Abstract: Metal micro-bumps, which play important roles in electrical interconnection, heat transfer and mechanical support, are the key to area array based packaging. Area array packaging, represented by ball grid array packaging (BGA), chip scale packaging (CSP) and flip chip packaging (FCP), has rapidly become the mainstream in the field of mid to high-end chip packaging due to its advantages such as high silicon wafer utilization rate, short interconnect paths, short signal transmission delay and small parasitic parameters. However, micro-bumps in different application fields have the characteristics of large size span and wide material range, which makes it difficult to have a technology that can achieve preparation of metal micro-bumps in different materials within the full size range. The current mainstream micro-bump preparation technologies are summarized in this paper, including the advantages & disadvantages of each technology and its application range, common micro-bump materials, etc. Finally, the development trend of current micro-bump preparation technologies is prospected.