Computer-automated shadow moiré method and applications for 3D surface profiling

Among numerous methods for 3D surface profiling, classic shadow moiré method has been kept as the most popular one due to its full-field feature and low cost. This thesis focuses on a computer-vision shadow moiré method with a scope to improve the measurement resolution, accuracy and efficiency. The computer automation is basically realized through the introduction of a phase-shifting technique that is incorporated with a new multi-grid least-square unwrapping algorithm. The method is enhanced by implementing a few additional image processing techniques. These techniques, when implemented, result in improved measurement accuracy and enable easy applications to irregularly shaped surfaces. The study also proposes a new, automated system calibration approach that is based on a real-time image subtraction. A data normalization process is studied to resolve possible confusions in the presentation of the original data. The verification test results show that the modified shadow moiré technique has achieved the initial goal, in that the measurement resolution now reaches a few percentage of the fringe sensititivity.

Computer-automated shadow moiré method and applications for 3D surface profiling

Among numerous methods for 3D surface profiling, classic shadow moiré method has been kept as the most popular one due to its full-field feature and low cost. This thesis focuses on a computer-vision shadow moiré method with a scope to improve the measurement resolution, accuracy and efficiency. The computer automation is basically realized through the introduction of a phase-shifting technique that is incorporated with a new multi-grid least-square unwrapping algorithm. The method is enhanced by implementing a few additional image processing techniques. These techniques, when implemented, result in improved measurement accuracy and enable easy applications to irregularly shaped surfaces. The study also proposes a new, automated system calibration approach that is based on a real-time image subtraction. A data normalization process is studied to resolve possible confusions in the presentation of the original data. The verification test results show that the modified shadow moiré technique has achieved the initial goal, in that the measurement resolution now reaches a few percentage of the fringe sensititivity.

In-situ-Röntgenverfahren zur Messung von Verwindung und Wölbung elektronischer Komponenten während eines Lötvorgangs

ZusammenfassungDie Röntgeninspektionstechnik ist aus der Werkstoffanalytik und der physikalischen Fehlersuche nicht mehr wegzudenken. Besonders interessant für die Zuverlässigkeitsforschung auf dem Gebiet der elektronischen Aufbau- und Verbindungstechnik ist die Beobachtung des mechanischen Verhaltens von Baugruppe und Bauelement unter thermischer Belastung. Viele Erkenntnisse dazu konnten durch Thermoiré-MessungenThermoiré-Messung = Messung der Topologie einer Probenoberfläche durch Anwendung des Schattenmoiré-Verfahrens (siehe Abschnitt 2). erzielt werden (H. Wohlrabe, K.-J. Wolter: „Changes of the coplanarity of SMT-Components during Soldering and their Measurement,“ 3rd Electronics System Integration Technology Conference ESTC, Berlin, Germany, September 13–16, 2010; Y. Wang, P. Hassell: „Measurement of Thermal Deformation of BGA Using Phase-shifting Shadow Moiré,“ submitted to Post Conference Proceedings, SEM 97’ Spring Conference, Bellevue, WA, June 2–4, 1997. DOI:10.1109/EPTC.1997.723923). Für verdeckte Strukturen, wie die Anschlüsse von BGAs, ist diese Methode ohne Präparation und Zerstörung der Originalgeometrie nicht einsetzbar. Vergleichbare Ergebnisse verspricht hier die Beobachtung der Vorgänge mittels Röntgenstrahlung in einer beheizbaren In-situ-Kammer, an deren Entwicklung und Weiterentwicklung seit einigen Jahren am IAVT/ZmPIAVT = Institut für Aufbau- und Verbindungstechnik der TU Dresden; ZmP = Zentrum für mikrotechnische Produktion der TU Dresden. geforscht wird. Besonderes Augenmerk muss dabei auf die Algorithmen zur Bildverarbeitung und geometrischen Entzerrung gelegt werden.