Methods for forming ground vias in semiconductor packages

1. Field of the Invention A tape ball grid array (TBGA) semiconductor package having a one metal layer interconnect substrate is provided. Further provided is a method for making the TBGA package having electrical connection through the one metal layer interconnect substrate down to a ground plane. The method includes: (a) defining at least one via hole through the one metal layer interconnect substrate; (b) filling the at least one via hole of the one metal layer interconnect substrate with a first solder ball; (c) reflowing the first solder ball; (d) placing a second solder ball over the reflowed first solder ball; and (e) reflowing the second solder ball to attach the second solder ball to the reflowed first solder ball. The reflowed first solder ball and the reflowed second solder ball form a ground via connection to the ground plane of the TBGA.