A thin film transistor and the backplane board including this

The present invention changes the position of the gate electrode and adjusting the taper of the gate electrode to be on the thin film transistor and a backplane board including this address the disconnection generated during the crystallization of the active layer, the transistor of the present invention, the flats on the substrate and portion and was having portions inclined to the ends, the inclined portion width (a) non-(h / a) of a large height (h) is covered with a 1.192 or less with the gate electrode, the gate electrode, the gate insulating film located on said substrate, on the gate insulating film, and it includes a source electrode and a drain electrode connected to the active layer and the active layer at both ends of the poly-Si corresponding to the gate electrode.