Apparatus for securing a substrate in an electrochemical deposition system are provided. In one aspect, an apparatus is provided for securing a substrate in an electrochemical deposition system having a contact ring for contacting a plating surface of the substrate, a thrust plate having an annular shoulder at least partially formed therein, the thrust plate adapted to move axially relative to the contact surface, and a flexible seal disposed on the thrust plate comprising a base portion for attaching to the annular shoulder of the thrust plate and a body portion extending outwardly from the base portion and defining a sealing surface for engaging a back surface of the substrate. The apparatus may be disposed in an electrochemical deposition system.