Uroda

Operation Principle of BGA Rework Station
https://www.seamarkzm.com/operation-principle-of-bga-rework-station.html


Professionals who have done BGA infrared rework station work know that "warming up" is the prerequisite for successful rework. PCB processing at high temperature (315-426°C) for a long time will bring many potential problems. Thermal damage, such as pad and lead warping, substrate delamination, white spots or blistering, and discoloration. The "invisible" damage to PCB caused by high temperature is even more serious than the problems listed above. The reason for the huge thermal stress is that when PCB components at room temperature suddenly contact a soldering iron with a heat source of about 370°C, a desoldering tool or a hot air head to stop local heating, there will be a temperature difference of about 349°C on the circuit board and its components, resulting in "Popcorn" phenomenon.

Therefore, regardless of whether the PCB assembly plant uses wave soldering, infrared vapor phase or convection reflow soldering, each method generally requires preheating or heat preservation treatment, and the temperature is generally 140-160°C. Before the implementation of reflow soldering, a simple short-term preheating of the PCB can deal with many problems during rework. This has been successful for several years in the reflow soldering process. Therefore, the benefits of stopping preheating in the prevalence of PCB components are manifold.