Panelisation
Panelisation is the practice of arranging multiple PCBs in a single manufacturing panel to reduce fabrication cost and enable automated SMT assembly. The two main methods are V-cut (straight-line scoring for rectangular boards) and tab-routing with mouse bites (perforated tabs for irregular shapes).
What it is
A PCB panel is the working unit at the fabricator and assembler — typically 18×24 inches (457×610 mm) or similar standard sizes. Individual boards are arranged within the panel using one of two depanelisation methods. Depanelisation is the process of separating boards from the panel after assembly.
V-cut (also called V-scoring) cuts triangular grooves on the top and bottom of the panel along the board edges, leaving roughly one-third of the board thickness intact. Boards are snapped apart after assembly. V-cut is faster, cheaper, and ideal for rectangular boards. The trade-off is that components must stay at least 0.5-1.0 mm from the V-cut line to avoid stress damage during separation.
Tab-routing uses a router bit to cut around each board, leaving small tabs (typically 2-3 mm wide) connecting boards to the panel. The tabs include "mouse bites" — perforated holes that make the tabs easy to break. Tab-routing supports irregular board shapes, overhanging connectors, and slots, but is more expensive and leaves small protrusions (0.2-0.5 mm) at the tab locations.
Breakaway rails — extra panel material on the panel edges — are often added for SMT machine handling. Rails typically need fiducial marks and a clear area for clamping.
When it matters
Panelisation affects both fabrication cost and assembly feasibility. Multi-up panels (multiple boards per panel) reduce per-board cost because the fabricator amortises setup over more units; this is the standard model for production runs above roughly 10 boards. Below that volume, single-up panels are common.
Specifying panelisation wrong creates assembly problems. Components too close to V-cut lines crack during depanelisation. Tabs placed under heavy components cause stress damage. Missing fiducials prevent SMT machine alignment. For irregular shapes, V-cut is not an option — tab-routing is the only choice. For production assembly, a panelisation drawing should accompany the Gerber files showing panel dimensions, board orientation, tab/V-cut positions, fiducial locations, and breakaway rail dimensions.
At Nordic PCB
Our certified suppliers can panelise boards for you based on volume, board shape, and assembly needs — you can specify the panel layout yourself, or let us recommend an optimal configuration in the quote. For irregular shapes or production runs, our DFM review includes panel-level checks: component clearance from V-cut lines, tab placement away from sensitive components, and fiducial mark presence. Breakaway rails are included by default for any panel intended for SMT assembly.
Related terms
- Fiducial marks
Fiducial marks are small copper reference dots on a PCB (typically 1 mm diameter) used by automated assembly machines to align the board precisely before placing components. Three fiducials per side enable rotation and skew correction. Their absence or incorrect placement can prevent SMT assembly entirely.
- SMT
SMT (Surface Mount Technology) is the dominant PCB assembly method where components are placed directly onto the surface of the board and soldered using reflow ovens. It enables smaller, denser, double-sided boards and supports nearly all modern component packages including BGAs, QFNs, and 0402 passives.
- DFM
DFM (Design for Manufacturability) is a structured review of your PCB design against a fabricator's process limits — trace widths, drill sizes, annular rings, solder mask clearances, and stack-up choices — to catch issues before tooling starts. A good DFM review prevents rework, scrap, and missed delivery dates.
- Gerber file
A Gerber file is the industry-standard format that describes each layer of a PCB — copper, solder mask, silkscreen, and drill data — as 2D vector geometry. A complete Gerber package is the minimum a fabricator needs to quote and build your board.