Testing apparatus for testing a ball grid array device

A testing apparatus for testing a ball grid array (BGA) device, the device having a bottom face formed with a plurality of signal solder balls, a plurality of ground solder balls, and a plurality of voltage source solder balls, the voltage source solder balls being arranged in a squarely looped array at a central portion of the bottom face of the BGA device, the ground solder balls being arranged in rows within the squarely looped array and being spaced apart from the voltage source solder balls, said testing apparatus comprising:

• a movable carrier having a top face recessed to form a cavity of square shape which is adapted to receive the BGA device and which has a cavity bottom face, and a centering member disposed at a center part of said cavity bottom face and adapted to center the squarely looped array of the voltage source solder balls relative to said center part of said cavity bottom face, said centering member including ridge means projecting upward from said cavity bottom face and adapted to engage and prevent positional deviation of the squarely looped array of the voltage source solder balls when the BGA device is seated on said cavity bottom face;
• a tester including a testing circuit unit provided with a testing circuit layout, a surface mount matrix disposed on top of said testing circuit unit, and a hollow frame member mounted on top of said surface mount matrix, said frame member having an inner wall face confining a square central opening to expose said surface mount matrix so as to permit said surface mount matrix to make a direct electrical contact with the BGA device when the BGA device is placed in said central opening, said inner wall face being free of means for aligning and guiding and contacting margins of the BGA device relative to said surface mount matrix;
• and
• a moving device movable from said carrier to said frame member and adapted to remove the BGA device from said carrier and to locate the BGA device in said central opening of said frame member.