Jun 19, 2017 · 1. MT7688 in dual row QFN package can be routed with 4mil PCB technology. You still need BGA for RAM chip, but routing a 16 bit DDRII is actually not that hard. If you use only 1 DDRII chip, you don't need to consider termination issues, plus MT7688 onl y goes up to DDR2 400, so the clock frequency is only 200MHz. 2.