CIRP Encyclopedia of Production Engineering

Living Edition
| Editors: The International Academy for Production Engineering, Sami Chatti, Tullio Tolio

Optical Inspection

  • Aarief Syed-Khaja
  • Miriam Rauer
  • Joerg FrankeEmail author
Living reference work entry



Optical inspection methods detect failures by a nominal-actual value comparison. Two different methods are developed for individual fields of application: the solder paste inspection (SPI) and the automatic optical inspection (AOI). SPI is the optical inspection of the printed solder paste on the circuit board after the solder paste printing process. AOI is a test method for process monitoring and quality control in electronics production.

Theory and Application

Solder Paste Inspection (SPI)

Theory: Solder paste inspection (SPI), also called automated solder paste inspection, in-line solder paste inspection, or 3D solder paste inspection, is a quality assurance method developed as part of the quality management system for the optical inspection of the printed solder paste in electronics production. The inspection may be completely automated and integrated into the production line to improve the quality of the printing process, subsequently reduce...

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  1. Berger M (2012) Test- und Prüfverfahren in der Elektronikfertigung. Vom Arbeitsprinzip bis Design-for-Test-Regeln [Test and inspection methods in the electronics production. From working principle to Design-for-Test-Rules]. VDE, Berlin (in German)Google Scholar
  2. Boiger M (2005) Hochleistungssysteme für die Fertigung elektronischer Baugruppen auf der Basis flexibler Schaltungsträger [High-performance-systems for the manufacturing of electronic components based on flexible circuit carriers]. Fertigungstechnik Erlangen (159) Meisenbach, Bamberg (in German)Google Scholar
  3. da Silva HG, Amaral TG, Dias OP (2010) Automatic optical inspection for detecting defective solders on printed circuit boards. In: 36th annual conference of the IEEE industrial electronics (IECON 2010), Glendale, USA, pp 1087–1091Google Scholar
  4. Park T-H, Kim H-J (2005) Path planning of automatic optical inspection machines for PCB assembly systems. In: 2005 International symposium on computational intelligence in robotics and automation, EspooGoogle Scholar
  5. Scheel W, Hanke H-J (1999) Montage [Assembly]. Baugruppentechnologie der Elektronik [Electronics Assembly Technology]. Verlag Technik, Berlin (in German)Google Scholar
  6. Stiny L (2010) Fertigung und Test elektronischer Baugruppen. Technologie, Fertigungskonzepte, Prüftechnik [Manufacturing and testing of electronic component groups. Technology, manufacturing, testing]. Christiani, Konstanz (in German)Google Scholar
  7. Strauss (1989) SMD Oberflächenmontierte Bauteile - Eine Einführung in die Praxis der Oberflächenmontage [SMD surface-mount components – introduction into surface-mount technology]. VTT Verlag für Technische Texte, Bonn (in German)Google Scholar
  8. Woelflick P (2012) Automatische Optische Inspektion (AOI) in der Elektronikfertigung [Automated optical inspection (AOI) in electronic manufacturing]. DVS-Berichte 272:267–272 (in German)Google Scholar

Copyright information

© CIRP 2019

Authors and Affiliations

  1. 1.Institute for Factory Automation and Production Systems (FAPS)Friedrich-Alexander-University of Erlangen-Nuremberg (FAU)NurembergGermany
  2. 2.Packaging and Interconnection LaboratoryAschaffenburg University of Applied SciencesAschaffenburgGermany

Section editors and affiliations

  • Joerg Krueger
    • 1
  • Kirsten Tracht
  1. 1.IWFTechnische Universität BerlinBerlinGermany