Dynamic surface tension model

Surface tension data is required to analyze this dispensing process in underfill encapsulation.

To model surface tension, we use the dynamic temperature-dependent surface tension model by Han, shown below.

The surface tension equation can be described by the following equation:

where:

• is the surface tension,
• and are data-fitted coefficients, and
• is temperature.

The equilibrium contact angle can be described by the following equation:

where

• is the equilibrium contact angle, and
• , and are data-fitted coefficients.

The time dependence of the viscosity can be represented by:

where:

• is the contact angle at time,
• 
• 
• is the viscosity
• , the contact angle at time zero, is a data-fitted coefficient, and
• is a data-fitted coefficient.