Abstract: A multi-layer aluminum nitride ceramic, multi-heating element substrate is provided for forming electrical bonds between integrated circuits and an interposer structure using a thermocompression bonding process. The individually energizable heater element traces can be run through common regions of the heater surface platform. A network of cooling vias can be run through other parts of the substrate. The traces are then separately controlled and energized during a predetermined routine resulting in a temperature profile that maintains a substantially constant temperature plateau phase near a reflow temperature, and a more uniform temperature across the spaced apart surface regions of the heater substrate, thus imparting a more precisely uniform heating to the parts being bonded.