EP0258606A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process for manufacturing thermal ink jet printheads and thin film resistor printhead produced thereby
Assignee: HP Inc
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Filing: 1987-07-22
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Granted: —
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Expires: 2007-07-22
Abstract
Abstract The specification describes a new and improved thermal ink jet printhead and fabrication process therefor wherein the heater resistors are formed on one area of an insulating substrate and relative large area electrical contacts are formed on an adjacent area of the insulating substrate. A barrier layer is formed over the conductive trace pattern defining the heater resistors on the one area, and a small via in this layer provides an electrical path between the large area electrical contacts and the conductive trace pattern, and thus provides a current drive path for the heater resistors. The small via provides minimum exposure of the barrier sidewall area and area of the conductive trace pattern and thus improves device reliability and fabrication yields and also improves electrical contact to the printhead. Alternatively, the barrier layer may be made less than laterally coextensive with the conductive trace material to thereby leave a small area of the trace material available for metal overlay connection to the large area contact pad which is formed to the side of the conductive trace material.
Inventors
- 👤 John L. Stoffel
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 16:28
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/135; B41J2/16; B41J2/1621; B41J2/164; B41J2/1642; B41J2/14; B41J2/14016; B41J2/14088; B41J2/14112; B41J2/14129; B41J2/1601; B41J2/1603; B41J2/1626; B41J2/1628; B41J2/1631; B41J2/1646; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49099
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
116 words
A process for fabricating a thin film resistor printhead structure which includes: a. forming a resistive layer on an insulating substrate and a conductive trace pattern laterally coextensive therewith and having an opening therein defining a resistive heater element, b. forming an insulating barrier layer atop said conductive trace material and exposing a predetermined area of said conductive trace pattern, and c. forming a metal overlay pattern extending from said conductive trace pattern and down over an adjacent area of said insulating substrate, whereby the metal over said adjacent area of said insulating substrate provides a relatively large and flat electrical contact area remote from said conductive trace pattern for spring biased contacts and the like.
Claim 2
Dependent Claim
116 words
A process for fabricating a thin film resistor printhead structure which includes: a. forming a resistive layer on an insulating substrate and a conductive trace pattern laterally coextensive therewith and having an opening therein defining a resistive heater element, b. forming an insulating barrier layer atop said conductive trace material and exposing a predetermined area of said conductive trace pattern, and c. forming a metal overlay pattern extending from said conductive trace pattern and down over an adjacent area of said insulating substrate, whereby the metal over said adjacent area of said insulating substrate provides a relatively large and flat electrical contact area remote from said conductive trace pattern for spring biased contacts and the like.
Claim 3
Dependent Claim
30 words
The process defined in claim 1 wherein a small via is etched in the barrier layer for receiving said metal overlay pattern in electrical contact with said conductive trace pattern.
Claim 4
Dependent Claim
43 words
The process defined in claim 1 which includes forming said insulating loarrier layer of smaller lateral dimension than said conductive trace pattern to thereby leave an edge of said conductive trace pattern exposed to receive said metal overlay pattern in electrical contact therewith.
Claim 5
Dependent Claim
124 words
A thin film resistor printhead and interconnect structure including, in combination: a. a resistive layer and a conductive trace pattern formed laterally coextensive on a predetermined area of an insulating substrate, and said conductive trace pattern having an opening therein defining a resistive heater element, b. an insulating barrier layer formed atop said conductive trace material and exposing a predetermined area of said conductive trace pattern, and c. a metal. overlay pattern extending from said conductive trace pattern and down over and on an adjacent area of said insulating substrate under which no conductive trace pattern appears, whereby the metal over said adjacent area of said insulating substrate provides a relatively large and flat electrical-contact area for receiving spring biased contacts and the like.
Claim 6
Dependent Claim
124 words
A thin film resistor printhead and interconnect structure including, in combination: a. a resistive layer and a conductive trace pattern formed laterally coextensive on a predetermined area of an insulating substrate, and said conductive trace pattern having an opening therein defining a resistive heater element, b. an insulating barrier layer formed atop said conductive trace material and exposing a predetermined area of said conductive trace pattern, and c. a metal. overlay pattern extending from said conductive trace pattern and down over and on an adjacent area of said insulating substrate under which no conductive trace pattern appears, whereby the metal over said adjacent area of said insulating substrate provides a relatively large and flat electrical-contact area for receiving spring biased contacts and the like.
Claim 7
Dependent Claim
29 words
The structure defined in claim 4 wherein small via is made in said insulating barrier layer to expose said conductive t:race pattern for connection to said metal overlay pattern.
Claim 8
Dependent Claim
44 words
The structure defined in claim 4 wherein said insulating barrier layer is formed of smaller lateral dimension than said conductive trace pattern to thereby leave an edge area of said conductive trace pattern exposed to receive said metal overlay pattern in electrical contact therewith.
References Cited (Backward Citations)
No citation records indexed.
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