solving

a thin layer of 500X500 um2(area) and 500e-9 m thickness of semiconductor is held at 300 kelvin. heat flu of 500e-9 watts is applied to its top surface. I am not getting transient response of temperature increase w.r.t. time(miliseconds.). Time steps 0:0.0005:0.030. Please help me in doing this analysis.

Thank you in advance....