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Nolan Johnson chatted with George Milad, national accounts manager for technology at Uyemura about what is driving change in the wet process marketplace and how chemistries must fit into next-generation product design while also meeting new environmental requirements.
Nolan Johnson: George, regarding changes in wet processes, some market drivers are moving, preserving margins, increasing yields, improving upon environmental concerns, and getting better capabilities and smaller features. From your perspective, where’s the market for wet processes going and what’s pushing it?
George Milad: Well, when you say wet processes, you’re talking about chemical processes like board shop chemistries and where they’re headed. Mostly, there are developments in surface finishing and plating; those two areas are quite active. For example, the IPC Plating Committee also publishes specifications, and we are in the midst of revising the ENIG specification.
Johnson: So, there’s the chemical process side as well as the equipment that is used. Is there more action in one of those two areas than the other, or are both of them in motion right now?
Milad: As far as the equipment, there are tendencies to automate. Water usage and environmental control in wet processing are also evolving. Further, there are chemicals being used today that are not allowed on the REACH program environmentally. And there is an effort to minimize the use of these harmful chemicals, such as formaldehyde in electroless copper and cyanide in gold. There are new developments in surface finish to meet criteria, needs, and specific purposes, such as very fine-line work, as well as electroless copper plating via filling.
Johnson: In Richard DePoto’s interview with Pete Starkey from IPC APEX EXPO earlier this year, one of the points that stood out for me was his comment that Uyemura works to drop the chemistry right into existing lines. It seems that putting in a new chemistry/wet process line to hold a different line and set of chemicals is a highly restrictive process for a lot of fabricators.
Milad: That is true. If I’m using chemistry from a certain supplier, and it’s not meeting my needs, and I want to change to a different supplier, it is very important that the supplier can fit their chemistry into my existing equipment and does not force me to buy new equipment. I think that’s what Richard was referring to.
Johnson: Pardon me for showing a lack of understanding of chemical engineering, but what goes into lining up the chemistries like that? For somebody who isn’t a chemistry expert working with PCB fabrication, what is so different about the chemistries currently under development compared to what they used to be?
Milad: If you’re talking about under development, that is one thing. We were just talking about making the chemistry fit the existing equipment, but that’s a different issue after the development of chemical processes to meet new board designs. Designers are coming up with things that the present chemistries cannot meet, so they are moving forward with new chemistries to meet the designs. The new designs have much tighter lines and spaces and much smaller holes for next-generation, 5Gtype products.
Johnson: How do you change the chemistry for that?
Milad: We have a substantial R&D team that is always looking forward to the next challenge, so they are very busy developing new products. It’s not changing chemistries; instead, it’s a new set of products. Usually, they are designed to fit existing equipment. Sometimes, new equipment might be advantageous, but most of the time, they would develop products that fit the existing equipment.
For example, Uyemura is developing a gold bath that is cyanide-free, which is important; it’s not a requirement today, but it will be in the near future. We’re also developing chemistries that are formaldehyde-free because it’s a hazardous chemical too. It is in use, and it’s not prohibited, but people are expecting that it will be and should be. There’s this direction based on meeting environmental needs, and then there is the development that is designed to meet more complex and sophisticated designs. We work on both ends to provide the chemistry for next-generation that will meet new environmental requirements.
To read the full article, which appeared in the August 2019 issue of PCB007 Magazine, click here.