Evaluating Desorption Baking Cycles for Moisture Sensitive Integrated Circuits
Baking moisture sensitive ICs requires matching package thickness and carrier heat ratings to balance desorption speed against intermetallic lead oxidation risks.
Nitrogen Purge Oven
Atmosphere Control
An industrial thermal system utilizes an inert gas environment to perform heating, curing or soldering processes without exposing the workpieces to atmospheric oxygen. Implementing a nitrogen purge oven allows manufacturers to reduce oxygen levels inside the chamber to below fifty parts per million. This low-oxygen environment prevents the oxidation of metal surfaces and solder alloys at elevated temperatures.
Oxygen Monitoring
Zirconia or electrochemical oxygen sensors continuously measure the residual oxygen concentration within the heated zones. These sensors provide feedback to the gas control system, adjusting the flow of nitrogen to compensate for any air ingress. Consistent monitoring is essential because even a minor rise in oxygen levels can degrade the quality of the thermal process.
Flow Optimization
The distribution of the inert gas must be uniform across the entire heated volume to prevent localized pockets of higher oxygen concentration. Internal manifolds and recirculating fans disperse the gas evenly, maintaining a stable laminar flow. This flow design prevents the turbulence that could draw ambient air into the chamber through the loading ports.
Reflow Quality
Using an inert atmosphere improves the wetting of the solder and reduces the formation of voiding in the solder joints. Improved wetting leads to stronger mechanical bonds and better electrical conductivity in the finished assemblies.