Zinc oxide resistor and its manufacturing method

Patent 7362209 Issued on April 22, 2008. Estimated Expiration Date:

December 2, 2023. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Potentially non-linear resistor and process for producing the same
Patent #: 4420737
Issued on: 12/13/1983
Inventor: Miyoshi , et al.

Zinc oxide varistor structure
Patent #: 4959262
Issued on: 09/25/1990
Inventor: Charles, et al.

Zinc oxide ceramics and method for producing the same
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Inventors

Assignee

National Institute for Materials Science

Application

No. 10537492 filed on 12/02/2003

US Classes:

338/20, Current and/or voltage (e.g., ballast resistor)338/22R, Thermistor type338/21, Voltage surge-responsive or lightning arrester type428/329, Iron oxide or aluminum oxide252/519.51Additional diverse metal containing

Examiners

Primary: Lee, K.

Attorney, Agent or Firm

Westerman, Hattori, Daniels & Adrian, LLP.

Foreign Patent References

2-219203 JP 08/01/1990
10-270214 JP 10/01/1998
2000-228302 JP 08/01/2000

International Classes

H01C 7/10
H01C 7/13

Abstract

Disclosed are a zinc oxide resistor structure, and methods of forming a glass layer and a resistor, which are required for producing the resistor structure. The zinc oxide resistor comprises zinc oxide grains and an oxide glass layer which contains bismuth and boron and intervenes between the zinc oxide grains. The oxide glass layer residing between the zinc oxide grains changes the electric properties between the grains to achieve a higher resistance and a non-ohmic characteristic of a voltage-dependent resistance value in the resistor. This non-ohmic characteristic can be applied, particularly, to a non-ohmic device to be compatible with a low-voltage operation. Differently from conventional resistors, the oxide glass layer intervening between the zinc oxide grains can achieve an enhanced mechanical strength of a junction in the device.

Other References

Y. Sato et al., Current-Voltage Characteristics across [0001]Twist Boundaries in Zinc Oxide Bicrystals, Journal of the American Ceramic Society, 85 (8), Aug. 2002, pp. 2142-2144.
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