Issue link: https://iconnect007.uberflip.com/i/1475010
AUGUST 2022 I SMT007 MAGAZINE 75 pany to lose money because of the downtime. We switched to a paste that did not have this issue and even though it was a little more expensive, the new paste saved us thousands of dollars," Andy said. "Another thing that I learned was that the f luxing action of s o l d e r p a s t e g o e s b e y o n d removing oxides from the PWB pads," Sue said. "e flux must also be an oxygen barrier to pro- tect the solder par ticles dur- ing reflow." She then showed a PowerPoint slide that depicted all the functions of a solder paste flux (Figure 2). "Wow, the flux in the solder paste is really quite complex—it has to perform so many functions," Andy said. "It is easy to see why Chuck calls it a highly- engineered material." ey continued to prepare their slides for the upcoming workshop. As they headed out for a brief moonlit stroll, Andy commented, "e next class is on component placement and line balancing. For line balancing, I'm going to have to lean on you heavily for this one." Will Andy be able to teach line balancing without heavily leaning on Sue? Stay tuned to find out. SMT007 References 1. Trigonometry mnemonics, Wikipedia.com. 2. "Response to Pause: A Critical Solder Paste Parameter," by Ronald C. Lasky, Indium Corporation. Ronald C. Lasky is an instruc- tional professor of engineering for the Thayer School of Engineering at Dartmouth College, and senior technolo- gist at Indium Corporation. To read past columns, click here. Figure 2: The composition and many functions of a solder paste flux are shown.