Method of stabilizing the electrical resistance of a metal oxide film

• US 3,108,019 A
• Filed: 02/14/1958
• Issued: 10/22/1963
• Est. Priority Date: 02/14/1958
• Status: Expired due to Term

• Current Assignee: James K. Davis
• Original Assignee: James K. Davis
• Inventors: Davis, James K.
• Application Number:
  US03/715,213
• Time in Patent Office: 2,076 Days
• US Class Current: 427/58
• CPC Class Codes: C03C 17/245 by deposition from the vapour phase
• CPC Class Codes: C03C 2217/21 Oxides
• CPC Class Codes: C03C 2217/211 SnO2
• CPC Class Codes: C03C 2218/152 by cvd
• CPC Class Codes: C03C 2218/32 After-treatment
• CPC Class Codes: H01C 17/30 adapted for baking
• CPC Class Codes: Y10T 29/49099 Coating resistive material on a base

Claims

1. A METHOD OF PRODUCING AN ELECTRICAL RESISTANCE ELEMENT ADAPTED TO OPERATE AT A PREDETERMINED TEMPERATURE WHICH COMPRISES FORMING AN ELECTROCONDUCTIVE METAL OXIDE FILM ON A SUBSTRATE, SUBJECTING THE FILM TO A HIGH TEMPERATURE HEAT TREATMENT THAT IMPARTS AN ABNORMALLY HIGH, UNSTABLE RESISTANCE VALUE TO THE FILM, THEREAFTER ACCELERATING THE RATE AT WHICH THE ELECTRICAL RESISTANCE OF THE FILM DECREASES FROM THE ABNORMALLY HIGH VALUE TO A VALUE THAT IS MORE NEARLY STABLE AT THE INTENDED OPERATING TEMPERATURE BY SUBJECTING THE FILM TO A SECOND HEAT TREATMENT IN A MILDLY REDUCING ATMOSPHERE AND AT A TEMPERATURE INTERMEDIATGE THE INTENDED OPERATING TEMPERATURE OF THE RESISTANCE ELEMENT AND THE TEMPERATURE OF THE INITIAL HEAT TREATMENT, AND DISCONTINUING THIS SECOND HEAT TREATMENT WHEN THE DESIRED ACCELERATED DECREASE HAS BEEN ACHIEVED, THEREBY PRODUCING A RESISTANCE ELEMENT HAVING A MORE STABLE RESISTANCE AT ITS INTENDED OPERATING TEMPERATURE.