JPS58122703A - Method of producing 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 of invention The present invention relates to a method of manufacturing a voltage nonlinear resistor.

Technical background of the invention and its problems The conventional method for manufacturing voltage nonlinear resistors uses Zn, which is the main component.
O, as a subcomponent “ff0j 18bIOm m c
o, o, 1Mn0. After adding a small amount of metal oxide such as A40g, heating and molding, the temperature is 1100-1300℃.
It was to be sintered at a temperature of . The voltage nonlinear resistor thus obtained has excellent nonlinear characteristics and is used as a surge absorbing element in various power equipment.

However, when used as an internal element of a power surge arrester, there are the following drawbacks.

When an impact current is applied, there is a large change in
The nonlinear characteristics in the large current range are also not satisfactory, and the characteristics in the small current range also vary widely (depending on the manufacturing lot).

By the way, the conventional improvement in nonlinearity in the large current range is due to a trace amount of A! in the ZnO crystal. A so-called valence control method is known in which ions, Gm ions, In ions, etc. are diffused during sintering to lower the Zn0O resistivity. By the way, AJ, Gajn, etc. affect the characteristics at minute amounts of several to several hundred ppm. However, in the conventional method of simply mixing and molding together with the main component ZnO and subcomponents and sintering, these ultra-trace amounts of AJ,
Ga and In components were not sufficiently and uniformly dispersed in the ZnO crystal, and most of them were incorporated into the spinel crystal and grain boundary phase. This is considered to be the reason why it was not possible to sufficiently stabilize the characteristics in the small current range and the characteristics with respect to the impulse current. In addition, even slight changes in the mixing conditions can cause changes in the diffusion state of the Aj, Ga, and In components into the ZnO crystal, which is thought to be the cause of variations in properties between lots. was developed in view of the above drawbacks, and aims to provide a method for manufacturing a voltage nonlinear resistor that has excellent large current range characteristics and shock current characteristics, and also has a small buffer dP in small current range characteristics. .

Summary of the Invention The present invention creates a state in which the AI acid component is uniformly diffused into the ZnO crystal by pre-mixing only Aj, Oa and the main component ZnO, and calcining the hot metal. After that, other subcomponents (B i, 01, 8blO1, Co-yield, Mn
It is characterized by adding and heating the mixture (O, etc.) and firing the mixture into a shaped ridge.

EXAMPLES OF THE INVENTION The present invention will be explained below using examples.@First, the main component Z
The total amount of nO and Mu4os, which is one of the subcomponents, is weighed, water is added thereto, one cup is mixed in a pot mill, and after drying, it is calcined at 950°C. After pulverizing this in a bot mill, other subcomponents such as Bt, OL, 8B snow OH, Co-Zheng, MnO, etc. were added and mixed, this mixture was molded, placed in an electric furnace, fired at 1250℃ for 2 hours, and after cooling. Polished to 45φX
A sintered body of 22 tm was obtained. The polished surface was subjected to KAAj irradiation to attach electrodes. The nonlinearity in the large current region of the voltage nonlinear resistor obtained in this way is the voltage when a current of 10 KA is passed through the element (VioxA) and the voltage when a current of 1 mA is passed through the element (V1wa). ) ratio (V l0KA//
v1 mm). Also, the impact current characteristics are 8x20μ
It was expressed as the rate of change in vl-me after applying 5lQKA 10 times at 30 second intervals. 1st! IK The embodiment of the present invention and the conventional example were each sampled from 10 lots and compared.

Table 1 and the drawings show the small current range characteristics of the present invention example and the conventional example (V
It is clear from Table 1 and the drawings [K, large IE watershed characteristics (VIOKA/Vl m), impulse current characteristics (Δv1 %) and small current range characteristics (Vt %/Ran 1
-) have been improved, and the characteristics of 7 have been significantly stabilized with less chitness between each lot.

The factors contributing to these improvements in properties and increased stability include:
Mul, 0. This is thought to be because the Aj acid component was sufficiently uniformly diffused into the ZnO crystal by preheating and calcining it with ZnO.

Other embodiments of the invention Aj, 0. Instead, Ga, 0. , Into, similar results were obtained.

As described in detail, the present invention provides a voltage nonlinear resistor that has improved large current range characteristics, shock current characteristics, and small current range characteristics, and has small characteristic fluctuations between manufacturing units. can be provided.

[Brief explanation of the drawing]

The drawing is a comparative characteristic diagram showing variations in small current region characteristics between manufacturing lots according to the conventional example and the present invention.

Claims (1)

[Claims] Main component ZnOK% kl嘗Os, Gas's
+ "At least one type of MOS is added and this mixture is calcined, and B1101 is added as a subcomponent to this calcined product.
,8blO1,co,o,. A method for manufacturing a voltage nonlinear resistor, which involves adding and mixing a metal oxide such as MnO, shaping the mixture, and then sintering it.