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(11) | EP 0 771 657 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A modular, fault tolerant liquid ink print head |
| (57) A print head assembly has a plurality of monolithic print head modules wherein nozzles
are etched through a silicon chip substrate, at the bottom of ink channel pits which
are etched part way through the substrate. The ink channel pits are staggered to maintain
the strength of the substrate. The outline of each module follows the staggered array
of ink channel pits at the ends of its chip. The staggering at one end of the chip
is the complement of the staggering at the opposite end of the chip, allowing two
module chips to be butted together. This allows the arrangement and spacing of nozzles
in joinder regions between print head modules to be identical to nozzles in other
regions of the print heads. The preferred manufacturing process uses anisotropic etching on a 〈100〉 single crystal silicon wafer to form ink channels and nozzle barrels, and simultaneously to separate the chips from the wafer. |