Indium solderbumps are usually used in interconnection between focal plane arrays (FPAs) and Si read out integrated circuits (ROICs) by flip-chip bonding. The fabrication of indium bump array is a critical technology in this process. In this paper, the 16times16 indium bump array was fabricated by electroplating method. The indium bump is 100 mum in pitch and 40 mum in diameter. Lift-off method and IBE process were adopted to try to remove the seed layer. Ti/Pt/Au(200 Aring/300 Aring/800 Aring) by sputtering method and Ti/Pt/Au/ep Au(200 Aring/300 Aring/800 Aring/3-4 mum) by electroplating after sputtering were investigated as UBM (under bump metallization) of indium bump. The reliability of indium bumps with different UBM was evaluated by cross-section analysis and shear test.