M. –H. Chang,1 D. Das,1 S. W. Lee,3 and M. Pecht1,2*
1Center for Advanced Life Cycle Engineering, Department of Mechanical Engineering,
University of Maryland, College Park, MD 20742, U.S.A.
2Center for Prognostics and System Health Management,
City University of Hong Kong, Hong Kong, China
3EPACK lab c/o TTC, Department of Mechanical Engineering,
Hong Kong University of Science & Technology, Hong Kong, China
Unlike other electronic component manufacturers, many LED manufacturers do not provide board-level thermal cycling test results as part of the part information. The users of LEDs need to determine the durability of solder joints under their application conditions and circuit board material and geometry. Simulation of solder joint reliability can help system developers to make design decisions. The properties of mechanical, material, thermal and electrical specification data provided by the LED manufacturers are not in a form that can be directly used as inputs to board-level simulation.
The assessment of interconnect reliability needs to consider the local thermal environment that is created in a package and interconnects during its operation. Any test results on interconnect reliability that do not take into account the operating environment of LEDs in lighting applications and the construction and material properties of the board are not useful input to design decisions. This article provides simulation process results of interconnect reliability of LED assemblies for various load conditions under thermal cycling and power load. The differences between various conditions depend on package modeling assumptions, maximum and minimum ambient temperature, ramp and dwell time, power load causing temperature rise of the LED packages, and board design.
Keywords: LEDs, reliability, solder joints, and virtual qualification.
Complete article is available to CALCE Consortium Members.