Authored by Nitesh

When it comes to PCB assembly, designing an individual circuit board is just the starting point. To make manufacturing and assembly efficient, you need to think bigger—literally. That’s where panelization comes in, the process of grouping multiple PCBs into a single panel. This step can streamline production, reduce costs, and ensure your electronics come out ready for action. But panelization isn’t a slapdash process; it’s a technical craft that demands precision. Let’s dive into the key guidelines to panelize your PCB like a pro.

What’s PCB Panelization All About?

In electronics, PCB panelization means arranging multiple circuit boards onto one larger panel for PCB assembly. It’s like tiling a floor—each PCB is a tile, and the panel is the foundation that holds them together during fabrication, soldering, and testing. The goal? Boost efficiency, cut down on handling, and keep everything aligned. To pull it off, though, you need to nail the technical details, from spacing to separation methods.

1. Define Your Panel Size

First, figure out your panel’s dimensions. A typical minimum size for PCB assembly is 50 x 50 mm, while maximums often reach 330 x 530 mm, depending on the equipment used. These limits ensure compatibility with standard manufacturing tools like pick-and-place machines. You can design the panel yourself or let your assembler handle it—just make sure to specify your circuit board layout when submitting your files.

2. Pick the Right Panelization Method

How you connect your PCBs in the panel depends on their shape and assembly needs. Here’s a breakdown of the main techniques:

V-Scoring (V-Cut/V-Groove)

  • Ideal For: Rectangular PCBs.
  • Spacing: Either 0 mm (boards touch) or 3 mm (with a gap).
  • Details: V-scoring cuts continuous grooves into both sides of the panel—usually at a 30° to 45° angle—leaving a thin web (e.g., 0.012” or 0.3 mm thick). The cuts must run uninterrupted, so for mixed circuit board designs, consider a different method.
  • Pros: Affordable, clean breaks.
  • Cons: Limited to straight edges; components near the edge (within 0.15” or 3.81 mm) risk damage.

Tab Routing

  • Ideal For: Irregular PCB shapes or electronics with edge components.
  • Spacing: 1.6 mm between boards to fit router bits (typically 0.093” or 2.36 mm).
  • Types:
    1. With Breaking Holes (Stamp Holes):
      • Hole size: 0.45 mm minimum, often 0.55–0.6 mm.
      • Hole spacing: ≥0.35 mm.
      • Holes per tab: 5–6 for strength and easy separation.
      • Example: A 2 mm tab with six 0.55 mm holes breaks cleanly with minimal force.
    2. With Solid Tabs (No Holes):
      • Tab width: ≥2 mm.
      • Depaneling: Needs manual breaking or milling, leaving rougher edges (up to ±0.005” or 0.127 mm).
  • Pros: Versatile for complex layouts.
  • Cons: Tabs must avoid sensitive areas.

Combined V-Scoring and Tab Routing

  • Ideal For: Hybrid PCB designs with mixed edges.
  • Spacing: 3 mm for V-scoring, 1.6 mm for tab routing.
  • Details: Merges the precision of V-scoring with the flexibility of tabs. Alignment must be tight—within ±0.002” (0.05 mm)—to ensure smooth separation.

Choose based on your circuit board’s geometry and component placement.

3. Add Fiducials and Mounting Holes

Precision in PCB assembly hinges on alignment and stability:

  • Fiducial Marks: These copper dots (typically 1.0 mm diameter with a 1.7 mm soldermask opening) guide automated machines. Place 3 per panel, centered on the edge rails, about 0.2” (5 mm) from the edges. For dense electronics, add local fiducials on individual PCBs.
  • Mounting Holes: Unplated holes (e.g., 0.125” or 3.175 mm diameter) secure the panel during production. Use 4 per panel, one in each corner, at least 0.25” (6.35 mm) from the edge.

4. Get Spacing and Keep-Out Zones Right

Spacing keeps your PCBs safe and manufacturable:

  • Between Boards: 0 mm or 3 mm for V-scoring, 1.6 mm for tab routing.
  • Panel Border: Leave a 0.5” (12.7 mm) margin around the panel for handling—some setups need 0.75” (19.05 mm).
  • Component Buffer: Keep parts 0.1” (2.54 mm) from edges for tab routing, or 0.15” (3.81 mm) for V-scoring, to avoid depaneling damage.

5. Plan for Depaneling

Separating PCBs from the panel is the final hurdle:

  • V-Scoring: Snaps cleanly if cuts are precise (within ±0.002” or 0.05 mm).
  • Tab Routing with Holes: Breaks at 5–6 stamp holes, leaving slight edge roughness.
  • Solid Tabs: Requires milling or manual force—test to ensure no stress on electronics.

Run a prototype to confirm your circuit board holds up.

6. Document Clearly

Make your panel design foolproof:

  • Mark board outlines, tab/score lines, and fiducial/hole locations in your Gerber files.
  • Add notes like “V-scoring at 3 mm” or “Tabs with 0.55 mm holes, 6 per tab.

Enhancing Electronics with Effective Panelization

Panelizing your PCB blends careful design with practical know-how. Whether it’s V-scoring or tab routing, these guidelines ensure your circuit board fits PCB assembly smoothly. At Karkhana.io, a 100,000 sq. ft. facility with 7 SMT lines, 5 through-hole lines, and tools like robotic soldering, 3D AOI, and X-ray inspection supports this process with full traceability and quality checks. It works for all kinds of electronics, from HDI PCBs to rigid-flex designs for automotive, IoT, or consumer use. Panelization goes beyond just a circuit board—it sets up efficient production, including sourcing, testing, and logistics. Collaborate with Karkhana.io, test your panel, and optimize your PCB for real-world results.