Embodiments of the invention include methods, systems, and computer program products for checking semiconductor package via proximity rules. Aspects of the invention include receiving, by a processor, the via proximity rules and a semiconductor package design including one or more package layers and a plurality of vias. Each via is mapped to a cell in a three-dimensional array and a via stack including each via is identified. The via stacks are checked against the via proximity rules. A list of via stacks which did not satisfy the via proximity rules is displayed on a user interface.