is LP3991TL-1.3/NOPB collapsing-or-noncollapsing-bga-balls? Thanks
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is LP3991TL-1.3/NOPB collapsing-or-noncollapsing-bga-balls? Thanks
The difference is in how the solder pad area is defined on the pcb: by the solder mask opening; or by the copper pad surface.
For larger pitch package (>0.60mm), we suggest to use 'non solder mask defined' pad (NSMD) where the solder mask opening is larger than solder pad. There will be a gap in-between to allow the solder joint wrap around the PCB pad. This is 'collapsing'.
For fine pitch package (<=0.50mm), we suggest to use 'solder mask defined' pad (SMD) where the pad is larger than the solder mask opening so the solder ball would not wrap around the pad. This is 'non-collapsing'.