公开(公告)号：US11462343B2

公开(公告)日：2022-10-04

申请号：US16771393

申请日：2018-12-11

Applicant: KOA CORPORATION

Inventor： Yuichi Abe ,  Seiji Karasawa ,  Michio Kubota ,  Yoji Gomi ,  Koichi Minowa

IPC: H01C1/14 ,  H01C1/02 ,  H01C17/02

Abstract: 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.

公开(公告)号：US11370712B2

公开(公告)日：2022-06-28

申请号：US16467624

申请日：2017-12-07

Applicant: KOA CORPORATION ,  JFE MINERAL COMPANY, LTD.

Inventor： Yoji Gomi ,  Kenichi Iguchi ,  Etsurou Udagawa ,  Yuko Echizenya ,  Yoshimi Nakata

IPC: H01B1/08 ,  C04B35/453 ,  C01G9/02 ,  H01C7/12

Abstract: 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/cm3, and tap density of 0.50 to 1.00 g/cm3. 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.

公开(公告)号：US11011290B2

公开(公告)日：2021-05-18

申请号：US16903674

申请日：2020-06-17

Applicant: KOA CORPORATION

Inventor： Yuichi Abe ,  Seiji Karasawa ,  Michio Kubota ,  Yoji Gomi ,  Koichi Minowa

IPC: H01C17/28

Abstract: 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.

公开(公告)号：US20200343028A1

公开(公告)日：2020-10-29

申请号：US16771334

申请日：2018-12-11

Applicant: KOA CORPORATION

Inventor： Yuichi Abe ,  Seiji Karasawa ,  Michio Kubota ,  Yoji Gomi ,  Koichi Minowa

IPC: H01C17/28

Abstract: 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.

公开(公告)号：US11370671B2

公开(公告)日：2022-06-28

申请号：US15734863

申请日：2019-06-04

Applicant: KOA CORPORATION ,  JFE MINERAL COMPANY, LTD.

Inventor： Naomi Ishida ,  Yoji Gomi ,  Kenichi Iguchi ,  Etsurou Udagawa ,  Yuko Echizenya ,  Yoshimi Nakata

IPC: H01B1/08 ,  C01G9/02 ,  H01C7/12 ,  C01G9/00 ,  H01C7/112 ,  B82Y40/00

Abstract: 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/cm3 or greater, and tap density of 0.80 g/cm3 or 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.

公开(公告)号：US10892074B2

公开(公告)日：2021-01-12

申请号：US16771334

申请日：2018-12-11

Applicant: KOA CORPORATION

Inventor： Yuichi Abe ,  Seiji Karasawa ,  Michio Kubota ,  Yoji Gomi ,  Koichi Minowa

IPC: H01C17/28

Abstract: 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.

公开(公告)号：US20200312490A1

公开(公告)日：2020-10-01

申请号：US16903674

申请日：2020-06-17

Applicant: KOA CORPORATION

Inventor： Yuichi Abe ,  Seiji Karasawa ,  Michio Kubota ,  Yoji Gomi ,  Koichi Minowa

IPC: H01C17/28

Abstract: 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.