Rheology and processing of pastes for electronic packaging materials: Novel rheological characterisation techniques for lead-free solder pastes and electrical conductive adhesives

The stencil printing of pastes (solder paste and electrical conductive adhesives) is a very important stage in the assembly of electronic packages. There is wide agreement in industry that the paste printing process accounts for the majority of assembly defects, which originate from poor understanding of the correlation between the paste rheology and the printing process. The development of new pastes formulations is a complex process. As a result more extensive rheological characterisation techniques are required to understand the flow behaviour of the pastes under different shear conditions. This book focuses on the rheological characterisation of pastes and their correlation to the stencil printing process. A general guideline has been developed from the extensive set of results from this research, in particular, on the aspect of correlating key paste performance indicators to the rheological test methods. The book is aimed at paste and electronic manufacturers with an interest of incorporating rheology as a research and quality assurance tool in their formulation and production processes.