Wafer Level Chip Scale Packaging (WLCSP)

WLCSP process flow:

Wafer level package:

  • Wafer Inspection
  • RDL Redistribution layer (optional)
  • UBM Under Bump Metallization
  • Bumping (Ball placement) (smallest ball of 60 um , SAC)

Wafer level Test:

  • Wafer level probing
  • Cantilever or vertical probing
  • Wafer sort

Back end and conditioning:

  • Back grinding
  • Laser marking (optional)
  • Wafer singulation , sawing
  • Tape & Reel, waffle pack or wafer on blue tape
  • AOI (automatic inspection)