JP2553679B2 - Resistor and manufacturing method thereof - Google Patents

Description

The present invention is mainly applied to color televisions, video tape recorders,
The present invention relates to a resistor used in video recorders such as tape recorders, audio equipment, and other electronic application equipment, and a manufacturing method thereof.

2. Description of the Related Art The prior art will be described by taking the variable resistor shown in FIGS. 3 and 4 as an example. FIG. 3 is a side sectional view of the variable resistor, and FIG.
FIG. 4 is a front view of the resistor which is the main part, and FIG. 4b is a side view of the resistor which is the main part. According to FIGS. 3 and 4, the conventional variable resistor is composed of a resistor 10, a slider 11 and a shaft 12, in which the resistor 10 includes an insulating substrate 13, a resistor portion 14,
Conductive part 15 (front conductive part 15a, side conductive part 15b, rear conductive part 15
It is composed of c).

The conductive portion 15 has a function of an electrode of the resistance portion 14 and a function of a terminal for mounting the variable resistor on the printed board.

Therefore, it is necessary to form the conductive portion by connecting to the front surface, the side surface, and the back surface of the insulating substrate.

In a typical example of the conventional method of forming the same, a conductive material such as a silver-palladium paste is first printed on the surface of the insulating substrate by screen printing on a ceramic substrate, baked, and then a predetermined portion of the back surface is formed. After forming a conductive portion in the same manner as above, the side surface was formed by screen printing or roll printing, and after baking, preliminary soldering was performed.

However, in the conventional resistor 10, as described above, the conductive portion includes the front surface conductive portion 15a, the back surface conductive portion 15c, and the side surface conductive portion 15b.
Because it is formed individually, the conductive film on the corners 15d of the insulating substrate becomes thin and the silver palladium paste is used as shown in FIG. And the corner part 15
The conductive film of d becomes thin, and silver is diffused even during the soldering process when mounting it on a printed circuit board. As a result of the decrease in the thickness of the film, there was a problem that the electrical connection reliability was poor.

Further, when an attempt is made to increase the film thickness on the corner portion 15d, the film thickness on the front surface and the back surface is increased, and a step is formed at a portion connected to the resistance portion, which causes a large variation in the resistance value.

Further, there are three steps only for forming the film of the conductive portion 15, each time it takes man-hours for changing the mask, setting the printing conditions, setting the paste viscosity, etc., and increasing the cost.
It required complicated management.

Means for Solving the Problems In order to solve the problems of the prior art, the present invention forms an insulating substrate by forming a groove in a portion where a conductive portion is formed in advance with an insulating material, and a synthetic resin capable of plating the groove. Is embedded, and a conductive film is formed on this by plating.

Effect According to the present invention described above, the conductive portion is formed of a platable synthetic resin, and the conductive film is formed on the conductive portion by plating to make the film thickness uniform, and
A film can be formed on the back surface at the same time, the process can be simplified, the step on the surface of the substrate can be reduced, and it is possible to obtain a resistor with a small variation in resistance value, making it possible to manufacture inexpensive and highly reliable resistors. It is a thing.

Embodiment An embodiment of the present invention will be described with reference to the variable resistors shown in FIGS. 1 and 2.

FIG. 1 is a side sectional view of a variable resistor, and FIG. 2 is a perspective view of an insulating substrate used for the resistor of the present invention.

According to FIGS. 1 and 2, 1 is an insulating substrate, 4 is a resistor portion formed on the insulating substrate 1, and the conductive film 3a of the insulating substrate 1 corresponding to both ends of the resistor portion 4 and A recessed groove 8 and a corner portion 9 are formed in a lower portion of a portion where the back surface conductive film 3c and the side surface conductive film 3b which are extended are formed, and the recessed groove 8 and the corner portion 9 are formed.
Is filled with a platable synthetic resin 2. In particular, the corner portion 9 is formed of the platable synthetic resin 2 with a roundness. Furthermore, the conductive film 3a, the side surface conductive film 3b,
The conductive film 3 including the back conductive film 3c is formed. Reference numeral 6 is a shaft that holds a slider 5 that rotates on the resistance portion 4.

The resistor 10 'is an insulating substrate 1 having two concave grooves 8.
The recessed groove 8 is filled with a synthetic resin 2 which can be plated with a rounded corner portion 9, and conductive films 3 are respectively formed on the synthetic resin 2 which can be plated by a plating method. It is formed through a step of providing the resistance portion 4 by printing or the like so that both ends thereof are connected to each other. Further, by optimizing the thicknesses of the platable synthetic resin 2 and the conductive film 3, the resistance portion 4 can be provided without a step.

As described above, the insulating substrate 1 and the synthetic resin 2 that can be plated
Then, the resistor 10 'is formed by the conductive film 3 and the resistor portion 4 provided continuously to the conductive film 3. Explaining specific examples below, wholly aromatic polyester (Vectra A130, Polyplastics) is used for the insulating substrate 1, and wholly aromatic polyester (Vectra LCX322, poly Plastic company)
Was used, and copper 5 cumylon and nickel 3 micron were formed on the conductive film 3 by electroless plating.

According to this, as shown in Fig. 1, the film thickness at the corners is uniform, so even in the solder dip test (eutectic solder H63A, made by Senju Metal Co., Ltd., temperature 260 ℃ ± 5 ℃)
According to the present invention, an electrically non-contact state was maintained in 0 seconds, but the electrically connected state could be maintained for 2 minutes or more.

Further, in forming the resistance portion, the step between the conductive portion and the substrate surface is filled with the synthetic resin 2 and the conductive film 3 so that the groove 8 can be made small, and the squeegee pressure is evenly applied during screen printing. Since the film thickness of the resistance part is stable, the variation can be reduced from 4.0% to 2.5% by the coefficient of variation, and the yield is improved.

A ceramic material such as alumina or forsterite is generally used for the insulating substrate 1, but synthetic resin without plating may be used, and the insulating substrate 1 is provided with a groove 8. It does not matter if the groove penetrates.

EFFECTS OF THE INVENTION As is apparent from the above-described embodiment, the present invention is: 1) Since the front surface, the side surface, and the back surface are continuous and the corners are rounded, a conductive portion having an even edge thickness is formed. Since it does not use silver-palladium as a conductive material, it does not cause silver diffusion during soldering and does not reduce the film thickness, so the solder heat resistance is significantly improved. 2) The resistance between the conductor and the board surface is small When forming parts by printing, the effect of steps is eliminated and the squeegee pressure stabilizes, resulting in a uniform film thickness and improved yield. 3) When forming conductive parts, it is possible to plate only the parts to be plated. Since the resin is used, the plating can be selectively performed without performing a treatment such as masking, so that the process can be simplified.

And so on.

[Brief description of drawings]

FIG. 1 is a side sectional view of a variable resistor using a resistor according to an embodiment of the present invention, FIG. 2 is a perspective view of the same insulating substrate, and FIG. 3 is a variable resistor using a conventional resistor. FIG. 4 is a side sectional view of the resistor, FIG. 4a is a front view thereof, FIG. 4b is a side view thereof, and FIG. 5 is an enlarged view of a main part of FIG. 4b. 1 ... Insulating substrate, 2 ... Platable synthetic resin, 3 ...
Conductive film, 4 ... resistor, 8 ... groove, 9 ... corner,
10 ... resistor.

Claims (2)

(57) [Claims] 1. An insulating substrate having a resistance portion, a conductive film formed by plating, which is continuously provided at both ends of the resistance portion and extends to a side surface and a back surface, and a conductive film of the conductive film. A resistor comprising a plateable synthetic resin having a rounded corner at the bottom and a groove formed in the insulating substrate filled with the synthetic resin. 2. An insulating substrate having a plurality of grooves is filled with a synthetic resin capable of being plated so as to have a rounded corner portion, and a plurality of conductive films are plated on the synthetic resin capable of being plated. A method of manufacturing a resistor, which is formed by forming a resistor portion by connecting both ends to each of the conductive films.