Issue link: https://iconnect007.uberflip.com/i/1038326
22 PCB007 MAGAZINE I OCTOBER 2018 These are all things where you don't need to be on site. Matties: Do the customers care so much about being green or are they primarily driven by the technology? Stepinski: They care about the whole thing. Some are much more interested in the technol- ogy, while others are interested in the automa- tion or in being green. Matties: But in the end, it is probably about the technology. Stepinski: We have a couple of original equip- ment manufacturers (OEMs) who are very in- terested in the green side. Matties: Let's talk about the test equipment in your process. Stepinski: We chose CIMS as our key suppli- er for testing. We have two scanners with two types of confocal microscopy built into them. We can check the top and bottom of the trans- mit and the height of the copper. All the checks are recorded. If a customer asks, "How are we going to look for a line width control on this design?" our engineers release a core from their desk onto the line, and an hour and 15 minutes later, the test core has been measured wherever measurement was specified, and it just kicks out the side. "Here's your mini tab and histogram. Is this okay?" Matties: Your approach to automated optical inspection (AOI) is different as well? Stepinski: Our AOI inspection needs to be thor- ough for the types of boards we build. We found that when fabs check line width, it's not with AOI machines. They typically have some small system at the end of the DS line where they use white light microscopy. On 3-mm lines, 10% impedance is usually going to hold about 5% on line-width control. If you do that, it gauges more than 100% of the area; it's not capable of resolving it accurately. The gauge R&R of this test is horrid. Matties: Do you include your drills in the in- spection/test loop as well? Stepinski: We do. Our concept is most people have a coupon for signal integrity that checks a few nets for impedance. We're going a step further. Our drills are from Schmoll, which are 3D back-drilling boxes attached to half of our drills. Wherever we check the nets or imped- Figure 8: This bank of Schmoll Modul series drilling machines are outfitted with 3D back-drillings boxes.