| 摘要 |
PURPOSE:To obtain a thermal head having a long life in which any crack in its protecting film is filled with a resin, by vacuum-impregnating a heat-resisting resin into any crack formed in a protecting film on a heating resistor provided on an insulating substrate. CONSTITUTION:A thermal head 21 is clamped by a sample lifting mechanism 24. A heat-resisting resin 23, such as polyimide resin, is filled in a tub 22. A chamber 20 is evacuated of air to produce a vacuum on the order of several Torr. A handle 25 is actuated such that the thermal head 21 is lowered and dipped into the heat-resisting resin 23. Under this state, air is introduced into the chamber 20 until the pressure in the chamber 20 is equal to the atmospheric pressure. The thermal head 21 is pulled up from the heat-resisting resin 23. Any excess resin adhering to the surface of the thermal head 21 is wiped off. The thermal head 21 is heated in order to harden the resin. Thus, the resin 15 is forced into any crack of flaw in the protecting film 14, so that the crack or the like is filled with the resin 15. |
