Typically, primary electrical connection between a semiconductor chip
and an external solder ball contact on a Ball Grid or Chip Scale Package is by
way of a via extending through a dielectric substrate. The aspect ratio between
via diameter and depth is critical for reliable and high yield solder ball attachment
during printed circuit board assembly. Excellent ball adherence and reliability
of BGA solder ball contacts is achieved through controlling the aspect ratio of
the substrate vias by partially plating a solid solderable conductor core in each
via. An improved via structure is disclosed wherein the depth of the viva is reduced
without the negative effects of alternate methods, such as thinner substrates,
or wider vias.