Low-profile MEMS thermal printhead die having backside electrical connections

摘要

A thermal printhead die is formed from an SOI structure as a MEMS device. The die has a printing surface, a buried oxide layer, and a mounting surface opposite the printing surface. A plurality of ink delivery sites are formed on the printing surface, each site having an ink-receiving and ink-dispensing structure. An ohmic heater is formed adjacent to each structure, and an under-bump metallization (UBM) pad is formed on the mounting surface and is electrically connected to the ohmic heater, so that ink received by the ink-delivery site and electrically heated by the ohmic heater may be delivered to a substrate by sublimation. A through-silicon-via (TSV) plug may be formed through the thickness of the die and electrically coupled through the buried oxide layer from the ohmic heater to the UBM pad. Layers of interconnect metal may connect the ohmic heater to the UBM pad and to the TSV plug.

主权项

1. A method of manufacturing a MEMS thermal printhead die on an SOI structure having a top surface, a buried oxide layer, and a mounting surface opposite the top surface, the method comprising steps for:
(a) forming a plurality of ink-delivery sites on the top surface, wherein each ink-delivery site comprises a plurality of ink-dispensing pores formed through the SOI structure; (b) forming an ohmic heater adjacent to at least one of the ink-dispensing pores; (c) forming at least one under-bump metallization (“UBM”) pad on the mounting surface; and (d) forming at least one through-silicon via (“TSV”) plug, the TSV plug electrically coupling the ohmic heater to the UBM pad through the thickness of the printhead die.