Chemical cycles.

Kyzen burst onto the electronics assembly scene in 1990 with a simple yet revolutionary product that gave manufacturers a low-ozone-depleting alternative to banned cleaners like CFCs. A small yet publicly held (over-the-counter) firm, Kyzen's fortunes have risen incrementally the past two years as the move to Pb-free products has led an upsurge in cleaning. Vice president Tom Forsythe spoke with CIRCUITS ASSEMBLY in October.

Ed.: For the full interview, visit circuitsassembly.com/cms/content/view/4150.

CA: The industry keeps trying to eliminate cleaning through developments such as no-clean solders and yet the need persists. What gives?

TF: Rest assured, it is not good to be a cleaning technology guy when the soil is called "no-clean required"; refrigerators and penguins come to mind.

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With cleaning eliminated from such a broad swath of the market, process issues that cleaning routinely solved in the past have occasionally returned. It turns out that cleaning does add value to more than just high reliability assemblies and devices. Certainly, a majority of our largest customers are cleaning no-clean fluxes, and for good reason. It can improve yields, and that saves money! Unfortunately, many engineers do not even consider cleaning a no-clean to solve these sorts of issues, even though it is cheap, simple and effective.

CA: Cleaning is primarily associated with high-rel products like aerospace and medical. But as our columnist Terry Munson regularly points out, contamination is often the culprit in field failures of all classes of assemblies. Does the resistance to clean owe primarily to cost, time or another factor?

TF: We believe the resistance has evolved. At first, it had a simple root cause. If a young engineer approached his boss proposing a cleaning process as part of this new, no-clean SMT transition, he or she was often shot down with, "What don't you understand about no-clean, youngster?" with cost being the culprit. As time has passed, the floor space used by the cleaners has been absorbed by other equipment or simply eliminated, and inline cleaners are generally not small tools. However, we believe today's driver is an absence of a broad-based understanding on the value that cleaning can deliver.

That is why we continue to publish technical articles at a furious rate, more than a dozen during the past year or so. It is a great deal of work, but our goal is to let engineers know when and where a cleaning process can enhance their operation and improve the profitability of that operation, which is everyone's bottom line.

CA: What cleaning problems do BGAs and flip chips present, and what's your standard recommendation for those packages? What are some ways to determine whether a package is suitable for cleaning?

TF: As with most cleaning processes today, flip chips and BGAs are most often cleaned in an aqueous process, though there are exceptions. These devices epitomize the drumbeat of miniaturization, which presents its own cleaning challenges. Legacy technologies introduced three or 13 years ago generally have real difficulty with these applications. However, the more modern materials, which oddly enough have been designed for these exact challenges, do an exceptional job.

Specific recommendations are driven first by current facility and regulatory constraints such as having equipment in place, and effluent concerns and air emission concerns. With that definition, we move to evaluate the soils--meaning the paste or flux material--in our applications lab. Fortunately, this testing is an everyday occurrence at Kyzen, and our database has recommendations on hundreds of materials with tens of thousands of individual test points ready to review with customers. Then comes process confirmation testing with their devices, and finally we're ready for introduction and scale up.

CA: The plethora of environmental regulations must sometimes leave you wondering just what exactly your role is: developing cleaners or tracking effluent laws. To what extent do customers rely on you to help them meet local regulations?

TF: Now you have targeted another driving issue: fear of regulations. Since the earliest days of Kyzen, we have acted as unpaid advisors to many customers, helping them identify, understand and comply with local and national environmental regulations. We call this stewardship. It takes two things to pull this off: first, veteran field and technical people who have the expertise to be credible advisors in these areas, and second, the organization giving those talented veterans the backing to spend the time helping the customer through the issue. At Kyzen, we see a huge opportunity to provide value to our customers in these areas, but it is time-consuming and expensive.