Electronic Products & Technology


SMTA Ontario Chapter Webinar

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March 02, 2022

Effect of  QFN I/O pad solder paste overprint on thermal pad void reduction

Speaker: Norman Armendariz, PhD
Time: 12:00pm EST
Event platform: Zoom
Pre-registration is required. Only registered attendees will receive the link to participate.
12:00-12:10pm – Introductions
12:10-12:45pm – Presentation
12:45-1:00pm – Q&A
Webinar Abstract:
QFN- Quad Flat No-lead SMT-surface mount technology components have been increasingly used and becoming smaller for applications requiring a high level of thermal performance and reliability.  QFN device thermal pad regions have been observed w/ excessive void densities >30% in area, which limits the thermal conductivity or performance of the device and often requires subsequent costly rework.  Voids also become more dominant as the surface area of the thermal pad regions decrease, if not correspondingly reduced in size or density.  Real-time imaging using an XRT-x-ray transmission radiographic machine equipped with a programmable reflow temperature profile thermal or “hot” stage providing further insight to the formation mechanisms.  Various surface finishes, reflow profiles, solder paste volumes and over-print values were characterized for the single largest void and void densities.   Paper will discuss void formation and reduction mechanisms using conventional and real-time X-ray imaging under simulated thermal reflow conditions, which showed a statistically significant reduction of large voids and void density using the solder paste over print method.
About speaker:
Norman Armendariz is an Engineering Fellow at Raytheon responsible for materials engineering design, materials analysis, process equipment development, micro-analytical metrology development, production support and technology roadmaps associated with the manufacturing of CCA- circuit card assemblies used in missiles, smart munitions, ground based radars, and mobile sensors across multiple US and international sites.  Norm has over 25 years of industrial experience, having worked for LTV, Lockheed/NASA, Motorola, Intel, Texas Instruments and American University.    He holds an interdisciplinary PhD in Chemical Engineering from New Mexico State University, MS in Materials Science Engineering from the University of Illinois at Urbana-Champaign, and BS in Metallurgical Engineering from Colorado State University, with 9 US patents and 29 peer-reviewed publications.

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