Thermal characterization of surface mount devices

A methodology for the thermal characterization of surface mount devices (SMDs) is proposed. Measured data are shown only for the relative evaluation of various thermal test conditions and environments. Specific topics covered include the design of a suitable thermal test board; the mounting and orientation of the device for the thermal measurement in still and moving air environments; and collection, analysis and presentation of the data and detailed documentation of the test conditions and environment. The latter is especially important if the measurements are to be repeated by the SMD vendor or duplicated by the SMD user. The thermal test board design is discussed from the standpoint of existing standards and low-cost alternatives. The moving air environment, implemented with a variation of an industry standard design and designed to provide up to 1000 linear feet per minute capability, is discussed with the intent of establishing a new industry standard design.<>