Patent ID: 8846519
Filing Date: 2014-09-30
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device, comprising the steps of: providing a chip having an active surface and a plurality of bonding pads on the active surface; forming an underbump metallurgy (UBM) layer on the active surface and the bonding pads; forming a photosensitive layer on the UBM layer; forming a plurality of openings on the photosensitive layer, wherein each opening exposes part of the UBM layer and corresponds to one bonding pad, and each opening has a coplanar first and second dimension parallel to the active surface, the first dimension being more than 1.2 times the second dimension; depositing at least a first metal layer in the openings of the photosensitive layer, wherein the first metal layer is formed on the UBM layer; depositing at least a second metal layer in the openings of the photosensitive layer, wherein the second metal layer is formed on the first metal layer; removing the photosensitive layer to expose the UBM layer; removing the exposed UBM layer to expose the active surface of the chip; and applying heat so as to reflow the second metal layer at the predetermined temperature without reflowing the first metal layer and form a plurality of bumps on the corresponding bonding pads, wherein each bump has a pillar part and a top part.