A heater chip has a substrate and at least one die, made of silicon, and a bond non-adhesively attaching them. The substrate, thick enough to resist bowing, has ink supply vias from back to front surfaces. The die has ink flow vias from back to front surfaces and circuitry including heater elements adjacent the front surface interspersed with ink flow vias. A metal through the die connects a conductor on a front of the substrate to a heater element on a front of the die. A wire bond connects to the front of the substrate, but is offset from die.