Patent ID: 8658464

Claim:
A method comprising: placing a mold chase over a bottom package, wherein the bottom package comprises a connector at a top surface of the bottom package, wherein the mold chase comprises a cover, and a pin under and connected to the cover, wherein the pin occupies a space extending from a top surface of the connector to the cover, wherein the pin comprises: an upper portion having a tapered profile, and wherein from a top to a bottom of the upper portion, widths of the upper portion gradually reduce; and a lower portion connected to the upper portion and having a substantially vertical sidewall; filling a polymer into a space between the cover of the mold chase and the bottom package; curing the polymer; and after the step of curing the polymer, removing the mold chase, wherein the connector is exposed through an opening in the polymer, and wherein the opening is left by the pin of the mold chase.