2. Panel Borders

What Are Panel Borders?

In modern PCB production, individual boards are rarely fabricated in isolation. Instead, manufacturers use panelisation, ie. the process of arranging multiple identical PCBs on a single larger panel. This improves process efficiency, reduces material waste, and streamlines automated assembly.

The panel border refers to the additional material surrounding the PCBs within a panel. While not part of the final product, these borders are essential for providing mechanical stability and handling support during production.

Why Are Panel Borders Important?

Most automated equipment, such as solder paste printers, pick-and-place machines, AOI systems, and wave soldering machines, require a minimum board footprint to operate correctly. Panel borders ensure these size constraints are met, especially when working with small or unusually shaped boards.

Many production lines rely on conveyor systems to move PCBs through each process. These systems grip unpopulated edge areas, so the panel border must remain clear of components to prevent damage or interference during transfer.

Components placed too close to the PCB edge may collide with clamps or fixtures, leading to mechanical stress or misalignment during processing.

To maintain design integrity, avoid placing copper traces, vias, or plated holes near the panel edge. Doing so can lead to electrical or mechanical issues during depanelisation or downstream assembly.

During the solder paste printing stage, the presence of adequate border space ensures proper alignment between stencil and PCB. Without this buffer, stencil lift or misregistration can lead to incomplete or uneven paste deposits, which reduces print quality and may result in assembly defects.

At NOTE, we recommend a minimum 10 mm border around each panel or PCB whenever possible. This added clearance improves durability, print quality, and handling stability, particularly in low- to mid-volume production runs where material efficiency is less critical.

In high-volume environments, panel borders may be reduced to minimise material usage, but always ensure there's a balance between efficiency and mechanical reliability.

Designers should also factor in thermal performance and structural rigidity. Panels must endure multiple heat cycles—from reflow to wave soldering—and thin borders can warp under thermal stress, causing misalignment or poor component soldering.

Component weight and placement must also be considered. Heavier components require additional support to prevent board flex or tilt during processing. In such cases, extending the panel border helps maintain planarity and weight distribution.

For PCBs that feature overhanging or off-board components, increase the spacing between adjacent boards within the panel. This simplifies installation and reduces the risk of damage during reflow or handling—ultimately resulting in higher manufacturing yields.

Finally, ensure uniform copper distribution across both the individual PCBs and the panel as a whole. Electroplating processes can introduce stress if copper is unevenly applied. Adding copper pours or balancing grids can help maintain a flat, warp-resistant structure throughout the panel's lifecycle.