If you are new to a PCB shop, there is a good chance your first real job is at the back end of the line. Maybe you run the AOI station or pull boards at final inspection and flag the ones that do not pass.
I want you to notice something: Every board you reject has already been built. The copper was plated and the layers pressed before you ever saw it. Your job is to catch the mistake, not to stop it from happening. That is a problem, but not with you. Unfortunately, it has always been the way most shops go about achieving quality.
The Guy Who Figured This Out in the 1950s
Much of what we call Lean and Six Sigma grew out of the work of quality expert W. Edwards Deming. He had a rule: You cannot inspect quality into a product. By this, he meant that by the time a board reaches inspection, the quality is already decided. Inspection can sort good from bad, but it cannot make a bad board good. If your shop is producing defects, the cause lies upstream in the plating bath, the press, or maybe in the way one shift sets up a machine differently than the other.
Deming’s wisdom taught manufacturers to shift their energy toward understanding the process and fixing its gaps and imperfections. If you do that, you’ll have fewer defects, and need less inspection.
Bad approach: Make the board, inspect it, find the defect, throw it away, repeat
Better approach: Figure out why the defect happens, change the process, stop making the defect
Everyone agrees to this on paper. Yet, almost no one does it in practice, because understanding is hard, and inspection is easy.
Where AI Shows Up
I spent a big chunk of my career on PCB shop floors, and now I spend my days teaching small manufacturers how to use AI to their greatest benefit. When I walk into a shop that says it is "using AI," nine times out of 10, they mean AI-powered inspection. It’s a camera with a smart model behind it that can spot a short or a void faster and more accurately than a person with an eye loupe. That is real, and it is good. If you can catch more defects with fewer false calls, you should.
To continue reading this article, which appeared in the September 2026 I-Connect007 Magazine, click here.