Baby wants held for naps

Need some suggestions. My baby will be 6 months on Monday. He sleeps 10-12 hours at night in his pack n play in our room. But, during the day he wants to be held for all naps. I don't feel comfortable letting him cry for more than a couple minutes. I try to lay him down when he's already asleep but most times, he wakes right up. I've tried to pat his tummy and soothe him but he doesn't go for it. I don't mind holding him, but I'd like to get him to sleep in his crib for naps. Any ideas?