. A ball grid array package test module, comprising:
ball grid array (BGA) packages each including a circuit board, a semiconductor chip mounted on the circuit board, and a plurality of solder balls arrayed in a matrix on a bottom surface of the circuit board;
a module board including module board substrate, and a plurality of board pads disposed on at least one side of the module board substrate, the BGA packages being mounted to said module board on at least one side of the module board substrate with each of said board pads contacting a respective one of the solder balls of the BGA packages; and
test architecture associated with each of said BGA packages, the test architecture including
package test signal lines each connected to a respective one of the solder balls of the BGA package, and extending along a bottom surface of the BGA package and terminating at a location disposed outwardly of the matrix of solder balls of the BGA package,
board test signal lines corresponding to said package test signal lines and each extending along said module board from a first position, juxtaposed with respect to a said location at which one of the package test signal lines terminates, to a second position located to the side of the BGA package,
probe pads disposed on said module board at a said second position, and said probe pads connected ends of said board test signal lines, respectively, and
electrical junctions each connecting a corresponding pair of said package test signal and board test signal lines, each of said junctions extending between a said location at which the package test signal line of said pair terminates and a said first position from which the corresponding board test signal extends.