Technical Guidance: V-Cut Panelization Standards

For boards with regular rectangular shapes, V-cut (V-scoring) panelization is an efficient method. This process involves cutting V-shaped grooves of a specific depth on both sides of the panel along the board boundaries, leaving a thin web of material (typically about 1/3 of the board thickness) that allows easy manual separation after SMT assembly. After separation, minor thread-like fibers or rough edges may remain and can be lightly scraped off. Due to material expansion and cracking during depaneling, V-cut boards have a slightly larger dimensional tolerance of ±0.4 mm. PCBs panelized using this method are called "V-cut panelized boards." JLCPCB’s standard SMT assembly fully supports V-cut panelization.

V-cut processing

Here are a few key points regarding our V-cut processing:

■ V-Cut Angle: 25 degrees(standard, uniform on both sides).

■ V-Cut Panel Size: Both length and width must be 70 mm or more. If both horizontal and vertical V-cuts are used, the maximum panel size is typically 475 × 475 mm.

■ V-Cut Connectivity: Rectangular boards can be connected on all four sides or on two opposite sides (the minimum width of the connecting edge should be 3 mm, and for board thicknesses of 0.8 mm and below, the minimum width of the connecting edge should be 5 mm).

■ V-Cut Direction: Can only be in a straight line (starting at one end and ending at the other, no skipping), and only double-sided V-cut, not single-sided V-cut.

■ V-Cut Routing Clearance: The copper layer, traces/solder pads, etc., need to be at least 0.4mm away from the V-cut centerline to avoid exposing copper or damaging traces during V-cut (in addition, try to keep mounting holes away from the V-cut line to prevent holes from breaking during separation).

In regular V-cut scenarios, there is no gap between boards, maximizing material utilization. When V-cut edges coincide with routed slots, the circular milling tool may leave small protruding acute angles after separation. These can usually be removed manually if needed. To avoid this, add a 3-5 mm process edge (tab) between boards, allowing the tool full access for clean edges.

Considering the requirements for SMT assembly, the appropriate panelization method should be chosen.

A) The distance from the fiducial to the board edge should be appropriate (JLCPCB's SMT requires a minimum of 3.85 mm from the center of the fiducial to the board edge) so that they are not blocked by SMT machine guide rails.

B) For components protruding from the board, empty slots (CNC) should be created on the process edge to facilitate SMT assembly.

C) For board areas that need to be milled out, please mark "CNC" on the same layer as the board outline.

D) For board areas that need to be V-cut, please mark "V-CUT" on the same layer as the board outline.

E) Board edges with arcs or protrusions should not be V-cut. Edges with recessions should avoid V-cut if possible and use milling instead to ensure there are no sharp angles in the recessed slots.

F) The minimum width for load-bearing connecting edges inside the board is 3mm.

■ V-Cut Remaining Thickness and Separation
JLCPCB uses double-sided 25° V-cut scoring, typically leaving approximately one-third (1/3) of the board thickness as the connecting web. This design ensures the panel remains rigid during SMT assembly while allowing easy manual separation afterward.

• For standard thicknesses (≥0.6 mm), the remaining thickness provides a good balance between strength and breakability.
• Note: V-cut is not supported for 0.4 mm board thickness.
  After separation, slight dimensional deviation (±0.4 mm) and minor fiber residue are normal due to material properties.

■ V-Cut Panel Size: Minimum 70 mm × 70 mm (both length and width). When both horizontal and vertical V-cuts are used, the maximum panel size is 475 × 475 mm. Panels outside this range cannot undergo V-cut processing.

■ Additional Notes: V-cut is not supported for 0.4 mm board thickness. Panels must use double-sided V-cut only.

Requirements

① 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.

② 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.

③ 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.

V-Cut vs Other Panelization Methods

JLCPCB primarily supports three main panelization methods: V-Cut (V-Scoring), Mouse Bite (Stamp Hole / Perforated Tab), and Tab Routing (Breakaway Tabs). Understanding the differences helps designers choose the most suitable method based on board shape, production volume, edge quality requirements, and cost considerations.

V-Cut (V-Scoring)

V-Cut is the preferred method for regular rectangular boards. It involves cutting 25° V-shaped grooves on both sides of the panel, leaving approximately one-third (1/3) of the board thickness as the connecting web.

Advantages:

• Zero spacing between boards → highest material utilization (often >90%).
• Fast processing and easy manual separation after SMT.
• Lowest cost for high-volume rectangular panels.
• Smooth, straight edges after separation (minor fiber residue can be scraped off).

Limitations:

• Only suitable for straight-line connections (no curves, arcs, or irregular shapes).
• Higher mechanical stress during breaking, requiring ≥0.4 mm (recommended ≥1.0–2.0 mm) clearance for components and traces.
• Not supported for 0.4 mm board thickness; minimum panel size 70×70 mm.
• Slightly larger dimensional tolerance (±0.4 mm).

Mouse Bite (Stamp Hole) Panelization

Also known as “universal panelization,” mouse bites use sets of small drilled holes (typically 0.60 mm diameter, 5–8 holes per set) connected by narrow tabs to hold the boards together.

Advantages:

• Suitable for irregular, curved, L-shaped, or complex board outlines.
• Lower mechanical stress on components during separation.
• Supports JLCPCB’s economic SMT assembly service.
• Greater design flexibility — components can be placed closer to board edges.

Limitations:

• Requires 1.6 mm or 2 mm spacing between boards → lower material utilization than V-Cut.
• Leaves slightly serrated edges at tab locations, which may need light deburring or sanding.
• Slightly higher processing cost compared to pure V-Cut.

Tab Routing (Full Breakaway Tabs)

This method uses CNC routing to cut most of the outline, leaving solid or wider tabs for connection. It is often combined with mouse bites.

Advantages:

• Best edge quality and precision.
• Excellent for very fragile boards or when minimal stress is critical.
• Highly flexible for complex designs.

Limitations:

• Highest cost and longest processing time.
• More material waste due to wider routing paths.

Comparison Table：

Recommendation

• Choose V-Cut for standard rectangular boards in high-volume production to maximize cost efficiency and material utilization.
• Choose Mouse Bite for irregular shapes or when using JLCPCB’s economic SMT service.
• Use Tab Routing or hybrid approaches when edge quality and minimal stress are the top priorities.
  Hybrid panelization (V-Cut on some axes + Mouse Bite on others) is also supported when necessary.

For the best results, always download JLCPCB’s final engineering files after panelization review and verify compatibility with your stencil and fixtures.

Example Panel Layouts

The following examples demonstrate recommended V-Cut panelization layouts. These illustrations show proper implementation of V-Cut rules, including straight-line scoring, connecting edge requirements, and SMT compatibility considerations.

FAQ about V-Cut Panelization Standards

Conclusion

By following the V-Cut panelization standards outlined in this document, you can achieve high material utilization, excellent SMT compatibility, and cost-effective production for your rectangular PCB designs. Proper V-Cut implementation requires attention to minimum panel size, copper clearance, connecting edge width, and double-sided straight-line scoring. Always remember to download the final engineering files from the JLCPCB system after order review — this is the most critical step to ensure your stencils, fixtures, and assembly process perfectly match the fabricated panels.  

Adhering to these guidelines will minimize production issues, improve board quality, and help you successfully bring your projects to market. Should you have any further questions, feel free to contact JLCPCB technical support.