Automated Optical Inspection Solutions

Advancing Precision in PCB Inspection

As electronic components become smaller and more complex, traditional 2D AOI struggles to detect critical defects such as lifted leads, insufficient solder, and warpage. 3D Automated Optical Inspection (AOI) solves these challenges by providing precise height and volume measurements, ensuring more accurate defect detection and reducing false calls.

How 3D AOI Differs from 2D AOI

Unlike 2D AOI, which relies on flat imaging, 3D AOI creates a detailed volumetric profile of each PCB, enabling manufacturers to inspect solder joints, component placement, and board quality with metrology-grade accuracy. Koh Young’s True 3D AOI technology delivers consistent, repeatable results, improving production efficiency and reducing costly rework.

Structured Light Projection & Moiré Interferometry

Koh Young’s 3D AOI systems project structured light onto the PCB surface, measuring the phase shift of reflected light to calculate height variations with micron-level accuracy. This ensures reliable component and solder joint inspection, even for highly reflective surfaces.

Multi-Angle Imaging for Comprehensive Coverage

Unlike conventional systems that capture images from a single viewpoint, multi-angle cameras enable Koh Young’s 3D AOI to detect lifted leads, tombstoning, and skewed components. This ensures defects are identified regardless of orientation or shadowing effects.

Automated Board Warpage Compensation

PCB warpage can lead to false defect detection or missed faults. Koh Young’s automated warpage compensation adjusts for board deformations, ensuring consistent, high-precision inspection without operator intervention.

Superior Defect Detection & Process Optimization

3D AOI enables manufacturers to identify critical defects such as head-in-pillow, solder bridges, and insufficient solder with exceptional accuracy. By integrating AI-driven analytics, Koh Young’s AOI solutions provide real-time defect trends, allowing manufacturers to optimize processes and improve first-pass yield.

Reduced False Calls and Improved Reliability

Traditional 2D AOI systems often generate false calls due to variations in lighting and contrast. Koh Young’s 3D AOI technology eliminates these issues, ensuring only true defects are flagged, minimizing unnecessary rework, and improving inspection reliability.

Scalability for High-Density, High-Reliability Production

With the rise of miniaturized components in industries such as automotive, aerospace, and medical electronics, the need for high-precision inspection has never been greater. Koh Young’s 3D AOI technology supports high-density PCB designs, ensuring quality assurance without compromising throughput.

Four Constraints Narrow the Range Quickly

Component height. This is the hard limit and the one most often discovered too late. Standard configurations measure to 4 or 5 millimetres. The Zenith UHS handles up to 10 millimetres in most configurations, and the Zenith 2, Zenith Alpha HS+ and Alpha UHS+ reach 25 millimetres for tall components and connectors.

Throughput. The Zenith range runs from 7.1 to 26.2 cm²/sec. The Zenith UHS roughly doubles that, reaching 52.3 cm²/sec at 8M and 20 microns, which is where it earns its place on high-volume lines. Buying throughput beyond what the line can feed is wasted capital; buying too little turns inspection into the bottleneck.

Board format. Long boards need extended handling: the USX configurations carry boards up to 1,300 millimetres, or 1,500 millimetres on USX 2.0, with PCB weights to 30 kilograms. Flexible circuits are a separate case entirely. The Zenith F is built for FPCB assembly at 12M and 10 microns with a 1 millimetre measurement height, and a rigid-board machine is not a substitute.

Inline or offline. Most lines inspect inline. Large backplanes and server panels often cannot, which is what the Zenith S is for: an offline system accepting boards up to 650 by 600 millimetres, 0.4 to 8 millimetres thick, at 31.1 cm²/sec.

If the boards are mixed and the runs are short, programming time matters more than any of the above. Auto-programming reduces it by around 70 percent, which on a high-mix line is usually the larger saving.

AOI and Solder Paste Inspection Do Different Jobs

AOI verifies the board after reflow. It does not replace inspection at the printer, where most defects originate and where correction is cheapest. Lines running both catch different failures at the stage each is cheapest to fix. See our solder paste inspection guide for that half of the process.