• Parijs, L. Van
• Khtatba, K.
• Noh, Y.
• Mannan, Samjid Hassan
• Paknejad, Seyed Amir
• Mansourian, Ali

Abstract

The behaviour of sintered silver die attach at high temperature has been investigated. Assemblies were made by sintering a commercially available paste composed of Ag nanoparticles with zero applied pressure on the die. The morphology of the cross sectioned surface of assemblies remains stable even at temperatures of up to 400 °C. This behaviour remained consistent even inside vacuum or after acid cleaning of the free surface. In contrast, the same sintered Ag material in the interior of a joint or sintered under a glass cover slip showed rapid microstructural changes even at 300 °C. These samples were investigated using an optical microscope to analyse the changes in the microstructure after storage at 200 to 500 °C. The observations showed a 20% increase in silver grain size after only 5 h storage at 300 °C. However, in the case of a free surface, no changes were observed after 60h storage at 400 °C. These observations were combined with DSC experiments in order to suggest the cause of the difference in behaviour. The results suggest ways of stabilizing sintered silver materials so that they can be used in applications up to 400 °C without significant structural changes occurring in the material.

Topics

• nanoparticle
• surface
• grain
• silver
• grain size
• experiment
• glass
• glass
• differential scanning calorimetry
• sintering