| 摘要 |
PURPOSE:To obtain a heat generator for a thermal head having high heat resistance and stable resistivity, by doping polysilicon with arsenic and adjusting the concn. of the carrier of said polysilicon to a specified value. CONSTITUTION:The heat generating part of a thermal head consists of an alumina substrate 5, a glaze layer 4 for heat accumulation, a heat generating resistor layer 3, lead electrodes 2, 2' composed of aluminum and an abrasion resistance protective layer 1 composed of Si-B-N and, when voltage is applied between lead electrodes 4, 5, the current corresponding to the resistance of the heat generating resistor layer 3 flows to said resistor layer 3 to generate heat, and the thermal color ribbon contacted with the surface of a protective layer 1 under pressure is heated through the protective layer 1 and, further, the coloring material of the ribbon is transferred to the paper contacted with the surface of the protective layer 1. The heat generating resistor layer is composed of polysilicon doped with arsenic and adjusted in carrier concn. and, by controlling the doping condition of arsenic, the heat generating resistor layer with carrier concn. of 5X10<18>-7X10<10>/cm<2> and resistivity of 1X10<-3>-1X10<-1>OMEGA-cm can be obtained and the resistance value thereof does not change for a long time even at high temp. like 500 deg.C. |
