| CPC H01L 21/486 (2013.01) [H01L 23/49827 (2013.01)] | 11 Claims |

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1. A package substrate, comprising:
a core with a first surface and a second surface opposite from the first surface, wherein the core comprises a single material continuous from the first surface to the second surface;
a via hole through the single material of the core, wherein the via hole comprises:
a first portion;
a second portion;
a perforated ledge between the first portion and the second portion; and
an adhesion layer in the via hole, wherein the adhesion layer covers the entire first portion of the via hole and a surface of the perforated ledge facing the first portion of the via hole, and wherein the adhesion layer covers a part of the second portion of the via hole; and
a via filling the via hole.
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