Sample & Method
An Infra-red led emitter is inspected by scanning acoustic microscopy. Probe frequency is adapted to the characteristics of the system. In this case, considering the large thickness of the package a 50 MHz transducer is used. Our phase inversion algorithm identifies and highlights the delaminated areas. In addition, A-scan inspection is used to confirm these findings.
Thorough scanning acoustic inspection discloses defects at different locations. First of all, minor acceptable delamination is observed at the rear side of the paddle. However, the detected delamination on the lead-frame wire bonding area compromises the system performance. On the other hand, one lead is delaminated over its entire length. This delamination extends from the external surface of the package up to the active area and represents a severe risk of water ingress.
Assessment as per different test methods
In Alter Technology Scanning Acoustic Microscopy inspection is conducted in accordance with different inspection methods. Next table summarizes the inspection result for these different criteria.
Senior Materials and Test Engineer
Francisco Javier has a Degree in Physics and a Ph.D. in Materials Science both from the University of Seville and has conducted different Post-doctoral stays at the University of Mons (Belgium), University of Trento (Italy) and the Spanish National Research Council
He works as materials and physical test senior engineer within the Destructive and Physical Analysis Department. In Alter Technology laboratories, his main tasks address the characterization of EEE parts by advanced microscopy techniques and the conception of new test procedures.