Patent ID: 8376524
Filing Date: 2013-02-19
Classification: B41J

Abstract:
1. A thermal inkjet printhead chip structure comprising: a substrate; an oxide layer formed on the substrate; at least one driver circuitry formed on the substrate and surrounded by the oxide layer, the at least one driver circuitry each comprising a source, a drain and a gate; a dielectric layer formed on the at least one driver circuitry, the dielectric layer having a plurality of openings formed therethrough to expose the source and the drain; a buffer layer formed on the dielectric layer, the buffer layer covering and electrically connected to the source and the drain; a resistive layer separate from the buffer layer formed on and above the buffer layer and having at least one heating area, the resistive layer extending above the source and the drain and electrically connected to the source and the drain through the buffer layer, wherein the resistive layer at least overlaps with the buffer layer on the heating area, wherein the at least one heating area each has a length ranging from 10 to 100 micrometers and a width ranging from 10 to 100 micrometers, and the resistance coefficient of the buffer layer at the at least one heating area is 1.5 to 15 times of the resistance coefficient of the resistive layer at the at least one heating area; and a conductive layer formed on the resistive layer and partially covered the resistive layer to expose the at least one heating area.