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.