Reliability, electrical performance and properties of solder (63/37) bumped flip chip components

Increasing number of the I/O's and higher frequency components together with miniaturisation of electronic devices requires new, smaller, higher performance and cost effective packaging technologies. One promising solution to meet all these requirements is the flip chip interconnection method. Flip chip components offer: excellent electrical and thermal performance and smallest possible package size. To achieve reliable and high performance flip chip interconnections the structure of the bump and the assembly process must both be optimised. Experimental results show that by using well known TiW/Au under bump metallurgy (UMB1) with extra layer of nickel (UMB2) a reliable and a high performance bump base structure for solder bumps can be achieved. if process parameters and materials used in the flip chip process are optimised, reliability of the flip chip interconnection can be excellent. This paper presents electrical and physical characteristics and temperature cycling reliability test results of solder bumped flip chip components using TiW/Au/Ni metallurgy.