Design of a Novel Tridimensional Silicon MEMS ThermoElectric Generator

A novel design of a MEMS ThermoElectric Generator (TEG) with a tridimensional structure manufactured with standard silicon-based processes is presented. The proposed 5 mm × 5 mm TEG embeds 221 cells connected electrically in parallel each composed of the electrical series of 15 pn-polysilicon-based thermocouples. Heat can be transferred from a hot side at temperature TH to a cold side at temperature TC by means of high-thermal-conductivity copper paths immersed in low-thermal-conductivity resin mold that composes the package. The working principle has been validated through 3D finite-element simulations. An in-process test structure has been experimentally tested. An output voltage V TEG of -3.3 mV has been measured for a temperature difference ΔT=TH-TC of 6 °C, resulting in V_TEG / ΔT =-550 μ V / ° C The final TEG device is expected to have an enhanced thermoelectric conversion efficiency due to the molding injection which will optimize the temperature difference across the thermocouples minimizing thermal leakage.