| CPC H01L 23/49838 (2013.01) [H01L 23/49816 (2013.01); H01L 23/3128 (2013.01)] | 27 Claims |

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23. A three-dimensional pad structure, comprising:
a substrate;
a pad disposed on the substrate, wherein a perimeter of the pad is covered with a solder mask; and
recessed regions provided on a top surface of the pad, wherein the recessed regions are interconnected with one another to form a network or interlacing pattern; and
at least one protruding feature between the recessed regions.
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