Two types of heating resistor for thermal inkjet printhead have been proposed to improve the energy efficiency. The conventional structure of heating resistor is very complex and exhibits very poor energy conversion efficiency due to the thermal consideration.
A structure is proposed, which uses ink itself as a heating resistor. It does not need a conventional heating resistor and passivation layers. This type of heating resistor can be applicable to a commercial inkjet printhead if the electrical resistance of the ink can be reduced and some minor problems in the fabrication process are solved.
Another type of a heating resistor is a diffused poly-Si film without passivation layers, which reduce thermal energy loss. From the aging and ink ejection characteristic of the poly-Si resistor, it is inferred that the suggested diffused-poly-Si resistor can be directly used in inkjet printhead.
The suggested technologies can be applied to achieve inexpensive energy-efficient thermal inkjet printheads.
