What Is PCB Panelization? Types, Guidelines & Design Tips [2026]

If you’ve ever wondered why your PCB manufacturer asks about panelization when you submit a design, you’re not alone. After spending over a decade in PCB design and manufacturing, I can tell you that PCB panelization is one of those topics that separates hobby-level projects from production-ready designs.

Let me walk you through everything you need to know about PCB panelization—from the basics to advanced design tips that’ll save you time, money, and headaches in production.

What Is PCB Panelization?

PCB panelization is a manufacturing technique where multiple printed circuit boards are grouped together on a single larger panel for simultaneous fabrication and assembly. Think of it like baking cookies—you don’t bake one cookie at a time; you fill the entire baking sheet to maximize oven efficiency.

In practical terms, your individual circuit board designs are arranged in an array on a manufacturing panel (typically 18″ x 24″ in North America), processed together through all fabrication steps, and then separated into individual boards at the end.

This approach exists because most SMT assembly equipment has minimum size requirements. Conveyor belts, pick-and-place machines, and reflow ovens are designed to handle panels, not individual small boards. Without panelization, boards smaller than 50mm x 50mm simply can’t move through modern assembly lines efficiently.

Why PCB Panelization Matters for Your Project

From my experience working with both startups and established manufacturers, here’s what panelization actually delivers:

Cost Reduction: Processing 20 boards simultaneously costs significantly less than processing them individually. Material utilization improves, setup times decrease, and handling errors drop. In my experience, proper panelization can reduce per-board manufacturing cost by 15-30% compared to single-board processing.

Production Efficiency: A panel moves through the assembly line as a single unit. Solder paste printing, component placement, reflow soldering, and inspection all happen once per panel rather than once per board. This translates to faster turnaround times and higher throughput.

Better Quality Control: Uniform panel designs ensure consistent heat distribution during soldering, reducing defects like cold joints or tombstoning. The rigid panel structure also prevents warping that can occur with thin individual boards during reflow.

Simplified Handling: Small boards are fragile and hard to handle. The panel structure protects individual boards during manufacturing and shipping. Technicians have something to grip without touching solder paste or placed components.

Testing Efficiency: Panels can include test points and programming headers in the rail areas, enabling batch testing before depanelization. This catches defects before boards are separated, reducing handling of defective units.

PCB Panelization Cost Factors

Understanding what affects panelization costs helps you optimize your design:

Cost Factor	Impact	Optimization Strategy
Panel utilization	High	Maximize boards per panel through rotation or resizing
Rail width	Medium	Use minimum width that meets assembly requirements
Routing complexity	Medium	Simplify board outlines where possible
Tab count	Low	Balance separation ease vs panel strength
Mixed designs	Variable	Combine only compatible designs

Types of PCB Panelization Methods

Choosing the right panelization method depends on your board shape, component placement, and edge requirements. Here’s a detailed breakdown of each approach.

V-Scoring (V-Groove) Panelization

V-scoring involves cutting V-shaped grooves into both sides of the panel along the separation lines. The blade removes approximately one-third of the board thickness from the top and one-third from the bottom, leaving a thin web of material connecting the boards.

How it works: A rotating circular blade (typically 30° or 45° angle) scores straight lines from one panel edge to the other. After assembly, boards are separated by snapping along these score lines or using a dedicated depaneling machine.

Best applications: Rectangular boards with straight edges, high-volume production, designs without edge-hanging components.

Limitations: V-scoring only works for straight lines running edge-to-edge. You can’t score around curves or stop mid-panel. Components must maintain at least 3mm clearance from score lines.

Tab Routing Panelization

Tab routing uses a CNC router to cut away most of the material between boards, leaving small connecting tabs (typically 2-5mm wide) that hold the array together. These tabs are later broken or cut during depanelization.

How it works: The router follows your board outline, leaving strategic connection points. These tabs can include perforations (mouse bites) to make separation easier.

Best applications: Irregular board shapes, designs with edge-hanging connectors, boards requiring smooth finished edges in specific areas.

Limitations: Routing is slower than V-scoring, generates FR4 dust, and leaves small protrusions where tabs were attached.

Mouse Bites (Perforated Tab Routing)

Mouse bites are a variation of tab routing where small perforated holes (typically 0.3-0.5mm diameter) are drilled along the tabs. These perforations create a weak point that allows easier hand separation.

How it works: After routing the board outline, a series of overlapping drill holes are placed along each tab. The remaining material between holes acts as a weak link.

Best applications: Prototypes and low-volume production, boards that will be separated manually, designs where some edge roughness is acceptable.

Limitations: Leaves jagged edges that may require sanding. Not suitable for boards requiring smooth mounting edges or tight enclosure fits.

PCB Panelization Methods Comparison Table

Feature	V-Scoring	Tab Routing	Mouse Bites
Board Shape	Rectangular only	Any shape	Any shape
Edge Finish	Smooth	Smooth (except tab points)	Rough (requires sanding)
Separation Force	High	Medium	Low
Overhanging Components	Not allowed	Supported	Supported
Processing Speed	Fast	Slow	Medium
Tooling Cost	Low	Medium	Low
Best For	High volume	Complex shapes	Prototypes

PCB Panel Design Guidelines

Getting panelization right requires attention to specific design rules. I’ve seen projects delayed for weeks because panels failed in assembly. Here are the guidelines I follow for every project.

Standard Panel Sizes

Most manufacturers work with standard panel sizes to optimize their equipment. While custom sizes are possible, sticking to standards reduces cost and lead time.

Panel Size (inches)	Panel Size (mm)	Usable Area	Common Use
12 x 16	305 x 406	~10 x 14	Small boards
12 x 18	305 x 457	~10 x 16	Standard
18 x 24	457 x 610	~16 x 22	Most common (North America)
21 x 24	533 x 610	~19 x 22	Large boards

The 18″ x 24″ panel remains the industry standard in North America. In Asia, metric equivalents like 460mm x 610mm are common. Always confirm panel size with your manufacturer before finalizing your design.

Breakaway Rails and Frame Design

Breakaway rails (also called tooling rails or frames) are non-functional strips added around the panel edges. They provide space for tooling holes, fiducials, and conveyor grip areas.

Standard rail width: 12.7mm (0.5 inch) is most common, though 5mm to 25mm options exist depending on board complexity and assembly requirements.

When to add rails on 2 edges vs 4 edges: Use 4-edge frames when components hang over any edge, when wave soldering is required, or when boards are very thin (< 1.0mm). Two-edge rails work fine for most SMT-only assemblies with adequate component clearance.

Fiducial Marks Requirements

Fiducial marks are small copper reference points that help pick-and-place machines align components accurately. Proper fiducial placement is critical for assembly yield.

Specification	Requirement
Diameter	1.0mm (standard), range: 1.0-3.0mm
Shape	Circular, bare copper
Clearance area	2x to 3x the fiducial diameter, free of copper and soldermask
Quantity	3 per panel (minimum), placed at corners
Edge distance	Minimum 5mm from panel edge
Soldermask	Opening around fiducial, no mask coverage

Place fiducials on the short edges of the panel when possible. This prevents conveyor grippers from obscuring them during assembly.

Tooling Holes Specifications

Tooling holes secure the panel during drilling, assembly, and testing. They ensure consistent alignment across all manufacturing steps.

Specification	Requirement
Diameter	2.0-3.0mm (2.0mm most common)
Type	Non-plated through holes (NPTH)
Location	Corners of panel, within rail area
Clearance	6mm diameter component-free zone around each hole
Quantity	3-4 per panel

Spacing and Clearance Rules

Proper spacing prevents damage during depanelization and ensures components aren’t affected by separation stress.

Board-to-board spacing:

• V-scoring: 0mm possible (score line is the separation)
• Tab routing: Minimum 2.0mm (2.54mm recommended) to allow router bit passage
• Mixed methods: Follow the larger requirement

Component-to-edge clearance:

• V-score panels: Minimum 3mm from score line
• Tab routing: Minimum 3mm from board edge, 5mm from tab locations
• SMT components: Keep 0.5mm additional clearance for sensitive parts

Trace-to-edge clearance: Maintain at least 0.2mm (8 mils) from board edges to prevent copper exposure during routing.

PCB Panelization Design Tips From the Field

After working through hundreds of panel designs, these tips have saved me from costly mistakes.

Tip 1: Optimize Board Orientation for Maximum Yield

Board orientation within the panel significantly impacts material utilization. For non-rectangular boards, try rotating alternating rows 90° or 180° to minimize wasted space. Many CAD tools can calculate optimal arrangements automatically.

For rectangular boards, simple step-and-repeat usually works best. However, if your board is nearly square, test both portrait and landscape orientations—sometimes a 90° rotation fits one more board per panel.

Tip 2: Consider Wave Soldering Requirements

If your assembly includes through-hole components requiring wave soldering, panel design becomes more critical. Wave solder pallets grip the panel edges, so:

• Use minimum 10mm rails on all four sides
• Avoid placing through-hole components within 5mm of board edges
• Consider jump scoring (non-continuous V-scores) to maintain panel rigidity during wave soldering

Tip 3: Match Layer Stackup for Mixed Panels

Mixed panels (different board designs on one panel) can reduce costs for low-volume production. However, all boards must share identical:

• Layer count and stackup
• Board thickness
• Copper weight
• Surface finish
• Soldermask and silkscreen colors

If any specification differs, separate panels are required.

Tip 4: Plan for Depanelization Equipment

Know how your boards will be separated before finalizing the panel design. Hand depanelization works for prototypes but causes stress on components. Automated depaneling routers or laser systems require specific tab designs and clearances.

For laser depanelization (best for thin boards ≤1.0mm), maintain 100μm minimum clearance from components to cutting line. For mechanical routing, allow 1.5mm minimum.

Tip 5: Add Test Points and Programming Connectors to Rails

The breakaway rails offer free real estate for test points, programming headers, or even QR codes for traceability. Use this space for:

• JTAG/SWD programming connectors
• Bed-of-nails test points
• Serial number labels
• Impedance test coupons

Since rails are discarded after depanelization, these features add zero cost to the final product.

PCB Depanelization Methods

Depanelization is the final step—separating individual boards from the panel after assembly. The method you choose affects edge quality, component stress, and production speed.

Manual Depanelization

Hand-breaking works for prototypes and small batches. Use wide-nose pliers to bend each tab until it cracks, then bend in the opposite direction for clean separation. Never twist boards or apply lateral force—this stresses solder joints.

Mechanical Routing

Dedicated depaneling routers use small-diameter carbide bits to cut through tabs. This provides clean edges and minimal stress. Processing speed: 10-30 seconds per panel depending on tab count.

Laser Depanelization

Laser cutting offers the highest precision and lowest mechanical stress. Ideal for flexible PCBs, thin rigid boards, and high-density assemblies with components near edges. Processing time is longer than mechanical routing but edge quality is excellent.

Punching/Die Cutting

High-volume production sometimes uses custom dies to punch boards from panels. Initial tooling cost is high, but per-piece processing is extremely fast. Only economical for production runs exceeding 100,000 units.

Step-by-Step PCB Panelization Process

Understanding the complete workflow helps you communicate effectively with manufacturers and catch potential issues early.

Step 1: Evaluate Your Board Design

Before panelization, assess your individual board design:

• Measure board dimensions and identify the smallest dimension
• Note any overhanging components or connectors
• Check component clearance from all board edges
• Determine if edges need to be smooth for enclosure mounting

Step 2: Select Panelization Method

Based on your evaluation, choose V-scoring, tab routing, or a combination. Consider your production volume—V-scoring suits high volume while tab routing offers more flexibility for lower quantities.

Step 3: Calculate Panel Utilization

Work with your manufacturer to determine how many boards fit on their standard panel size. Most will provide this calculation, but you can estimate using available area divided by individual board area plus spacing.

Step 4: Design the Panel Array

Create the panel layout in your CAD software, including:

• Board arrangement and orientation
• Breakaway rails with proper width
• Fiducial marks in correct positions
• Tooling holes at specified locations
• V-score lines or routing paths with tabs

Step 5: Generate Panel Documentation

Export complete panel Gerber files, including:

• All copper layers
• Soldermask layers
• Silkscreen layers
• Drill files (separate for plated and non-plated holes)
• Board outline with panelization features
• Assembly drawings showing fiducials and tooling holes

Step 6: Verify With Manufacturer

Submit panel design for DFM (Design for Manufacturability) review. Address any feedback before production begins.

PCB Panelization Software Tools

Modern PCB design software includes panelization features, though capabilities vary significantly.

Software	Panelization Features	Best For
Altium Designer	Advanced panelization with embedded board arrays	Professional, complex panels
KiCad	Basic panelization via KiKit plugin	Hobbyists, startups
EasyEDA	Cloud-based auto-panelization	Quick prototypes
OrCAD/Allegro	Full panelization suite	Enterprise production
CAM350	Panel editing and verification	Manufacturing prep
DipTrace	Built-in panelization tools	Small to mid-size projects

For KiCad users, I recommend the KiKit command-line tool—it generates panels from .kicad_pcb files with configurable mouse bites or V-scores in seconds.

Common PCB Panelization Mistakes to Avoid

These errors appear in my inbox weekly. Learn from others’ mistakes:

Ignoring manufacturer guidelines: Every fab house has specific panelization requirements. Request their design guide before starting panel layout.

Placing components too close to edges: The 3mm rule exists for good reason. Depanelization stress can crack solder joints on edge components.

Using V-score with overhanging connectors: USB ports, card-edge connectors, and headers extending past the board edge will be damaged by V-score blades.

Insufficient tab strength: Too few tabs or too narrow tabs cause panels to break during shipping or assembly. Three tabs per edge minimum for boards over 50mm.

No fiducials or wrong fiducial placement: Missing fiducials means manual alignment during assembly—slow and inaccurate.

Useful Resources for PCB Panelization

Here are resources I regularly reference:

Design Tools & Plugins:

• KiKit (KiCad Panelization) – https://github.com/yaqwsx/KiKit
• Altium Panel Editor Documentation – https://www.altium.com/documentation
• EasyEDA Panelization Guide – https://easyeda.com

Industry Standards:

• IPC-2221 Generic Standard on Printed Board Design
• IPC-2222 Sectional Design Standard for Rigid Organic Printed Boards

Manufacturer Resources:

• JLCPCB Panelization Help – https://jlcpcb.com/help
• PCBWay Design Guidelines – https://www.pcbway.com/helpcenter
• Sierra Circuits Panel Requirements – https://www.protoexpress.com/kb

Community & Learning:

• Hackaday Panelization Articles – https://hackaday.com/tag/panelization
• Electronics Stack Exchange – https://electronics.stackexchange.com

Frequently Asked Questions About PCB Panelization

What is the minimum PCB size that requires panelization?

Generally, boards smaller than 50mm x 50mm require panelization for SMT assembly. Most pick-and-place machines and conveyor systems can’t reliably handle smaller individual boards. However, even larger boards benefit from panelization for efficiency gains. If your manufacturer’s equipment has a minimum conveyor width of 50mm (about 2 inches), anything smaller must be panelized.

Can I put different PCB designs on the same panel?

Yes, this is called mixed panelization or heterogeneous paneling. All designs must share identical specifications: layer count, board thickness, copper weight, surface finish, and soldermask color. Mixed panels work well for prototyping multiple designs simultaneously, but assembly becomes more complex since pick-and-place programming must accommodate different component placements.

How do I choose between V-scoring and tab routing?

Choose V-scoring for rectangular boards with straight edges, no overhanging components, and when smooth edges are required. Choose tab routing for irregular shapes, boards with connectors extending past the edge, or when you need to control exactly where separation points occur. Many panels use both methods—V-scoring for straight edges and tab routing for complex areas.

What’s the standard spacing between boards in a panel?

For V-scoring, boards can be placed with zero gap since the score line serves as the separation. For tab routing, maintain minimum 2.0mm spacing (2.54mm recommended) to allow the router bit to pass between boards. Some manufacturers require 3.0mm for thick boards or complex routing paths. Always verify with your specific manufacturer.

How many fiducials do I need on a PCB panel?

Place a minimum of 3 fiducials per panel, located near three corners. This allows the pick-and-place machine to calculate panel orientation and compensate for any skew. For very large panels or high-precision assemblies, consider adding fiducials to individual boards within the panel as well. Fiducials should be 1.0mm diameter with a clear 2-3mm radius soldermask opening.

Conclusion

PCB panelization isn’t just a manufacturing convenience—it’s a fundamental design consideration that affects cost, quality, and production timeline. By understanding the different panelization methods, following proper design guidelines, and avoiding common mistakes, you’ll create panels that move smoothly through production.

Start with your manufacturer’s specific requirements, choose the right separation method for your board shape and components, and leave adequate clearances for fiducials, tooling holes, and depanelization. With proper planning, panelization becomes a powerful tool for reducing costs and improving production efficiency.

Whether you’re building ten prototypes or ten thousand production units, getting panelization right from the start saves redesigns, delays, and budget overruns down the line.