A metal pillar with cushioned tip is disclosed. The cushioned tip offsets height difference among metal pillars. So that the height difference among metal pillars gives no significant effect to electrical coupling. The cushioned tip is a metal sponge. Additional one embodiment shows a second metal is plated on a tip of the metal sponge. A hardness of the second metal is greater than a hardness of a metal of the metal sponge, so that the second metal can stab into a corresponding metal sponge for electrical coupling.