LT1051 and LT1053: why SW package??

Question

Sorry: this is a trivial question, maybe not worthy of anyone's time, but it's really a mystery to me, so: why would anyone want the SW packages for the LT1051 and LT1053 parts?? They simply include extra pins (4 for LT1053, 8 for LT1051) at all corners of the package, which seems pointless. What is the intended purpose of these pins on this package? 
 -jar

PaulCA · Accepted Answer

Hello jarFlooby , 
 Currently, there are two types of packages that are available for LTC1051/LTC1053. They are the SW package and N package. 
 The SW package is a Wide SOIC package that is also an on-board solder kind of package. On the other hand, the N package is a Narrow PDIP package that is a through hole solder kind of package. Depending on what soldering type and size of package is needed/required, we can choose from these two. As for the NC pins, they are created to filler space or even out the number of pins. These pins are not connected to the internal circuit of the chip. I hope this helps. Kind Regards, 
 Paul)