What is PCB Panelization? Precautions and Optimization Strategies

March 13, 2026

In PCB design, panelization is a critical operation that involves multiple factors such as production feasibility and cost control. Below is a detailed analysis of why panelization is necessary, which situations require it, whether it is feasible not to panelize, and precautions to consider:

01 Why Panelize? Reasons for Panelization

1. Meeting Production Equipment Size Requirements

When a single PCB is too small, especially with one side less than 50mm, it often fails to meet the minimum processing standards of production equipment, preventing the machine from functioning properly. Panelization combines these small boards into a size that meets equipment specifications. At the same time, the maximum panel size must be controlled, generally not exceeding 700mm×600mm, to ensure efficiency in subsequent processes like placement.

2. Reducing PCB Material Waste

For irregularly shaped PCBs or multiple PCBs sharing the same processes, producing them individually can result in significant material waste. Panelization allows these boards to be arranged rationally, making full use of the panel space and improving resource utilization.

3. When Panelization is Necessary

• A single PCB has one side less than 50mm and does not meet the minimum size requirements of production equipment.

• The board has an irregular shape, reducing material utilization if produced singly.

• Multiple PCBs share the same processes, allowing panelization to reduce waste and improve efficiency.

Feasibility of Not Panelizing

If a single PCB meets the minimum size requirements of production equipment, has a regular shape, and offers high material utilization, it may be feasible not to panelize. However, for small-sized, irregularly shaped, or multiple boards with identical processes, skipping panelization can lead to production difficulties and increased costs. Therefore, panelization is generally recommended.

02 Precautions for Panelization

Panel Shape
To facilitate production, the panelized shape should ideally be square, avoiding excessive length-to-width ratios to enhance stability and efficiency during manufacturing.

Panelization Methods

• Regular-shaped boards typically use V-groove scoring for panelization.

• Irregularly shaped boards, which cannot utilize V-grooves, are generally panelized using the tab-routing method with mouse bites.

Tooling Strip/Process Edge Settings
When components are located less than 3mm from the board edge, a process edge (tooling strip) must be added. This is usually applied to the longer side, explaining why many individual boards require such edges.

Mark Points and Hole Placement
After panelization, remember to add three fiducial marks and place four non-plated tooling holes on the outer process edge. The diagonal marks should not be aligned in a straight line; they need to be slightly offset.

Space Reservation

• A clearance of greater than 0.5mm should be reserved between components and the V-groove line to ensure the scoring tool operates correctly and prevents damage to components.

• The spacing between individual boards within the panel must account for the width of components, especially for connectors located near the board edge, considering their physical dimensions.

03 Panelization Optimization Strategies

Methods to Increase Panel Utilization
Improving panel utilization is key to reducing costs. Here are some effective methods:

Optimize PCB Layout
By arranging PCBs closely and reducing spacing, panel utilization can be significantly increased. For example, using step-and-repeat techniques, for non-gold-plated edge connections, the standard spacing for routing is 100 mils (2.54mm), while for scoring, spacing can be zero. Additionally, using a scoring process allows grooves to be placed between PCBs on the panel, enabling tighter packing and even eliminating the space needed for routing paths.

Rational Design of Borders
Reserve border width appropriately based on the PCB's layer count and technical requirements. For single and double-layer products, a border width of 500 mils (1.27cm) is typical. For multilayer boards, this may need to increase to 750 mils (1.905cm). For PCBs with controlled impedance requirements, an additional 1-inch (2.54cm) border area might be needed for test coupons. Optimizing border design helps reduce unnecessary space waste.

Using Standard Panel Sizes
Choosing the right panel size is crucial for optimizing panelization costs:

• North America: Common panel sizes include 12x18 inches, 18x24 inches, and 21x24 inches, with 18x24 inches being the most common. These standard sizes help manufacturers optimize production processes, improving material utilization and efficiency. Maximizing material utilization on standard panel sizes can significantly impact the price and lead time of multilayer boards.

• Asia: Manufacturers often provide custom panel sizes based on customer requirements to maximize utilization. For some specialized applications, opting for larger panel sizes can minimize processing costs per unit area. For instance, when handling large orders, Asian manufacturers may prioritize larger panel sizes to enhance production efficiency and lower costs.

Considering Special Requirements and Customization
In panel design, special needs and customization must also be considered:

Special Testing Requirements
For PCBs requiring controlled impedance, an additional 1-inch (2.54cm) border area is often needed for test coupons. Furthermore, PCBs conforming to military standards require placement of military standard test coupons, which may necessitate larger border areas depending on the manufacturer's design. These special testing needs reduce available space but ensure the high performance and reliability of the PCBs.

Assembly Requirements
To facilitate assembly, it is generally necessary to maintain a border of at least 0.375 inches to 500 mils (9.525mm to 12.7mm) around the panel. Assembly rails (breakaway portions) typically extend into this border area to keep the PCBs away from the panel edge. A well-designed assembly rail enhances assembly efficiency and reduces the risk of damage during the process.

Customization Services
In Asia, manufacturers often provide customization services based on specific customer needs, including custom panel sizes, special material selections, and unique processing techniques. This flexibility allows manufacturers to better meet diverse customer requirements and enhance market competitiveness.