“Pay no attention to the man behind the curtain.” This famous quote from The Wizard of Oz conjures up the image of Dorothy, the Tin Man, the Cowardly Lion and the Scarecrow discovering that the great Wizard of Oz isn’t as grand or as magical as he seems. He is in fact just a guy operating a bunch of controls behind the green curtain. Today, references to “the man behind the curtain” imply someone making decisions and making things happen behind the scenes. Process engineering at EMS companies and PCB fabricators could be considered “the man behind the curtain.”
I recently spoke with Holly Olsen from Electronic Systems Inc. about the fact that customers rarely tour their PCB fabricators or EMS suppliers to learn the processes and challenges behind building this custom engineered product. Without these visits, knowledge of some of the behind-the-scenes decisions that are made day in and day out to help ensure the best yields are easy to overlook. Holly and I thought it would be interesting to touch on a few of the key processes and decisions that are made behind the scenes and are often invisible to the customer.
The deliverable is an assembled printed circuit board. But throughout processing at both the EMS provider and the PCB fabricator, product is manufactured in larger panels and then broken down to the final product. Most EMS providers prefer to specify their own panelization. This allows them to determine fiducial size and location, tooling holes and breakoff points that best suit their unique process and equipment needs. The size of the board, components that overhang the edge of the board, and board shape and thickness all play a part in the design of the ideal panel for processing.
This article originally appeared in the September 2017 issue of The PCB Magazine, click here.