JPS60158602A - Voltage nonlinear 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 [Technical field to which the invention pertains] The present invention relates to a structure of a voltage nonlinear resistor formed into a chip, which corresponds to the integration of recent electronic circuits. This type of voltage nonlinear resistor is generally required to have a large vehicle pressure nonlinearity coefficient and at the same time a large impact discharge resistance.

[Prior art and its problems]

When the voltage is below a certain value, the resistance value is very high and almost no current flows, but when the voltage exceeds a certain value, the resistance value decreases rapidly and a large current automatically flows. As a voltage non-linear resistor having the above characteristics, a φ feed body whose main component is a metal oxide such as ZnO (zinc oxide) to which a small amount of impurity is added is becoming mainstream.

This is manufactured using the same process as ordinary ceramics.
Ru. First, several trace amounts of additives are added to ZnO as the main component, thoroughly mixed, and then the particles are made uniform using a powder mill. This powder is molded and fired at a high temperature of 1,000"0 or higher. The sintered body thus formed is polished and subjected to surface treatment such as electrode attachment, and then lead wires are soldered to it. Such ZnO% viscosity is connected to each other through another layer around the ZnO particles, namely the boundary layer.The voltage nonlinearity is due to the nature of this boundary.The specific resistance of this particle is Since it is much smaller than that of the layer, when pressure is applied to the high 1, most of it is added to this boundary layer, causing a current increase phenomenon similar to that of a Zener diode.

Furthermore, this type of voltage nonlinear resistor mainly composed of ZnO has a tendency to be changed from the conventional resin-molded disk type to the chip type in response to recent integration. The present invention also relates to this chip-type voltage nonlinear resistor. Chip-type zinc oxide resistors include those with a structure in which one piece has voltage non-linear resistance as shown in Figs. As shown in FIG.

Figure 1 is a cross-sectional view of a resistor having one voltage non-linear resistance in one individual, Figure 2 is an external perspective view of the same resistor as seen diagonally from above, and Figure 3 is the same resistor as above. It is a perspective view seen diagonally from below. In the figure, l is an element formed by sintering using Zno as the main raw material, and 2 is one of the two electrodes of element 1, which is connected from one surface of element 1 to the other surface through the side surface. It is shaped like an encyclopedia.

3 is the other electrode, and since electrodes 2 and 3 face each other on the same surface with an interval at least equal to or greater than the thickness of element 1, usually the discharge occurs before the discharge in the thickness direction of element 1. , no radiation occurs between opposing electrodes on one and the same surface. Figure 4 is a cross-sectional view of a resistor with two voltage non-linear resistances in one individual.
FIG. 5 is a perspective view of the resistor shown in FIG. 4, viewed diagonally from above;
Figure 6 is a perspective view of the same resistor as seen diagonally from below, where 11 is an element, and 12 and 12 are two parts of element 11, respectively.
One electrode of each resistor is shown, and 13 is the other electrode. As shown in FIG. 1, also in FIG. 4, the respective electrodes 12, 12', 33 face each other with an interval at least equal to the thickness of the element 11.

However, in the conventional resistor shown in FIGS. 1 to 6 described above, the raw material powder is press-molded, so the ends have right-angled edges as shown at P in FIG. 1 and Q in FIG. 2. Therefore, the metal electrode 2 should be moved around this edge.
, 12.12' is formed by coating and baking a metal paste containing an organic binder, the thixotropy (thixotropy) of the paste during coating and the shrinkage phenomenon caused by the binder scattering during baking may cause problems, especially at right-angled edges. The drawbacks were that the metal electrodes were thinner and were more prone to cuts.・Furthermore, this electrode breakage phenomenon occurs even when the electrode is slightly broken.
When an N-connection current flows through a resistor, in FIG.
Since the current flows through the inside of the element 1 from the opposite part to the electrode 3, the current density increases at the edge of the corner electrode, and the electrode metal changes due to heat generation, causing electrode breakage. It is easy to be promoted and become large. Furthermore, as the electrode breakage becomes larger, discharge also occurs between electrodes 2 and 3, which are on the same surface.As a result, the impact discharge resistance of the resistor decreases, and the electrode ends up at the edge. 2 may break completely and separate. In this case, there is a risk that the gap between the electrodes 2 and 3 will be in a state of inadequacy.

[Purpose of the invention]

The present invention eliminates the above-mentioned drawbacks and provides a voltage nonlinear resistor in which the impact discharge resistance does not deteriorate by testing electrodes with uniform thickness even at the edges and making the electrode metal difficult to break at the edges. With the goal.

[Key points of the invention]

To obtain a nonlinear resistor in which the thickness of a metal electrode in contact with the angular edge of a plate-shaped porcelain body is made uniform by making the shape of the angular edge into a curved surface.

[Practice of the invention]

Embodiments of the invention will be described based on the drawings.

Figure 47 is a cross-sectional view of a voltage non-linear resistor which is a part of this invention/AIi+lJ, and similarly to Figure 1, it has one non-linear resistor in each individual. However, the difference is that the edges of the corners are curved as shown by R. Figure 8 is an external perspective view of the same resistor as seen from above;
The figure is a perspective view of the exterior as seen from below. Furthermore, FIG. 10 is a cross-sectional view of a voltage nonlinear resistor which is an example of another example of the present invention, and similarly to FIG. However, the difference is that the edges are curved as shown by S. FIG. 11 is a perspective view of the resistor as seen from above, and FIG. 12 is a perspective view of the resistor as seen from below. That is, after baking a powder produced by adding a small amount of additives to ZnO and using a normal ceramic method, a niremen l- 21, 31
It was molded into. For example, to obtain such a curved surface shape, known techniques such as lapping, sandblasting, and forning can be used. The shapes of the corners of the metal electrodes 22, 32, 32 to be surface-treated on the outer periphery of the element 21.31 can also be curved to follow the corner R2S of the element, and by doing so, the entire The electrode can have a uniform thickness.

〔Effect of the invention〕

According to this invention, in the chip-shaped voltage non-linear resistance ceramic as described above, the edge part of the electrode to be surface-treated on the outer peripheral surface of the element is arranged as a curved surface with a uniform thickness, so that the electrode does not break. , there was no decrease in impact discharge resistance.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a voltage nonlinear resistor with a conventional structure.
The figure is an upper external perspective view of the above resistor, Figure 3 is a lower external perspective view of the same resistor, Figure 4 is a cross-sectional view of a voltage non-linear resistor with a different conventional structure, and Figure 5 is the same as the above resistor. FIG. 6 is a perspective view of the upper appearance of the resistor, FIG. 7 is a cross-sectional view of a voltage nonlinear resistor according to an embodiment of the present invention, and FIG. 8 is an upper appearance of the resistor. FIG. 9 is a perspective view of the lower external appearance of the above resistor, FIG. 10 is a cross-sectional view of a voltage non-linear resistor according to another embodiment of the present invention, and FIG. 11 is an upper external view of the same resistor. A perspective view, FIG. 12 is a lower external perspective view of the same resistor. 21.31: Element, 22, 23, 32, 32,
33: Metallic pole, 3 figures, 26 figures, 9 figures 1, 12 circles

Claims (1)

[Claims] 1) A plurality of electrodes are provided on one surface of the plate-shaped porcelain element, and at least one of the electrodes extends to the other surface through the side surface of the element, A voltage nonlinear resistor characterized in that the corners of a plate-shaped porcelain body covered with an electrode extending through the porcelain body are curved.