Thermo-pneumatic actuator fabricated using silicon-on-insulator (SOI)

A method for forming a printhead comprising a plurality of thermo-pneumatic actuators as part of a thermo-pneumatic actuator array, wherein the method comprises:

• providing a substrate and a plurality of individually addressable resistors;
• forming a patterned standoff layer over the substrate, wherein an opening in the patterned standoff layer exposes a region over each resistor of the plurality of resistors;
• attaching a device layer of a silicon-on-insulator (SOI) wafer to the patterned standoff layer to form a working fluid chamber from the exposed region over each resistor of the plurality of resistors, thereby forming a plurality of working fluid chambers;
• etching a handle layer of the SOI wafer using a dielectric layer of the SOI wafer as an etch stop layer to form a plurality of recesses within the handle layer, wherein each recess overlies one of the resistors;
• attaching a nozzle plate comprising a plurality of nozzles to the handle layer, wherein an ink chamber is defined by each recess of the plurality of recesses in the handle layer and the device layer of the SOI wafer provides a thermo-pneumatic actuatable membrane between the working fluid chamber and the ink chamber for each of the plurality of thermo-pneumatic actuators.

A printer, comprising:

• a printhead comprising a plurality of thermo-pneumatic actuators as part of a thermo-pneumatic actuator array, wherein the thermo-pneumatic actuator array comprises:
• a heater wafer comprising:
• a substrate;
• and
• a plurality of resistors, wherein each resistor of the plurality of resistors is individually addressable;
• a silicon-on-insulator (SOI) wafer comprising:
• a device layer that provides a thermo-pneumatic actuatable membrane between a working fluid chamber and an ink chamber for each of the plurality of thermo-pneumatic actuators;
• a dielectric layer attached to the device layer;
• and
• a handle layer attached to the dielectric layer, wherein the dielectric layer physically separates the device layer from the handle layer and a thickness of the handle layer determines a height of the ink chamber;
• and
• a nozzle plate comprising a plurality of nozzles,
• wherein the nozzle plate is attached to the handle layer;
• and
• a printer housing that encases the printhead.

A printhead comprising a plurality of thermo-pneumatic actuators as part of a thermo-pneumatic actuator array, wherein the thermo-pneumatic actuator array comprises:

• a heater wafer comprising:
• a substrate;
• a plurality of resistors, wherein each resistor of the plurality of resistors is individually addressable;
• and
• a patterned planarized standoff layer overlying the substrate, wherein the device layer is attached to the planarized standoff layer;
• a silicon-on-insulator (SOI) wafer comprising:
• a device layer that provides a thermo-pneumatic actuatable membrane between a working fluid chamber and an ink chamber for each of the plurality of thermo-pneumatic actuators, wherein a thickness of the patterned planarized layer determines a height of the working fluid chamber;
• a dielectric layer attached to the device layer;
• and
• a handle layer attached to the dielectric layer, wherein the dielectric layer physically separates the device layer from the handle layer;
• and
• a nozzle plate comprising a plurality of nozzles,
• wherein the nozzle plate is attached to the handle layer.