Issue link: https://iconnect007.uberflip.com/i/1389320
JULY 2021 I SMT007 MAGAZINE 45 Conversely, the other techniques are essen- tial in determining what is present that is caus- ing the problem identified by SIR. at is why the overall "toolbox" of test methods is crucial in helping to predict circuit reliability. Such fur- ther examination is best described as a "tool- box" of various test techniques, the most com- mon of which, is ion chromatography or FTIR. In conclusion, users must demand their material supplier to provide the SIR data used to qualify their product. en select your pre- ferred material set and run an evaluation to the IEC 61189-5-502. If unacceptable data is found, it will be necessary to run ion chro- matography and/or FTIR to determine what might be causing a problem. e recommended procedure would be to test a B-52 sample extracted at each individual process stage, starting with bare copper. In this way, it is possible to identify at which process step the SIR data changed and endeavour to find alternative materials or equipment adjust- ments. SMT007 References 1. "Process Control of Ionic Contamination Achiev- ing 6-Sigma Criteria in the Assembly of Electronic Circuits," P. Eckold, M. Routley, L. Henneken, G. Naisbitt, R. Fritsch, U. Welzel, published at IPC APEX EXPO Conference and Exhibition 2017. Also refer to IPC WP-019B for more information. Graham Naisbitt is president of GEN3. He is a member of IEC TC91 WG2, WG3 & WG10, is a maintenance leader for a number of published documents having to do with cleanliness, and is on numerous IPC sub- committees and task groups on solderability and cleaning. Naisbitt is also the author of The Printed Circuit Assembler's Guide to Process Validation. The onset of the COVID-19 pandemic spurred an immediate need to develop new, innovative sys- tems in supply chains and infrastructure. And for three Norwegian graduate students enrolled in the MIT Professional Education Advanced Study Program (ASP), spring 2020 was the moment when technology, innovation, and preparation met opportunity. Lars Erik Matsson Fagernæs, Bernhard Paus Græsdal, and Herman Øie Kolden were all students at the Norwegian University of Science and Tech- nology (NTNU) but only met after they arrived on the MIT campus for their ASP in 2019. The friends had already been working on a drone- related project and pivoted to the idea of making a drone to transport biological sam- ples. They chose a fixed-wing quadcopter design that combines vertical takeoff and landing with efficient long-distance travel. Their prototype drones were built at MIT and tested in the John- son Athletic Center around its run- ning track. They found inspiration in the work of MIT professors like Russ Tedrake, director of the Center for Robotics at the Com- puter Science and Artificial Intelligence Laboratory (CSAIL) and a professor of electrical engineering and computer science. In building their drone, Fagernæs, Græsdal, and Kolden had to overcome a number of tech- nical issues, including icing, vibrations, and vari- able temperatures. Evolving EU drone regulations necessitated building redundant systems and a parachute in case of malfunction. However, the biggest challenge was the distance they needed to fly, 120 kilometers from start to end. An auton- omous flight of that length had never been com- pleted in Scandinavia before. "People thought we were crazy," Fagernæs recalls. "But we were lucky enough to speak to the right people at the hospi- tal who were desperate for a solu- tion, and they decided to give us a chance. So, we have been work- ing ever since, day and night." (Source: MIT News) Developing Drones to Address Pandemic-related Challenges in Scandinavia