I would like to inquire about the theoretical basis used in Ansys Mechanical for trace mapping during PCB thermal warpage analysis.
Based on my validation and test results, I observed that Ansys Mechanical appears to adopt a rule-of-mixture approach for the equivalent CTE calculation of traces, where only the volume fraction of the constituent materials is considered.
I would like to better understand the rationale behind Ansys’s choice of the rule of mixture for CTE homogenization. In many publications and references, the Turner model is often recommended for effective CTE prediction, as it accounts for the stiffness effect of each constituent material.
In addition, I would like to ask whether there are any references, internal documents, or published studies that compare different homogenization theories (such as the rule of mixture versus the Turner model) in the context of trace modeling or PCB thermal warpage analysis.
Any clarification on the assumptions, applicability, or limitations of the current approach in Ansys Mechanical would be greatly appreciated.
Thank you very much for your support.
