Advanced Packaging Metrology
Advanced Packaging has experienced enormous development and growth over the last few years. The exponential increase in demand for high density devices has led to a tremendous need for new packaging solutions. Since further die shrinking is complicated and expensive, there is a shifted focus to start scaling the packages instead. This has driven a corresponding need to implement innovative process control to ensure high yield, long term reliability and overall performance of the product.
In particular, fan-out wafer-level operations go beyond the usual work-scope of standard packaging houses. These require a more sophisticated metrology loop for process control to keep each step tight to specification. However, the visual inspection is restricted and the reconstituted wafers reveal a high amount of surface irregularities and height deviations. Thus, the determination of step height and critical dimensions (CDs) presents a real challenge.