PCB Panelization Design Guide: V-Score, Tab-Route & Cost Optimization

What is PCB Panelization?

In the world of electronics manufacturing, efficiency is currency. PCB Panelization (also known as creating a "PCB array") is a fabrication technique where multiple smaller circuit board units are arranged and connected on a single larger substrate (the "panel") to be processed simultaneously.

While prototyping often involves single boards, mass production almost always requires panelization. Why? Because moving 50 individual small boards through an SMT (Surface Mount Technology) assembly line is slow and prone to error. Moving one panel containing 50 boards is fast, stable, and cost-effective. Unless your PCB is exceptionally large or requires specialized processing, NextPCB always recommends designing a panel to maximize throughput and yield.

The Economics: How Panels Reduce Manufacturing Costs

Understanding panel utilization is crucial for procurement managers and engineers aiming for low cost PCB production. PCB laminates typically come in standard manufacturing sheet sizes (e.g., 18" x 24"). The goal is to fit as many boards as possible onto these sheets with minimal waste.

Improving Material Utilization

From a fixed panel cost, increasing the number of boards packed into one panel directly lowers the price per unit. However, geometry plays a massive role here. Simply rotating a board can dramatically change the yield.

Consider the example below involving identical PCBs. By analyzing the dimensions, we can see how orientation impacts density:

The Analysis: In the comparison above, simply rotating the boards 90 degrees allows for 60% more boards on the same panel size. This is a classic example of DFM (Design for Manufacturability) optimization. Professional PCB fabricators like NextPCB will usually optimize this for you during the engineering query (EQ) phase, but providing a pre-optimized array design ensures you get the most accurate quote upfront.

Common Panel Types and Applications

Depending on your project needs, panels generally fall into two categories:

1. Homogeneous Panel (Multiplier Panel)

This consists of identical PCB designs repeated across the panel. This is the industry standard for mass production, allowing for high-speed turnkey PCB assembly and simplified inventory management.

2. Heterogeneous Panel (Mixed Multiplier / Combination)

This method combines different PCB designs (e.g., a mainboard and a daughterboard) onto a single panel. This is often called a "family panel."

• Pros: Ideal for prototyping systems where you need one of each board type simultaneously. It saves setup costs (NRE charges).
• Cons: If the boards have different layer counts or copper weights, they cannot be panelized together.

Methods Deep Dive: V-Scoring vs. Tab-Routing

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

V-scoring involves cutting a triangular groove into the top and bottom of the PCB. The boards are snapped apart after assembly.

• Internal Layer Clearance: Crucial DFM tip—Copper foils in internal layers must stay at least 0.5mm away from the V-cut line to prevent exposed copper or shorts after cutting.
• Component Clearance: Keep SMT components 0.5mm to 1.0mm away from the V-cut to avoid solder joint stress cracks.

2. Tab-Routing (Mouse Bites)

For irregular shapes, we use routing with "Mouse Bites" (perforated tabs).

• Mechanical Stress: Place tabs away from heavy components like transformers or large inductors.
• Overhang/Flash: Tab removal leaves a small protrusion (0.2mm to 0.5mm). Ensure your enclosure design accounts for this "flash" or specify a "recessed tab" design.

Comparison: V-Scoring vs. Tab-Routing

Essential Features: Rails, Fiducials, and Tooling Holes

To support high-speed 2026 SMT standards, your panel requires a process frame:

• Break-away Rails: 3mm - 5mm edges for conveyor gripping.
• Asymmetric Fiducials: Place fiducials at corners. To prevent 180-degree rotation errors in the SMT line, ensure the fiducial arrangement is slightly asymmetric.
• Tooling Holes: 3.0mm non-plated holes for mechanical alignment.

Critical Engineering: Warpage, X-outs, and Clearances

1. Warpage Control

Large panels or panels with thin PCBs (< 1.0mm) are prone to bending (warpage) during the high temperatures of reflow soldering. For 2026 high-density designs, NextPCB recommends adding stiffeners or internal rails if the panel width exceeds 200mm to ensure flatness and prevent solder defects.

2. X-out Policy (Bad Board Marks)

In high-volume manufacturing, it is common for one or two units in a panel to fail electrical testing.

• Standard Policy: Unless otherwise specified, NextPCB may include panels with "X-outs" (failed boards marked with a black marker) to optimize material usage.
• SMT Impact: Ensure your assembly house's Pick & Place machines are configured to recognize X-out marks to skip faulty boards. If you require "No X-outs," please specify during quoting as this may affect the final price.

3. Stress Analysis for Tabs

Mouse bites should never be placed near high-stress zones. Breaking the tabs generates vibration; if placed too close to a ceramic capacitor or a BGA, it can lead to latent micro-cracks in the components.

NextPCB Panel Capabilities and Specifications

• Minimum Panel Size: 50mm x 50mm.
• Maximum Panel Size: 600mm x 500mm.
• Min V-Cut Thickness: 0.6mm.
• Standard Routing Gap: 1.6mm or 2.0mm.

FAQ: Frequently Asked Questions about PCB Panels

What is "Panel Rigidity" and why does it matter?

Rigidity refers to how well the panel resists bending. If your board has heavy components like power modules, the panel may sag during soldering. In such cases, we suggest wider process rails or increasing the PCB thickness.

How do I handle the "flash" left by mouse bites?

If your PCB must fit into a tight enclosure, design the mouse bites to be "recessed" within the board edge. This way, the breakout nub stays inside the board's boundary rather than protruding outwards.

Does NextPCB check my copper-to-V-cut clearance?

Yes. Our DFM (Design for Manufacturability) check includes verifying clearances. If we find internal copper too close to a V-cut line (risking shorts), we will raise an Engineering Query (EQ) before production.

Ready to Optimize Your PCB Production?

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About the Author

Lolly Zheng- Sales Account Manager at NextPCB.com

Four years of proven sales experience across electronic components and PCBA industries, with strong expertise in key account acquisition, customer relationship management, and contract negotiations. Focused on driving revenue growth through strategic client development and solution-based selling. Experienced in expanding high-value accounts, securing long-term partnerships, and consistently exceeding sales targets in competitive markets.

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