The reactive viscosity model describes the temperature, shear rate, and cure dependance of thermoset materials. This model can be used in a Reactive Molding, Microchip Encapsulation, or Underfill Encapsulation analysis.
The following equation is used for determining the viscosity of these materials: 
where:
-
is the viscosity (Pa. sec.) -
is the shear rate (1/sec.) -
is the temperature (deg K) -
is the degree of cure (0 - 1), -
, and -
, 
, 
, 
, 
, 
, 
, 
, and 
(gelation conversion) are data-fitted coefficients.
Note: Use this model for thermoset materials that do not show yield behavior at low shear rates. For materials that do show yield behavior at low shear rates, use the Herschel-Bulkley-WLF viscosity model. For underfill encapsulants, use the viscosity model for Underfill Encapsulation.