Issue link: https://iconnect007.uberflip.com/i/1518339
64 SMT007 MAGAZINE I APRIL 2024 address issues and variances with the product or the process. What Barrett appreciates is that the systems communicate between SPI and AOI. "Blind solder joints can be broken down to three things: paste, part, and profile," he says. "If any one of these fails, the joint fails. If I know what's going on at the SPI, I can better predict what will happen at the AOI. For me, it's a much better sense of control at the front end of the process. We purchased the machines for process monitoring but found that we needed them to help set up the process first. Right off the bat, we realized the impact of any printing variability on false calls at the AOI. We could make a change in the printing process, mea- sure the change with the SPI, and then watch the AOI flag the change. By setting up the pro- cess to the desired results and tuning the SPI to this process, we significantly reduced the num- ber of false calls at the AOI." e largest variable is paste, "not just whether it's there, but how much is there," he says. "Koh Young's SPI allows us to measure it, which means we control it. Now we just do the work upfront to determine what we want to obtain in the desired results, and then we have confidence that every board will meet that requirement or be rejected with details (mea- surements) on the reason for that rejection." TJ Peacock is a manufacturing engineer at ADCO Circuits and says that some of the new products require intense engineering through- out the entire process. "Koh Young's solution really helps us," he says. "We verify the sten- cil and heights on the Speedprint printer, for example." He's able to make use of the data collected on the machines. "We have been able to see most of our problems in the screen printer, whether that be board support or something else," Pea- cock says. "If we see line defects, we can trace them back to a specific problem with the screen printer, and in some cases, we've found real problems with the boards. Sometimes board- stretch is an issue, and Koh Young can detect that for us."