A method includes forming a first dielectric layer, forming a first redistribution line comprising a first via extending into the first dielectric layer, and a first trace over the first dielectric layer, forming a second dielectric layer covering the first redistribution line, and patterning the second dielectric layer to form a via opening. The first redistribution line is revealed through the via opening. The method further includes forming a second via in the second dielectric layer, and a conductive pad over and contacting the second via, and forming a conductive bump over the conductive pad. The conductive pad is larger than the conductive bump, with a first center of conductive pad being offsetting from a second center of the conductive bump. The second via is further offset from the second center of the conductive bump.