The BGA Assembly traditional welding ball production method including cutting thread or punching metal layer metal particles by small mechanical process. Particles into hot oil pool, melting solders drops for small round. When oil cooling, solder drop solidified into ball. This process has its inherent limitations, because every mechanical operation of particle increased a certain amount of the size and consistency of deviation, produce can't accept accumulation effect causes the rough size deviation.
Influence of solder ball performance another factor is known defects effects. Say simply is oxidation. We all know welding ball in the operation, storage and transport processes, with each other and with the vessel wall collision will become black. pcba china Oxidation if serious, at the same time, because of the traffic is insufficient or oxidation layer is too thick in the backflow don't improve, will be to produce a very adverse. These can be in welding ball and its connected substrate pad caused by inadequate between the welding. Obviously, reduce the oxidation of process will be very important.
Last but also the important factor is the solder ball geometry size,pcb assembly diameter and roundness. Most solder ball suppliers the x and y directions solder ball measuring its diameter. This is not the best, because it is easy to miss the largest and smallest solder ball diameter. Roundness is also a need to take into account, but only few solder ball suppliers to consider.
Performance of the best BGA Assembly solder ball should almost is round. The ball geometry size is very important. First of all, now the solder ball deposition equipment is very precise, any odd shapes of solder ball may cause equipment happen obstacles, thus greatly affect production. Second, if in the same BGA used on different diameter welding the ball and the difference is very big, it will cause coplanar problem.