Intelligent Manufacturing Systems & Nano Tech Co., Ltd. (IMS NANOTECH), a leader in domestic compound semiconductor test and assembly equipment located in Korea, has recently developed a high-accuracy LED surface tester that uses the Cognex VisionPro® tool, PatMax® and a CVL® tool, called SearchMax™, which has helped continue their success in the market.

　　IMS NANOTECH’s latest LED test equipment promises great accuracy and productivity offering a three-CCD color camera-based high-precision test that uses Cognex PatMax software. This brand new AOI (Automatic Optical Inspection) machine can significantly increase final yield rates by precisely detecting various process errors (e.g., chip damage, metal coating errors, scratches, contamination, markings, double chips, layer peeling, etc.) through a wafer-level chip surface test.

　　Lee Min-hyeong, the president of IMS NANOTECH, said, “As the domestic LED market sharply increases, the level of demand for test equipment has gradually increased as well. With an abrupt increase in production and wafer size from 2 inches to 4 and 6 inches, high-accuracy test performance as well as rapid processing has become more important.” He added, “By detecting a variety of errors which can occur during the process in advance, the quality of finished goods can be guaranteed, and productivity can be improved as well.”

Superior alignment and color test
　　The chip-level LED test performance greatly varies depending on optical systems (e.g., camera, lens, etc.) and software algorithms. In particular, a chip alignment detection tool, which is one of the core test equipment software, is a critical standard in estimating test performance.

　　IMS NANOTECH created a chip alignment application that is required in conducting an LED chip-level surface test that uses the PatMax tool found in VisionPro vision software. The PatMax geometric pattern matching tool provides superior test performance in omnidirectional alignment (e.g., chip slope, direction, location, etc.) even under the most unfavorable conditions. In addition, IMS created a high-precision alignment function and high-speed test function, which is optimized to detect various errors by integrating the SearchMax CVL software tool. This tool performs color matching, discrimination, and monitoring through various methods such as shear, rotation, scaling, and asymmetry for pattern improvement.

　　Mr. Lee Min-hyeong said, “We have compared many solutions distributed by various vision system suppliers. Among them, the VisionPro PatMax tool was outstanding in various fields such as performance, accuracy, and speed.” He continued, “Above all, we have made this decision because of Cognex’s good reputation in the market.”

Cognex tools in assembly equipment
　　Meanwhile, IMS NANOTECH has also applied the Cognex vision solution to assembly equipment, such as a chip die bonder, as well as to the LED surface tester. The company’s president said, “We plan to keep expanding the compound semiconductor assembly equipment market 2011 by combining our development know-how and Cognex’s advanced vision technology.”

　　Cognex’s VisionPro vision software is applicable to almost all applications in a quick and flexible manner regardless of the type of hardware. It consists of various advanced tool libraries which are optimized for high speed and high performance. It can satisfy the requirements on all vision systems from the positioning of a geometrical object to inspection, individual product check, and verification.