Optical method for the measurement of the thermomechanical behaviour of electronic devices

We present in this paper a laser probing method for the study of the surfac e deformation and thermomechanical behaviour of electronic components. The method has been applied to running power devices and creep analysis of sold er joints in after-fabrication processes. The set-up allows following the w hole surface deformation as a function of time even in the long-term range. The method is based upon electronic speckle pattern interferometry (ESPI) and allows measuring surface normal deformation with a 10 nm resolution. (C ) 1999 Elsevier Science Ltd. All rights reserved.