Temperature Cycling Solder Fatigue with Ansys Sherlock Software

This course reviews how to perform a temperature cycling Solder Fatigue analysis inside of Ansys Sherlock™ electronics reliability prediction software. This includes setting up a project in Ansys Sherlock software, solder fatigue background, defining the loads and life cycle, running the analysis, and reviewing the results. The primary failure mode of interest is solder fatigue.

• The fatigue performance of solder joints is significantly influenced by the board properties, thermal stresses, and package dimensions. During changes in temperature, the component and printed board will expand or contract by dissimilar amounts due to differences in their respective coefficient of thermal expansion (CTE).
• This difference in expansion or contraction will place the second-level solder joint under a repetitive shear load. Typically, the shear load, or stress, is sufficient to cause inelastic strain of the solder joint. Repeated temperature cycling leads to an accumulation of strain which can damage the solder joint. With each additional temperature cycle, this damage increases, resulting in crack propagation and eventual failure of the solder joint.
• The failure of solder joints due to thermo-mechanical fatigue is one of the dominant wear-out mechanisms in electronic products.

Learning Outcomes:

Following completion of this course, you will be able to:

• Perform a temperature cycling solder fatigue analysis on a PCB, including setup and viewing results.
• Input thermal maps, from either CFD results or a thermal camera, to account for temperature gradients in cases of power cycling.

Prerequisites:

• Completion of the Ansys Sherlock Getting Started or prior knowledge of Ansys Sherlock software.
• Some working knowledge of temperature cycling loads and solder fatigue is a plus.

Please note: These training materials were developed and tested in the 2024 R2 release.