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106 SMT007 MAGAZINE I FEBRUARY 2020 area, and onto the solder mask. Precise control was vital to avoid solder-balling. Solder paste print inspection was becoming a critical oper- ation in the surface mount assembly process, and state-of-the-art 3D systems were capable of measuring height, volume, and area of paste deposits, computing stencil offsets and detect- ing defects such as bridges and missing fea- tures. Willis concluded his presentation with an introduction to low-temperature, lead-free sol- der alloys and pastes. Alloys were based on tin- bismuth or tin-bismuth-silver, melting in the range of 138–140°C, and with typical peak- reflow temperatures in the range of 160–170°C. His experiences of early versions were that they had a tendency to slump, could display a range of particle sizes and shapes, and could exhibit minor solder-balling. However, they were use- ful for heat-sensitive assemblies and were sometimes used in conjunction with SAC305 alloys. A lively Q&A session occupied the next half- hour, with Willis responding to queries on tack testing, cleaning chemistries, printing prob- lems, temperature profiling, stencil design, mechanical support of assemblies, ESD con- trol, and intrusive reflow. "All good fun, and I get to play as well!" With his encyclopaedic knowledge and emphasis on practical process assessment to help attendees gain a proper understanding of the problem and get the most out of basic common-sense methods—before turning to more elegant and expensive instru- mental techniques and his extensive collection of unique video clips to illustrate and demon- strate every aspect—Bob Willis's relaxed and entertaining style provided an exceptional learning experience. SMT007 Solder paste particles from the 1980s were not good. "We're pleased to welcome Eileen Drake to our Board of Directors," said GSUSA National Board President Kathy Hopinkah Hannan. "Eileen is an extraordinary business- woman who has served our nation first as an Army avi- ation officer and now as a leader in the aerospace and defense industry. Her leadership experience will be of tremendous value to our organization as it forges ahead into a dynamic future." Girl Scouts is the nation's preeminent lead- ership development organization for girls, with programs from coast to coast and across the globe. "I am honored to be selected to serve on Girl Scouts' National Board of Directors," said Drake. "Over its 107- year history, Girl Scouts has made huge contributions to the development of girls as leaders and citizens. With our nation's growing needs in STEM, leadership and diversity, this organization's work is more important than ever." Drake joined Aerojet Rocketdyne in March 2015 as chief operating officer. A former Army aviation officer, Drake also worked in leadership roles at Ford Motor Company and United Technologies. Since becoming CEO at Aerojet Rocketdyne, Drake has overseen a fun- damental reorganization of the company, creat- ing efficiencies and developing new capabilities. Drake also serves on the board of Woodward Inc., as well as the Board of Governors and Executive Com- mittee of the Aerospace Industries Association. Through- out her career, Drake has been passionate about promot- ing STEM initiatives and advancing the work of Girl Scouts. Aerojet Rocketdyne CEO and President Eileen Drake Selected to Serve on National Board of Directors of Girl Scouts of the USA

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