Speaker: Prof. Pradeep Lall, Auburn University
Meeting Date: Thursday, March 18, 2020
Time: Checkin via WebEx at 11:50 AM; Presentation at 12:00 noon (PST)
Location: on the Internet (WebEx)
Summary: There is an increased emphasis on the use of thin and flexible form-factors for electronic products. Rigid electronics uses glass-epoxy impregnated substrates for the assembly of components. The use of additive flexible-electronics opens opportunities for seamless integration of the electronics assemblies on non-planar surfaces in addition to achieving a shorter product ramp-up to first prototype owing to the elimination of the print and etch processes and mask tooling. A number of printing processes have emerged for the additive fabrication of electronics including aerosol-jet printing, inkjet printing, direct-write and screen printing. A number of inks have emerged for solutions related to the printing of interconnects and dielectrics. However, the process knowledge related to the interaction of the print-quality with the process parameters is missing in open literature. The lack of process-knowledge and process-property interactions is an impediment for use in large-scale production of additive printing methods. In this presentation, results from the study of process-property-performance relationships in process development of additively printed multi-layer substrates with z-axis interconnects are presented. Data on the fabrication of substrates is presented using the aerosol-jet printing process. A number of print parameters have been studied including carrier mass-flow rate, sheath mass-flow rate, ink flow rate, stage speed, standoff height, chiller temperature, platen temperature, and sintering process parameters. Electrical performance has been quantified using resistance measurements. The mechanical performance has been quantified using nano-indentation, and shear load to failure of the printed traces. Better understanding of the effect of each process parameter in the printed lines will allow users to select appropriate process parameters for design functional performance. Process parameter drift over a long production run may be important for a high-volume production environment. The effect on the print process may be in the form of line consistency and resistance –- both of which have been quantified in this study through the quantification of process-capability for z-axis interconnects. Data is presented on 2-layer, 5-layer and 8-layer substrates.
Bio: Pradeep Lall is the MacFarlane Endowed Distinguished Professor with the Department of Mechanical Engineering and Director of the NSF-CAVE3 Electronics Research Center at Auburn University. He holds Joint Courtesy Appointments in the Department of Electrical and Computer Engineering and the Department of Finance. He is a member of the technical-council, academic co-lead of the asset-monitoring TWG of NextFlex Manufacturing Institute. He is the author and co-author of 2-books, 14 book chapters, and over 700 journal and conference papers in the field of electronics reliability, safety, energy efficiency, and survivability. Dr. Lall is a fellow of the ASME, fellow of the IEEE, a Fellow of NextFlex Manufacturing Institute, and a Fellow of the Alabama Academy of Science. He is recipient of the Auburn Research and Economic Development Advisory Board Award for Advancement of Research and Scholarship Achievement, IEEE Sustained Outstanding Technical Contributions Award, National Science Foundation’s Alex Schwarzkopf Prize for Technology Innovation, Alabama Academy of Science’s Wright A. Gardner Award, IEEE Exceptional Technical Achievement Award, ASME-EPPD Applied Mechanics Award, SMTA’s Member of Technical Distinction Award, Auburn University’s Creative Research and Scholarship Award, SEC Faculty Achievement Award, Samuel Ginn College of Engineering Senior Faculty Research Award, Three-Motorola Outstanding Innovation Awards, Five-Motorola Engineering Awards, and over Thirty Best-Paper Awards at national and international conferences.