Older Micron TSOP packages advertise a feature, “off-center parting line.” What does this refer to? Is this a feature of the lead frame? I have heard that OCPL has some vague mechanical reliability or maybe packaging yield benefits. Can anyone discuss OCPL in more detail?
Seems to be a mechanical arrangement that allows packages to be stacked. From a patent.
From paragraph ,
The top package 102 is mounted over the bottom package 110, such as a TSOP having an off-centered parting line (OCPL) as shown by the position of a bottom lead 112 off-set from center within a bottom pack age body 114. It is understood that the bottom lead 112 may be a portion of a lead frame (not shown).
Probably a more modern solution would be to stack dies inside the package, if necessary, to increase density.