Koa Corporation

Jfe Mineral Company, Ltd.

Koa Corporoation

Yoji Gomi

Koichi Minowa

Seiji Karasawa

Michio Kubota

Yuichi Abe

Kenichi Iguchi

Yoshimi Nakata

Etsurou Udagawa

Yuko Echizenya

Naomi Ishida

Tatsuya Kanzaki

An object is to provide a resistor manufacturing method and a resistor capable of suppressing variation in the thickness of a thermally conductive layer intervening between a resistive body and electrode plates. The method of manufacturing the resistor according to the present invention includes a step of forming an uncured first thermally conductive layer on a surface of a resistive body, a step of curing the first thermally conductive layer, a step of laminating an uncured second thermally conductive layer on a surface of the first thermally conductive layer, and a step of bending electrode plates respectively disposed at both sides of the resistive body, curing the second thermally conductive layer, and performing adhesion between the resistive body and the electrode plates via the first thermally conductive layer and the second thermally conductive layer.

Resistor manufacturing method and resistor

Focusing on zinc oxide itself, which is a main raw material for a zinc oxide varistor (laminated varistor), a predetermined amount of additive is added to a zinc oxide powder having crystallite size of 20 to 100 nm, particle diameter of 20 to 110 nm found using a specific area BET method, untamped density of 0.60 g/cmor greater, and tap density of 0.80 g/cmor greater. This allows a zinc oxide sintered body to secure uniformity, high density, and high electric conductivity, resulting in a zinc oxide varistor with high surge resistance, capable of downsizing and cost reduction. Moreover, addition of aluminum (Al), as a donor element, to the zinc oxide powder allows control of sintered grain size in conformity with the aluminum added amount and baking temperature, and also allows adjustment of varistor voltage, etc.

Zinc oxide varistor

Focus is on zinc oxide itself, which is a base material for a zinc oxide varistor (laminated varistor), wherein specified quantities of additives are added to a zinc oxide powder having a crystallite size of 20 to 50 nm, grain diameter of 15 to 60 nm found using the specific surface area BET method, untamped density of 0.38 to 0.50 g/cm, and tap density of 0.50 to 1.00 g/cm. This allows securing of uniformity, high compactness, and high electrical conductivity of a zinc oxide sintered body, and provision of a zinc oxide varistor having high surge resistance.

Zinc oxide varistor and method for manufacturing same

The present disclosure provides a method for manufacturing a resistor. The method may include providing a resistor structure having a layer of first thermally conductive material covering at least a surface of the resistive body, the first thermally conductive material being semi-cured, semi-hardened and substantially non-fluid, and the layer of first thermally conductive material having a first thickness; bending a pair of electrodes at the opposite ends of the resistive body toward a surface of the layer of first thermally conductive material; and pressing the pair of electrodes against the surface of the layer of first thermally conductive material, while maintaining in a heated state the first thermally conductive material to cause further curing and hardening of the first thermally conductive material and a reduction in the first thickness, so as to obtain a cured and hardened thermally conductive layer having a desired second thickness.

Method for manufacturing resistor, and resistor

An object is to provide a method for manufacturing a resistor capable of suppressing variations in the thickness of a thermally conductive layer interposed between a resistive body and electrode plates. The method for manufacturing a resistor according to the present invention includes a step of forming an unhardened thermally conductive layer on a surface of a resistive body, a step of bringing the thermally conductive layer into a semi-hardened state, and a step of bending electrode plates respectively disposed at both sides of the resistive body, further hardening the thermally conductive layer, and performing adhesion between the resistive body and the electrode plates via the thermally conductive layer.

Method for manufacturing resistor

A surface mounting varistor for high voltages and current pulses without any risk of burning a mounting board is provided. A covering material for a varistorhas a duplex (two layer) structure made from a first mold layerand a second mold layer, and a leg with a predetermined height is formed on the bottom of the covering material. As a result, a space (void) formed between a varistor elementand a mounting boardwhen the varistoris mounted on the boardallows avoidance of the risk of burning the board, even if the varistor short-circuits.

Growing community of inventors

Nagano, Japan

Yoji Gomi