Embodiments are directed to a method of forming a semiconductor chip package and resulting structures having a mixed under-bump metallization (UBM) size and pitch on a single die. A first set of UBMs having a first total plateable surface area is formed on a first region of a die. A second set of UBMs having an equal total plateable surface area is formed on a second region of the die. A solder bump having a calculated solder height is applied to a plateable surface of each UBM. The solder height is calculated such that a volume of solder in the first region is equal to a volume of solder in the second region.