Kuo said wireless charging increases the internal temperature of smartphones, so he expects the rumored iPhone 8 with an OLED display and glass casing to have a new 3D Touch module with “additional graphite sheet lamination” in order to prevent the device from malfunctioning due to overheating.

Read more………….. 

https://www.macrumors.com/2017/02/09/2017-iphones-wireless-charging/