Reliability evaluations on a new tape ball grid array (TBGA)

Results of a co-operative study of a new type of Tape Ball Grid Array (TBGA) are reported. Results obtained by a component manufacturer (LSI Logic) in reliability assessment of this new package type are reported together with results obtained during board mounting trials and subsequent reliability stress testing at board level by a system assembly house (Bull Electronics Europe). The various test techniques used by the component manufacturer during component qualification are described and discussed in terms of the potential failure mechanisms detected by each of the stress tests. Likewise the various electrical, thermal and mechanical tests applied to the mounted package are also discussed in relationship to the end use environment. Results are presented of package level tests together with those of packages mounted to boards both with and without an external heat-sink. The study concludes that with careful package design and construction together with good board assembly and heatsink attachment methods applied to the package, a highly reliable package and board assembly system can be achieved