Most PCBs are individually routed—meaning they’re not panelized. That doesn’t mean that, sometimes, sending them to a PCB assembler in a panel isn’t a good idea or even required. Generally assemblers don’t require panels—sometimes called a pallet—but there are some cases when they do.
If the individual PC board, destined for Full Proto service, is smaller than 0.75″ x 0.75″, it needs to be panelized. If a PC board needing Short Run production service is less than 16 square inches, it needs to be in a panel of at least 16 square inches to qualify for Short Run.
Why else might you want to panelize PC boards?
1. Protection
If you’ve got a lot of small boards, it’s easier to handle and protect then when they’re in a panel. A few panels can be more safely packed coming and going from your company to an assembler.
2. Safety
You may be able to get the boards through a factory faster. If you have a really large number and need them super fast, panelizing them may enable that fast turn. With a lot of boards, sometimes it simply isn’t physically possible to put them all on the machine, run them and take them off, in a short turn time. Panelize them and the machine will be running longer for each board change, which reduces the total run time.
3. Cost
It may also cost you less. If you use leadless parts like BGAs, QFNs, or LGAs, you can usually reduce your cost a bit by panelizing the boards. Leadless parts cost a little extra because of the X-Ray test needed, but the extra handling is mostly per board, rather than per part. One panel of 10 boards with 10 BGA, in total, will cost a little less than 10 individual boards with one BGA each.