Let’s talk about the V-cut issue of the circuit board

V-Cut Array Design Specifications

V-Cut panelization is applicable to regularly shaped boards. This fabrication method involves creating V-shaped grooves of controlled depth at the panel edges, facilitating post-assembly separation. Residual fibrous strands along separation lines – characteristic of V-scored boards – can be removed through light abrasion. Material expansion during detachment introduces marginally wider dimensional tolerances (±0.4mm) compared to alternative panelization methods. PCBs interconnected through this V-groove technique are designated as V-scored array boards.

V-Cut Machining Specifications
Key technical parameters for our V-scoring operations:

1. Groove Angle: Standard 25° configuration
2. Panel Requirements: Minimum 70 mm in both X/Y dimensions
3. Array Connections:
   • Full perimeter or dual-edge bonding for rectangular boards
   • Minimum bridge width: 3 mm (5 mm required for substrates ≤0.8mm thick)
4. Scoring Constraints:
   • Linear routing only (continuous start-to-end paths)
   • Mandatory dual-side grooving (no single-side alternatives permitted)

• V-Cut Clearance Requirements: Maintain a 0.4mm minimum offset between conductive features (traces, pads, copper layers) and the V-cut centerline to prevent copper exposure or circuit damage during scoring. Mounting holes must also be positioned outside the V-cut path to eliminate fracture risks during repaneling.

V-Cut Spacing Protocol:
For standard V-cut penalization, zero spacing is maintained between boards. Non-V-groove designs require 1.6mm or 2mm inter-board spacing.

Critical Note for Slot Alignment:
When V-groove edges intersect with routed slots, the circular milling bit’s geometry prevents full access to adjacent board areas, potentially leaving acute protrusions post-depaneling. These may be manually trimmed if required. To eliminate such defects during fabrication, incorporate a 3–5mm process edge between boards to enable complete tool access and automatic sharp-edge removal.

SMT-Optimized Panelization Guidelines
To ensure assembly compatibility, adhere to these design principles:

A) Fiducial Placement: Maintain ≥3.85mm clearance from fiducial center to board edge (per JLCPCB SMT specifications) to prevent interference with pick-and-place machinery.

B) Component Clearance: Implement relief slots on process edges via CNC milling for components extending beyond board profiles.

C) Milling Zones: Designate “MILLING” labels on the outline layer for areas requiring mechanical cutting.

D) V-Groove Identification: Annotate “V-SCORE” markers on the outline layer for V-groove routing sections.

E) Edge Geometry Restrictions:

• Avoid V-scoring on curved/protruding edges
• Prioritize milling over V-grooves for recessed edges to eliminate residual sharp edges

F) Structural Integrity: Minimum 3mm width required for internal structural bridges.

Design Compliance Guidelines

1. Text/Outline-Based Panelization: For customer-specified panel layouts lacking Gerber data, non-compliant features (breakaway tabs, bridge locations, clearances) will be optimized internally. Clients must independently include tooling holes and fiducials – no additions will be made beyond provided documentation.
2. Gerber-Defined Panels: Customer-supplied Gerber files requiring tooling holes or fiducials must contain these features natively. Unspecified elements will not be supplemented during production.
3. Heterogeneous Array Handling:
   • Non-uniform unit boards/process edges in customer drawings: Default to zero-clearance array optimization
   • Gerber-based panels: Strict adherence to file specifications

Critical Notice:
To ensure PCB/stencil/fixture dimensional congruence, always reference engineering files for auxiliary tooling fabrication.