JP2000124016A - Manufacture of chip-type variable resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method with which a chip-type variable resistor can be manufactured inexpensively without requiring much labor by constituting a continuous automated production line. SOLUTION: A method of manufacturing a chip-type variable resistor is composed of a placing process for bringing a lower surface 1b of an insulating substrate into contact with a bottom plate 5a of a terminal hoop 10 by placing a semi-finished article on the hoop 10, a soldering process for connecting the electrodes 3 of the semi-finished article to the leg sections 5b of the hoop 10 by soldering after the placing process, and a cutting process for cutting off the bottom plate 5a from a frame 12, by cutting the projecting sections 5d of the hoop 10 after the soldering process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a chip-type variable resistor, and more particularly to a method of manufacturing a semi-fixed chip-type variable resistor.

[0002]

2. Description of the Related Art First, a conventional chip type variable resistor will be described with reference to the drawings. FIG. 15 is a perspective view showing a conventional chip-type variable resistor, and FIG. 16 is a cross-sectional view showing a state where the conventional chip-type variable resistor is mounted on a printed wiring board.

[0003] As shown in FIGS.
Numeral 0 is made of a ceramic material, fired and formed into a substantially rectangular shape, and has an upper surface 30a, a lower surface 30b, and side surfaces 30c. In addition, a large-diameter hole 30d provided at a substantially central portion is provided.
And an arc-shaped notch 30e provided on one side surface 30c.

On the upper surface 30a of the insulating substrate 30, a resistor (not shown) is formed in an arc shape by printing so as to surround the hole 30d. Also, its vertical x horizontal x thickness dimensions are
It has a large size of about 4 mm × about 3.5 mm × about 0.8 mm (having a volume of about 11.2 mm ² ).

The first electrode 31 is provided on the upper surface 30 of the insulating substrate 30.
A pair of resistors is provided at both ends of a resistor (not shown) provided at a, and each is electrically connected to the resistor. The second electrode 32 is made of, for example, silver paste or the like, and is connected to the upper surface 30a, the side surface 30c, and the lower surface 30b of the insulating substrate 30 and applied, and has a U-shaped cross section. It is electrically connected to one electrode 31.

The third electrode 33 is made of, for example, silver paste or the like, and is applied so as to surround the hole 30 d in the lower surface 30 b of the insulating substrate 30. The central shaft 34 has a cylindrical central shaft portion 34a and an operation portion 34b provided at one end (upward) of the central shaft portion 34a. This center axis 3
4 is rotatably caulked to the lower surface 30b of the insulating substrate 30 while being inserted through the hole 30d of the insulating substrate 30, and is connected to the third electrode 33 at this caulked portion.

[0007] The slider 35 is made of an elastic metal plate and has a substantially rectangular holding portion 35a and a contact portion 35b provided in an arc shape from the holding portion. The slider 34 is fixed to the center shaft 34 by appropriate means, and a contact portion 35
b is arranged so as to elastically contact a resistor (not shown). For this reason, the slider 34 is held rotatably with respect to the insulating substrate 30.

Next, a state in which a conventional chip type variable resistor is mounted on a printed wiring board will be described. FIG.
As shown in the figure, the printed wiring board 20 is made of, for example, a synthetic resin material containing glass or the like, and has a flat plate shape. A desired conductive pattern 21 is formed on at least one surface of the printed wiring board 20. This printed wiring board 20
The above-described conventional chip-type variable resistor is mounted on the conductive pattern 21 of FIG. At this time, cream solder (not shown) is applied on a predetermined conductive pattern 21, and the second electrode 32 and the third electrode 33 of the chip type variable resistor are mounted so as to be connected to the cream solder. I do.

[0009] The chip type variable resistor soldered to the printed wiring board in this manner,
It is electrically and mechanically connected.

Next, a method of manufacturing a conventional chip type variable resistor will be described. FIG. 17 is a plan view of a main part showing a material base plate of an insulating substrate for explaining a method of manufacturing a conventional insulating substrate of a chip-type variable resistor. FIG. 18 shows a conventional method of manufacturing a chip-type variable resistor. It is a process drawing explaining.

As shown in FIG. 17, a raw material base plate 50 is made of a ceramic material, is fired, and has a plurality of insulating substrates 30 and holding portions 51 for holding the respective insulating substrates 30.
And A plurality of vertical lines 52 and a plurality of horizontal lines 5 are provided between each of the plurality of insulating substrates 30.
3 are provided.

The material base material 50 as described above is formed in the step of firing the material base material shown in FIG. next,
In the printing process of the resistor and the first electrode shown in FIG.
A resistor and a first electrode are respectively formed on the upper surface of each of the 0 insulating substrates 30 by printing or the like. Next, in the step (C) of dividing the material base material, a vertical line 52 of the material base material 50 is formed.
The material base material 50 is divided by the horizontal line 53 to form a single insulating substrate 30.

Next, in a step (D) of applying the second and third electrodes, a silver paste or the like is applied to predetermined portions of the upper surface 30a, the lower surface 30b, and the side surface 30c of the insulating substrate 30, The second electrode 32 and the third electrode 33 are formed. Next, (E)
In the second and third electrode plating steps, for example, nickel plating is performed on the second electrode 32 and the third electrode 33 formed by coating, and a nickel coating layer is applied. By this nickel plating, the second and third electrodes 3 made of silver paste are formed.
Silver solder erosion generated at the time of soldering of 2, 33 can be prevented. Next, in the step (F) of assembling the central shaft and the slider, the central shaft 34 and the slider 35 are incorporated into the insulating substrate 30 and integrated to complete a single chip type variable resistor.

[0014]

However, in the conventional method of manufacturing a chip-type variable resistor, a single-piece insulating substrate in which a base material 50 is divided and a resistor and a first electrode 31 are formed on an upper surface 30a is provided. The second electrode 32 and the third electrode 33 are respectively provided on the manufactured single insulating substrate 30.
And a plating step of performing nickel plating. For this reason, in the conventional method of manufacturing a chip-type variable resistor, continuous automation of the manufacturing process is difficult, and there is a problem in that the cost is increased by taking individual and separate manufacturing processes.

[0015]

According to the present invention, there is provided a method of manufacturing a chip-type variable resistor, comprising the steps of: connecting an insulating substrate, a resistor provided on an upper surface of the insulating substrate, and both ends of the resistor; A semi-finished product having a pair of electrodes provided on an upper surface of an insulating substrate, a frame, a protrusion connected to the frame, a bottom plate connected to the protrusion, and a leg bent upward from the bottom plate. A terminal hoop made of a metal plate having
A mounting step of mounting the semi-finished product such that the lower surface of the insulating substrate is in contact with the bottom plate of the terminal hoop, and after the mounting step, the electrode of the semi-finished product and the leg of the terminal hoop. And a cutting step of cutting the protruding portion of the terminal hoop to separate the bottom plate from the frame after the soldering step.

Further, in the method of manufacturing a chip-type variable resistor according to the present invention, the bottom plate has a substantially quadrangular shape, and the first leg and the second leg are bent upward from side edges of the substantially quadrangular adjacent legs. And the positioning of the insulating substrate with respect to the terminal hoop by contacting the side surface of the insulating substrate with the first leg and the second leg during the mounting step. is there.

Further, the method of manufacturing a chip-type variable resistor according to the present invention has a bending step of bending the tip of the leg of the terminal hoop toward the upper surface side of the semi-finished insulating substrate before the soldering step. That is.

Further, the method of manufacturing a chip-type variable resistor according to the present invention has a structure in which a projection is formed between the first leg and the second leg, and the projection is cut during the cutting step. To separate the bottom plate from the frame.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A chip type variable resistor according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing a chip-type variable resistor according to an embodiment of the present invention, FIG. 2 is a top view showing a chip-type variable resistor according to an embodiment of the present invention, and FIG. FIG. 4 is a bottom view showing a chip-type variable resistor according to an embodiment; FIG. 4 is a cross-sectional view showing a chip-type variable resistor according to an embodiment of the present invention; FIG. 6 is a main part top view showing a chip type variable resistor according to an embodiment of the present invention, and FIG. 7 is an insulating substrate of the chip type variable resistor according to an embodiment of the present invention. FIG. 8 is a bottom view illustrating an insulating substrate of the chip-type variable resistor according to the embodiment of the present invention, and FIG. 9 is a diagram illustrating an insulating substrate of the chip-type variable resistor according to the embodiment of the present invention. FIG. 10 is a side view, and FIG.
It is sectional drawing in a line.

As shown in FIG. 1 to FIG.
Is made of a ceramic material and fired into a substantially rectangular shape, and has a small size of about 3.5 mm × about 3 mm × about 0.8 mm (having a volume of about 8.4 mm ² ).
The upper surface 1a, the lower surface 1b, and the side surfaces 1c1
1c4, and a circular hole 1d provided at the center portion penetrating from the upper surface 1a to the lower surface 1b. Also, the upper surface 1a
A substantially circular concave portion 1e is provided at the center of the lower surface 1b so as to surround the hole 1d, and a rectangular shallow groove-like groove 1f is provided at a substantially central portion of the lower surface 1b. One end of the groove 1f is provided. The side surface 1c1 is open to the outside.

Further, one of the opposed side surfaces 1c1 and 1
At c3 (vertical direction in FIG. 2), a wide, substantially rectangular notch 1h and a narrow, substantially rectangular notch 1i are provided, and the other opposing side surface 1c2 and side surface 1c4 (FIG. 2). (In the left-right direction), a pair of rectangular cutouts 1j are provided opposite to the cutouts 1i with an electrode 3 to be described later interposed therebetween.

The notch 1i is formed on the lower surface 1b.
A pair of rectangular recesses 1 is provided at each corner on the side (see FIG. 2).
g, and the recess 1g is formed so as to be recessed from the lower surface 1b, and at the same time, two adjacent side surfaces 1c which are orthogonal to each other.
2 and the side surface 1c3, and the side surface 1c3 and the side surface 1c4 are formed so as to be connected to each other, and their directions are open to the outside. The depth t2 between the recess 1g and the groove 1f is, for example, about 0.2 mm. This recess 1
g is a side surface 1c2, 1 which is orthogonal to and adjacent to the concave portion 1g.
Although the description has been made on the assumption that the c3 direction (and the side surfaces 1c3 and 1c4) are open, the present invention is not limited to this, and a shape in which three side directions are open or two opposing side directions are open may be used.

The resistor 2 is made of, for example, cermet paste, and is formed by printing or the like in a substantially arc shape around the recess 1e on the upper surface 1a of the insulating substrate 1. Electrode 3
Is made of, for example, silver paste, is substantially rectangular, is provided on the upper surface 1a of the insulating substrate 1, is connected to both ends of the resistor 2, and a pair is formed by printing or the like. The electrodes 3 are arranged near the corners formed by the side surfaces 1c2, 1c3 and the side surfaces 1c3, 1c4 of the insulating substrate 1 adjacent to each other at right angles.

The terminal 4 is made of a metal plate such as steel or copper, and is punched and bent to form a pair of first terminals 5.
And the second terminal 6. The thickness (plate thickness) t3 of the terminal 4 is, for example, about 0.15 mm.
It is.

The first terminal 5 is substantially rectangular (square).
Bottom plate 5a, first leg 5b and second leg 5c, and first leg 5b and second leg 5c, each of which is bent upward from two mutually adjacent and side edges of the bottom plate 5a. And a projection 5d projecting outward from the bottom plate 5a.
The first leg 5b has a wide base 5e and a narrower base 5e extending upward from the base 5e and bent so as to be substantially parallel to the bottom plate 5a. The second second leg 5c has the same width from the root to the tip 5g, and has the same width as the tip 5f.
The tip 5g is bent so as to be substantially parallel to the bottom plate 5a.

The first terminal 5 is attached to the insulating substrate 1. More specifically, the bottom plate 5a of the first terminal 5 is accommodated in contact with the concave portion 1g of the lower surface 1b of the insulating substrate 1, and is stored therein. The first leg 5b and the second leg 5c of the
Are arranged along two adjacent side surfaces 1c2, 1c3 and side surfaces 1c3, 1c4 at right angles to the corner where the concave portion 1g is provided, and further, a first leg 5b and a second leg 5c.
Are bent to the upper surface 1a side of the insulating substrate 1. In this state, the distal ends 5f and 5g of the first leg 5b and the second leg 5c are bent along the outer edge of the electrode 3 provided on the upper surface 1a of the insulating substrate 1 on the resistor 3 side. Therefore, the electrode 3 is located at a predetermined distance from the corner of the insulating substrate 1.
A relatively large area not covered by the tips 5f and 5g is formed. In addition, the first terminal 5 has side surfaces 1c3, 1c at which the first leg 5b and the second leg 5c are orthogonal to each other.
4 and the side surfaces 1c2, 1c3 are arranged in contact with each other, which facilitates positioning of the insulating substrate 1 during assembly as described later.

In this state, the bottom plate 5a of the first terminal 5 which is in contact with the recess 1g of the insulating substrate 1 has a depth t2 of about 0.2 mm, for example, of the recess 1g.
Is about 0.15 mm, for example, so a gap t1 (t1 = t2 = about 0.05 mm) is provided between the lower surface 1b of the insulating substrate 1 and the lower surface of the bottom plate 5a. −
t3) is formed. That is, the concave portion 1g of the insulating substrate 1
And the bottom plate 5a of the first terminal 5 is accommodated therein. In addition, as a result of conducting various experiments on the gap t1, the inventor has confirmed that the gap t1 may be in the range of 0 <t1 ≦ 0.1 mm.

The second terminal 6 has a substantially rectangular bottom plate 6a.
And a cut-and-raised portion 6b that is cut and raised at one end of the bottom plate 6a, and a cylindrical hollow shaft portion 6c that is provided by drawing at the other end of the bottom plate 6a. .

The second terminal 6 is attached to the insulating substrate 1. More specifically, the bottom plate 6a of the second terminal 6 is housed in the groove 1f of the lower surface 1b of the insulating substrate 1 and abuts on the hollow terminal 6c. Is inserted into the hole 1d of the insulating substrate 1, and the cut-and-raised portion 6b is arranged so as to extend in the direction of the upper surface 1a along the inner wall of the cutout 1h provided on the side surface 1c1 of the insulating substrate 1.

In this state, a gap of about 0.05 mm is formed between the lower surface 1b of the insulating substrate 1 and the lower surface of the second terminal 6, like the first terminal 5.

The slider 7 is made of a metal plate such as stainless steel, copper, or an alloy thereof, and is punched, bent, and integrally processed, and is formed into a substantially disk-shaped holding portion 7a by drawing.
An operation unit 7b disposed above the holding unit 7a;
a, and a substantially U-shaped sliding portion 7c extending from FIG. A circular hole 7d (see FIG. 4) is formed at the center of the holding portion 7a, and a cross-shaped hole 7e is formed at the center of the operation portion 7b.

The holding portion 7a of the slider 7 is
Of the second terminal 6 is inserted into the hole 1d of the insulating substrate 1, and the distal end of the hollow shaft 6c is inserted into the hole 1d. Then, the slider 7 is caulked to the hole 7d of the holding portion 7a. In this state, the slider 7 is rotatably held with respect to the insulating substrate 1. At this time, the slider 7 is in contact with the second terminal 6.

At this time, the sliding portion 7c of the slider 7
Is elastically contacted with the resistor 2 provided on the upper surface 1 a of the insulating substrate 1, and the sliding portion 7 c slides on the resistor 2 in response to the rotation of the slider 7. .

The solder 9 has a common melting point (for example, about 18
(0 ° C.), which is a high-temperature solder having a higher melting point, and the melting point is in a temperature range of 220 ° C. to 330 ° C. The solder 9 includes the electrode 3 provided on the upper surface 1 a of the insulating substrate 1 and the tip 5 f of the first leg 5 b of the first terminal 5.
And the tip 5g of the second leg 5c. At this time, a relatively large area that does not cover the tip 5f and the tip 5g of the electrode 3 is a soldering area, and the tip 5f and the tip 5g are connected to the electrode 3 in this soldering area.
And soldered. The reason that the temperature range of the melting point of the solder 9 is 220 to 330 degrees is that if the melting point is too low, it may cause re-separation at the time of mounting, which may cause inconvenience. This requires a large amount of heat, and the heat is likely to adversely affect the surrounding components.

Next, a method of manufacturing the chip type variable resistor according to the embodiment of the present invention will be described. FIG. 13 is a process chart illustrating a method for manufacturing a chip-type variable resistor according to the present invention. As shown in FIG. 13, first, in the first step (A), a drawn hollow cylindrical shaft portion 6c and a feed hole 11 are formed in the terminal hoop 10.

Further, frame portions 12 are formed on the terminal hoop 10 at predetermined intervals, and a pair of first terminals 5 are formed.
And the second terminal 6 are formed.
The cut and raised portion 6b is formed by being cut and raised, and the first leg portion 5b and the second leg portion 5 of the pair of first terminals 5 are formed.
c are respectively bent upward from two side edges of the bottom plate 5a.

Here, the terminal hoop formed in the drawing / bending / cutting step will be described in detail. 11 is a plan view of a main part showing a terminal hoop in a manufacturing process of the terminal of the chip-type variable resistor according to the embodiment of the present invention, and FIG. 12 is a sectional view taken along line 12-12 in FIG.

As shown in FIGS. 11 and 12, the terminal hoop 10 is made of a strip-shaped metal plate such as steel or copper.
It is formed by a punching, bending and cutting process. The terminal hoop 10 has a substantially rectangular frame portion 12 formed continuously and a plurality of feed holes 11 provided at predetermined intervals so as to face each other in the width direction of the frame portion 12.

The frame 12 has a pair of protrusions 5d protruding inward from the vicinity of the feed hole 11 and connected to the frame 12, and a substantially square bottom plate 5a connected to each of the protrusions 5d. (First terminal 5) and two adjacent feed holes 11
And a second terminal 6 protruding inward from the frame portion 12 and connected to the frame portion 12. Further, the bottom plate 5a is formed with a first leg 5b and a second leg 5c that are bent upward with the protrusion 5d interposed therebetween as described above.

Next, as shown in FIG. 13, in the mounting and caulking process (B), the device was manufactured in another process (not shown), and the resistor 2 and the electrode 3 were provided on the upper surface. Insulating substrate 1
Is placed on the bottom plate 5 a of the first terminal 5 and the second terminal 6 formed so as to be connected to the frame 12 of the terminal hoop 10. At this time, the side surfaces 1c3 and 1c2 (and the side surfaces 1c3 and 1c4) of the semi-finished insulating substrate 1 are brought into contact with the first leg portion 5b and the second leg portion 5c of the first terminal 5 to insulate the terminal hoop 10. This is a step for positioning the substrate 1. At this time, the second hole is formed in the hole 1d of the insulating substrate 1.
The hollow shaft portion 6c of the terminal 6 is inserted and arranged.

After this mounting step, the upper surface 1 of the insulating substrate 1
The front ends 5f and 5g of the first leg 5b and the second leg 5c are bent toward the side a, and the first terminal 5 and the second terminal 6 are bent.
And a bending step of caulking the semi-finished product. In this bending step, the respective tips 5f and 5g of the first leg 5b and the second leg 5c are bent along the outer edge near the boundary of the electrode 3 with the resistor 2, and the electrode 3 , A relatively large soldering area is provided.

Next, in the soldering step (C), the first leg 5b of the first terminal 5 and the tip 5f of the second leg 5c,
5 g is soldered with a high-temperature solder in a soldering area provided on the electrode 3, and the first terminal 5 and the electrode 3 are connected.

Next, in the slider mounting / cutting step, the slider 7 is mounted on the semi-finished product to which the first terminal 5 is soldered, and the mounted slider 7 is mounted on the second terminal 6. Hollow shaft part 6
c, and the semi-finished product, the slider 7 and the second terminal 6 are integrated with each other.
In the vicinity of the cut-and-raised portion 6b and the protrusion 5d of the first terminal 5
To separate the chip-type variable resistor as a single product from the frame 11.

Next, a method of mounting the chip-type variable resistor according to the embodiment of the present invention, in which the chip-type variable resistor is mounted on a printed circuit board, will be described. FIG. 14 is a cross-sectional view showing a state where the chip-type variable resistor according to the embodiment of the present invention is mounted on a printed wiring board.

As shown in FIG. 14, the printed wiring board 20
Is a flat plate made of, for example, a synthetic resin material containing glass, and a desired conductive pattern (not shown) is formed on at least one surface of the printed wiring board 20. The above-described chip-type variable resistor of the present invention is mounted on a conductive pattern (not shown) of the printed wiring board 20. At this time, the cream solder 13 is formed on a predetermined conductive pattern.
Is applied, and the first terminal 5 and the second terminal 6 of the chip type variable resistor are mounted so as to be connected to the cream solder 13.

The melting point of the cream solder 13 is, for example,
A melting point of about 180 degrees is used. The melting point of about 180 degrees is lower than that of high-temperature solder (the melting point is 220 to 330 degrees) in which the first terminal 5 is soldered to the electrode 3. Solder is used. In this state, the printed wiring board 20 on which the chip-type variable resistor is mounted is placed in a reflow furnace (not shown: the temperature in the reflow furnace is about 220 ° C.), and the chip-type variable resistor is printed. Wiring board 20
It is generally known that the solder is not melted unless the temperature of the reflow furnace is set to a temperature higher by about 40 to 50 degrees than the melting point of the solder. The first terminal 5 and the electrode 3 of this chip-type variable resistor are connected by soldering with high-temperature solder, and the temperature in the reflow furnace is set at a temperature about 40 to 50 degrees higher than the melting point of the cream solder 13. Therefore, at the temperature in the reflow furnace, the cream solder 13 is melted, and the high-temperature solder is not melted, so that a stable solder connection is made.

At this time, between the lower surface of the insulating substrate 1 of the chip type variable resistor and the lower surface of the bottom surface 5a of the first terminal 5,
Further, a gap is formed between the lower surface of the insulating substrate 1 and the lower surface of the second terminal 6, and the side surfaces of the concave portion 1 g of the insulating substrate 1 and the groove portion 1 f are open. In soldering the first and second terminals 5 and 6 of the chip-type variable resistor to the printed wiring board 20, the flux and the solvent in the cream solder 13 surely scatter from the open portion in the side direction through the gap. Is done.

In the embodiment of the present invention, the tip portions 5g, 5f of the first terminal 5 are formed by bending both.
Although soldered, it is not always necessary to bend them together, and it is not necessary to solder both.

[0049]

As described above, according to the method of manufacturing a chip-type variable resistor of the present invention, a frame, a protrusion connected to the frame, a bottom plate connected to the protrusion, and a bottom plate bent upward from the bottom plate. A terminal hoop made of a metal plate having
A step of placing the semi-finished product on the terminal hoop and contacting the lower surface of the insulating substrate with the bottom plate of the terminal hoop, and soldering the electrode of the semi-finished product and the leg of the terminal hoop after the placing step. And a cutting step of cutting the protruding portion of the terminal hoop and separating the bottom plate from the frame after the soldering step. Since it can be configured, there is an effect that it is possible to provide an inexpensive method of manufacturing a chip-type variable resistor without any trouble.

Further, in the method of manufacturing a chip type variable resistor according to the present invention, in the mounting step, the side surface of the insulating substrate is brought into contact with the first leg portion and the second leg portion so that the insulating substrate with respect to the terminal hoop is formed. Since the (semi-finished product) positioning is performed, the positioning of the insulating substrate with respect to the terminal hoop can be reliably performed, and a method of manufacturing a chip-type variable resistor having a good yield can be provided.

Further, the method of manufacturing a chip-type variable resistor according to the present invention includes, before the soldering step, a bending step of bending the tip of the leg of the terminal hoop toward the upper surface of the semi-finished insulating substrate. Therefore, the insulating substrate (semi-finished product) and the terminal of the terminal hoop (first terminal) can be securely attached.

Further, the method of manufacturing a chip-type variable resistor according to the present invention has a structure in which a projection is formed between the first leg and the second leg, and the projection is cut during the cutting step. Since the bottom plate is separated from the frame, there is no waste in the position where the protruding portion is formed, and a continuous automated manufacturing line can be configured more easily. .

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a chip-type variable resistor according to an embodiment of the present invention.

FIG. 2 is a top view showing the chip-type variable resistor according to the embodiment of the present invention.

FIG. 3 is a bottom view showing the chip-type variable resistor according to the embodiment of the present invention.

FIG. 4 is a sectional view showing a chip-type variable resistor according to an embodiment of the present invention.

FIG. 5 is a main part side view showing the chip type variable resistor according to the embodiment of the present invention.

FIG. 6 is a main part top view showing the chip-type variable resistor according to the embodiment of the present invention.

FIG. 7 is a top view showing an insulating substrate of the chip-type variable resistor according to the embodiment of the present invention.

FIG. 8 is a bottom view showing an insulating substrate of the chip-type variable resistor according to the embodiment of the present invention.

FIG. 9 is a side view showing an insulating substrate of the chip-type variable resistor according to the embodiment of the present invention.

FIG. 10 is a sectional view taken along line 10-10 of FIG. 7 of the present invention.

FIG. 11 is an essential part plan view showing a terminal hoop in a step of manufacturing terminals of the chip-type variable resistor according to the embodiment of the present invention;

FIG. 12 is a sectional view taken along line 12-12 in FIG. 11;

FIG. 13 is a process diagram illustrating a method for manufacturing a chip-type variable resistor according to the present invention.

FIG. 14 is a cross-sectional view showing a state where the chip type variable resistor of the present invention is mounted on a printed wiring board.

FIG. 15 is a perspective view showing a conventional chip-type variable resistor.

FIG. 16 is a cross-sectional view showing a state in which a conventional chip-type variable resistor is mounted on a printed wiring board.

FIG. 17 is a plan view showing a main part of a material base plate of an insulating substrate for describing a method of manufacturing a conventional insulating substrate for a chip-type variable resistor.

FIG. 18 is a process diagram illustrating a method for manufacturing a conventional chip-type variable resistor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating board 1a Upper surface 1b Lower surface 1c1, 1c2, 1c3, 1c4 Side surface 1g Depression 1f Groove 2 Resistor 3 Electrode 4 Terminal 5 First terminal (terminal) 5a Bottom plate 5b First leg 5c Second leg 5d Projection 5e Part 5f, 5g Tip part 6 Second terminal (terminal) 6a Bottom plate 6b Cut-and-raised part 6c Hollow shaft part 7 Slider 7c Sliding part 9 Solder (high-temperature solder) 10 Terminal hoop 11 Feed hole 12 Frame part A Drawing / cutting・ Bending process B Mounting / caulking process C Soldering process D Cutting process

Claims (4)

[Claims] 1. A semi-finished product comprising: an insulating substrate; a resistor provided on an upper surface of the insulating substrate; and a pair of electrodes connected to both ends of the resistor and provided on the upper surface of the insulating substrate. A terminal hoop made of a metal plate having a frame, a protrusion connected to the frame, a bottom plate connected to the protrusion, and a leg bent upward from the bottom plate. Placing the semi-finished product such that the lower surface of the insulating substrate abuts against the bottom plate, and soldering the electrode of the semi-finished product and the leg of the terminal hoop after the placing process And a cutting step of cutting the protruding portion of the terminal hoop to separate the bottom plate from the frame after the soldering step. Production method. 2. The bottom plate has a substantially rectangular shape, and has a configuration in which the leg portions have a first leg portion and a second leg portion bent upward from side edges of the adjacent substantially rectangular shape. The positioning of the insulating substrate with respect to the terminal hoop is performed by bringing a side surface of the insulating substrate into contact with the first leg and the second leg during the placing step. 2. A method for manufacturing the chip-type variable resistor according to 1. 3. The method according to claim 1, further comprising, before the soldering step, a bending step of bending a tip end of the leg of the terminal hoop toward an upper surface of the insulating substrate of the semi-finished product. 3. The method for manufacturing a chip-type variable resistor according to 1 or 2. 4. A structure in which the projecting portion is formed between the first leg portion and the second leg portion, and the projecting portion is cut during the cutting step to separate the bottom plate from the frame. 3. The method of manufacturing a chip-type variable resistor according to claim 2, wherein: