What is PCB Mouse bite？Definition, Processes, Components Types and Application

What is  PCB Mouse bite?

The PCB Mouse bite, also called perforated breakaway tabs or pcb breakaway tabs, 

are the sharp edges left over after stamp hole depanelization 

when PCBs are manufactured in a panel using break-routing/break-off tabs. 

Mouse bite PCB structures consist of a line of tiny holes in a circuit board—just like the holes around postage stamps

permitting small PCBs to be used in an array.

These rows of holes earned the nickname "mouse bites" because the indentations left behind 

after they break resemble the bite marks of a mouse that nibbled on the board. 

Mousebite PCB perforation is standard for FR4 panels.

 Drilling these holes leaves rough edges of extra material sticking out the side, 

while a V-groove PCB with a V-scored edge is smoother. 

How to Design  Mousebite PCB

If you panelize individual PCBs within the panel, you only need to mouse bite the PCB edge. 

For routed boards, mousebites are typically seen on both the rail side and the board side.

Routing a board and adding mouse bite PCB tabs is more expensive than a simple v-score, 

but non-rectangular outlines rely on this method. 

One important aspect is to have a clean edge after the breakaway tab is removed. 

Slight inset perforations are preferred because they leave an edge requiring little to no post-processing

The spacing between PCB breakaway tabs can range from 60 mm to 90 mm, 

but I recommend 77 mm from center to center as shown in Figure 3.

Try not to exceed 100 mm between tabs and try to evenly space them apart.

Advantages of Using PCB Mouse Bite


Mouse bites in PCBs are particularly used in high-volume manufacturing due to their ability to separate individual PCBs from a panel. 

The following are some of the advantages of using PCB mouse bites.

1.In high-volume and small-size PCB manufacturing, thousands of small PCBs are manufactured together in a single sheet. 

The mouse bites allow clean separation of individual PCBs by applying pressure along the mouse bite area.

2.Unlike the V-scoring method, mouse bites have less mechanical stress on the PCB board. 

It greatly reduces the risk of cracks in PCBs.

3.Unlike V scoring or the mechanical cutting method, 

the mouse bite PCBs allow greater design flexibility because mouse bites are suitable for irregular shapes.

4. Always use tabs evenly across the edges of the panel.

The Practices for Designing Mouse Bites in PCBA
Use these design tips to optimize mouse bite depanelization:

1.Maintain Clearance – Keep at least 1.5–2 mm from mouse bites to copper, components, or routing.
2.Hole and Spacing Specs – Follow 0.5–0.6 mm hole diameter, 0.35–0.4 mm spacing; limit to 5–8 holes per tab.
3.Symmetrical Placement – Balance panel strength by placing mouse bite sets opposite each other.
4.Tooling Marks & Fiducials – Use dedicated layers (e.g., in Altium) to define mouse bite and tooling positions for manufacturability.
5.Smooth Separation – Plan for edge cleanup steps post-depanelization, such as light filing or polishing.

6. How to Choose PCBA Suppliers for Mouse Bite Panels

To select top-tier suppliers for mouse bite implementation, evaluate these criteria:
1.Panelization Capabilities – Ability to produce mouse bite panels for irregular shapes seamlessly.
2.Precision Drilling – High-accuracy CNC or laser systems to maintain tight hole specs.
3.Process Consistency – Ensure consistent hole patterns across production batches.
4.Experience with Edge Finishing – Ability to offer post-depanel edge cleanup or smoothening.
5.Full Turnkey Services – From design-for-manufacturing (DFM) to assembly and testing

this ensures your mouse bite PCBs maintain structural integrity and functionality.

Summary & Key Takeaways for Mousebite PCB1.

Mouse bite refers to small perforations used in PCB panelization, enabling easy breakup of multiple boards without complex tools.
2.It’s ideal for irregular shapes, high-volume builds, or thin boards.
3.Design for proper hole sizing, spacing, and component clearance to avoid mechanical failures.
4.Evaluate suppliers on both design capabilities and panel handling expertise.
5.By mastering the details of mouse bite depanelization, engineering teams and procurement stakeholders 

can ensure both performance and manufacturability in their electronics products.