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Autofocus system for off-line focusing error compensation in micro laser fabrication process  

Kim, Sang-In (Center for Robot & Manufacturing Tech., Institute for Adv. Eng.)
Kim, Ho-Sang (Center for Robot & Manufacturing Tech., Institute for Adv. Eng.)
Publication Information
Journal of the Korean Society for Precision Engineering / v.26, no.6, 2009 , pp. 50-58 More about this Journal
Abstract
Micro laser fabrication techniques can potentially be used for the manufacture of microstructures on the thin flat surfaces with large diameter that are frequently used in semiconductor industries. However, the large size of wafers can cause the degraded machining accuracy of the surface because it can be tilted or distorted by geometric errors of machines or the holding fixtures, etc. To overcome these errors the off-line focusing error compensation method is proposed. By using confocal autofocus system, the focusing error profile of machined surface is measured along the pre-determined path and can be compensated at the next machining process by making the corrected motion trajectories. The experimental results for silicon wafers and invar flat surfaces show that the proposed method can compensate the focusing error within the level of below $6.9{\mu}m$ that is the depth of focus required for the laser micromachining process.
Keywords
Autofocus System; Off-line Focusing Error Compensation; Laser Micromachining; Confocal Theory; Error Compensation Table;
Citations & Related Records
Times Cited By KSCI : 5  (Citation Analysis)
연도 인용수 순위
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