US5122812A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal inkjet printhead having driver circuitry thereon and method for making the same
Assignee: HP Inc
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Filing: 1991-01-03
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Granted: 1992-06-16
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Expires: 2011-01-03
Abstract
Abstract An improved thermal inkjet printhead and manufacturing method in which driver circuitry (e.g. MOSFET transistors), heating resistors, and a specialized arrangement of conductive elements are used. A substrate is provided having a plurality of drive transistors thereon. A layer of resistive material (e.g. a tantalum-aluminum mixture) is deposited on the substrate and directly connected to the source, gate, and drain of at least one transistor. A layer of conductive metal (e.g. aluminum) is deposited on a portion of the resistive layer, forming both covered and uncovered regions thereof. The uncovered region functions as a heating resistor, and the covered regions function as direct electrical contacts to the transistor, thereby minimizing the number of conductive elements in the printhead. The resistor is positioned beneath an ink-retaining cavity, and is designed to heat ink therein for expulsion through an orifice plate.
Inventors
- 👤 Ulrich E. Hess
- 👤 Duane A. Fasen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:06
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/135; B41J2/14; B41J2/14016; B41J2/14088; B41J2/14112; B41J2/14129; B41J2/16; B41J2/1601; B41J2/1603; B41J2/1621; B41J2/1631; B41J2/164; B41J2/1642; B41J2/1646; B41J2202/00; B41J2202/01; B41J2202/13
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
228 words
A thermal inkjet printhead structure comprising: a substrate; at least one drive transistor formed on said substrate, said drive transistor comprising a plurality of electrical contact regions thereon; a layer of electrically resistive material affixed to said substrate, said layer of electrically resistive material being in direct physical contact with said electrical contact regions of said drive transistor, said layer of electrically resistive material comprising at least one metal therein; a layer of conductive material directly affixed to a portion of said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said uncovered section functioning as a heating resistor, said layer of electrically resistive material being covered with said layer of conductive material at said electrical contact regions of said drive transistor, said layer of conductive material comprising at least one metal therein; a portion of protective material positioned on said heating resistor; and a plate member having at least one opening therethrough, said plate member being secured to said portion of protective material, said portion of protective material having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto.
Claim 2
Dependent Claim
228 words
A thermal inkjet printhead structure comprising: a substrate; at least one drive transistor formed on said substrate, said drive transistor comprising a plurality of electrical contact regions thereon; a layer of electrically resistive material affixed to said substrate, said layer of electrically resistive material being in direct physical contact with said electrical contact regions of said drive transistor, said layer of electrically resistive material comprising at least one metal therein; a layer of conductive material directly affixed to a portion of said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said uncovered section functioning as a heating resistor, said layer of electrically resistive material being covered with said layer of conductive material at said electrical contact regions of said drive transistor, said layer of conductive material comprising at least one metal therein; a portion of protective material positioned on said heating resistor; and a plate member having at least one opening therethrough, said plate member being secured to said portion of protective material, said portion of protective material having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto.
Claim 3
Dependent Claim
18 words
The printhead structure of claim 1 wherein said drive transistor is a metal oxide semiconductor field effect transistor.
Claim 4
Dependent Claim
22 words
The printhead structure of claim I wherein said layer of electrically resistive material is comprised of a mixture of tantalum and aluminum.
Claim 5
Dependent Claim
27 words
The printhead structure of claim 1 wherein said layer of conductive material is comprised of a metal selected from the group consisting of aluminum, copper, and gold.
Claim 6
Dependent Claim
104 words
The printhead structure of claim 1 wherein said portion of protective material comprises: a first passivation layer positioned on said resistor, said first passivation layer being comprised of silicon nitride; a second passivation layer positioned on said first passivation layer, said second passivation layer being comprised of silicon carbide; a cavitation layer positioned on said second passivation layer, said cavitation layer being comprised of a metal selected from the group consisting of tantalum, tungsten, and molybdenum; and an ink barrier layer positioned on said cavitation layer, said ink barrier layer being comprised of plastic, said plate member being secured to said ink barrier layer.
Claim 7
Dependent Claim
302 words
A thermal inkjet printhead structure comprising: a substrate; at least one drive transistor formed on said substrate, said drive transistor comprising a plurality of electrical contact regions thereon; a layer of electrically resistive material affixed to said substrate, said layer of electrically resistive material being in direct physical contact with said electrical contact regions of said drive transistor, said layer of electrically resistive material being comprised of a mixture of aluminum and tantalum; a layer of conductive material comprised of a metal selected from the group consisting of aluminum, copper, and gold directly affixed to a portion of said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said uncovered section functioning as a heating resistor, said layer of electrically resistive material being covered with said layer of conductive material at said electrical contact regions of said drive transistor; a first passivation layer positioned on said resistor, said first passivation layer being comprised of silicon nitride; a second passivation layer positioned on said first passivation layer, said second passivation layer being comprised of silicon carbide; a cavitation layer positioned on said second passivation layer, said cavitation layer being comprised of a metal selected from the group consisting of tantalum, tungsten, and molybdenum; an ink barrier layer positioned on said cavitation layer, said ink barrier layer being comprised of plastic; and a plate member having at least one opening therethrough, said plate member being secured to said ink barrier layer, said ink barrier layer having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto.
Claim 8
Dependent Claim
302 words
A thermal inkjet printhead structure comprising: a substrate; at least one drive transistor formed on said substrate, said drive transistor comprising a plurality of electrical contact regions thereon; a layer of electrically resistive material affixed to said substrate, said layer of electrically resistive material being in direct physical contact with said electrical contact regions of said drive transistor, said layer of electrically resistive material being comprised of a mixture of aluminum and tantalum; a layer of conductive material comprised of a metal selected from the group consisting of aluminum, copper, and gold directly affixed to a portion of said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said uncovered section functioning as a heating resistor, said layer of electrically resistive material being covered with said layer of conductive material at said electrical contact regions of said drive transistor; a first passivation layer positioned on said resistor, said first passivation layer being comprised of silicon nitride; a second passivation layer positioned on said first passivation layer, said second passivation layer being comprised of silicon carbide; a cavitation layer positioned on said second passivation layer, said cavitation layer being comprised of a metal selected from the group consisting of tantalum, tungsten, and molybdenum; an ink barrier layer positioned on said cavitation layer, said ink barrier layer being comprised of plastic; and a plate member having at least one opening therethrough, said plate member being secured to said ink barrier layer, said ink barrier layer having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto.
Claim 9
Dependent Claim
271 words
A thermal inkjet printing apparatus comprising: a housing having at least one outlet therethrough; storage means within said housing for retaining a supply of liquid ink therein; and a printhead secured to said housing, said printhead being in fluid communication with said storage means through said outlet and comprising: a substrate; at least one drive transistor formed on said substrate, said drive transistor comprising a plurality of electrical contact regions thereon; a layer of electrically resistive material affixed to said substrate, said layer of electrically resistive material being in direct physical contact with said electrical contact regions of said drive transistor, said layer of electrically resistive material comprising at least one metal therein; a layer of conductive material directly affixed to a portion of said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said uncovered section functioning as a heating resistor, said layer of electrically resistive material being covered with said layer of conductive material at said electrical contact regions of said drive transistor, said layer of conductive material comprising at least one metal therein; a portion of protective material positioned on said heating resistor; and a plate member having at least one opening therethrough, said plate member being secured to said portion of protective material, said portion of protective material having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto.
Claim 10
Dependent Claim
271 words
A thermal inkjet printing apparatus comprising: a housing having at least one outlet therethrough; storage means within said housing for retaining a supply of liquid ink therein; and a printhead secured to said housing, said printhead being in fluid communication with said storage means through said outlet and comprising: a substrate; at least one drive transistor formed on said substrate, said drive transistor comprising a plurality of electrical contact regions thereon; a layer of electrically resistive material affixed to said substrate, said layer of electrically resistive material being in direct physical contact with said electrical contact regions of said drive transistor, said layer of electrically resistive material comprising at least one metal therein; a layer of conductive material directly affixed to a portion of said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said uncovered section functioning as a heating resistor, said layer of electrically resistive material being covered with said layer of conductive material at said electrical contact regions of said drive transistor, said layer of conductive material comprising at least one metal therein; a portion of protective material positioned on said heating resistor; and a plate member having at least one opening therethrough, said plate member being secured to said portion of protective material, said portion of protective material having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto.
Claim 11
Dependent Claim
20 words
The apparatus of claim 7 wherein said drive transistor of said printhead is a metal oxide semiconductor field effect transistor.
Claim 12
Dependent Claim
24 words
The apparatus of claim 7 wherein said layer of electrically resistive material of said printhead is comprised of a mixture of tantalum and aluminum.
Claim 13
Dependent Claim
29 words
The apparatus of claim 7 wherein said layer of conductive material of said printhead is comprised of a metal selected from the group consisting of aluminum, copper, and gold.
Claim 14
Dependent Claim
106 words
The apparatus of claim 7 wherein said portion of protective material of said printhead comprises: a first passivation layer positioned on said resistor, said first passivation layer being comprised of silicon nitride; a second passivation layer positioned on said first passivation layer, said second passivation layer being comprised of silicon carbide; a cavitation layer positioned on said second passivation layer, said cavitation layer being comprised of a metal selected from the group consisting of tantalum, tungsten, and molybdenum; and an ink barrier layer positioned on said cavitation layer, said ink barrier layer being comprised of plastic, said plate member being secured to said ink barrier layer.
Claim 15
Dependent Claim
345 words
A thermal inkjet printing apparatus comprising: a housing having at least one outlet therethrough; storage means within said housing for retaining a supply of liquid ink therein; and a printhead secured to said housing, said printhead being in fluid communication with said storage means through said outlet and comprising: a substrate; at least one drive transistor formed on said substrate, said drive transistor comprising a plurality of electrical contact regions thereon; a layer of electrically resistive material affixed to said substrate, said layer of electrically resistive material being in direct physical contact with said electrical contact regions of said drive transistor, said layer of electrically resistive material being comprised of a mixture of tantalum and aluminum; a layer of conductive material comprised of a metal selected from the group consisting of aluminum, copper and gold directly affixed to a portion of said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said uncovered section functioning as a heating resistor, said layer of electrically resistive material being covered with said layer of conductive material at said electrical contact regions of said drive transistor; a first passivation layer positioned on said resistor, said first passivation layer being comprised of silicon nitride; a second passivation layer positioned on said first passivation layer, said second passivation layer being comprised of silicon carbide; a cavitation layer positioned on said second passivation layer, said cavitation layer being comprised of a metal selected from the group consisting of tantalum, tungsten, and molybdenum; an ink barrier layer positioned on said cavitation layer, said ink barrier layer being comprised of plastic; and a plate member having at least one opening therethrough, said plate member being secured to said ink barrier layer, said ink barrier layer having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto.
Claim 16
Dependent Claim
345 words
A thermal inkjet printing apparatus comprising: a housing having at least one outlet therethrough; storage means within said housing for retaining a supply of liquid ink therein; and a printhead secured to said housing, said printhead being in fluid communication with said storage means through said outlet and comprising: a substrate; at least one drive transistor formed on said substrate, said drive transistor comprising a plurality of electrical contact regions thereon; a layer of electrically resistive material affixed to said substrate, said layer of electrically resistive material being in direct physical contact with said electrical contact regions of said drive transistor, said layer of electrically resistive material being comprised of a mixture of tantalum and aluminum; a layer of conductive material comprised of a metal selected from the group consisting of aluminum, copper and gold directly affixed to a portion of said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said uncovered section functioning as a heating resistor, said layer of electrically resistive material being covered with said layer of conductive material at said electrical contact regions of said drive transistor; a first passivation layer positioned on said resistor, said first passivation layer being comprised of silicon nitride; a second passivation layer positioned on said first passivation layer, said second passivation layer being comprised of silicon carbide; a cavitation layer positioned on said second passivation layer, said cavitation layer being comprised of a metal selected from the group consisting of tantalum, tungsten, and molybdenum; an ink barrier layer positioned on said cavitation layer, said ink barrier layer being comprised of plastic; and a plate member having at least one opening therethrough, said plate member being secured to said ink barrier layer, said ink barrier layer having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto.
Claim 17
Independent Claim
212 words
A method for manufacturing a thermal inkjet printhead structure comprising the steps of: providing a substrate having at least one drive transistor thereon, said drive transistor comprising a plurality of electrical contact regions thereon; applying a layer of electrically resistive material onto said substrate and onto said electrical contact regions of said transistor, said layer of electrically resistive material comprising at least one metal therein; applying a layer of conductive material directly onto said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said layer of conductive material covering said layer of electrically resistive material on said electrical contact regions of said transistor, said uncovered section functioning as a heating resistor, said layer of conductive material comprising at least one metal therein; applying a portion of protective material onto said resistor; and securing a plate member having at least one opening therethrough onto aid portion of protective material, said portion of protective material having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto.
Claim 18
Independent Claim
212 words
A method for manufacturing a thermal inkjet printhead structure comprising the steps of: providing a substrate having at least one drive transistor thereon, said drive transistor comprising a plurality of electrical contact regions thereon; applying a layer of electrically resistive material onto said substrate and onto said electrical contact regions of said transistor, said layer of electrically resistive material comprising at least one metal therein; applying a layer of conductive material directly onto said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said layer of conductive material covering said layer of electrically resistive material on said electrical contact regions of said transistor, said uncovered section functioning as a heating resistor, said layer of conductive material comprising at least one metal therein; applying a portion of protective material onto said resistor; and securing a plate member having at least one opening therethrough onto aid portion of protective material, said portion of protective material having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto.
Claim 19
Dependent Claim
21 words
The method of claim 13 wherein said layer of electrically resistive material is comprised of a mixture of tantalum and aluminum.
Claim 20
Dependent Claim
26 words
The method of claim 13 wherein said layer of conductive material is comprised of a metal selected from the group consisting of aluminum, copper, and gold.
Claim 21
Dependent Claim
89 words
The method of claim 13 wherein said applying of said portion of protective material comprises the steps of: applying a passivation layer comprised of silicon nitride onto said resistor; applying a second passivation layer comprised of silicon carbide onto said first passivation layer; applying a cavitation layer comprised of a metal selected from the group consisting of tantalum, tungsten, and molybdenum onto said second passivation layer; and applying an ink barrier layer comprised of plastic onto said cavitation layer, said plate member being secured to said ink barrier layer.
Claim 22
Independent Claim
268 words
A method for manufacturing a thermal inkjet printhead structure comprising the steps of: providing a substrate having at least one drive transistor thereon, said drive transistor comprising a plurality of electrical contact regions thereon; applying a layer of electrically resistive material onto said substrate and onto said electrical contact regions of said transistor, said layer of electrically resistive material being comprised of a mixture of tantalum and aluminum; applying a layer of conductive material comprised of a metal selected from the group consisting of aluminum, copper, and gold directly onto said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said layer of conductive material covering said layer of electrically resistive material on said electrical contact regions of said transistor, said uncovered section functioning as a heating resistor; applying a first passivation layer comprised of silicon nitride onto said resistor; applying a second passivation layer comprised of silicon carbide onto said first passivation layer; applying a cavitation layer comprised of a metal selected from the group consisting of tantalum, tungsten, and molybdenum onto said second passivation layer; applying an ink barrier layer comprised of plastic onto said cavitation layer; and securing a plate member having at least one opening therethrough onto said ink barrier layer, said ink barrier layer having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto.
Claim 23
Independent Claim
268 words
A method for manufacturing a thermal inkjet printhead structure comprising the steps of: providing a substrate having at least one drive transistor thereon, said drive transistor comprising a plurality of electrical contact regions thereon; applying a layer of electrically resistive material onto said substrate and onto said electrical contact regions of said transistor, said layer of electrically resistive material being comprised of a mixture of tantalum and aluminum; applying a layer of conductive material comprised of a metal selected from the group consisting of aluminum, copper, and gold directly onto said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said layer of conductive material covering said layer of electrically resistive material on said electrical contact regions of said transistor, said uncovered section functioning as a heating resistor; applying a first passivation layer comprised of silicon nitride onto said resistor; applying a second passivation layer comprised of silicon carbide onto said first passivation layer; applying a cavitation layer comprised of a metal selected from the group consisting of tantalum, tungsten, and molybdenum onto said second passivation layer; applying an ink barrier layer comprised of plastic onto said cavitation layer; and securing a plate member having at least one opening therethrough onto said ink barrier layer, said ink barrier layer having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto.
Claim 24
Independent Claim
265 words
A method for manufacturing a thermal inkjet printing apparatus comprising the steps of: providing a substrate having at least one drive transistor thereon, said drive transistor comprising a plurality of electrical contact regions thereon; applying a layer of electrically resistive material onto said substrate and onto said electrical contact regions of said transistor, said layer of electrically resistive material comprising at least one metal therein; applying a layer of conductive material directly onto said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said layer of conductive material covering said layer of electrically resistive material on said electrical contact regions of said transistor, said uncovered section functioning as a heating resistor, said layer of conductive material comprising at least one metal therein; applying a portion of protective material onto said resistor; securing a plate member having at least one opening therethrough onto said portion of protective material, said portion of protective material having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto; providing a housing having storage means therein for retaining a supply of liquid ink, said housing further comprising at least one outlet therethrough; and securing said substrate to said housing at a position thereon so that said ink receiving cavity of said printhead is in fluid communication with said storage means through said outlet.
Claim 25
Independent Claim
265 words
A method for manufacturing a thermal inkjet printing apparatus comprising the steps of: providing a substrate having at least one drive transistor thereon, said drive transistor comprising a plurality of electrical contact regions thereon; applying a layer of electrically resistive material onto said substrate and onto said electrical contact regions of said transistor, said layer of electrically resistive material comprising at least one metal therein; applying a layer of conductive material directly onto said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said layer of conductive material covering said layer of electrically resistive material on said electrical contact regions of said transistor, said uncovered section functioning as a heating resistor, said layer of conductive material comprising at least one metal therein; applying a portion of protective material onto said resistor; securing a plate member having at least one opening therethrough onto said portion of protective material, said portion of protective material having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto; providing a housing having storage means therein for retaining a supply of liquid ink, said housing further comprising at least one outlet therethrough; and securing said substrate to said housing at a position thereon so that said ink receiving cavity of said printhead is in fluid communication with said storage means through said outlet.
Claim 26
Dependent Claim
21 words
The method of claim 18 wherein said layer of electrically resistive material is comprised of a mixture of tantalum and aluminum.
Claim 27
Dependent Claim
26 words
The method of claim 18 wherein said layer of conductive material is comprised of a metal selected from the group consisting of aluminum, copper, and gold.
Claim 28
Dependent Claim
90 words
The method of claim 18 wherein said applying of said portion of protective material comprises the steps of: applying a first passivation layer comprised of silicon nitride onto said resistor; applying a second passivation layer comprised of silicon carbide onto said first passivation layer; applying a cavitation layer comprised of a metal selected from the group consisting of tantalum, tungsten, and molybdenum onto said second passivation layer; and applying an ink barrier layer comprised of plastic onto said cavitation layer, said plate member being secured to said ink barrier layer.
Claim 29
Independent Claim
321 words
A method for manufacturing a thermal inkjet printing apparatus comprising the steps of: providing a substrate having at least one drive transistor thereon, said drive transistor comprising a plurality of electrical contact regions thereon; applying a layer of electrically resistive material onto said substrate and onto said electrical contact regions of said transistor, said layer of electrically resistive material being comprised of a mixture of tantalum and aluminum; applying a layer of conductive material comprised of a metal selected from the group consisting of aluminum, copper, and gold directly onto said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said layer of conductive material covering said layer of electrically resistive material on said electrical contact regions of said transistor, said uncovered section functioning as a heating resistor; applying a first passivation layer comprised of silicon nitride onto said resistor; applying a second passivation layer comprised of silicon carbide onto said first passivation layer; applying a cavitation layer comprised of a metal selected from the group consisting of tantalum, tungsten, and molybdenum onto said second passivation layer; applying an ink barrier layer comprised of plastic onto said cavitation layer; securing a plate member having at least one opening therethrough onto said ink barrier layer, said ink barrier layer having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto; providing a housing having storage means therein for retaining a supply of liquid ink, said housing further comprising at least one outlet therethrough; and securing said substrate to said housing at a position thereon so that said ink receiving cavity of said printhead is in fluid communication with said storage means through said outlet.
Claim 30
Independent Claim
321 words
A method for manufacturing a thermal inkjet printing apparatus comprising the steps of: providing a substrate having at least one drive transistor thereon, said drive transistor comprising a plurality of electrical contact regions thereon; applying a layer of electrically resistive material onto said substrate and onto said electrical contact regions of said transistor, said layer of electrically resistive material being comprised of a mixture of tantalum and aluminum; applying a layer of conductive material comprised of a metal selected from the group consisting of aluminum, copper, and gold directly onto said layer of electrically resistive material, said layer of electrically resistive material having at least one uncovered section wherein said layer of conductive material is absent therefrom, said layer of conductive material covering said layer of electrically resistive material on said electrical contact regions of said transistor, said uncovered section functioning as a heating resistor; applying a first passivation layer comprised of silicon nitride onto said resistor; applying a second passivation layer comprised of silicon carbide onto said first passivation layer; applying a cavitation layer comprised of a metal selected from the group consisting of tantalum, tungsten, and molybdenum onto said second passivation layer; applying an ink barrier layer comprised of plastic onto said cavitation layer; securing a plate member having at least one opening therethrough onto said ink barrier layer, said ink barrier layer having a section thereof removed directly beneath said opening through said plate member in order to form an ink receiving cavity thereunder, said heating resistor being positioned beneath and in alignment with said ink receiving cavity in order to impart heat thereto; providing a housing having storage means therein for retaining a supply of liquid ink, said housing further comprising at least one outlet therethrough; and securing said substrate to said housing at a position thereon so that said ink receiving cavity of said printhead is in fluid communication with said storage means through said outlet.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-16 | 1995-12-16 | 1996-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-16 | 1999-12-16 | 2000-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-16 | 2003-12-16 | 2004-06-16 | $7700.00 | Window Closed / Lapsed |