US Patent 10153240 Method of packaging semiconductor devices

Methods and apparatus are disclosed which reduce the stress concentration at the redistribution layers (RDLs) of a package device. A package device may comprise a seed layer above a passivation layer, covering an opening of the passivation layer, and covering and in contact with a contact pad. A RDL is formed above the passivation layer, above and in contact with the seed layer, covering the opening of the passivation layer, and electrically connected to the contact pad through the seed layer. The RDL has an end portion with a surface that is smooth without a right angle. The surface of the end portion of the RDL may have an obtuse angle, or a curved surface.