Abstract: An ink jet cartridge assembly for use in an ink jet printer has a body with at least one inner ink chamber. A printhead is carried by the body and has a plurality of ink jetting orifices in fluid communication with the ink chamber. A tape automated bonding circuit carried by the body includes a flexible tape and a plurality of electrical traces. The flexible tape includes a chip window with a peripheral edge. The printhead is disposed within the chip window at a distance from the peripheral edge. Each electrical trace has a bottom side adjacent the body, a substrate held portion carried by the flexible tape, a free trace portion extending between the peripheral edge of the chip window and the printhead, and a printhead held portion connected with the printhead. The tape automated bonding circuit further includes a photoimagable coating which covers the bottom side of each electrical trace on all of the substrate held portion and the free trace portion, but does not cover the printhead held portion.

Abstract: A flexible circuit on an ink jet print head cartridge provides electrical connection between a control circuit in an ink jet printer and electrical contacts on a print head integrated circuit. During operation of printer, the contacts and the flexible circuit are exposed to a corrosive ink contained in the cartridge. The flexible circuit includes a first conductor for electrically connecting to a contact on the print head integrated circuit. The first conductor carries a first voltage when the flexible circuit is connected to the control circuit. A second conductor is disposed adjacent the first conductor for electrically connecting to another contact on the print head integrated circuit. When the flexible circuit is connected to the control circuit the second conductor carries a second voltage which is different from the first voltage. Thus, a voltage difference exists between the first conductor and the second conductor.

Abstract: Method and apparatus is described for detecting faults, such as cracks, in ink jet printhead heater chips using a resistor on the heater chip. The resistor is located adjacent to at least one edge of the heater chip. One method, for example, includes the steps of measuring the resistance of the resistor at a first temperature and comparing the measured electrical resistance to a theoretical calculated resistance. Another method, for example, includes the steps of measuring the resistance at a first temperature, heating the chip, and measuring the resistance at a second temperature. Faults are detected by comparing expected changes in resistance or temperature to measured changes.

Abstract: The invention is directed to an ink jet cartridge assembly, including a cartridge body and a print head. The cartridge body includes a die cavity and at least one groove disposed in communication with the die cavity and with an ambient environment. The print head is disposed at least partially within the die cavity. An adhesive is disposed within the die cavity between the body and the print head for bonding the print head to the body. The at least one groove defines a vent to the ambient atmosphere for a gas which may be produced during curing of the adhesive.