PCB Panelization, is a manufacturing technique, in which several small printed circuit boards are grouped together by CAM engineer or designer for forming as a panel. PCB Panel is also called PCB Array or PCB Matrix. The panel can include one design or multiple different designs. If the panel only includes one piece or single board, it is 1up. If includes 10 pieces boards, it is 10up. Panelization improve PCB material usage rate to low down PCB cost, and make automated PCB assembly faster and less expensive.

Frames

Frames, or called Breakaway Rails can be added to the panel. Rails of frame can be added on 2 edges (long edge but not short edge) or 4 edges of the panelized boards. The rails of the frame are commonly 12.7mm wide, which is half of an inch (25.4/2=12.7mm). Of course, rail widths of 5mm, 6mm, 7mm, 8mm and 10mm are also available, but need to get approval by both of your PCB fabricator and PCB assembler upon different PCB designs.
Frames seems to increase PCB order cost, but in some cases it is worth it.

  • Breakaway rails on panels often includes tooling holes, fiducials, test coupon, and may include hatched copper pour or similar patterns for even copper distribution over the whole panel in order to avoid bending.
  • If any pars hang over the edges, or any parts are too closed to the edges, they have clearance from machinery, and board support if they are heavy.
  • If a board has a particularly long connector, then we should extend the frame on that edge to the longer to support that extra long connector.
  • The frame gives the technician something to hold as they are handling the product. Without anything to hold, it’s easy for fingers to get into solder paste or pre-reflowed, post-placement parts and thus ruin the product.
  • Frames enable us to use fixtures in the machinery so that we can hold them down properly. Very thin boards need to be mounted onto a dummy thick board for processing. Without a frame we would have nothing to adhere the tape to for fixtures.
  • Adding frame rails on thick rigid and rigid-flex board panels can omit the cost of reflow carriers.

Fiducials

Fiducials should be added to the corners of frames during PCB panelization. Fiducials should be 1mm in diameter with a 2mm masking area. Ideally, these fiducials would be on the short length of the frame. This is because almost all machines grasp the PCB on the long edge of the PCB. Sometimes the tools that grasp the PCB cover the fiducials if they are on the long edge. Putting them on the short edge makes sure that nothing will ever cover those fiducials from view of the camera. There should only be 3 fiducials on the panel, not 2, not 4. For very long printed circuit boards, we also can add extra fiducials for each single board if we get approval by customer.

Tooling Holes

Tooling holes, which not as relevant as they used to be, are still valuable to have and don’t cost any extra to add. We generally put 4 of them in the corners and make them 3.175mm in diameter (which is 1/8’’ which was a standard pin size that most of the industry standardized on in the 80’s.)

Refer to PCB Panelization Guidelines