Investigation Of Microchannel Heat Sink With Complicated Channel Structure Based On MEMS Technologies

With the trend from the microminiaturization of macro devices to the independent exploitation of micro devices, dimension of devices are brought into small space by MEMS technologies. Transition of matter and energy in devices are limited due to microminiaturization of structures, which results in difficulties of heat transformation in devices whose power consumption are so high. On the other hand, in the microelectronics filed, with the rapid development of the integrity of the devices in the chip, the problem of heat management of chips due to temperature sensitivity of microelectronic devices become more and more important. Microchannel heat sink with high heat transfer efficiency provides an effective solution for the problem mentioned above.Traditional microchannel heat sink comprises of parallel microchannels. Heat from the cooled device is transferred to the coolant with forced convection. With the development of MEMS technologies, applying MEMS technologies to solve the problem of heat management in micro system improves the structure adaptability and heat transfer characteristics of microchannel heat sink and the structure of microchannel heat sink become complicated compared with the traditional structure.A novel microchannel heatsink with short distance transverse channel array and thin heat spreader was investigated based on the traditional structure and MEMS technologies. The transverse channels near to the heat source provide a short heat transfer path. Short distance of transverse channel makes more coolant under the developing status, which increases the heat transfer efficiency. Compared to the traditional structure, transverse channel arrays increase the heat exchange area between the channel and coolant. On the other hand, using thin heat spreader provides a heat transfer path with low thermal resistance. The novel structure combined the transverse channel array and thin heat spreader to form a novel design. The key heat transfer performances of traditional and novel structure are compared employing ANSYS and CFX software packages. The relative analysis confirms the rationality of the design. Making use of superiority of MEMS technologies on complicated structure fabrication and different materials compatibility, a sample with novel structure was manufactured by integrating the silicon and Non-silicon microfabrication technologies. A test system including IR (infrared spectra) detector was set up to show the abecedarian characteristics of the novel microchannel heat sink.The novel structure had more efficient heat transfer performance than traditional structure under all of the conditions employed in simulation. Tests showed that the thermal resistance of the novel structure was about 1.87?С/W with the low coolant velocity 6.79ml/min. When the coolant velocity increased to 800ml/min, the result of the simulation showed that the whole thermal resistance was down to 0.09?С/W. Based on the above structure, a heat enhancement element was added at the back of the substrate. Applying the parameter simulation method, simulations of the microchannel heat sink with different structure were performed. The results showed that the effect of dimensions of the microchannels on the heat transfer characteristics was inconspicuous compared with the effect of channel conformation.The related micromachining technology has been studied for microchannel heat sink with complicated structure. Parameters and materials have been selected. The basic micromachining technologies were used including sputtering, electroplating, photolithography, etching and eutectic bonding. In order to ensure the devices being fabricated successfully, some normal micromachining technologies have been modified according to the design and actual requirement.