Ultra-slim package design for millimeter wave application

For millimeter wave (mm-wave) application, the Fan-out Wafer Level Package (FOWLP) technology offers attractive possibilities. But the cost of traditional FOWLP Redistribution Layer (RDL) is relative expensive than normal substrate. This paper use low cost coreless substrate and chip last technology, called Fan-out Chip Last Package (FOCLP) to design 77~79 RF differential signals for automotive radar and show good electrical performance as FOWLP package. The performance of ultra-slim package is also much better than FCCSP package. The trace design, dielectric material effect and bump variation has been analyzed. RF signals of mm-wave are quite sensitive to the parasitic parameter of the interconnection.