| 摘要 |
PURPOSE:To obtain a thermal head free of lowering of image quality due to paper dust, by covering with an SiO2 film a part in the vicinity of a heat generating resistor a part of which is not provided with a glaze. CONSTITUTION:This thermal head comprises an alumina substrate 11, a partial glaze 12, a common electrode conductor 13, rectangular conductors 14, a heat generating resistor 15, individual conductors 16, a resistor protective layer 17 and an SiO2 film 18. Since not only the common electrode conductor 13 but also the part not provided with the glaze is covered by the SiO2 film not thicker than the partial glaze, even when a defect is present in the resistor protective layer 17 on the part not provided with the glaze, the defective part is protected by the SiO2 film, so that the thermal head produced is high in reliability. The SiO2 film is provided by applying a liquid coating agent comprising SiO2 as a main constituent, followed by heating. |
