Robust printhead chip mounting suitable for long inkjet printheads
An inkjet printhead includes: a rigid elongate manifold having ink supply channels extending along its length and a plurality of ink outlets defined therein; a shim attached to the manifold, the shim having a plurality of shim apertures for receiving ink from the ink outlets; and a plurality of printhead chips adhesively bonded directly to the shim, each printhead chip receiving ink from one or more of the ink outlets. The the shim is formed of a metal alloy having a CTE of 5 ppm/° C. or less.
1. An inkjet printhead comprising:
a rigid elongate manifold having one or more longitudinal ink supply channels extending along its length and a plurality of through-holes extending transversely from a respective ink supply channel, each through-hole meeting with a lower surface of the manifold to define an ink outlet;
a shim attached to the lower surface of the manifold, the shim having a plurality of shim apertures for receiving ink from the ink outlets; and
a plurality of printhead chips adhesively bonded directly to the shim, each printhead chip receiving ink from one or more of the ink outlets via one or more of the shim apertures,
wherein the shim and the manifold are each comprised of a metal alloy having a coefficient of thermal expansion of 5 ppm/° C. or less.
2. The inkjet printhead of claim 1 , wherein the shim and the manifold are each comprised of an alloy of iron and at least one other metal selected from the group consisting of: nickel, cobalt and chromium.
3. The inkjet printhead of claim 1 , wherein the manifold is a one-piece structure.
4. The inkjet printhead of claim 1 , wherein the manifold is comprised of a same material as the shim.
5. The inkjet printhead of claim 1 , wherein the manifold has a longitudinal ink cavity defined in a lower surface thereof, and wherein the shim is attached to a lower surface of the manifold so as to bridge across the longitudinal ink cavity.
6. The inkjet printhead of claim 5 , wherein the longitudinal ink cavity has a roof and sidewalls extending between the roof and the lower surface, the plurality of ink outlets being defined in the roof.
7. The inkjet printhead of claim 6 , wherein a longitudinal rib divides the ink cavity into longitudinal ink feed channels at either side of the rib, the rib having a lower surface coplanar with the lower surface of the manifold.
8. The inkjet printhead of claim 7 , wherein the shim is bonded to the lower surfaces of the rib and the manifold.
9. The inkjet printhead of claim 7 , wherein each printhead chip has a central portion aligned with the rib and opposite side portions overlapping with respective longitudinal ink feed channels.
10. The inkjet printhead of claim 1 , wherein the shim and a printed circuit board are adjacently bonded to a lower surface of the manifold.
11. The inkjet printhead of claim 10 , wherein the shim and the printed circuit board have coplanar lower surfaces.
12. The inkjet printhead of claim 11 , wherein the lower surface of the manifold is stepped to accommodate different thicknesses of the shim and the printed circuit board.