| 摘要 |
PURPOSE:To realize a thermal head of good setting quality at a low cost, by establishing a protruding porous alumina layer provided to a specific position on an insulating substrate, and a heating resistor layer so formed as to cover the abovementioned porous alumina layer. CONSTITUTION:A mould 7 for casting is installed onto an alumina substrate 1, and boehmite sol 6 is casted from a hole 7a, which is dried at 100 deg.C for 1h to a gel state. Then, the mould 7 is removed from the substrate 7, and the boehmite sol 6 remaining on the substrate 6 is heated at 600 deg.C and is burnt for 3h. By repeating abovementioned procedure several times, a porous alumina layer 5 of a specified size is formed. Then, a heating resistor layer 2 is formed by vapor deposition of tantalum nitride on the alumina substrate 1 and on the porous alumina layer 5, and an electric conductor layer 3 is formed thereon by vapour deposition of aluminum. Then, aluminum on a crest of the heating resistor layer 2 is removed and lastly, a protection layer 4 is formed by vapour deposition of silicon dioxide. |
