| 摘要 |
PURPOSE:To suppress current concentration and the stress concentration due to thermal expansions of individual electrodes and provide a thermal head less liable to generate initial troubles even in use thereof under a high-power condition and having a stable useful life, by providing a hole at a central part of a side at which a heating resistor and an individual electrode in a head abut against each other. CONSTITUTION:A hole 20 is provided at the center of the side at which an individual electrode 8 and a heating resistor 13 abut against each other, and includes both the electrode 8 and the resistor 13. With this heating resistor configuration, the path of an electric current flowing in from a common electrode 9 is divided near the individual electrode 8, as indicated by arrows 14. Therefore, no current concentration occurs, and accordingly, concentrated heat generation and stress concentration in a protective film are suppressed. In addition, the hole 20 ensures that the protective layer at an upper part of the hole 20 and Ta2O5 constituting an etching-resistant layer are connected direct to each other. The protective layer is ordinarily formed of an oxide such as SiO2, Al2O3 and Ta2O5, it is adhered to Ta2O5 of the etching-resistant layer with a very strong adhesion. Accordingly, due to the presence of the hole 20, the effect of the stress due to thermal expansion of the individual electrode 8 on the heating resistor 13 is alleviated. |
