> manufacture empty packages That's the crux. You don't buy mass-produced empty packages to put the parts in. Packaging happens by putting the IC die, pins and

> manufacture empty packages That's the crux. You don't buy mass-produced empty packages to put the parts in. Packaging happens by putting the IC die, pins and bonding wires which connect them together inside a mold and filling it with plastic. It's probably cheaper and certainly lower-tech to replace markings on existing chip than produce a new one.