JPS62190702A - Resistant substrate for 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 (Field of Industrial Application) The present invention is applicable to small and thin consumer electronic devices such as videos, headphone stereos, car stereos, and televisions, which are becoming smaller, lighter, and more multifunctional. The present invention relates to a resistance base consisting of a terminal and a resistance element for constructing a variable resistor.

(Prior Art) Conventionally, this type of resistance substrate has been disclosed, for example, in Japanese Patent Application Laid-Open No. 58-46.
As described in Japanese Patent No. 604, a structure as shown in FIG. 14 was common.

That is, the drawn portions 31a of the eyelet terminal 31, which is formed by drawing and punching a metal plate, are attached to the current collector coating portions 33 at both ends of the resistance coating 35 formed on an insulating substrate 32 such as a phenolic resin laminate. It was passed through the provided through hole 34, opened at the tip of the drawn portion 31a of the eyelet terminal, and fixed by compression caulking. Note that FIG. 15 shows a state in which the eyelet terminal 31 is fixed to the insulating substrate 32.

In addition, when configuring it as a variable resistor, soldering tends to loosen the caulking due to the heat of soldering, which tends to impair the stability of electrical contact. Insert molding is often performed when resin molding the housing of a variable resistor.

(Example of insert molding: see Japanese Patent Application Laid-Open No. 60-68601) (Problems to be Solved by the Invention) In such a conventional configuration, the eyelet terminal is drawn, so there is a limit to the processing. Small terminals cannot be configured. Further, in order to sufficiently withstand cracking caused by caulking when attaching the terminal, a large area such as the distance between the end of the insulating substrate and the terminal attachment hole is required. Furthermore, since the terminals are attached by caulking, the height of the caulked portion increases the thickness of the variable resistor. As described above, there are limits to constructing a small and thin type variable resistor.

An object of the present invention is to provide a resistance base for making a variable resistor smaller and thinner.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a thin insulator such as a resin film with a plurality of through holes, and one end of the through hole is formed on the back surface of the insulator. A terminal board whose other end protrudes from the edge of the insulator is fixed with an insulating adhesive. A current collector is formed around the through hole on the surface of the insulator, and is electrically connected to the terminal plate through the through hole with conductive paint.
A resistive film is formed across the current collecting portions. Furthermore, a housing is formed by resin molding with the necessary portions of the resistive film, insulator, and terminal board exposed.

(for production) The effect of this technical means is as follows.

In other words, the mechanical fixation of the terminal plate and the resistance film is achieved by fixing the terminal plate and the insulator with an insulating adhesive, and by passing the through hole in the insulator and connecting it to the current collector formed around it. This is done by fixing with a conductive paint that electrically connects the parts, and fixing with a molded resin that makes up the casing.

Therefore, it has a structure that can sufficiently withstand mechanical external forces,
Further, even against thermal influences, contact is maintained mainly due to the elasticity and adhesive force of the resin component of the conductive paint, and a good electrical connection can be obtained.

According to the present invention, the thickness is reduced because caulking is not performed, and a large area is not required to withstand caulking, and as a result, a small and thin variable resistor can be constructed. It is possible to supply resistor substrates of

(Example) Hereinafter, an example will be described in detail based on the accompanying drawings. FIG. 1 shows an embodiment of the present invention, in which 1 is a terminal plate, 2 is a film-like insulator, 3 is an insulating adhesive, 4 is a current collector made of conductive paint, and 5 is a current collector made of conductive paint. A resistive film, 6 a housing made of molded resin, and 7 holes formed by pins that support the terminal board during molding of the housing.

Next, the specific configuration of each part of the above embodiment will be explained. Second
The figure is a plan view of an insulator for forming a resistance film, where 2 is a thin insulator made of a resin film, etc., 10a and 10'b are through holes (connection holes) for connecting the terminal board and the resistance film. (The method will be described later), 12 is a through hole for positioning, and 11 is a blank part for forming the insulator 2 into a required shape. Further, 13 is the assumed position of 4 central through holes which may be required depending on the structure of the variable resistor.

FIG. 3 is a plan view of the terminal board, in which 1 is a terminal board configured into an arbitrary shape, 1a and 1b are terminal extraction parts, 14
is a positioning through hole. Further, the terminal plate 1 is formed by punching or etching a metal plate, and its surface is covered with a material such as silver or solder that has good electrical conductivity and can be soldered.

FIG. 4 shows a state in which the terminal plate 1 shown in FIG. 3 is bonded to the back surface of the insulator 2 shown in FIG. 2 with an electrically insulating adhesive. Insulating adhesive 3 for the hatching part
This is the adhesion position due to the through holes 10a and 10b of the insulator.
Do not apply insulating adhesive around the area. Further, the through holes 12 and 14 for positioning are used for positioning and bonding.

FIG. 5 is a plan view showing the position of the current collector 4. FIG.

The current collector 4 is made by printing adhesive conductive paint such as silver paste mainly consisting of a conductive material and a resin component around the through holes 10a and 10b on the surface of the insulator 2, including the inside of the through holes. It is formed by drying or other methods to electrically and mechanically connect the terminal plate and the current collector.

FIG. 6 is a diagram showing the structure of the resistive film 5, which is formed by printing and drying a resistive paint. Reference numeral 15 denotes a portion where the current collecting portion 4 and the resistive film 5 overlap, and by forming the current collecting portion 4 and the resistive film 5 in such an overlapping manner, the current collecting portion 4 and the resistive film 5 are electrically and mechanically connected. As a result, the resistive film 5 and the terminal board 1 are electrically and mechanically connected. 16a and 16b are arbitrary terminal cutting positions, and after the terminal is cut, the resistance value of the resistive film 5 (the total resistance value when the variable resistor is configured) is obtained between the terminal extraction portions 1a and 1b.

FIG. 7 is a plan view showing the state after insert resin molding. In FIG. 7, reference numeral 6 denotes an insert-molded resin housing, and a terminal extraction portion 1a.

1b, a portion of the resistive film 5, and an unnecessary portion of the insulator 2 are exposed. Here, the terminal board 1 and the insulator 2 are firmly fixed by the housing 6. Further, the shape of the housing (including the shape of the exposed portion) is determined by the insert resin molding die.

8 is the assumed position of the central boss of the housing, 9 is the assumed position of the central hole of the housing, 17a and 17b are arbitrary insulator cutting positions, and when the variable resistor is completed, together with the terminal extraction part mentioned above, Cut and separated.

Next, other embodiments of the present invention will be described.

The above-mentioned embodiments were constructed by bonding together a terminal in a nearly completed shape and an insulator, and the area to be bonded with an insulating adhesive was relatively small. Here, an insulator in an unfinished state and a terminal in a semi-finished state are bonded in advance using an insulating adhesive over a large bonding area, and after bonding, the shape is adjusted by press processing, and then the current is collected. Department,
What forms the resistive film portion will be described below.

FIG. 8 shows the insulator 20, and FIG. 9 shows the insulator 20.
10 shows the terminal board 21, and FIG. 10 shows the terminal board 21.
This shows a state in which the terminal plate 21 is attached to the back surface of 0. In FIG. 10, 22 is a bonding position with an insulating adhesive, and the bonding area is larger than that of the first embodiment. However, the peripheral portions of the insulator through holes 23a and 23b are not bonded.

FIG. 11 is a plan view showing the processing position after the terminal board 21 and the insulator 20 are bonded together, and 24 is a blank portion.

FIG. 12 is a plan view showing the current collector 25. FIG.

FIG. 13 is a plan view showing the resistive film 26.

Thereafter, by molding the resin and cutting predetermined portions, the resistor base shown in FIG. 1 is constructed.

(Effects of the Invention) As described above, according to the present invention, a resistance base for a variable resistor that has sufficient mechanical strength and is highly reliable in electrical connection without using a caulking method. As a result, there is an advantage that a small and thin variable resistor can be constructed.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a resistor base according to an embodiment of the present invention, and FIG.
The figure is a plan view of the insulator, FIG. 3 is a plan view of the terminal board, FIG. 4 is a plan view showing the terminal board and insulator bonded together, and FIG. 5 is a plan view of the current collector. 6 is a plan view showing the resistance film, FIG. 7 is a plan view showing the state after the housing is molded, and FIG. 8 is a plan view of the insulator in another embodiment of the present invention. FIG. 9 is a plan view of the terminal board, and FIG. 10 is
FIG. 11 is a plan view showing a state in which the terminal board and the insulator are bonded together; FIG.
13 is a plan view showing the resistance film, FIG. 14 is a perspective view showing the conventional terminal fixing method, and FIG. 15 is the terminal fixing method in the conventional example. It is a sectional view showing a state. 1.21...Terminal board, 2,20...Insulator, 3
... Insulating adhesive, 4,25... Current collector, 5,
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Claims (1)

[Claims] A film-like insulator having a plurality of through-holes for connecting terminal boards, and an insulating adhesive on the back side of the insulator so that one end closes the through-hole and the other end protrudes from the edge of the insulator. A plurality of terminal plates made of metal plates fixed with
A current collecting portion made of a conductive paint provided on the surface of the insulator in a peripheral area including the plurality of through holes and electrically connected to the terminal plate through the through hole; 1. A resistance base for a variable resistor, comprising a resistance film formed astride the resistance film, and a resin-molded casing that exposes the resistance film, an insulator, and a necessary portion of a terminal plate.