Patent ID: 8608288

Claim:
A printhead, comprising: a silicon wafer substrate having a first side, including a row of chambers and a second side opposite the first side of the silicon wafer substrate; a plurality of self-aligned holes disposed along a first side of the row of chambers for feeding ink to the row of chambers and a plurality of self-aligned holes disposed along a second side of the row of chambers for feeding ink to the row of chambers, wherein the second side of the row of chambers is opposite to the first side of the row of chambers, wherein each self aligned hole has a feed opening on the first side of the silicon wafer substrate, the feed opening having a length between 10 microns and 100 microns and a width between 10 microns and 100 microns; and each self aligned hole extending from the first side of the silicon wafer substrate to the second side of the silicon wafer substrate, wherein each self-aligned hole is smaller at the first side of the silicon wafer substrate than at the second side of the silicon wafer to form a retrograde profile angle; a drop forming mechanism in the chamber; a nozzle plate proximate to the drop forming mechanism; a source of fluid for supplying fluid to the self-aligned holes; and wherein each chamber is defined between chamber walls, and wherein edge of each feed opening is 0-5 microns away from the chamber walls and the drop forming mechanism.