PURPOSE: To raise the wear resistance and crack resistance of the heating resistor layer of a thermal head by providing a protective film composed of Si, H, and N as main components, having x-value (for the surface on the heating resistor layer side) smaller than x-value for the outer surface and the x-value varying from the surface on the heating resistor layer side to the outer surface.
CONSTITUTION: On an alumina ceramic base plate 1 having glazed smooth surface, a Cr-Si thin layer and a Cr-A film as a heating resistor layer and an electrode layer 3 are laminated by a vacuum film forming method, e.g., vapor deposition method, etc. On the pattern of such a structure, a protective film 4 composed of SixHyN is formed by reaction of a mixture of gases of SiH4, NH3, and N2 by a P-CVD method. The x-value of the protective film 4 varies from 0.2 to 0.9 continuously from the surface on the heating resistor layer to the outer surface, and the protective film 4 is excellent in hardness, wear resistance, and crack resistance, as well as having a high toughness.
KAWAHITO MICHIYOSHI
MORI YOSHIHARU
KAMEI TSUNEAKI
