PRINTHEAD HAVING HEATED SHIELD PLATE
FIG14 is a sectional bottom perspective of the shim and printhead chip mounting arrangement
Use of a singular shim 66 having a pair of longitudinal shim sections 66A and 66B minimizes relative skew of the first row 14 and second row 16 of printhead chips 70 by ensuring parallelism between the two shim sections 66A and 66B. Alignment of the shim 66 relative to the manifold 25 is facilitated using mechanical alignment tabs 61 on the shim, which engage with alignment features 63 in the form of recesses defined in the lower surface (see FIG14). It will be appreciated that the shim 66 has a number of alignment tabs 61 positioned for engagement with a corresponding plurality of alignment features 63 in the manifold 63. A plurality of alignment tabs 61 ensures alignment in both x- and y-axes.
sectional view
67
shim trusses
14
first row
73
respective bond pad
63
alignment features
64
second portions second portion
56
ink feed channels
16
second row second rows
61
alignment tabs
70
printhead chips printhead chip
68
voids
['1. An inkjet printhead (1) comprising: a manifold (25) having a plurality of ink outlets (50) defined in a manifold surface; a plurality of printhead chips (70) mounted to the manifold surface (52) via a shim (66), the printhead chips being aligned with the ink outlets; a PCB (18) mounted to the manifold surface and offset from the ink outlets, the PCB being electrically connected to the printhead chips, wherein a lower surface of the PCB is coplanar with a lower surface of the shim; and a shield plate (20) bonded to the PCB and part of the shim, the shield plate covering the PCB, wherein: the shield plate has one face in thermal contact with the PCB and an exposed opposite face defining a lower surface of the printhead; and the shim has at least one void region (68) offset from the printhead chips, the void region thermally isolating part of the shield plate from the manifold.', '6. The inkjet printhead of claim 5 comprising first and second rows of printhead chips, the first row of printhead chips having a respective first PCB and the second row of printhead chips having a respective second PCB, wherein the first and second PCBs are positioned at opposite distal longitudinal sides of the first and second rows of printhead chips.']