Moisture Sensitive Parts Opened before the Line Was Ready
Opening moisture-sensitive parts before line release exposes components to ambient humidity, risking thermal delamination during reflow unless floor life is tracked and restored.
Antoine Equation
Vapor Pressure
Thermodynamic relations expressing the relationship between temperature and the saturated vapor pressure of pure substances determine the outgassing characteristics of materials under vacuum or elevated temperatures. The antoine equation provides a mathematical model to calculate this pressure using three substance-specific empirical coefficients. It utilizes a semi-empirical approach derived from the Clausius-Clapeyron relation, offering high accuracy over limited temperature ranges.
Fabricators apply this formula to predict how solvent remnants and moisture in epoxy resins will vaporize during assembly.
Outgassing Rate
Analytical estimation of material volatile loss in low pressure environments prevents contamination and void formation during high temperature reflow. Engineers use the antoine equation to determine the rate of volatile organic compound release from liquid photoimageable solder masks and flux residues. Calculating these pressures allows the assembly line to optimize pre-bake cycles, ensuring that volatile components are fully driven off before boards enter the reflow oven.
If these calculations are neglected, escaping gases can create micro-voids in solder joints or cause solder balls to scatter across the assembly.
Thermal Limit
Temperature thresholds of organic compounds used in board manufacturing dictate the processing window for lamination and curing. This equation allows the calculation of critical transition points where liquid compounds migrate into the gas phase. It helps define the maximum allowable temperatures for baking processes, below which the material remains stable.