Issue link: https://iconnect007.uberflip.com/i/1088168
MARCH 2019 I SMT007 MAGAZINE 61 In our process, we can collect data—copper percentage, core thickness, prepreg style, what the dimensional movements will be—and we can predict the scaling factors without doing any kind of samples. This reduces cycle time and the overall cost and increases quality. After it drills in the tooling, our system will automatically de-flash, edge polish, rotate 90 degrees, do the other two sides, do a high-pres- sure rinse and wash, measure every panel in nine-point locations on overall thickness, and collect real-time SPC on our pressed out thick- nesses. This is another example of a smart pro- cess. We can collect data on any stackup. And when you look at the control limits, you will see we are right in there; we do all of this with only a couple of technicians. Matties: This must have reduced cycle time quite a bit. Dudnikov: Yes. Well, you can't really feel it, but if you spend time in factory one and this factory, the velocity of the product is much faster here. A great area to really get a feel for the product velocity is after routing and final clean. Each board is measured for warpage and hole check on a conveyorized process. The boards fly through our process. In our inner layer fabrication, we use liquid resist, and then it goes into the yellow room exposure, which is all fully automatic. Next, it goes down the DES line. Then, every core gets 100% inline AOI both sides and is serialized. After verification, cores go right into horizontal alternative oxide. It's a serpentine and continuous process. All the etchers here are also vacuum etchers. Again, if you compare it to a conventional shop in the U.S., you would etch it, rack it, and then you would have to wait until the AOI ma- chine opens up. Next, you would manually sit there, AOI each one, and bring it to your verification station. In some cases, only one side can be "AOI-ed" at a time, which is a much slower process flow. We are currently working on integrating AI to have the verification system learn different defects in real time. It will be able to determine whether it's a pseudo or real defect. All of the AOI data gets stored so we can do yield analy- sis. For each core after verification, we can go back and see if it had a short or an open, and then roll this up into Pareto charts and defect mapping. In imaging, we have more than 12 double- sided automatic exposure machines with very good side-to-side registration and no operators. We do 100% LDI on outer layer and contact printing inner layer because the LDI gives you Automated warpage measurement and hole check line. Inline AOI with DES line monitoring.