A laser-assisted infrared scanning technique for evaluating bonded connections on beam lead microcircuits

An argon ion laser and an ir microscope have been combined to function as a unique combination for non- destructively testing the quality of bonded connections in microcircuits of the beam lead type. A microcircuit is heated with the focused beam from the laser and scanned with the microscope to determine the temperature pattern. Nonbonded microcircuits, poorly bonded microcircuits, and a multiplicity of adjacent poorly bonded leads have been detected by using this scanner. Preliminary results have indicated that a single nonbonded connection in an array of well bonded connections may be detected. An analytical check by computer analysis demonstrates the validity of the experimental data.