An embodiment of the disclosure includes a conductive pillar on a semiconductor die. A substrate is provided. A bond pad is over the substrate. A conductive pillar is over the bond pad. The conductive pillar has a top surface, edge sidewalls and a height. A cap layer is over the top surface of the conductive pillar. The cap layer extends along the edge sidewalls of the conductive pillar for a length. A solder material is over a top surface of the cap layer.