| 摘要 |
<p>PURPOSE:To contrive to prolong the life of a thermal head, by forming the protective film of a heat generating layer from two predetermined layers consisting of an oxidation resistant layer and an anti-wear layer. CONSTITUTION:A protective film covering the heat generator 2 of a thermal head is formed of two layers consisting of an oxidation resistant layer 6 comprising a polyimide resin or a polyimide resin containing a filler such as SiC and an anti-wear layer 7 comprising an epoxy resin containing a filler such as CrO3 or SiC. The layer 6 comprising the same polyimide resin as a base board well follows the expansion and contraction of the heat generator 2 and prevented from rupture due to stress to effectively prevent the oxidation of said heat generator 2 while anti-wear property is enhanced by the layer 7 using the hard filler-containing epoxy resin to make it possible to attain to prolong the life of the thermal head.</p> |
