Patent ID: 6547989
Filing Date: 2003-04-15
Classification: H01C

Abstract:
An inorganic PTC device, comprising:an inorganic-metal composite body comprising an electrically insulating inorganic matrix and first electrically conductive particles uniformly dispersed in said matrix and forming a three-dimensional conductive network extending from a first surface of said body to an opposed second surface thereof; an intermediate layer formed on each of said first and second surfaces of said body, said intermediate layer comprising inorganic particles and second electrically conductive particles uniformly dispersed therein, wherein said second particles (i) have a higher melting point temperature than said first particles, and (ii) will not form a eutectic allay or intermetallic compound with said first particles during manufacture or use of said device; and an outer electrode layer adhered to each of said intermediate layers, said outer electrode layer consisting essentially of third electrically conductive particles that are compositionally different from said first and second particles.