Ball-Induced Porosity Formation
Porosity near the weld bead forms due to incomplete fusion caused by balling effect when the energy density is too low. This leads to missing weld areas and can cause mechanical stability issues.
Physicochemical mechanism of action
During the balling effect, spheres form from the molten material that do not fully melt. This happens especially with too low energy density or insufficient heating time. The lack of melting leads to pore formation near the ball grid array (BGA).
Metallurgical relevance & risks in welding
BGA-near porosity can lead to incomplete weld fusion and reduced mechanical properties. This increases the risk of cracks and decreases the strength of the joint. Pores can also cause electrical insulation problems, especially in electronic devices.
Workshop practice & instructions
To avoid BGA-near porosity, it is crucial to ensure sufficient energy density and heating time. This can be achieved by adjusting welding parameters such as voltage, temperature, and time. Optimal damping of the molten material and careful control of the weld zone are also important.