A Better Search: How Cognex Pioneered Geometric Pattern Matching

To achieve high yields, electronic hardware and OLED and LCD display manufacturers demand the highest accuracy and precision in the automation equipment powering their assembly lines. In the world of miniaturized electronics, the percentage of product that conforms to specification is highly dependent on precise component placement. Only machine vision can locate, align, and guide these components with the required precision and speed to help electronics manufacturers meet their production goals.

From the simple guidance of a camera module onto its housing to the high-precision alignment of a pixel mask layer onto an OLED panel, the first and most critical step in an electronics manufacturing application is locating an object within the camera’s field of view. Object location can be extremely challenging for OLED and LCD display manufacturers, who deal with critical dimensions several orders of magnitude smaller than the overall device being manufactured.

Cognex has pioneered a series of advances in object location that have redefined the way electronics Original Equipment Manufacturers (OEMs) and display manufacturers approach object location. Cognex helped move past blob analysis and binary template matching by introducing the first commercially viable “Search” technology based on normalized correlation. This innovation set the stage for later breakthroughs of geometric pattern-finding that have changed the way manufacturers assemble their hardware and devices.

In 1997, Cognex introduced PatMax, the first set of geometric pattern search algorithms for machine vision applications. Geometric pattern matching surpassed the limitations of normalized correlation by representing an object as a geometric shape, independent of shading and a discrete grid. Geometric pattern search techniques represent the best method for locating key features, patterns, and fiducials for displays, assemblies, and other electronic components. Machine vision systems based on geometric pattern search are now used throughout the electronics manufacturing process, for everything from aligning the electrodes and organic layer of an OLED screen to precisely placing electronic components and adhesive during module assembly. Although there are other geometric pattern-finding algorithms available in the machine vision marketplace, PatMax from Cognex remains the preferred tool for electronics alignment applications due to its superior robustness, reliability and accuracy.