Panelisation is not about packing the most units onto a panel. Its job is to make every unit behave the same way through lamination, reflow and depaneling. On a 610×1100 mm working panel, hold the border at 8–12 mm, keep module spacing at 2.0 mm, provide three tooling holes and two diagonal fiducials, and align every module to the glass-weave direction — only then do utilisation and first-pass yield hold up at the same time.
1. Fix the panel size first, then talk about utilisation
610×1100 mm is our maximum processing size and, for most high-layer-count presses and exposure units, the practical ceiling as well. The first constraint on layout is not area but what the equipment can clamp, expose and rout. Take a 100×80 mm module: after a 10 mm border, five across and thirteen down gives 65 pcs at 77.5% utilisation; rotate the module 90° and seven across by ten down gives 70 pcs at 83.5% — a 7.7% gain on the same working panel simply by changing orientation.
- Border of 8–12 mm on all four sides; use the high end on the long edges.
- Calculate utilisation as net module area divided by panel area; re-lay anything in production below 78%.
- Keep module sizes on one panel as uniform as possible — mixed layouts leave offcuts that cannot be reused.
2. Glass-weave direction sets shrink consistency within a panel
Glass fabric shrinks differently along the roll direction and across the width. Run the long edge of each module along the roll direction and the expansion of every module after lamination lands closer together. A mixed orientation does not fail on the spot; it shows up as directional bow at the panel edge after reflow, with modules near the centre sitting flat and edge modules warping. That bow has nothing to do with the laminate's own thermal expansion, so changing material will not fix it.
- Allow no more than two module orientations per panel, grouped by area rather than interleaved.
- For elongated modules, put the long edge along the roll direction and leave the short direction for routing compensation.
- For mirrored layouts, group front-side and back-side modules separately and keep a transition band of at least 3 mm between groups.
3. Spacing, routing and V-scoring cannot be mixed
Below 1.6 mm module spacing, a 2.0 mm router cannot enter the gap; you drop to a 1.0 mm cutter, double the number of passes, raise breakage and make burr control harder. V-scoring suits rectangular outlines with no components overhanging the edge. Once a header, a USB port or an antenna sits on the edge, that side has to be routed. Using both methods on the same edge means the V-score residual thickness and the rout depth weaken each other at the intersection — and that is exactly where the panel splits first.
- Module spacing of 1.6–2.0 mm, matching a single 2.0 mm routing pass.
- V-score residual at one third of board thickness, with 0.5 mm component-free zones on both sides.
- Bridge width of 3–5 mm, two to four per edge, placed away from the highest-stress corners.
4. Tooling holes, fiducials and break-away rails
When a panel reaches the SMT line, the line needs repeatable registration, not an elegant layout. Get tooling holes, fiducials and break-away rails wrong and the line falls back to manual alignment, losing both yield and takt time. These defects are invisible inside the board shop; they surface at the customer as placement offset and component loss.
- Three tooling holes of 3.0 mm or 4.0 mm, one of them offset by 1.0 mm as a poka-yoke.
- Fiducials of 1.0 mm bare copper with a 2.0 mm clear zone free of solder mask, legend and traces, placed diagonally in pairs.
- Break-away rail of at least 5 mm, present on both sides for double-sided reflow.
- Impedance coupons on the rail, long enough for the test fixture and never crossing a V-score line.
5. Five items for the panelisation review sheet
What panelisation reviews miss most is not the dimensions but how the panel will later be separated, placed and tested. Put the five items below on the review sheet and most rework is stopped before material is cut — including the case where a fiducial turns out to be severed by a V-score line after lamination is already complete.
- Utilisation: record the actual figure and justify anything below 78% in production.
- Border and datums: 8–12 mm on four sides, three tooling holes, two diagonal fiducials.
- Spacing and separation: module spacing of at least 1.6 mm, no V-score and rout mixed on one edge.
- Orientation: no more than two module orientations, aligned to the glass roll direction.
- Test and coupons: fixed positions, outside the effective module area, clear of separation lines.
AIPCB.cc supports up to 44 layers, a maximum panel size of 610×1100 mm, an aspect ratio up to 20:1 (25:1 for backplanes), ±8% impedance tolerance (±10% standard), ±8 μm line-width accuracy and up to 13 OZ heavy copper, with 24-hour prototype turnaround. Send your module dimensions, board outline and panelisation requirements to info@ipcba.com.cn, or call +86 138 2310 9230 to have the engineering team work out the layout and utilisation with you.
Send your Gerber files and stackup requirements; a 24-hour expedite channel is available.