I traveled to Penang, Malaysia to give a two-day workshop on Issues to be Resolved in SMT Assembly on August 7th and 8th. The workshop was part of EPCON Asia 2018 and was put on by The Knowledge Group. Survinder Kaur was our host and she made sure everything went smoothly.
I travel a bit, but seldom to Asia. In looking at a map, you might think you would travel as shown in the figure; however, a flat map cannot convey true distances on a sphere, it ends up that the shortest distance is flying over Greenland from JFK airport. I traveled first to Guangzhou, China, then to Penang. As I looked out my window at the Greenland glaciers, I thought: “If the plane has a problem, we’re in trouble.” Then it occurred to me that the same would be true flying over the Pacific Ocean.
Figure. When flying to southern China form New York City, you fly over Greenland, not as it might appear on the above map.
My biggest surprise, in Penang, was how inexpensive everything was. A 15-minute ride to the airport was $7.50. A full meal was only $10. If you are thinking of retiring there; however, you would have to get used to the 95ºF daily temperatures and very high humidity.
In my workshop, I covered many topics related to lead-free SMT assembly. I reviewed the history of lead-free, how we settled on SAC305, then discussed all of the common defect modes, such as head-in-pillow, graping, voiding, pad cratering, and tombstoning. I also discussed how to minimize these threats.
I then discussed mixed (lead-free and tin-lead) alloy systems, alternate alloys such as SACm and halogen free soldering. In my preparation, I was surprised to find that the majority of solder pastes today use halogen-free fluxes.
I finished with sections on how to evaluate a new solder paste and mitigate issues such as tin whiskers and tin pest, and then had a thorough discussion on reliability. If you would like a PDF of this almost 600-slide workshop, send me an email at firstname.lastname@example.org.