May 2, 2012
3D Bump Inspection Using Laser Triangulation
3D and 2D bump inspection is a critical component in manufacturing of bumped wafers. Continuous miniaturization and use of through silicon via (TSV) in 3D packages are pushing bump sizes smaller and smaller. The small bump size, small pitch and high number of bumps are challenging inspection technologies, requiring high accuracies and high throughput.
Laser triangulation is the dominant technology for 3D characterization of solder and pillar bumps used in conventional packaging techniques. The technology is a line scan laser with the ability to collect hundreds of 3D data points along one scan line in a fraction of a second. These data points can then be used to build a 3D model of the top of the bump and surface of the wafer for local height inspection. As bump size and pitch continue to decrease and bump numbers head towards tens of millions per wafer, the speed and accuracy of laser triangulation technology gives 3DIC manufacturers the ability to tightly control bump processes and detect bump defects.
Contact Us to request the white paper Laser Triangulation Provides Essential Metrology and Defect Inspection for Microbumps in 3DIC Manufacturing, presented at IWLPC 2011