Technical Guidance: Mouse Bite Panelization Guide
9 min
- What is Mouse Bite Panelization?
- Why Choose Our Mouse Bite Panelization Service
- Mouse Bite Design Guidelines
- Important Requirements for Non-Standard Panel Designs
- Advantages and Limitations of Mouse Bite Panelization
- FAQ about Mouse Bite Panelization Guide
- Conclusion
The conventional method of panelization uses V-grooves. However, for irregularly-shaped boards or special requirements (such as JLCPCB's economic SMT assembly), mouse bite panelization, which resembles postage stamps on an envelope, is required. PCBs panelized using this method are called "mouse bite panels" or "mouse bite connections".
Mouse bite panelization can be referred to as "universal panelization." As long as there is a position to add mouse bites, boards of various shapes can be interconnected using mouse bites. The number of mouse bite connection positions, their sizes, and the overall stability of the panel directly affect the quality of SMT assembly.
It should be noted that mouse bite panelization may result in serrated edges after the panels are separated.Note
What is Mouse Bite Panelization?
Mouse bite panelization, also known as tab routing with perforations, is often referred to as "universal panelization." As long as there is a position to add mouse bites, boards of various shapes can be interconnected. It works by creating a series of closely spaced holes that form a controlled weak point, providing enough strength to survive SMT assembly and handling while allowing easy separation afterward. The number of mouse bite connection positions, their sizes, and the overall stability of the panel directly affect the quality of the final assembly. It should be noted that mouse bite panelization may result in serrated edges after the panels are separated.
Mouse Bite vs V-Groove Panelization
Unlike V-groove panelization, which is ideal for straight rectangular boards and produces clean, smooth edges after separation, mouse bite panelization offers superior flexibility for irregular, curved, or complex board outlines. While V-grooves are faster to score on rectangular panels, mouse bites excel in universal applicability and are particularly suitable for economic SMT assembly where design flexibility is essential. The trade-off is the slightly serrated edge left by mouse bites, which can be easily managed with minor post-processing if needed.
Why Choose Our Mouse Bite Panelization Service
Our engineering team has extensive experience in mouse bite panelization and offers optimized processes tailored for high-quality SMT assembly. Non-compliant mouse bite spacing in customer files will be automatically adjusted to the recommended minimum of 0.3 mm to ensure panel stability, while preserving design intent as much as possible. This professional handling, combined with strict process controls, helps reduce risks of premature detachment during production and provides more consistent results compared to standard panelization services.
Mouse Bite Design Guidelines
■ Mouse Bite Size: It is recommended to use sets of 5 to 8 holes with a diameter of 0.60 mm each (it is not recommended to have fewer than 5 holes in a set). This configuration distributes stress evenly and improves breaking consistency.
■ Mouse Bite Spacing: The distance from hole edge to hole edge should be 0.35-0.4 mm. A minimum spacing of 0.3 mm should be ensured for sufficient connection strength (thinner boards may require slightly larger spacing).
■ Number of Mouse Bite Sets: At least 2 symmetrically placed sets are needed for boards within 30 mm wide on both sides. It is recommended to add a set of mouse bites every 50-60 mm, adjusting based on actual board size and component weight.
■ Mouse Bite Placement: Add mouse bite holes in the centerline of the board frame or extending one-third into the board. If there are vias, traces, mounting holes, or protruding components along the board edge, avoid placing mouse bites in those areas.
■ Panelization Spacing: The typical spacing is 1.6 mm or 2 mm, with a minimum requirement of 1.2 mm (going below this value may cause issues like drilling bit breakage or misalignment).
Note
To facilitate board separation, mouse bites should be positioned in the larger blank areas of the board.
Supplementary Dimensions Reference
| Parameter | Recommended / Minimum | Key Consideration |
|---|---|---|
| Holes per Set | 5–8 | Ensures even breaking force |
| Hole Diameter | 0.60 mm | Standard for reliable perforation |
| Hole Edge Spacing | 0.35–0.4 mm (min 0.3 mm) | Critical for panel stability |
| Panel Gap | 1.6–2 mm (min 1.2 mm) | Compatible with manufacturing tools |
❶ Mouse bites are not needed on the process edge side (as marked by the red circle in the figure). Mouse bites are only required to be added on one side of the board outline, but for connecting boards to other boards, mouse bites should be added on both sides (as indicated by the red arrows in the figure).
❷ For circular boards, it is recommended to add mouse bites in positions with blank board space, ensuring a lager blank board area to apply force to when separating the boards.
Note
To facilitate manufacturing, please add mouse bites according to the guidelines.
Important Requirements for Non-Standard Panel Designs
Regarding non-compliant panel files provided by customers, the following requirements are provided.
① If the spacing between mouse bites in the panel files provided by the customer is insufficient, our engineering team will adjust it to a minimum of 0.3mm (to ensure sufficient support and prevent accidental detachment) without notifying the customer.
② For non-compliant designs, because they require adjustments, we cannot guarantee that each production will be exactly the same. Thus, it's possible to have variations in the results between different batches. Please be aware!
③ For panel designs specified by the customer as text description or outline drawings without gerber files, we make our own adjustments for non-compliant positions (such as mouse bites, connection positions, clearances, etc.). Tooling holes and fiducials should be added by the customer. We do not add data that is not present on the drawings.
④ For panel designs provided by the customer as gerber files, if they require tooling holes or fiducials, please add them yourself. Data not present on the drawings will not be added by us.
⑤ For customer-provided panel layout drawings where unit boards (or process edge) are not identical, our engineering team will by default adjust them to zero spacing panelization. For panels supplied as gerber files, we follow the file's specifications.
To ensure that the PCBs match your stencil and fixture precisely, please download our engineering data from the system to create your stencil and fixture.A strong emphasis
Example Panel Layouts
Advantages and Limitations of Mouse Bite Panelization
Compared to V-groove scoring, mouse bites excel in handling complex and non-rectangular board outlines. They are particularly valuable in prototyping and small-to-medium production runs where design flexibility is prioritized. However, designers should always consider the trade-off of slightly rougher edges and plan for any necessary post-processing, such as light sanding, depending on the end-use requirements.
Best Practices for Successful Implementation
- Distribute mouse bite sets evenly to avoid localized stress concentrations.
- Verify clearances around mouse bite areas during the design review stage.
- Test a small prototype panel when working with heavy components or unusual board shapes.
FAQ about Mouse Bite Panelization Guide
Q:What is mouse bite panelization and when should I use it?
Mouse bite panelization (also known as tab routing with perforations) is a universal panelization method that connects individual PCBs using sets of small drilled holes. It is particularly recommended for irregularly shaped, curved, or complex boards where traditional V-groove panelization is not suitable. It is also ideal for economic SMT assembly that requires high design flexibility.
Q: What are the main differences between mouse bite and V-groove panelization?
V-groove panelization works best for rectangular boards and leaves smooth, clean edges after separation. In contrast, mouse bite panelization offers superior flexibility for non-rectangular and complex shapes. The main trade-off is that mouse bites typically leave slightly serrated edges, which may require minor post-processing (such as light deburring) depending on your application.
Q: Where should mouse bites be placed on the board?
Mouse bites should be positioned along the centerline of the board frame or extending one-third into the board, preferably in larger blank areas. Avoid areas with vias, traces, mounting holes, or protruding components near the edge. For boards connecting to each other, place mouse bites on both sides. No mouse bites are needed on the process edge (rail) side.
Q:What happens if my submitted panel design does not meet the guidelines?
Our engineering team will automatically adjust insufficient mouse bite spacing to the minimum 0.3 mm to ensure stability and prevent accidental detachment. For non-compliant designs, slight variations between production batches may occur. We recommend downloading and reviewing the final engineering files before creating stencils or fixtures.
Q: How can I ensure the best results with mouse bite panelization?
Follow the design guidelines, distribute mouse bites evenly, and place extra sets near heavy components. Keep the longest panel side preferably under 250 mm. Always perform a design rule check on mouse bite areas, and use the final engineering data for stencil and fixture preparation. For circular boards, prioritize positions with sufficient blank space for easy separation.
Conclusion
Mouse bite panelization is a highly flexible and versatile solution for modern PCB manufacturing, especially when dealing with irregular shapes and complex layouts. By following the design guidelines outlined in this document — proper hole sizing, adequate spacing, strategic placement, and sufficient support sets — designers can achieve excellent panel stability during SMT assembly while ensuring convenient depanelization.
Careful attention to these details, combined with professional engineering adjustments, will help minimize production risks and deliver high-quality finished boards. For best results, always review the final engineering files before proceeding with stencil and fixture preparation.
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