JPH04114401A - Chip type variable electronic part - Google Patents

Abstract

PURPOSE:To prevent occurrence of defective mounting of an electronic part caused by the bridge-like expansion of solder without lowering mounting density by a method wherein a variable rotor is provided on the upper surface of a chip-like insulated substrate in a freely rotatable manner, a notched part is provided on the corner parts on both ends of the side edge of the insulated substrate, and two electrodes are formed thereon. CONSTITUTION:A through hole 11 is perforated almost at the center part of chip-shaped insulated substrate 10, a resistance film 12 is formed on the upper surface of the substrate 10 concentrically with the through hole 11, and both ends 12a of the film 12 are extended toward one side edge 10a of the insulated substrate 10. A hollow shaft 14, on which a terminal plate 15 is integrally connected to the lower end, is inserted into the through hole 11, a rotor 13 is fixed to the upper end in a freely rotatable manner. An almost circular notched part 10c is formed on the corner parts of both ends of one side edge 10a of the insulated substrate 10, and an electrode 16, which is in continuity to both ends 12a and 12a of the resistance film 12, is formed on the above-mentioned notched parts. The resistor, the side face electrode films 16c and the terminal plate 15 on the other side edge 10b are attached to the circuit of each printed substrate by soldering.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to a chip-type variable resistor with variable resistance, in which a variable rotor is rotatably provided on the top surface of a chip-shaped insulating substrate. This invention relates to an improvement in a chip-type variable electronic component in which two electrodes are formed on one side edge of the insulating substrate.

[Conventional technology]

In general, chip type variable resistors are, for example,
7201, and also shown in FIGS. 10 and 11.
As shown in the figure, a through hole 2 is formed on the upper surface of a ceramic chip-shaped insulating substrate 1 having a through hole 2 formed approximately at the center.
A resistive film 3 is formed concentrically with the resistive film 3, and one end and the other end of the resistive film 3 are respectively extended toward electrode protrusions 4 protruding from one side edge 1a of the insulating substrate 1. both ends of which are electrically connected to the electrodes 5 formed on the electrode protrusion 4,
A hollow shaft 6 inserted into the through hole 2 is disposed on the upper surface of the insulating substrate 1.
A rotor 7 made of a metal plate was provided rotatably through the rotor, and the rotor-shaped sliding portion 7a was brought into contact with the resistive film 3, and the rotor 7 was electrically connected to the slider 7a through the hollow shaft 6. The center electrode 8 is exposed on the other side of the insulating substrate 1.

[Problem to be solved by the invention]

However, in the conventional configuration in which the electrodes 5 are formed on both electrode protrusions 4 protruding from one side edge 1a of the insulating substrate 1, the two electrodes 5 do not extend from the one side edge 1a of the insulating substrate 1. In addition to having a large protruding shape, the size of one side of the insulating substrate 1 in this type of chip resistor is extremely small, so the distance between both electrodes 5 is also extremely small. By soldering both electrodes 5 on one side edge 1a of 1 to a circuit such as a printed circuit board, when the resistor is mounted on a printed circuit board etc., the solder 9 for both electrodes 5 is connected in a bridge shape, and the printed circuit board is connected. There was a problem in that the resistors were often incorrectly attached to the board or the like.

To solve this problem, it may be possible to increase the length of one side edge 1a of the insulating substrate l and increase the distance between the two electrodes 5, but this would increase the size of the resistor. Therefore, the mounting density of printed circuit boards and the like will be reduced, which is not a good idea.

The present invention solves the problem of a chip-type variable electronic component in which two electrodes are formed on one side edge of an insulating substrate, without increasing the size of the electronic component. The purpose is to make it possible to prevent this.

[Means to solve the problem]

To achieve this object, the present invention provides a chip-type variable electronic component in which a variable rotor is rotatably provided on the upper surface of a chip-shaped insulating substrate, and two electrodes are formed on one side edge of the insulating substrate. In this method, notches are provided at the corners of both ends of one side edge of the insulating substrate, and both electrodes are formed in the notches.

[Action/effect of the invention]

By forming both electrodes in the notch in this way, both electrodes do not protrude from one side edge of the insulating substrate, or the amount of protrusion from one side edge of the insulating substrate is small. By forming the notch at both ends of one side edge of the insulating substrate, it is possible to increase the length of one side edge of the insulating substrate (without making it thicker) and increase the distance between both electrodes. Therefore, by soldering both electrodes on one side edge of an insulating substrate to a circuit such as a printed circuit board, when an electronic component is mounted on a printed circuit board, etc., the solder for both electrodes is connected in a bridge shape. This can be reliably prevented from being stored away without increasing the size of the insulating substrate.

Therefore, according to the present invention, when mounting a chip-type variable electronic component on a printed circuit board, etc., a mounting failure of the electronic component occurs due to the solder for two electrodes on one side edge of the insulating substrate being connected in a bridge shape. This has the effect of reliably preventing this from occurring without reducing the mounting density of the printed circuit board or the like.

〔Example〕

Next, an embodiment of the present invention will be described based on drawings (Figs. 1 to 5) in which the present invention is applied to a chip type variable resistor similar to the above. A chip-shaped insulating substrate formed in a rectangular shape is shown, a through hole 11 is bored approximately at the center of the insulating substrate 10, and a resistive film 1 is formed on the upper surface of the insulating substrate 10 concentrically with the through hole 11.
2, and both ends 12a of the resistive film 12 are connected to the insulating substrate 1.
0 toward one side edge 10a.

A rotor 13 made of a metal plate and formed into a substantially bowl shape with an upward opening is disposed on the upper surface of the insulating substrate 10, while a terminal plate 15 is integrally provided at the lower end of the through hole 11 of the insulating substrate IO. After inserting the connected hollow shaft 14 and fitting the rotor 13 onto the upper end of the hollow shaft 14, the rotor 13 is rotatably attached to the insulating substrate IO by caulking the upper end of the hollow shaft 14. .

The rotor 13 has a sliding portion 13a that comes into contact with the resistive film 12, and an upwardly opening engagement groove 13b for a driver tool that rotates the rotor 13.
It is formed by cutting and bending the metal plate that makes up 3.
On the other hand, the terminal plate 5 is exposed on the side surface of the other side edge 10b of the insulating substrate IO.

Then, the negative side edge 1 of the outer peripheral portion of the insulating substrate IO
Notches 10c each having a substantially arc shape in a plan view are formed at two corner portions located at both ends of the resistive film 12, and one end 1.
2a and the other end 12a are formed.

That is, both the electrodes 16 are formed at the positions of the notches 10c on the upper surface of the insulating substrate 0.
- City electrode film 16a and insulating substrate 1. () of thousands of
) is also formed at the location of both notches 10c, and the J-metal electrode film 16b is formed on the side surface of both notches 1()C. The side electrode film 1 (IC) is formed so as to be electrically conductive.
3. In the configuration of H below, this resistor connects the side electrode films 16c of both electrodes 16 on one side edge of the insulating substrate 10 and the terminal plate 15 on the other side edge 1011:1 of the printed circuit board. By attaching fBE to the circuit, it is mounted (mounted) on a printed circuit board.

In this case, both electrodes 16 for the resistive film 12 are formed in notches 10c provided at both ends of the side edges 10a of the insulating substrate 10, so that both electrodes 16 are connected to the insulating substrate 10. Either the two insulating substrates 1.0 do not protrude from the one side edge 10a, or the two insulating substrates 1.0 protrude from the one side edge 10a to a small extent, and both notches 1()c do not protrude from the one side edge 10a.
0, even if the length dimension of the one side edge 10a of the insulating substrate 10 is the same as the conventional one, the distance between both electrodes I6 = 1-modulus S can be reduced Therefore, when attaching both electrodes 16 to a circuit such as a printed circuit board, the electrodes 16 can be
It is possible to reliably prevent the solder 17 from forming a bridge-like connection without increasing the size of the insulating substrate 10.

The insulating substrate 10 provided with the resistive film 12 and both electrodes 16 can be manufactured from the ceramic material plate A through the steps shown in FIGS. 6 to 11.

That is, the ceramic material plate A is made up of a plurality of single-row ceramic material plates A1 (in the example, 10 insulating substrates 10) arranged in a row with the cutout portions 10c facing outward. In the example, three ceramic material plates A) are integrally connected at one side edge 10a of each insulating substrate 10 of the plurality of ceramic material plates A. At both ends of A, there are positioning notches A2. Ear piece A4゜A with A.
, are integrally connected, and there is a horizontal line line B1 and a vertical line for breaking between the two sides of each insulating substrate 10 and between each insulating substrate IO and both ear pieces 7 to 4A. Line B is provided.

First, as shown in FIG. 7, conductive bases I. After forming the upper surface electrode films 1, 6a of both electrodes 16 on each insulating substrate 10 by coating with ．． The lower surface electrode film 16b of both electrodes 16 on each insulating substrate 10 is formed by applying a conductive paste to the location Oe by screen printing.

(The lower surface electrode film 16b may be formed first), then,
As shown in FIG. 8, a resistance film I2 is formed on each insulating substrate 10 by applying a resistive film paste to the upper surface of each insulating substrate 10 in the - number of ceramic material plates A by screen printing. .

Next, as shown in FIG. 9, these - ceramic material plates A are divided into three ceramic material plates A1 in each row, as shown in FIG.
The outer circumferential surface is fitted into the notch 10e of the horizontal stripe [1 that breaks along the J line B1, and each insulating substrate 11 in each row of ceramic material plates A1, as shown in FIGS. 1O and 11]. A large number of disks 19 (11 disks in the embodiment) each having an arcuate cross section are provided so as to rotate in a fixed direction with the lower end of each disk 19 immersed in the conductive paste tank 20. Each row of ceramic material plates AI is placed toward the outer periphery of each disk 19,
A reciprocating mechanism equipped with a clamp 21 moves back and forth to fit the notch 1Oe in each insulating substrate 10 onto the outer periphery of each disc 19, and then retreats to remove the conductive paste 21 attached to the outer periphery of the disc 19. The side electrodes 16c of the electrodes 16 on each insulating substrate 10 are formed by coating the side surfaces of each notch 10e.

In this case, in order to form side electrode films 16c on the side surfaces of both notches 10c of each insulating substrate 10 in one row and each insulating substrate 10 in the other row constituting one row of ceramic material plates AI, for example, Discs 1 on both sides of the reciprocating mechanism
By arranging 9 groups and moving one row of ceramic material plates A1 to one group of disks 19, the notches 1 in each insulating substrate 10 of one row are formed. By forming a side electrode film 16c on the side surface of the Oc, and then moving one row of ceramic material plates A toward the other group of disks 19, a side electrode film 16c is formed on the side surface of the notch 10c in each insulating substrate 10 of the other row. A side electrode film 16c is formed, or a group of disks 19 is provided on only one side of the reciprocating mechanism, and a side electrode is formed in the cutout portion 10c of each insulating substrate 10 in one row of the one row ceramic material plate A1. After forming the film 16c, one row of ceramic material plates A is rotated 180° around its axis,
By moving this toward the group of disks 19, the side electrode film 1 is placed in the notch 10c of the insulating substrate 10 in the other row.
All you have to do is form 6c.

In this way, the electrode I6 and the resistive film 12 are attached to each insulating substrate 10.
After forming, each row of ceramic material plates A1 is broken into one row along the horizontal line of sight B1, and then each row of ceramic material plates is broken along the vertical line of sight B2.
The insulating substrate 1o is separated into individual pieces.

In addition, after forming the upper surface electrode film 16a, the lower surface electrode film 16b, and the resistance film 12 on the - ceramic material plates A, the - ceramic material plates A are broken into a row of ceramic material plates. - The side electrode film 16c may be formed for each row of ceramic material plates.

In this manufacturing process, if the electrode protrusion 4 is provided protruding from one side edge as in the conventional insulating substrate, the adjacent rows of ceramic material plates A will be removed from the electrode protrusion 4 on the insulating substrate 1. Since they are only connected to each other at certain points, the connection strength between the adjacent rows of ceramic material plates A1 is weak, making it difficult to increase the size of the ceramic material plates A1. When the film 16c is formed in the corner notch 10c of each insulating substrate 10, the adjacent rows of ceramic material plates A are connected over a long range at one side edge 10a of each insulating substrate 10. As a result, the mutual connection strength of the ceramic material plates A1 in one row can be improved, so the size of the ceramic material plates A can be increased, in other words, the number of insulating substrates 10 that can be manufactured in - times of steps can be increased, and the number of insulating substrates 10 can be increased. manufacturing efficiency can be improved.

In the above embodiment, the notch in the insulating substrate was formed in a substantially arc shape in plan view, but the notch in the present invention may be formed in a straight line in plan view, or may be formed in a straight line in plan view. It goes without saying that other shapes such as an L-shape may also be used.

It goes without saying that the present invention can be applied not only to chip-type variable resistors but also to other chip-type variable electronic components such as chip-type variable capacitors in which two electrodes are formed on one side edge of an insulating substrate. stomach.

[Brief explanation of drawings]

1 to 5 show embodiments of the present invention, FIG. 1 is a plan view of a chip type variable resistor, FIG. 2 is a left side view of FIG. 1, and FIG.
The figure is a bottom view of Fig. 1, Fig. 4 is a sectional view taken along IV-IV of Fig. 1, Fig. 5 is a partial sectional view taken along ■-V of Fig. 1, Fig. 6,
Figures 7, 8, and 9. FIG. 1O and FIG. 11 are diagrams showing the manufacturing process of the insulating substrate,
FIG. 12 is a plan view showing the prior art, and FIG. 13 is a sectional view taken along line xm-xm in FIG. 10...Insulating substrate, loa...-side edge, 10c
...Notch, 11...Through hole, 12...
・Resistance film, 13...Rotor, 13a...Sliding part, 14...Hollow shaft, 15...Terminal board, I6...
...Electrode, I6a...Top electrode film, 16b...
Bottom electrode film, L6C...side electrode film, 17 solder, work 8... conductive paste tank, 19... transfer disk, A... ceramic material plate. Patent Applicant: ROHM Co., Ltd. Agent Patent Attorney: 6 I Burned Patent Attorney: Tadashi Higashino

Claims (1)

[Claims] (1). In a chip-type variable electronic component, a variable rotor is rotatably provided on the upper surface of a chip-shaped insulating substrate, and two electrodes are formed on one side edge of the insulating substrate. 1. A chip-type variable electronic component, characterized in that notches are provided at the corners of both ends, and the electrodes are formed in both the notches.