JPH0622961Y2 - Ceramic material plate for chip type variable resistor - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a ceramic material plate used for manufacturing a ceramic chip substrate in a chip type variable resistor.

[Conventional technology]

Generally, a chip-type variable resistor has the same structure as a central hole 2 formed in a substantially central portion of the chip substrate 1 on the upper surface of a ceramic chip substrate 1 as shown in FIGS. 4 and 5. The resistance film 3 is formed in the shape of a mandrel, and the slider 4 slidably contacting the resistance film 3 is rotatably supported by a shaft 5 inserted in the center hole 2. Reference numerals 6 and 7 are end electrode terminals for both ends of the resistance film 3, and reference numeral 8 is provided in a recess 9 formed on the back surface of the chip substrate 1,
Moreover, the center electrode terminal is configured to be electrically connected to the shaft 5.

In this chip type variable resistor, the central hole 2
In the manufacture of the chip substrate 1 having the concave portions 9 and the concave portions 9, conventionally, as shown in FIG. 6, a ceramic material plate A in which a large number of chip substrates 1 are arranged in a plurality of rows and integrated into one chip substrate 1 is used. The central hole 2 and the recessed portion 9 are respectively provided in the
A vertical streak line A1 extending in the longitudinal direction and a horizontal streak line A2 perpendicular to the longitudinal streak line A1 are provided between the respective chip substrates 1, and the resistance film 3 and the end portions are formed on the upper surface of the ceramic material plate A at the respective chip substrates 1. After the electrode terminals 6, 7 and the like are formed by coating, a manufacturing method is adopted in which the chip substrates 1 are broken in the order along the lines A1 and A2.

In this case, the left and right edges of the ceramic material plate A are
The ear ears A3 and A4 for photographing are integrally formed, and the notches A5 and A of V-shaped positioning are formed on the ear ears A3 and A4.
6 is provided, and the notches A5 and A6 are used to perform positioning when forming the resistive film 3 by coating.

[Problems to be solved by the device]

Each chip base 1 on the ceramic material plate A is
Since each of the central hole 2 and the recessed portion 9 is provided, when the ceramic material plate A is manufactured, the ceramic raw material powder a is mixed with a pair of upper and lower molding dies B and C as shown in FIG. After molding by pressing with to solidify,
This is fired at a high temperature.

However, in this way, the ear pieces with the positioning notches A5 and A6 as described above are manufactured on the left and right edges of the ceramic material plate A manufactured by molding with the pair of molding dies B and C and then firing. When A3 and A4 are integrally formed, there is a problem in that the width dimension S of the ceramic material plate A is not uniform during firing, as described below.

That is, in the case where the ceramic material plate A having the two ear pieces A3 and A4 is molded by the pair of molding dies B and C, the portion of each chip substrate 1 of the ceramic material plate A is a pair of molding dies. By being strongly compressed due to the presence of the molding projection C1 of the recessed portion 9 provided in B and C and the molding projection B1 of the central hole 2, the density of the tissue in the corresponding portion is reduced by the two ear pieces of the ceramic material plate A. It becomes denser than the portions A3 and A4, in other words, the density of the tissue in the portions of the ear plates A3 and A4 of the ceramic material plate A becomes rougher than that of the chip substrate 1 of the ceramic material plate A. As a result, when firing at high temperature, the two ear pieces A
As shown by the chain double-dashed line D in FIG.
Since it shrinks more than other portions, the width dimension S of the ceramic material plate A becomes uneven between the portions of the two ear pieces A3 and A4 and the other portions.

As a result, each chip substrate 1 and the positioning notch A
When the resistive film 3 is applied to each chip substrate 1 on the ceramic material plate A due to the positional relationship with the A5 and A6 being displaced, the resistive film 3 is displaced from the center of the chip substrate 1 or both ears The size of each chip substrate 1 adjacent to the pieces A3 and A4 may vary.

The present invention provides a ceramic material plate capable of preventing this problem, that is, the width dimension of the ceramic material plate with unevenness when the molded ceramic material plate with ear pieces is fired at a high temperature. Is.

[Means for Solving the Problem] In order to achieve this object, the present invention provides a plurality of chip substrates having a central hole and a recessed portion arranged in a plurality of rows, and an edge with positioning notches for positioning. In a ceramic material plate for a chip type variable resistor, which is formed by connecting pieces integrally with each other and molding them integrally, a recess is formed in the portion of the both ear pieces.

[Function and effect of device]

In this manner, when the ceramic material plate with ear pieces is formed by molding, a recess is formed in the ear piece portion, the ear piece portion is strongly compressed, and the tissue in that portion is formed by each chip substrate. Since it becomes dense like the tissue in the part, when firing at high temperature, the part of the ear piece,
It is possible to prevent the parts from shrinking more than other parts, that is, the parts of the respective chip substrates.

That is, according to the present invention, it is possible to prevent unevenness in the width dimension of the ceramic material plate when firing the molded ceramic material plate with ear pieces at a high temperature. When the resistance film is applied by applying the resistance film, it is possible to surely prevent the resistance film from being displaced from the center of each chip substrate and the occurrence of dimensional variation in each chip substrate adjacent to the ear piece. Have.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings (FIGS. 1 to 3). In the drawings, reference numeral A indicates a large number of chip substrates 1 arranged in a plurality of rows, and V-shaped positioning on both edges thereof. 3 shows a ceramic material plate provided with ears A3, A4 having notches A5, A6 for use in the ceramic material plate A. As shown in FIG. By pressing and hardening to each other, between each chip substrate 1 and each chip substrate 1 and both ear pieces A3, A4.
And a vertical streak line A1 and a horizontal streak line A2 are respectively provided between and, and they are integrally molded.

At the time of this die molding, the recessed portion 9 is formed on the back surface of each chip substrate 1 by the projection B1 provided on one die B, and at the center of each chip substrate 1 is provided on the other die C. The central holes 2 are formed by the protrusions C1.

Then, the other molding die C located above the molding dies B and C is provided with a projection C2 at a portion corresponding to the two ear pieces A3 and A4, so that the ceramic material plate A
Simultaneously with the integral molding of, the recesses A7 and A8 are formed in the portions of the two ear pieces A3 and A4.

In this way, the ceramic material plate A with both ears A3 and A4
When the recesses A7 and A8 are formed in the portions of the both ear pieces A3 and A4 in the molding of (3), the portions of the both ear pieces A3 and A4 form the recesses A7 and A8 in the both ear pieces A3 and A4. Each chip that is strongly compressed by the projection C2 for forming, and the tissue in the portion of the binaural pieces A3, A4 is strongly compressed by the projection B1 for forming the recess 9 and the projection C1 for forming the central hole 2. It becomes dense like the texture of the substrate 1.

Therefore, when the ceramic material plate A after molding is fired at a high temperature, the portions of the two ear pieces A3, A4 are different from each other, that is, each chip substrate, as shown by the chain double-dashed line D in FIG. It is possible to reliably prevent the contraction larger than that of the first part.

It goes without saying that the recesses A7 and A8 for the two ear pieces A3 and A4 may be provided on the back surface or both front and back surfaces of the ceramic material plate A.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a plan view of a ceramic material plate, FIG. 2 is an enlarged sectional view taken along line II-II of FIG. 1, and FIG. Fourth vertical front view showing the state
The figure is a plan view of the chip-type variable resistor, and FIG. 5 is the V of FIG.
-V sectional view, FIG. 6 is a plan view of a conventional ceramic material plate, FIG. 7 is a sectional view taken along line VII-VII of FIG. 6, and FIG. 8 is a state of molding of a conventional ceramic material plate. It is a figure. 1 ... Chip substrate, 2 ... Center hole, 3 ... Resistive film, 4 ...
… Slider, 5 …… Axis, 6,7 …… End electrode terminal, 8 ……
Center electrode terminal, 9 ... Recessed portion, A ... Ceramic material plate, A1 ... Longitudinal line, A2 ... Horizontal line, A3, A4
...... Ear pieces, A5, A6 …… Positioning notches, A7, A
8 ... Recess, B, C ... Mold, B1, C1, C2 ...
Protrusion.

Claims (1)

[Scope of utility model registration request] 1. A chip mold formed by arranging a large number of chip substrates each having a central hole and a recessed portion in a plurality of rows, and connecting an end piece with a notch for positioning to an edge thereof to integrally mold the chip pieces. A ceramic material plate for a chip type variable resistor, characterized in that recesses are formed in the two ear pieces in the ceramic material plate for a variable resistor.