A method for forming a wafer level chip scale (WLCS) package device with a thick bottom metal comprising the step of attaching a lead frame comprising a plurality of thick bottom metals onto a back metal layer of a semiconductor wafer including a plurality of semiconductor chips having a plurality of bonding pads formed on a front surface of each chip, each thick bottom metal is aligned to a central portion of each chip; a plurality of back side cutting grooves are formed along the scribe lines and filled with a package material, the package material are cut through thus forming a plurality of singulated WLCS package devices.