A method of forming an opening through a substrate having a first side and a second side opposite the first side includes forming a trench in the first side of the substrate, forming a mask layer within the trench, forming at least one hole in the mask layer, filling the trench and the at least one hole,...http://www.google.es/patents/US7018015?utm_source=gb-gplus-sharePatente US7018015 - Substrate and method of forming substrate for fluid ejection device
Substrate and method of forming substrate for fluid ejection device
