I. Rosin joint caused by process factors
1. Missing solder paste
2. Insufficient amount of solder paste applied
3. Stencil, aging, poor leakage
II. Rosin joint caused by PCB factors
1. PCB pads are oxidized and have poor solderability
2. Via holes on the pads
III. Rosin joint caused by component factors
1. Deformation of component pins
2. Oxidation of component pins
IV. Rosin joint caused by equipment factors
1. The mounter moves too fast in the PCB transmission and positioning, and the displacement of heavier components is caused by large inertia
2. The SPI solder paste detector and AOI testing equipment did not detect the related solder paste coating and placement problems in time
V. Rosin joint caused by design factors
1. The size of the pad and the component pin does not match
2. Rosin joint caused by metallized holes on the pad
VI. Rosin joint caused by operator factors
1. Abnormal operation during PCB baking and transfer causes PCB deformation
2. Illegal operations in the assembly and transfer of finished products
Basically, these are the reasons for rosin joints in finished products in PCB processing of SMT patch manufacturers. Different links will have different probabilities of rosin joints. It even exists only in theory, and generally doesn’t appear in practice. If there is something imperfect or incorrect, please e-mail us.
Post time: May-28-2021
