JRM Vol.18 No.6 pp. 779-786
doi: 10.20965/jrm.2006.p0779


A Dual Imaging System for Flip-Chip Alignment Using Visual Servoing

Daljae Lee*, Xiaodong Tao*, Hyungsuck Cho*, and Youngjun Cho**

*Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-dong, Daejeon, Korea

**Mechatronics Team, Korea Institute of Industrial Technology (KITECH), Chungnam, Chunan-Si, Korea

April 5, 2006
June 26, 2006
December 20, 2006
flip-chip, dual imaging system (DIS), alignment, feature extraction, visual servoing

Electronic components must be precisely aligned on printed circuit (PC) boards in chip packaging, especially in flip-chip assembly. We propose a vision system to provide relative positioning information between the flip-chip and substrate to ensure accurate alignment. The dual imaging system (DIS) we introduce to ensure alignment consists of a zoom lens, beam splitter, mirror, charge-coupled device (CCD) and light-emitting diode (LED) illumination, and simultaneously observes solder bumps on flip-chips and pad patterns on substrates using one camera. Features are extracted from the preprocessed image frame containing the flip-chip and substrate to obtain positioning and orientation errors between the chip and substrate. Based on measured error, visual servoing determines the instantaneous velocity input of flip-chips at each servoing iteration time and controls relative positioning and orientation precisely on-line. Fine servoing on a 3-axis stages uses dual imaging for visual alignment. Experiments under different parameter conditions to evaluate dual imaging system and visual servoing algorithm performance confirmed the feasibility of our proposal.

Cite this article as:
Daljae Lee, Xiaodong Tao, Hyungsuck Cho, and Youngjun Cho, “A Dual Imaging System for Flip-Chip Alignment Using Visual Servoing,” J. Robot. Mechatron., Vol.18, No.6, pp. 779-786, 2006.
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Last updated on Mar. 05, 2021