Micro device design and fabrication for the experimental investigation of jet impingement on an array of micro pin fins

This work presents the design, fabrication, and demonstration of micro devices for the experimental investigation of heat transfer characteristics of jets impinging on an array of micro pin fins for high heat flux microelectronics and photonics cooling applications. The micro devices, fabricated using MEMS fabrication techniques, consist of an array of radially spaced micro pin fins with diameters ranging from 50 mu m-125 mu m, height of 230 mu m, pitch of 250 mu m, and a base area of 2 x 2 mm(2). The micro pin fins are of different geometries, namely circular, elliptical, hydrofoil, square, and rectangular. Single-phase and boiling heat transfer experiments were carried out using refrigerant R134a. Enhancement of both the single-phase and the two-phase heat transfer coefficients were observed. Due to the presence of the micro pin fins, the boiling heat transfer was characterized by the suppression of boiling hysteresis. With a better heater design, the proposed micro device is an excellent platform for studying jet impingement heat transfer on micro pin fins.