Where should the PCB depaneler go in your line?
· PCBRacks.com engineering team
Many lines depanel after in-circuit or functional test, because a fixture that takes a whole panel tests several boards at once, and panels are easy to handle. The drawback is that separation becomes the last mechanical event, and no electrical test follows it.
Depaneling before or after test
If you depanel after test, a capacitor cracked at the depaneler won't be tested again. Even when a later test exists, flex cracks in ceramic capacitors often pass it and fail in the field. A low-stress method that shears along the score keeps that last event small, and the method comparison shows how the options differ.
Depaneling before test means every board is tested after separation, so damage from it has a chance to show up. The cost is single-board fixtures and more handling of small parts.
Depaneling before or after coating
Coating panels is efficient: one masking setup and one pass cover several boards, but the separated edges stay bare. Some coating specs accept that, and some don't. Coating single boards after depaneling covers the edges, with more handling and masking per board.
Check the coating spec before you choose. It's easy to move a benchtop machine, but resizing racks and reworking coating masks around a new position takes longer.
Keeping panels to final assembly
Some products stay as panels until box build and get separated where they go into the enclosure. The breakaway rails then protect the boards through every storage step, which helps most when parts sit close to the board edges. Panels take more rack space than single boards, and every step before final assembly has to handle the larger size.
Bench layout
Give the depaneler room for one rack feeding panels in, one rack taking single boards out, and a bin for the breakaway rails. The racks on each side usually aren't the same size, so plan both when you place the machine.
The bench is a workstation like any other in your ESD area, so it'll need a grounded work surface and a wrist strap point for the operator. Lay out the bench so panels coming in and single boards going out never cross, and panels can't end up in the output rack.
Whichever position you pick, write it into the process sheet for each product. When a new product arrives with parts closer to the score than the last one, it's the first decision to recheck, and you don't want to find out at test.
Choosing a position
- Ceramic parts close to the score that can't be moved: depanel before test.
- Fixture cost matters most and separation is low stress: depanel after test.
- Edges must be coated: depanel before coating.
- Parts dense to the edge and final assembly close by: consider keeping panels to the end.
If you haven't chosen the machine yet, the depaneler finder matches one to your panel.
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