SIG Vision Measuring Machine: Fully Automatic Measurement Solution for PCB Panel Arrays (Multi-board Panels)

I. What Is a PCB Panel Array and Why Does It Require a Dedicated Measurement Solution?

In mass PCB production, to improve processing efficiency and reduce material costs, manufacturers typically arrange multiple small-format PCB sub-boards—either identical or of varying specifications—on a single base panel in a consolidated layout, forming what is known as a "panel array" (also referred to as a multi-board panel) for unified processing-. While this production approach maximizes equipment utilization and reduces board changeover frequency, it introduces unique challenges for subsequent dimensional inspection:

• Dual-level control of individual boards and the overall panel: Both the overall dimensions of the entire panel and the independent dimensions and feature positions of each sub-board must be measured and controlled.
• Complex positional relationships between sub-boards: The spacing and relative position accuracy between sub-boards directly affect the quality of individual boards after depaneling.
• High throughput pressure in batch inspection: A single panel often contains 6, 8, or even more sub-boards, making traditional piece-by-piece measurement methods incapable of meeting production line cycle time requirements.

Traditional measurement tools fall short when facing these challenges—manual point-by-point measurement is inefficient, contact-based measurement risks damaging thin substrates, and conventional vision measuring machines without dedicated panel measurement logic require separate programming for each sub-board, resulting in equally poor efficiency.

SIG fully automatic Vision Measuring Machine (OMM), tailored to the measurement characteristics of panel arrays, delivers an intelligent measurement solution based on coordinate nesting + loop copy, enabling efficient 100% inspection of PCB panel arrays through non-contact, high-precision optical dimensional measurement technology.

II. How Does the SIG Vision Measuring Machine Measure PCB Panel Arrays?

Targeting the unique structure of panel arrays, the SIG Vision Measuring Machine adopts the following measurement strategy:

Step 1: Establish the Global Workpiece Coordinate System

Secure the entire panel on the equipment's glass stage and establish a global coordinate system using the panel's overall length edge as the axial reference. This coordinate system serves as the directional reference for all subsequent measurements.

Step 2: Establish Sub-board Coordinate System and Program

Select one sub-board within the panel as the "master board," establish an independent coordinate system for this sub-board, and complete the measurement programming for all critical dimensions of this sub-board—including  length and width, edge clearance, hole diameter, position tolerance, line width/line spacing, and more.

Step 3: Nested Loop Copy Measurement

Based on the master board measurement program, nest and add loop statements for the X-axis and Y-axis, input the X and Y offset values between each sub-board, and the system will automatically copy the master board measurement program to every sub-board on the panel, completing full-panel measurement sequentially.

The core advantage of this solution is: only one programming session is required to complete automatic measurement of all sub-boards on the entire panel—no array function is needed—significantly reducing programming steps and inspection time.

III. What Geometric Dimensions Can Be Measured?

Leveraging the optical dimensional measurement technology of the SIG Vision Measuring Machine-, the following comprehensive measurement elements can be achieved for PCB panel arrays:

Panel-Level Measurements:

• Overall  length, width, and contour dimensions of the entire panel
• Overall flatness and warp of the panel (optional laser probe or white-light confocal sensor for automatic multi-point height data scanning and color deviation map output)
• Straightness and squareness of panel edges

Sub-Board Level Measurements:

• Individual sub-board length, width, edge clearance, hole-to-hole distance, hole-to-edge distance
• Line width/line spacing, pad dimensions, through-hole (PTH/VIA) diameter and position tolerance
• Component placement coordinates and angular offset
• Arc, angle, concentricity, and other geometric features

Inter-Sub-Board Relationship Measurements:

• X/Y axis spacing between sub-boards
• Position deviation of each sub-board relative to the global coordinate system
• Relative angular offset between sub-boards

3D Expanded Measurement (Optional):

Optional contact probe or laser sensor for 2.5D/3D data fusion to measure board thickness uniformity, solder joint height, and profile tolerance in three dimensions.

IV. What Production Pain Points Does This Solution Address?

Pain Point 1: Cumbersome and Inefficient Panel Measurement Programming

Traditional methods require separate programming for each sub-board—a 6-up panel requires 6 repeated programming sessions. The SIG loop copy solution requires only one programming session, with the system automatically completing full-panel copy measurement, dramatically reducing programming and inspection time to meet high-volume production cycle requirements.

Pain Point 2: Difficulty in Batch Control of Sub-Board Position Deviation

After processing, each sub-board in a panel array may exhibit overall offset or rotation relative to the design position. The SIG Vision Measuring Machine, through its dual-layer architecture of global and sub-coordinate systems, precisely measures the position deviation of each sub-board, enabling timely detection of alignment issues during the panelization process and preventing defective boards from advancing to the depaneling stage.

Pain Point 3: Inability to Accurately and Completely Measure Micro Features

Micro traces (line width/spacing ≤50μm) and miniature components (such as 0201, 01005 packages) are difficult for traditional tools to capture accurately. The SIG Vision Measuring Machine, equipped with an automatic zoom lens and AI edge extraction algorithms, ensures stable, repeatable detection of micro features.

Pain Point 4: Contact Measurement Damages Thin PCBs

Thin PCBs and flexible circuits are prone to deformation under contact measurement, leading to data distortion. SIG employs non-contact optical dimensional measurement, eliminating deformation errors caused by physical contact while preventing scratches to delicate solder joints and copper foil surfaces.

Pain Point 5: Difficulty Ensuring Dimensional Consistency After Depaneling

After depaneling, the dimensional consistency of each individual board directly impacts subsequent assembly quality. The SIG Vision Measuring Machine supports CAD drawing import and automatic comparison functionality, enabling automated batch inspection and SPC statistical analysis for same-batch panels, providing real-time monitoring of process variation to ensure every depaneled PCB meets design tolerance requirements.

V. Conclusion

Under the PCB panel array production model, inspection should not become a bottleneck constraining production line throughput—it should be a critical pillar ensuring product consistency. The SIG fully automatic Vision Measuring Machine, with its intelligent coordinate nesting + loop copy measurement solution, streamlines the complex full-dimensional inspection process of panel arrays, significantly improving inspection efficiency while ensuring precise control of critical parameters including dimensions, position tolerance, and flatness.

From the overall panel to each individual sub-board, from 2D geometric dimensions to 3D composite measurement, the SIG Vision Measuring Machine provides a complete, efficient, and non-contact geometric dimension measurement solution for PCB panel arrays.

For more technical details and application cases of Vision Measuring Machines, please visit the Sinowon official website: www.sinowon.com