US Patent 7372477 Thermal head and manufacturing method thereof

A method for manufacturing a thermal head is provided which includes the steps of forming a resistor layer and an insulating barrier layer, patterning the above two layers to form aligned heating resistors, forming a solid electrode layer over the heating resistors and the like, and partly removing the solid electrode layer to form opening portions and electrode layers for supplying electricity to the heating resistors. In the patterning step, part of the resistor layer and part of the insulating barrier layer, which are outside a heat generating area, are simultaneously removed to form the heating resistors having a planar U shape composed of a pair of effective heating portions and a connection portion connecting the above pair, the effective heating portions and the connection portion each having a predetermined length and width. The length of the connection portion is set to 5 μm or less.