A Study on the Low Energy Consumption Thermal Head Using Electroless Ni-W-P Alloy Films as Heating Resistors

The new type of thermal head with an electroless Ni-W-P film on a polyimide film substrate was investigated for the purpose of low cost and low energy consumption. The electroless plating method attained a fine patterned heating element and the polyimide substrate worked as a heat-insulating layer with a lower heat conductivity. In our simulation, the applied power was reduced about 50% by using polyimide film as the heat-insulating layer. The accumulation of heat could be suppressed by controlling the polyimide film thickness without reducing the advantage of low energy consumption. The new head, composed of screen-printed polyimide resin with SiC powder (10 µm thick) as the protective layer, an electroless Ni-W-P film (0.25 µm thick) as the heating element, a polyimide film (50 µm thick) as the heat-insulating layer, and an Al board (3.0 mm) as the heat sink, was produced. The new head shows the same dot size as that of the conventional thin-film-type head produced by vacuum technology, and its cost is lower than that of the conventional thin-film-type head. The new head produces the good printing quality with 60% of the power required by the conventional one. Therefore, the new head provides low cost and low energy consumption.