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Abstract

Additive manufacturing provides a pathway for producing printed hybrid electronic (PHE) assemblies in novel form factors, combining conventionally manufactured components with additively manufactured features. Aerosol jet printing (AJP) is one of the leading methods for PHEs, and understanding the reliability of AJP conductors under real-world loading conditions is critical to fully leveraging this technology.

This talk examines the thermomechanical fatigue reliability of sintered silver nanoparticle conductors in AJP electronics under temperature cycling across three substrate platforms: glass-FR4, Kevlar-epoxy, and aluminum nitride ceramic. These substrates span a wide range of thermal expansion behavior, and the results show that substrate selection is a primary driver of conductor fatigue life. Failure analysis across all three substrates consistently identified the transition region connecting printed traces to copper pads as the predominant failure site.

The substrate microstructure, specifically the woven fiber architecture of composite laminates, significantly influences the local thermomechanical strain experienced by the printed conductor. Conventional homogenized finite element models that treat the substrate as a uniform material fail to capture this effect and are unable to correctly rank fatigue performance across substrates. A microscale model that explicitly captures the weave geometry is required to better represent the effective thermomechanical properties of composite substrates, resolve these discrepancies, and account for position-dependent strain sensitivity introduced by the local fiber geometry. These findings highlight the importance of accounting for substrate microstructure when selecting composite materials and designing conductor layouts for reliable printed electronics.

Prabhat Janamanchi is a PhD candidate in Mechanical Engineering at the University of Maryland, College Park, and a member of the Center for Advanced Life Cycle Engineering (CALCE). Advised by Prof. Abhijit Dasgupta, his research focuses on the reliability of aerosol jet printed conductors in printed electronics under thermomechanical, vibration and electrochemical loading. His work combines accelerated testing, finite element modeling, and physics-of-failure approaches to assess fatigue and degradation in additively manufactured electronic assemblies.

Copyright(c) CALCE/University of Maryland