Mechanical and electrical characterisation of Au wire interconnects in electronic packages under the combined vibration and thermal testing conditions

摘要

This paper concerns the reliability of thermosonically bonded 25μm Au wires in theudcombined high temperature with vibration conditions, under which the tests have been carried out onudwire bonded 40-pin Dual-in-Line (DIL) High Temperature Co-fired Ceramic (HTCC) electronicudpackages. Mechanical, optical and electrical analysis has been undertaken in order to identify theudfailure mechanisms of bonded wires due to the combined testing. The results indicated a decrease inudthe electrical resistance after a few hours of testing as a result of the annealing process of the Au wireudduring testing. Shear and pull strength levels remained high in general after testing, showing noudsignificant deterioration due to the test under the combined high temperature and vibrationudconditions. However, a trend of the variation in the strength values is identified with respect to theudcombined conditions for all wire bonded packages, which may be summarised as: i) increase of theudtesting temperature has led to a decrease of both the shear and pull strength of the wire bonds; ii) theudmechanical behaviour of the wires is affected due to crystallization that leads to material softening andudconsequently the deformation of wire.