Intermetallic Compound Kinetics in Lead Free Solder Reliability Warranties
Excessive intermetallic layer growth and Kirkendall voiding cause brittle solder joint field failures that require precise contractual latent defect rules.
Activation Energy Arrhenius
Meaning
Numerical value defining the thermal sensitivity of a physical or chemical reaction rate. Engineers use activation energy arrhenius to calculate acceleration factors for electronic components during high temperature storage tests. The value indicates the energy barrier that must be overcome for a specific failure mechanism to proceed.
This calculation stops applying when the temperature exceeds the material transition point of the assembly.
Thermal Reliability
Heat serves as the primary stressor for chemical degradation in semiconductor packaging. An activation energy arrhenius value of 0.7 electron volts often describes the degradation of solder joints under thermal stress. This constant allows for the translation of laboratory test hours into expected service life under field conditions.
Calculation Basis
Mathematical models for reliability prediction rely on the relationship between temperature and the rate of reaction. The activation energy arrhenius provides the slope of the line when the natural logarithm of the failure rate is plotted against the reciprocal of absolute temperature. A higher value indicates that the failure mechanism is more sensitive to temperature fluctuations.
Reliability Limit
Acceleration models remain valid only within the linear range of the material behavior. When temperatures reach levels that induce phase changes or mechanical melting, the activation energy arrhenius no longer predicts the failure rate accurately. Accurate determination of this constant requires multiple test points at different temperatures to verify the consistency of the failure mode.