The evolution in PCB manufacturing—characterized by smaller chips, diverse packages, higher-density boards, and increasingly complex multi-layered designs—is driving a migration from traditional 2D measurements to advanced 3D techniques. Below, we delve into the specific camera requirements needed to support this transition.

Limitations of 2D Measurements

A standard top-view in 2D imaging can detect defects like shifts, rotations, and cracks but falls short when it comes to assessing component flatness or solder paste volume. For these tasks, a single image sufficed for basic measurements—but now we’re moving beyond that limitation.

The Need for Multi-Image Systems

Some early 3D measurement systems relied on just four to five images per inspected region of interest (ROI). However, more sophisticated approaches leverage 20 or even more images. This increase in data points serves dual purposes: improving accuracy and incorporating color vision capabilities.

Camera Requirements Undergo a Transformation

This shift toward multi-image acquisition significantly raises the bar for camera-based imaging systems. Two primary strategies can meet these demands:

Option 1: Higher Resolution Cameras with High Frame Rates

Higher-resolution cameras enable larger inspection areas while gathering more detailed data, enhancing measurement accuracy. However, since multiple images are required for quantitative analysis and overall system throughput must remain high, frame rates need to be carefully balanced—typically in the range of several hundred frames per second (e.g., 4 megapixels at 180 fps or even 25 megapixels at 32 fps).

Because these systems combine numerous images, consistency becomes critical. Parameters like black level and gain must remain identical across all captured images to ensure reliable results. Achieving this requires meticulous design and implementation by the camera manufacturer.

Option 2: Multiple Cameras

An alternative approach involves using multiple cameras to capture distinct views of each ROI. This strategy can reduce reliance on illumination systems while potentially lowering costs through the use of standard “lower-end” cameras, making it particularly attractive for scaling up high-end systems.

However, caution is warranted—cameras used in this setup must maintain extremely consistent performance and precise synchronization to guarantee accurate results, despite operating at lower frame rates.

Last Updated: 2025-09-04 19:04:49