Method of manufacture for a resistance heater and temperature sensor

A method of manufacturing a heater including a temperature sensor means, comprising the steps of:

• forming a serpentine shaped heater element pattern in a first thin sheet of resistive material, said pattern defining a first electrical current flow path;
• forming a serpentine shaped temperature sensor pattern in a second thin sheet of a material different from said first sheet and having a relatively high coefficient of resistivity, said second sheet substantially circumscribed by said first sheet and said sensor pattern being electrically insulated from said heater element pattern and having portions of a much thinner width than said heater element pattern portions, said temperature sensor pattern defining a second electrical current flow path independent of said first path, said steps being performed simultaneously by photoetching said patterns out of said sheets.