What you most likely peeled of was the NFC antenna. Near Field Communications is the protocol that lets things like ApplePay/Google Wallet & the wireless transfer of contacts, info, pics, etc work when you use the 'bump to transfer' feature. It has a range of about 2-3 inches! Possible it was also or instead the circuity that monitors your battery charge & temp. In either case, you didn't need to ruin it.