Abstract: An improved TAB circuit is provided for use with ink jet printer cartridges, which carries electrical signals to an array of nozzles on a heater chip. The TAB circuit eliminates bent or broken electrical circuit traces before being bonded to the heater chip by creating a chip window that partially overlaps the edges of the heater chip, and by bringing the electrical circuit traces to the chip window and terminating these circuit traces at a PI (polyimide) edge, which defines the inner perimeter of the chip window. The circuit traces thus are not unsupported at their ends before being assembled to the heater chip, and are automatically correctly positioned to make contact with bond pads of the heater chip when the overall TAB circuit is in correct registration therewith. The TAB circuit also provides an improved tolerance for a covercoat placement that will tend to prevent corrosive ink from coming into contact with these metal traces.

Abstract: An improved TAB circuit is provided for use with ink jet printer cartridges, which carries electrical signals to an array of nozzles on a heater chip. The TAB circuit eliminates bent or broken electrical circuit traces before being bonded to the heater chip by creating a chip window that partially overlaps the edges of the heater chip, and by bringing the electrical circuit traces to the chip window and terminating these circuit traces at a PI (polyimide) edge, which defines the inner perimeter of the chip window. The circuit traces thus are not unsupported at their ends before being assembled to the heater chip, and are automatically correctly positioned to make contact with bond pads of the heater chip when the overall TAB circuit is in correct registration therewith. The TAB circuit also provides an improved tolerance for a covercoat placement that will tend to prevent corrosive ink from coming into contact with these metal traces.