Patent ID: 7964106
Filing Date: 2011-06-21
Classification: H01L,H05K,Y10T

Abstract:
1. A method for fabricating a packaging substrate, comprising: providing a cladding sheet comprising a first metal foil, a second metal foil and an etch stop layer interposed between the first and second metal foils; patterning the first metal foil into a first circuit trace including a plurality of metal contact pads; laminating an insulating layer onto the first circuit trace; patterning the second metal foil into a plurality of bump pads; removing the etch stop layer that is not covered by the bump pads, thereby exposing a portion of the insulating layer and the first circuit trace; applying a solder mask onto the exposed insulating layer and the first circuit trace to fill spacing between the bump pads, wherein a top surface of each of the bump pads is not covered by the solder mask; and etching away a predetermined thickness of the top surface of each of the bump pads to form a bonding aperture in a self-aligned fashion.