Panasonic Intellectual Property Management Co., Ltd.

Ken Yanai

Yuto Akiyama

Masashi Takamura

Ryosuke Usui

Yuji Yamagishi

Naoki Mutou

Masaya Hattori

Sayaka Matsumoto

Tomomitsu Muraishi

Sayaka Watanabe

Takeshi Fujii

Yoshiyuki Saito

Michiya Watanabe

Yasuhiko Sasaki

Yoshiyuki Satou

Tomokazu Yamaguchi

A varistor component includes: a varistor-material sintered body; a first external electrode provided on a portion of a first lateral surface; a second external electrode provided on a portion of the first lateral surface; and a third external electrode provided on a portion of a second lateral surface. The first external electrode, the second external electrode, and the third external electrode are not provided on a third lateral surface or a fourth lateral surface. The first external electrode and the second external electrode are spaced apart from each other in a first direction on the first lateral surface. The third external electrode provided on the second lateral surface is located between the first external electrode and the second external electrode, when viewed in a second direction.

Varistor component

A multilayer varistor includes a sintered body and a first internal electrode, a second internal electrode, a third internal electrode, and a fourth internal electrode which are disposed in the sintered body. The first internal electrode, the second internal electrode, the third internal electrode, and the fourth internal electrode are arranged in an order of the first internal electrode, the third internal electrode, the fourth internal electrode, and the second internal electrode from a side of a first main face. The third internal electrode and the fourth internal electrode are electrically connected to each other. At least part of the first internal electrode and at least part of the third internal electrode overlap each other when viewed in a third direction. At least part of the second internal electrode and at least part of the fourth internal electrode overlap each other when viewed in the third direction.

Multilayer varistor

A multilayer varistor of the present disclosure includes a sintered body, a first internal electrode, a second internal electrode, a first external electrode, a second external electrode, and a high-resistance layer. The first internal electrode and the second internal electrode are disposed in the sintered body. The first external electrode is disposed on a surface of the sintered body and is electrically connected to the first internal electrode. The second external electrode is disposed on the surface of the sintered body and is electrically connected to the second internal electrode. The high-resistance layer covers at least part of the surface of the sintered body, and the high-resistance layer has a surface having a plurality of cracks.

A multilayer varistor includes: a sintered compact; an internal electrode provided inside the sintered compact; a high-resistivity layer arranged to cover the sintered compact at least partially and containing element Si; and an external electrode arranged to cover the high-resistivity layer partially, electrically connected to the internal electrode, and containing silver as a main component thereof. A ratio of a total mass of the alkali metals and the alkaline earth metals to a mass of the element Si in a surface region of the high-resistivity layer is equal to or less than 0.6.

A method for manufacturing a multilayer varistor includes: a first step including providing a multilayer stack in which a plurality of green sheet layers, each containing a Zn oxide powder as a main component and a Pr oxide powder as a sub-component, and a plurality of internal electrode paste layers, each containing a Pd powder, are alternately stacked; and a second step including forming a sintered compact, including an internal electrode inside, by baking the multilayer stack. The second step includes: a first sub-step including baking the multilayer stack by setting an oxygen concentration in an atmosphere at 1000 ppm by volume or less while increasing a temperature from 500° C. to 800° C.; and a second sub-step including baking, after the first sub-step, the multilayer stack by setting the oxygen concentration in the atmosphere at 1000 ppm by volume or more while increasing the temperature to a maximum allowable temperature.

Method for manufacturing multilayer varistor and multilayer varistor

A multilayer varistor has a stack structure including a plurality of layers stacked in a third direction. The multilayer varistor includes a first internal electrode electrically connected to a first external electrode, a second internal electrode electrically connected to the second external electrode, and a third internal electrode electrically connected to the third external electrode. The first internal electrode is disposed between the second internal electrode and the third internal electrode in the third direction.

A stacked varistor having a small variation in electrostatic capacitance is obtained. The stacked varistor includes first internal electrode projection extending from third internal electrode toward first end surface between first side surface and first varistor region, and second internal electrode projection extending from third internal electrode toward second end surface between first side surface and second varistor region. First internal electrode projection extends closer to first end surface than a line connecting point closest to first end surface of first varistor region and point closest to first end surface of third external electrode is. Second internal electrode projection extends closer to second end surface than a line connecting point closest to second end surface of second varistor region and point closest to second end surface of third external electrode is.

Stacked varistor

It is aimed to provide a laminated varistor capable of reducing stray capacitance to occur between an internal electrode and an external electrode, and also capable of reducing a variation in the stray capacitance due to a variation in the external electrode. A laminated varistor of the present disclosure has external electrodes on first end surface, second end surface, and first side surface of sintered body. No external electrode is provided on second side surface opposite to first side surface. Varistor regions in which internal electrodes overlap each other in a laminating direction are provided at positions closer to second side surface than to first side surface.

Chip resistor for reducing stray capacitance

A laminated varistor includes a varistor layer, a first internal electrode provided on an upper surface of the varistor layer, a second internal electrode provided on a lower surface of the varistor layer and facing the first internal electrode across the varistor layer in upward and downward directions, a first external electrode provided on a first side surface of the varistor layer and electrically connected to the first internal electrode, and a second external electrode provided on a second side surface of the varistor layer and electrically connected to the second internal electrode. The first internal electrode is extended from the first external electrode in a first extension direction. The first internal electrode includes first electrode strips arranged in a first arrangement direction perpendicular to the first extension direction and spaced apart from one another. This laminated varistor has improved surge-resistant characteristics.

Laminated varistor

A sintered body that includes ceramic layers and an internal electrode which are alternately stacked on one another is prepared. A first external electrode is formed on a side surface of the sintered body such that the first external electrode is connected to the internal electrode. An insulating layer is formed on a surface of the sintered body by applying a glass coating over an entire of the sintered body having the formed first external electrode. The insulating layer is exposed from the first external electrode. A second external electrode is formed on the first external electrode. This method provides the produced multilayer electronic component with a stable electric connection between the internal electrodes and the external electrodes.

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Hokkaido, Japan

Ken Yanai