Issue link: https://iconnect007.uberflip.com/i/782967
46 The PCB Magazine • February 2017 Kunz: The equipment is basically for both pro- cesses, photoresist and solder mask work, but of course Taiyo is concentrated on solder mask. For this reason, this venture was about solder mask. Matties: When you develop your equipment, dur- ing that process of coming up with new technolo- gies, how critical is it to have a partnership with Taiyo and the other ink suppliers? Kunz: It is very important. On one end, we have certain wavelengths available, and this has to match with the inks, or vice versa. Second, we have certain flexibilities in our wavelengths to adjust to different power levels. We must also learn from the ink suppliers how we can do that and to what extent it is useful. Of course, the ink manufacturers can help us to convince cus- tomers that their existing inks are maybe not very suitable for the future. Two years ago, cus- tomers of ours said, "Oh, nearly impossible to change the ink for our customers," but we see a trend in the market that this is changing. Also, their end customers are thinking they have to go this way because they want direct imaging at a decent cost. Matties: When direct imaging and a modified or new ink enter the market, how do the OEMs react to this? Is there a whole new qualification process that they go through for your technology and the inks combined? Kunz: There are different ways. Some are easy to change. Some, they are okay with if the ink remains basically the same but you just change the percentage of the components. Of course, there are others where it's very difficult because they must run a full qualification—like aero- space or automotive. So it's very mixed, but the supplier of PCBs has the problem that they can- not do one thing for one customer and another thing for another customer. So they should run one thing, maximum two things. They must find a common way for everybody, and this is the critical part. Matties: Now, with the direct imaging of solder mask, this is something that isn't exactly new but that hasn't been fully embraced yet. How is that process of acceptance coming along? Kunz: Yes, it's true. Resist work was done with the DI systems for many years. Obviously, the lasers were not suitable for the ink, and the inks were not suitable for the lasers or other light sources. The standard light sources, with a broad wavelength range, had to be adapted to the DI technology. For this reason, after starting with two wave- lengths, we have adapted our systems to four wavelengths to give us the best opportunities to address to the specific characteristic of the ink. Matties: When someone adopts the technology, what sort of process step reduction or cycle time reduction should they generally expect? Kunz: Well, I think the biggest advantage is that they get a better quality. They look for registra- tion, whereas saving the cost of films is a side issue which finances the purchase of a direct imaging machine, but basically, they look for registration, quality, less scrap. I think this is the main driver. Matties: Is there a speed component to it as well? Is there a cycle time in that process, from tradi- tional to direct? Thomas Kunz THE POWER OF THREE: SCHMOLL TALKS TECHNOLOGY