Electrically connecting electrically isolated printhead die ground networks at flexible circuit

摘要

A printhead assembly for an inkjet-printing device includes a printhead die and a flexible circuit connected to the printhead die. The printhead die includes a substrate, a first ground network electrically connected to the substrate, a device layer, and a second ground network electrically connected to the device layer. The first ground network and the second ground network are electrically isolated from one another within the printhead die. The first ground network and the second ground network are electrically connected to one another at the flexible circuit.

主权项

1. A printhead assembly for an inkjet-printing device, comprising:
a printhead die comprising:
a substrate;a metal layer primarily implementing a first ground network electrically connected to the substrate;a device layer;a surface metal layer, different than the metal layer, implementing a second ground network electrically connected to the device layer, the second ground network physically isolated from the first ground network within the printhead die itself such that the surface metal layer and the device layer are electrically disconnected from the metal layer and the substrate within the printhead die itself; and, a flexible circuit connected to the printhead die, wherein the first ground network and the second ground network are electrically connected to one another just by the flexible circuit, wherein the second ground network is a primary ground network and the first ground network is a quiet ground network in that more electrical current flows through the second ground network than through the first ground network.