If integrated circuits had longer leads, we could stand them vertically and save more space in layouts.
China, get on this.
(http://upload.wikimedia.org/wikipedia/commons/thumb/c/cb/SIL9_ST_TDA4601.jpg/220px-SIL9_ST_TDA4601.jpg)
Good start. But how about a 4x4 vertically oriented. Then you could keep the linear length the same and save up to a whole millimeter in width.
Mmm I see what you mean. I think the wire bonding from the die to the package leads would be weird. Everything in the SILP and DILP are planar so the bonder tip just moves in the plane of the pads. To keep it planar in the case you are thinking there would need to be additional routing from the bonding pads to the leads on the underside of the die. There probably isn't enough incentive to design or build a package like that. You could also mount the die face up but then everything would be really small to bond to and the pads may not fit. I agree though it would be nice.
Vertical DIP sockets are available in a number of different footprints.
http://www.digikey.ca/product-search/en?lang=en&site=ca&KeyWords=ed58432-nd
dave
Google bga (ball grid arrays) and flip chip ic's. You won't get much tighter layouts than those.