Patent ID: 7663213

Claim:
A wafer level chip size packaged chip device with a double-layer lead structure comprising: a substrate having formed thereon a silicon chip, with plurality of compatible pads disposed at the periphery of said chip on said substrate; a first glass disposed above said chip and said substrate; a layer of insulating material disposed at the back of said substrate; a first metal layer disposed at the back of said layer of insulating material, with a through hole at the center of said first metal layer; a first solder mask disposed at the back of said first metal layer, with at least one opening on said first solder mask so as to enable part of said first metal layer exposed through said opening of said first solder mask; a second metal layer disposed at the sides of said chip device and on the back of said first solder mask; plurality of solder bumps each attached to a bottom end of said second metal layer so as to enable electrical connection between said compatible pads and said solder bumps via said second metal layer and said first metal layer, wherein, said packaged chip device has T-shape junction between said compatible pads and said second metal layer, and has L-shape and U-shape junction between said first metal layer and said second metal layer, such that, each of said compatible pads and said solder bumps are electrically connected via T-, L-, U-shape junctions.