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US006260952B1
(12) United States Patent ao) Patent No.: us 6,260,952 Bi
Feinn et al. (45) Date of Patent: Jul. 17,2001
(54) APPARATUS AND METHOD FOR ROUTING POWER AND GROUND LINES IN A INK-JET PRINTHEAD
(75) Inventors: James A. Feinn, San Diego, CA (US);
Jeffery Steven Beck, Corvallis, OR
(US)
(73) Assignee: Hewlett-Packard Company, Palo Alto, CA (US)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 09/296,943
(22) Filed: Apr. 22, 1999
(51) Int. CI.7 B41J 2/14; B41J 2/16
(52) U.S. CI 347/50; 347/58
(58) Field of Search 347/50, 58, 63,
347/64
(56) References Cited
U.S. PATENT DOCUMENTS
4,663,640 5/1987 Ikeda 347/63
4,719,477 1/1988 Hess 347/59
4,862,197 * 8/1989 Stoffel 347/59
5,045,870 * 9/1991 Lamey et al 347/59
5,317,346 5/1994 Garcia 347/65
5,909,202 * 6/1999 Cathey 345/74
OTHER PUBLICATIONS
Hewlett-Packard Journal, Feb., 1994 pp. 41-45.
Hewlett-Packard Journal, May, 1985 pp. 27-33.
Hewlett-Packard Journal, Aug. 1992 pp. 77-83.
* cited by examiner
Primary Examiner—John Barlow
Assistant Examiner—Michael S. Brooke
(57) ABSTRACT
An ink-jet printhead having a thin film substrate, the substrate including a plurality of thin film layers including a gold thin film layer overlying a tantalum thin film layer, an underlying passivation layer and an aluminum thin film layer underlying the passivation layer. A portion of the substrate is disposed adjacent an outer edge thereof and an ink barrier layer overlies the thin film substrate, the barrier layer having a first edge. The substrate portion extends beyond the barrier layer first edge. A plurality of bond pads is disposed on the substrate portion. Power and ground traces are coupled to a respective bond pad and are dropped through vias in the substrate portion to the thin film aluminum layer underlying the passivation layer. The traces are returned through vias to the gold thin film layer at a location separated from the barrier first edge. The gold and tantalum material between the vias is removed thereby providing a region in the printhead wherein the barrier layer directly adheres to the passivation layer.
19 Claims, 4 Drawing Sheets
