1. Field of the Invention
The present invention relates to a heating resistor element component (thermal head) which is used in a thermal printer typically mounted onto a compact information equipment terminal such as a compact handy terminal, and is used for performing printing on a thermal recording medium through selective driving of a plurality of heating elements based on print data.
2. Description of the Related Art
Recently, thermal printers have been widely used in compact information equipment terminals. The compact information equipment terminals are driven by a battery, which leads to strong demands for electric power saving of the thermal printers. Accordingly, there have been growing demands for heating resistor element components having high heating efficiency.
As to increasing efficiency of the thermal head, there is known a method of forming a hollow portion in a lower layer of a heating resistor (for example, see JP 2007-83532 A). Among an amount of heat generated in the heating resistor, an amount of upper-transferred heat which is transferred to a wear-resistant layer formed above the heating resistor becomes larger than an amount of lower-transferred heat which is transferred to a supporting substrate located under the heating resistor, and thus energy efficiency required during the printing can be sufficiently obtained.
However, in the heating resistor element component disclosed in JP 2007-83532 A, a heat accumulating layer (insulating film) provided on a surface of the supporting substrate is required to have a thickness to some extent in terms of a mechanical strength, which imposes a limitation on reducing a thickness (size in a height direction) of the heating resistor element component.