Methods of conducting wafer level burn-in (WLBI) of semiconductor devices are presented wherein systems are provided having at least two electrodes (210, 215). Electrical bias (920) and/or thermal power (925) is applied on each side of a wafer (100) having back and front electrical contacts for semiconductor devices borne by the wafer. A pliable conductive layer (910) is described for supplying pins on the device side of a wafer with electrical contact and/or also for providing protection to the wafer from mechanical pressure being applied to its surfaces. Use of a cooling system (950) is also described for enabling the application of a uniform temperature to a wafer undergoing burn-in. Wafer level burn-in is performed by applying electrical and physical contact (915) using an upper contact plate to individual contacts for the semiconductor devices; applying electrical and physical contact using a lower contact plate (910) to a substrate surface of said semiconductor wafer; providing electrical power (920) to said semiconductor devices through said upper and lower second contact plates from a power source coupled to said upper and lower contacts plates; monitoring and controlling electrical power (935) to said semiconductor devices for a period in accordance with a specified burn-in criteria; removing electrical power at completion of said period (955); and removing electrical and physical contact to said semiconductor wafer (965).