Abstract: Annular reinforcement structures that can be used in wafer level chip scale packages (WLCSP) are described. The WLCSP comprises a substrate with an IC device and a bond pad connected to the IC device, a passivation layer protecting an outer portion of the bond pad, an annular ring structure formed on an inner portion of the bond pad, an under bump metal (UBM) layer covering the annular ring structure, and a solder ball attached to the UBM layer. The annular ring structure contains a substantially planar top with vertical or non-vertical sidewalls that slope down to the inner portion of the bond pad. The annular ring structure can slow the solder crack propagation in the solder ball and therefore increase the solder joint reliability in the WLCSP. As well, the annular ring structure can increase the surface area for solder attachment to the UBM layer, improving overall ball shear strength are described. Other embodiments are described.