Substrate for a heater assembly and method of manufacture thereof

Abstract

A substrate for a heating assembly comprising a mixture of a mica material with an electrically insulating material, the substrate having a thermal coefficient of expansion that is higher than pure mica. A method of manufacturing the substrate is also disclosed.

1 . A method of forming a mica material for a heater assembly, comprising:
 mixing a mica material with an electrically insulating material to form a substrate for a heater assembly, the substrate having a thermal coefficient of expansion that is higher than pure mica.   
     
     
         2 . The method of forming a mica material for a heater assembly of  claim 1 , wherein the electrically insulating material is aluminum nitride. 
     
     
         3 . The method of forming a mica material for a heater assembly of  claim 1 , wherein the electrically insulating material is at least one selected from a group consisting of zirconium oxide, aluminum oxide, and magnesium oxide. 
     
     
         4 . The method of forming a mica material for a heater assembly of  claim 1 , wherein the electrically insulating material is a silicate having a higher thermal expansion coefficient than pure mica. 
     
     
         5 . The method of forming a mica material for a heating assembly further comprising mixing the mica material with a powder in which at least one of particle size and binder volume are adjusted yield a roughened surface such that mechanical roughening is not necessary. 
     
     
         6 . A method of forming a heater assembly comprising:
 forming substrate of a mica material as in  claim 1 ;   thermally spraying a material onto the substrate to form a resistive heater layer.   
     
     
         7 . A method of forming a heater assembly as in  claim 6  further comprising apply a coating onto the resistive heater layer. 
     
     
         8 . A substrate for a heating assembly comprising a mixture of a mica material with an electrically insulating material, the substrate having a thermal coefficient of expansion that is higher than pure mica. 
     
     
         9 . A substrate for a heating assembly of  claim 8 , wherein the electrically insulating material is aluminum nitride. 
     
     
         10 . A substrate for a heating assembly of  claim 8 , wherein the electrically insulating material is at least one selected from a group consisting of zirconium oxide, aluminum oxide, and magnesium oxide. 
     
     
         11 . A substrate for a heating assembly of  claim 8 , wherein the electrically insulating material is a silicate having a higher thermal expansion coefficient than pure mica. 
     
     
         12 . A substrate for a heating assembly of  claim 8 , wherein the mixture further comprises a powder in which at least one of particle size and binder volume are adjusted to yield a roughened surface such that mechanical roughening is not necessary.