Electrical test of multichip substrates

For complex substrates, electrical test is a fundamental element of cost control and quality assurance. Test technologies for multi-chip substrate applications must handle densely wired products with small, tightly spaced contact features. Detection of latent defects or near defects is crucial in meeting reliability objectives. Cluster probe resistance. Capacitance, and electron beam approaches have all been applied to substrate electrical test. IBM's latent opens test is used to screen opens and near opens in thick and thin films and to characterize the interface of bonded metals in interconnection technologies. Key substrate test technology elements include: buckling beam top surface and spring probe bottom surface contact schemes, optical mapping and alignment techniques, automated product and data logistics, and the "full cluster" tester which contacts over 23000 test points at a single time.<
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