"Tiny Cooling Fan" electronic technology development, high-power device heating power increases, the heat flux density is increasing. Product thermal design has a critical impact on product reliability. To make good thermal design power devices, we must first understand the "Tiny Cooling Fan" thermal performance of power devices, and then select the appropriate cooling mode, the correct radiator duct design and analysis necessary to optimize the final specification, properly installed radiator allows the device to achieve the best cooling effect. "Tiny Cooling Fan" Device thermal performance parameters; the device manufacturers will offer the device soldering temperature, package, operating temperature range, the device junction temperature limit, the internal resistance and other information, which is carried out thermal design parameters are the basis and premise. Here some common thermal parameters one by one explanation: