No flow underfill: additional reliability and failure mode analysis

No‐Flow or fluxing underfills will play a key role in the future of flip chip processing. Properly formulated No‐Flow Underfills decrease manufacturing time and cost of producing flip chip packages. The reliability and processing ability allows these underfills to be incorporated into many unique applications. Processing yields and reliability on ceramic, flex and organic substrates will allow No‐Flow Underfills to be used successfully in future Bluetooth and wireless telecommunication products. This work gives the reliability of a commercially available No‐Flow Underfill on three flip chip and two BGA/CSP test vehicles. A detailed failure mode analysis of the underfill was also performed.