) the metal plate 7 A step of forming a resistor pattern 1 having a predetermined shape on the surface of the edge coating layer 8 by printing and baking; and (s) a broken line in the figure representing a predetermined outer shape of the metal plate 7 (for example, step (m)). And a step of punching and forming into a rectangular shape shown in FIG. The step (p) may be after the step (r).

  A characteristic of this manufacturing method is that a plurality of strip-like input / output terminal portions 17a, 17b, and 17c to be external lead terminals are first formed on the metal plate 7 by etching or punching (step (m)). Next, by forming a strong insulating film layer 8 on the entire surface of the metal plate 7, a conductive material such as a silver paste that can be soldered and formed on the respective surfaces of the input / output terminal portions 17a, 17b, and 17c. An electrode formed by paste or tin plating is completed as an external lead terminal. Of course, the inside of the input / output terminal portions 17a, 17b, and 17c is conducted as a part of the metal plate 7, but since the surface thereof is covered with the insulating coating layer 8, the insulating coating layer 8 Since the conductive paste layer or the conductive plating layer 9 on the input / output terminal portions 17a, 17b and 17c formed on the surface is not electrically connected to each other, it can be an external lead terminal.

  Further, in the present embodiment, the process of drilling the small holes and the process of attaching the external lead terminals 5a, 5b, and 5c by metal eyelets, which had to be performed manually, are omitted, so that the manufacturing process can be automated. This enables mass production of highly durable and reliable variable resistors.

  Furthermore, this manufacturing method uses a metal plate that is inexpensive as a substrate, has heat resistance compared to a resin substrate, etc., and has an extremely smooth surface, so that a resistor pattern and a conductor pattern can be formed with very high accuracy. It has the feature.

  In addition, as an effect of the above-described manufacturing method and the resistor substrate 19 manufactured thereby, there is almost no expansion / contraction due to humidity, and a high-accuracy resistor pattern can be obtained because there is almost no contraction even after high-temperature baking, It eliminates the need for dust removal because it does not generate dust such as glass, has a very smooth surface with low sliding noise, greatly extends its life, and heat conduction of metal substrates when soldering to terminals Since the rate is high, there is no risk that the terminal will loosen at the soldering temperature, the wattage of the resistor can be set high because it has good heat dissipation, and the heat resistance is high, so the polyimide resin that requires baking at high temperature is the resistance It can be applied as an ink varnish, and further realizes a variable resistor having excellent wear resistance.

  The resistor substrate 19 according to the present invention is for a slide volume. The resistor substrate 19 is used as a component resistor substrate, and a slider sliding on the resistor pattern 1 of the resistor substrate 19 is used. Needless to say, the rotary volume, rotary encoder, or slide volume having the same structure as that of the prior art including at least the knob mechanism that holds and moves the slider can be manufactured with a high yield in the same assembly process as in the prior art. Yes.

  As described above, it is clear that the various variable resistors using the resistor substrate based on the metal plate of the present invention described in detail have high reliability, high durability, and high accuracy.

It is a top view of the resistor board concerning the present invention. It is a longitudinal cross-sectional view of the input-output terminal part of the resistor board based on this invention. It is a manufacturing process flowchart of the resistor board based on this invention. It is a perspective view explaining the structure of the resistor board for conventional variable resistors. It is a longitudinal cross-sectional view of the input / output terminal part of the resistor board for conventional variable resistors. It is a perspective view explaining the structure of the resistor board | substrate for variable resistors disclosed by [patent document 1]. It is a longitudinal cross-sectional view of the input / output terminal part of the resistor board for variable resistors disclosed in [Patent Document 1].

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resistor pattern 2 Conductor pattern 7 Metal plate 8 Insulating film layer 9 Conductive paste layer or conductive plating layer 17a, 17b, 17c Strip-shaped input / output terminal part used as an external lead terminal 19 Resistor board

Claims (3)

A resistor substrate for a variable resistor, which is formed on a metal plate on which a plurality of strip-shaped input / output terminal portions serving as external lead terminals are formed, and on the entire front and back surfaces and side surfaces of the metal plate including the input / output terminal portions. A plurality of strips serving as the external lead terminals, and a conductor pattern and a resistor pattern having a predetermined shape reaching the input / output terminal portion formed on the surface of the insulating film layer. A resistor substrate comprising: a conductive paste layer or a conductive plating layer that is conductively connected to the conductor pattern and the resistor pattern, respectively, formed on the insulating film layer in the input / output terminal portion having a shape . Forming a plurality of strip-shaped input / output terminal portions serving as external lead terminals on the metal plate, forming an insulating film layer on the entire front and back and side surfaces including the input / output terminal portion of the metal plate, and Forming a solderable conductive paste layer or a conductive plating layer on the insulating coating layer in a plurality of strip-shaped input / output terminal portions serving as external lead terminals; and the insulating coating layer of the metal plate A step of printing and baking a conductor pattern of a predetermined shape and a resistor pattern of a predetermined shape to be conductively connected to the conductive paste layer or conductive plating layer of the input / output terminal portion on the surface; and the metal plate having a predetermined outer shape The method of manufacturing a resistor substrate according to claim 1, further comprising: The resistor board according to claim 1, at least a slider that slides on a resistor pattern of the resistor board, and a knob mechanism that holds and moves the slider. Variable resistor to do.

Images