Additional Algorithms for Sensor Chip Alignment to Blind Datums

Gary B. Hughes, FLIR Systems Inc.

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13 pages.

Copyright © 2006 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. This paper is also available at http://dx.doi.org/10.1117/12.683300.

NOTE: At the time of publication, the author Gary Hughes was not yet affiliated with Cal Poly.

Abstract

Alignment of the sensor focal plane array (FPA) to optical components is a critical design feature. Imaging system designs include reference datums that provide the basis for manufacturing alignment in each sub-assembly. Measurement of z and parallelism positioning can be problematic, since the relevant datum features are often beneath the mounting platform and are obscured to the measurement system. General algorithms for determining sensor chip alignment when datum features are inaccessible to the measurement system have been developed. Pre-characterization measurements of datum surfaces are stored for later use during alignment measurement to determine datum locations. The algorithms are useful for post-mounting alignment measurement, and can also be used for active manufacturing alignment. This paper presents additional algorithms that are useful for active alignment, including methods for determining rotation axes on the aligner-bonder system and for determining actuator motions to bring the FPA into alignment with datums. The algorithms have been successfully implemented for ultra-precision, active manufacturing alignment and post-alignment measurement of infrared imaging systems.