| 摘要 |
PURPOSE:To obtain a thermal head having favorable thermal response characteristics and consuming less electric power, by providing a single-crystal silicon plate, a porous silicon oxide layer and a non-porous insulator layer provided on the silicon oxide layer. CONSTITUTION:This substrate for a thermal head comprises a single crystal silicon plate 1 having high thermal conductivity, a layer of porous silicon oxide 2 provided by subjecting a resistor-forming surface of the plate 1 to anodic electrolysis and then to thermal oxidation, and a non-porous insulator layer 3 provided on the layer of silicon oxide 2. The silicon oxide layer 2 has a film thickness of 5-100 mum and a porosity of 30-70%. The non-porous insulator layer 3 is a silicon oxide film provided by sputtering, which has a film thickness of 0.1-2 mum. The silicon oxide layer 2 has low thermal conductivity and thermal capacity, because of the presence of fine pores. The non-porous insulator layer 3, which functions to seal the pores present at the surface of the silicon oxide layer 2, can be provided in a small thickness because the pores are small in size. Therefore, the overall thermal conductivity and thermal capacity can be reduced. |
