Methodology for Thermal Characterisation of Surface Mount Devices

Thermal characterisation of surface mount devices (SMDs) has become a growing concern as these components have increased in use—a situation aggravated by the lack of accepted industry standards for making thermal measurements. This paper attempts to provide better understanding of thermal resistance terminology, and to summarise some of the existing problems with current standards and common practices. A defined methodology for obtaining SMD thermal characteristics is proposed, involving measurement by vendors and confirmation by users, and suitable for use in meeting application‐oriented requirements. The importance of providing a clear and complete set of test condition information is also emphasised.