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JANUARY 2023 I DESIGN007 MAGAZINE 67 cessing minimizes the pad orientation differ- ence. HASL is not used for fine pitch compo- nents. is is because it increases fabrication and assembly rework for boards that have fine- pitch SMT devices with lead centers below 0.020" and presents coplanarity issues. Pros and Cons of HASL Pros • Economical and widely available • Excellent solderability • Can be reworked at the fabricator • Presents a very flat solder deposit Cons • Limited assembly reflow cycles, as the HASL process introduces a thermal shock before it gets to assembly • Not suited for fine pitch (due to uneven surface height) or high aspect through- holes • Standard SnPb HASL is not RoHS compliant • Lead-free HASL requires different assembly soldering parameters Understanding the cost drivers in PCB fab- rication and early engagement between the designer and the fabricator are crucial ele- ments that lead to cost-effective design suc- cess. Following your fabricator's DFM guide- lines is the first place to start. DESIGN007 Anaya Vardya is president and CEO of American Standard Circuits; co-author of The Printed Circuit Designer's Guide to… Fundamentals of RF/Microwave PCBs and The Printed Circuit Designer's Guide to… Flex and Rigid-Flex Fundamentals; and author of The Printed Circuit Designer's Guide to… Thermal Management: A Fabricator's Perspective. Visit to download these and other educational titles. He also co-authored "Fundamentals of Printed Circuit Board Technologies" and provides a discussion of flex and rigid flex PCBs at Real Time with… American Standard Circuits. David N. Graves, 65, passed away December 22, 2022. He worked with several firms, starting in 1974, and helped found UltraCAD Design Inc. in 1992. Twenty years later he joined Monsoon Solutions, Inc. where he spent the rest of his career before retiring in 2021. Dave was a superb designer, a patient mentor to colleagues and customers alike, and was well respected by everyone. He was inducted into the Top Gun Hall of Fame in March 2001, during the PCB Design Conference, West. (Source: Douglas G. Brooks, PhD) PCB Designer Dave Graves Passes Away

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