2134/3926
Samjid H. Mannan
Samjid H.
Mannan
D. Wheeler
D.
Wheeler
David Hutt
David
Hutt
David Whalley
David
Whalley
Paul Conway
Paul
Conway
Chris Bailey
Chris
Bailey
Solder paste reflow modeling for flip chip assembly
Loughborough University
2008
untagged
Mechanical Engineering not elsewhere classified
2008-11-07 16:54:43
Online resource
https://repository.lboro.ac.uk/articles/online_resource/Solder_paste_reflow_modeling_for_flip_chip_assembly/9559376
Solder paste printing and reflow can provide low cost
techniques producing the solder bumps on flip chips. Solder
paste consists of a dense suspension of solder particles in a
fluid medium (vehicle) that acts as an oxide reducing agent
(flux) during reflow, cleaning the metal surfaces of oxides.
This paper reports on optical observations of paste behaviour
at the small length scales associated with flip chip solder
joints, and attempts to model the process using
Computational Fluid Dynamics (CFD). Comparison of
optical observations and CFD modelling show that the
behaviour of the solder cannot be described simply by
surface tension and viscous flow effects and it is deduced
that oxides are still present on the solder surfaces during the
early stages of reflow. The implications for paste heating
method and solder volume are discussed, and a preliminary
CFD model (based on FIDAP) incorporating the effect of the
oxide layers is presented.