| 摘要 |
PURPOSE:To inhibit the deterioration of a protection film and thereby constitute a long-life thermal head by increasing the thickness of a protection film on a thermal resistor in accordance with the heat distribution in the surface of the thermal resistor. CONSTITUTION:A thermal resistor 2 of Ta-SiO2 is formed on an electrically insulated substrate 1 by sputtering technique, and on this thermal resistor, an electrode film is formed that supplies power to the thermal resistor. Thus an electrode pattern is formed using lithography technique. On this pattern, a protection film layer 4 is constituted that inhibits the oxidation of the thermal resistor during heating and resists abrasion during printing. Generally, this protection film consists of two layers; a lower SiO2 layer as an oxidation inhibition layer and an upper Ta2O5 layer as an abrasion-resistant layer. The film is 5 to 8mum thick. Thus a thermal head is formed that has a circular protection film with a diameter of about 100mum in the center of the thermal resistor. Consequently, the life of a thermal head can be easily increased. |
