2D Simulation of the Placement of a Pin-Through-Hole Component and Solder Paste Melting

Abstract

In the present work, a numerical model was developed to simulate the placement of a pin through-hole (PTH) component in an aperture containing solder paste by using Ansys Fluent® software. The work uses numerical tools to understand the physical process and the solder paste behaviour for future manufacturing improvements. The component movement was simulated with the dynamic mesh model through a user-defined function (UDF). Due to software limitations, the pin of the component is already contacting the solder paste at the start of the movement. additionally, the contact detection feature was activated to prevent the pin and PCB contact during the solder paste melting. Nevertheless, the component can still move in the domain if other forces act upon it, except in the direction where the contact would occur. The second point to address is the meniscus formation process. This begins with the evaporation of the solder paste flux, causing a volume reduction followed by the melting of the metallic beads. The simulation allowed us to see that the melted solder surrounded the pin through capillarity and reproduced the phenomena of this solder printing process. This work allowed to follow the behaviour of both the component and the solder paste.