Anisotropically etched ink fill slots in silicon
First Claim
1. A method for fabricating ink fill slots in thermal ink-jet printheads, comprising:
- (a) providing a silicon substrate having a <
100>
or <
110>
crystallographic orientation and two opposed, substantially parallel major surfaces, defining a primary surface and a secondary surface;
(b) forming a passivating dielectric layer on both said major surfaces;
(c) exposing a portion of said secondary surface of said silicon substrate underlying said dielectric layer;
(d) anisotropically etching said exposed portion through said substrate to expose a portion of said dielectric layer on said primary surface to form said ink fill slot;
(e) forming and defining thin film resistor elements and conductive traces on said dielectric layer formed on said primary surface;
(f) removing said exposed portion of said dielectric layer on said primary surface overlying said ink fill slot; and
(g) forming a layer on the major surface of said dielectric material and defining openings therein to expose said resistor elements to define a drop ejection chamber and to provide an ink feed channel from said resistor elements to a terminus region, said terminus region fluidically communicating with said ink fill slot for introducing ink from a reservoir to said drop ejection chamber.
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Accused Products
Abstract
An ink fill slot 18 can be precisely manufactured in a substrate 12 utilizing photolithographic techniques with chemical etching. N-type <100> silicon wafers are double-side coated with a dielectric layer 26 comprising a silicon dioxide layer and/or a silicon nitride layer. A photoresist step, mask alignment, and plasma etch treatment precede an anisotropic etch process, which employs an anisotropic etchant for silicon such as KOH or ethylene diamine para-catechol. The anisotropic etch is done from the backside 12b of the wafer to the frontside 12a, and terminates on the dielectric layer on the frontside. The dielectric layer on the frontside creates a flat surface for further photoresist processing of thin film resistors 16.
190 Citations
10 Claims
-
1. A method for fabricating ink fill slots in thermal ink-jet printheads, comprising:
-
(a) providing a silicon substrate having a <
100>
or <
110>
crystallographic orientation and two opposed, substantially parallel major surfaces, defining a primary surface and a secondary surface;(b) forming a passivating dielectric layer on both said major surfaces; (c) exposing a portion of said secondary surface of said silicon substrate underlying said dielectric layer; (d) anisotropically etching said exposed portion through said substrate to expose a portion of said dielectric layer on said primary surface to form said ink fill slot; (e) forming and defining thin film resistor elements and conductive traces on said dielectric layer formed on said primary surface; (f) removing said exposed portion of said dielectric layer on said primary surface overlying said ink fill slot; and (g) forming a layer on the major surface of said dielectric material and defining openings therein to expose said resistor elements to define a drop ejection chamber and to provide an ink feed channel from said resistor elements to a terminus region, said terminus region fluidically communicating with said ink fill slot for introducing ink from a reservoir to said drop ejection chamber. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification