Organic positive temperature coefficient thermistor and manufacturing method therefor

• US 7,341,679 B2
• Filed: 06/23/2004
• Issued: 03/11/2008
• Est. Priority Date: 06/24/2003
• Status: Expired due to Fees

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Handa, Tokuhiko
• Primary Examiner(s): Douyon; Lorna M.
• Assistant Examiner(s): Nguyen; Khanh Tuan
• Application Number:
  US10/873,105
• Publication Number:
  US 20050024180A1
• Time in Patent Office: 1,357 Days
• Field of Search: 252/519.12, 252/500, 252/502, 252/503, 252/512, 338/22.R, 338/224, 338/275, 264/616, 428/376, 219/505
• US Class Current: 252/500
• CPC Class Codes: H01C 17/065 by thick film techniques, e.g. serigraphy
• CPC Class Codes: H01C 7/027 consisting of conducting or semi-conducting material dispersed in a non-conductive organic material

Abstract

An organic positive temperature coefficient thermistor 10 having at least a pair of electrodes 2 and 3 positioned facing each other and a thermistor element 1 having a positive temperature coefficient of resistance which is positioned between the pair of electrodes 2 and 3, wherein the thermistor element 1 is a molded element consisting of a mixture which contains a polymer matrix and conductive particles having electronic conductivity, and wherein the thermistor element 1 has an amount of oxygen calculated by subtracting the amount of oxygen originally present in the various components of the mixture from the amount of oxygen contained in the thermistor element, which is 1.55 weight percent or less of the mass of the thermistor element.

Claims

1. An organic positive temperature coefficient thermistor, comprising a pair of electrodes positioned facing each other and a thermistor element positioned between said pair of electrodes and having a positive temperature coefficient of resistance,

wherein said thermistor element is a molded element consisting of a mixture which contains a polymer matrix and conductive particles having electronic conductivity,

wherein said thermistor element has an amount of oxygen calculated by subtracting the amount of oxygen originally present in the various components of said mixture from the amount of oxygen contained in said thermistor element, which is 1.55 weight percent or less of the mass of said thermistor element, and

wherein said oxygen is controlled by producing said thermistor element under an inert atmosphere.

2. The organic positive temperature coefficient thermistor according to claim 1, wherein said conductive particles are metal particles.

3. The organic positive temperature coefficient thermistor according to claim 1, wherein said conductive particles are made of nickel.

4. The organic positive temperature coefficient thermistor according to claim 1, wherein said conductive particles are filamentous.

5. The organic positive temperature coefficient thermistor according to claim 1, wherein said thermistor element further contains a low molecular weight organic compound.

6. A method for manufacturing the organic positive temperature coefficient thermistor, said thermistor comprising a pair of electrodes positioned facing each other and a thermistor element positioned between said pair of electrodes and having a positive temperature coefficient of resistance,

wherein said thermistor element is a molded element consisting of a mixture which contains a polymer matrix and conductive particles having electronic conductivity, and

wherein said thermistor element has an amount of oxygen calculated by subtracting the amount of oxygen originally present in the various components of said mixture from the amount of oxygen contained in said thermistor element, which is 1.55 weight percent or less of the mass of said thermistor element,

said method comprising a step for manufacturing said organic positive temperature coefficient thermistor, wherein the oxygen is removed from the atmosphere to which said components of said thermistor element are exposed.

7. An organic positive temperature coefficient thermistor, comprising a pair of electrodes positioned facing each other and a thermistor element positioned between said pair of electrodes and having a positive temperature coefficient of resistance,

wherein said thermistor element is a molded element consisting of a mixture which contains a polymer matrix and conductive particles having electronic conductivity,

wherein said thermistor element has an amount of oxygen calculated by subtracting the amount of oxygen originally present in the various components of said mixture from the amount of oxygen contained in said thermistor element, which is 1.55 weight percent or less of the mass of said thermistor element, and

wherein said calculated amount of oxygen represents oxygen that contaminates said thermistor element before and during manufacture of said thermistor element.