A method of sputter coating a glass substrate includes providing a glass substrate and providing a sputtering assembly for sputtering a coating onto the glass substrate in a vacuum deposition chamber. The sputtering assembly includes a backing plate and a separating element disposed on the backing plate. At least one target element is provided and disposed at and in contact with a surface of the separating element. The target element is not bonded the separating element when disposed at and in contact with the surface of the separating element. An expansion gap is provided at or adjacent to the target element to allow for expansion of the target element during the sputtering process. Material from the target element is sputtered and the target element is heated to a substantially elevated temperature during the sputtering process. The sputtering process coats a surface of the glass substrate with the target element material.