We propose several kinds of materials which have different thermal conductivity be the thermal conduction layers between the buffer oxide and substrate of a-Si:H TFT device. The thermal conduction layers, such as Cu, Al, Mo and Si3N4, have significant improvement for thermal accumulation during operation. To understand the transient thermal profile and temperature distribution, we performed by solving the temperature distribution and heat diffusion for a 2-D a-Si:H TFT model to avoid high temperature to damage the PI substrate for flexible electronics operation.