i am a huge fan for super setting in phases and usually opposing muscle groups.
if you want biceps you have to pay attention to them.
they get worked alot on back, but biceps are a muscle that, for the most part heal fairly quick. so a day for biceps is almost like training them twice a week. depending on your age, recovery time, and nutrition- it should not be a problem.
with that said make your bicep day a short one. 9-12 sets of 8-12 reps. I superset biceps with triceps, but the focus on the biceps. triceps get hit with shouldars and chest so too many sets of triceps will overtrain them.
how much time in between back and biceps?
i have tried many splits and saw gains with alot of them.( i too did biceps on back day for a couple months), but my favorite split is: back, off,,shouldars, legs, bis&tris, off, chest,