Maximizing ROI Through Better Wet Process Control

Estimated reading time: 2 minutes

Mike Carano is a program manager and SME for advanced packaging and PCB technologies at Trusted Semiconductor Solution. He has more than 40 years of experience in the electronics industry, with special expertise in manufacturing, performance chemicals, metals, semiconductors, medical devices, and advanced packaging.

For this issue, we reached out to Mike to learn more about how dialing in on wet process can benefit your bottom line.

“When things get out of control, the variation in your wet process begins,” Mike says. “Just because they look like good boards and may even pass electrical test, it does not necessarily mean you have good boards. Once the chemistry is headed toward the right or left side of the process control parameter cliff, the plating is compromised. If the copper is thinner than it should be, when the customer puts it into service, the board may fail after 500 cycles vs. the requisite 1,000 or 2,000 cycles. The root cause issue is that you plated 7/10ths of a mil of copper instead of one-mil of copper because you were not controlling your process. The fact that you passed your own electric test becomes inconsequential.”

What he’s really talking about is the need for a paradigm shift “where tight control of your processes is the way you manage your organization, wet process being one particular and crucial area of operations.”

With respect to process control, he tells his clients, “you have to stop thinking like a fabricator and think more like a semiconductor company.” Don't be solely reliant on your suppliers’ technical support to do the job either, he adds, because by then, it could be too late. “We all need to be laser-focused on precision. We need to be better at what we do. Perfection may not be attainable, but we should strive to get as close as we can. You achieve that through process control, which encompasses the critically essential skills of troubleshooting, root-cause analysis, problem-solving, and strategizing.

Marcy LaRont: Mike, PCB fabricators care about quality and yield because it ultimately translates to cost and profitability. Today, we also have sustainability goals and requirements. What should be the priorities in tightening up control?

Mike Carano: It has been frustrating over the years to witness the general lack of ability to troubleshoot and solve problems in some of the places I visit, which is why I write articles and present courses on advanced troubleshooting. I often see a “teeter-totter” mindset, this conundrum that you must sacrifice either quality or productivity and that somehow you can’t have both. Of course, the manufacturing folks err toward greater productivity, so you always have control over all your processes in real-time. Things will always go wrong. But when you simply rely on mass inspection, and don’t focus on process control, costs and rework go up, and productivity ultimately declines, all because of an imperfect system.

To read the rest of this article, which appeared in the August 2024 issue of PCB007 Magazine, click here.