The performance of micro heat pipes measured by integrated sensors

This study deals with silicon micro heat pipe (MHP) arrays which are powerful thermal devices for the cooling of microelectronic components. MHP arrays, consisting of non-circular hermetically sealed channels, are passive cooling systems. Their working principle is based on two-phase heat transfer. We report in this work on the fabrication and the characterization of all-silicon MHP arrays using integrated temperature sensor arrays. The MHP arrays consist in series of several tens of triangular shaped channels hermetically sealed using Si - Si direct bonding. We first show how we proceeded to integrate sensor arrays consisting of polycrystalline silicon thermistors in the all-silicon MHP arrays using simple and reliable microfabrication steps. Then, experimental thermal performances obtained using methanol as the working fluid are presented when varying the liquid charge, the heat sink temperature and the input power.