Other Parts Discussed in Thread: BQ51013B, TIDA-00668
We are in the process of laying out the BQ51003 on our PCB. We're trying to bring out the interior pins now and noted that the Gerbers in your reference designs (TIDA-0068A) use standard multilayer PCB board technology to do so. No buried vias, VIPPO, micro-vias or other technologies usually associated with BGA layout are shown in your design. In fact, every Gerber we can find in your BQ51003-related app notes uses standard multilayer PCB technology to bring out those interior pins.
We sent the Gerbers from TIDA-0068A to our PCB fabrication representatives and had them get quotes on these Gerbers from multiple vendors. We just wanted to see if the simplistic approach used in your layouts for this part was actually produceable. Note that these PCB vendors we queried on this are reputable, capable and very knowledgeable about the current state of the art and understand what can/cannot be done in practice. These are not low-end fabrication houses.
We got no bids to build boards based on your Gerber files. All vendors said there was absolutely no room for material or drill error built into these design files.
My intent here is not to bust TI's chops - you are an IC manufacturer - not PCB designers. I am writing to make sure we are not missing some super-secret layout files on the website that show how this could be done with standard board technology. Or - to have you confirm that our suspicions are correct and that any practical layout for this part requires VIPPO or microvias or some other special PCB technology.
