Particle Level Modelling of Solder Pastes Rheological Behaviour in Viscosity Measurement

In this paper, particle level modelling for solder paste viscosity measurement was described to investigate the non-Newtonian rheological behaviour of solder pastes. The model based on the rheometer arrangement in order to be able to measure the viscosity of solder pastes. The solid particles have a concentration of 50% in the total volume of solder paste, while the rest is the flux. The geometry of the rheometer was defined according to real test arrangements with a plate diameter of 1 0 mm, and with a gap distance between the plates of 0.5 mm. A 15 degree part of the rheometer plate was modelled to reduce the calculation time with achieving a fine mesh. The meshing was based on hexahedron elements while using tetrahedron elements at the corner. The particles were initialized in arbitrary distribution with a number of 57 thousand particles with an average particle diameter of 30 μ m. The particle diameter distribution investigated, and the method for arbitrary location distribution injected in the model.