ECLSBUPFCIEP · Environmentally conscious lead-free solder bump for ultra-fine pitch flip chip interconnect in electronic packaging

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Project objective

This research project is a fundamental study of lead-free solders for ultra-fine pitch flip chip interconnects in microelectronic packaging, where immersion solder bumping in combination with electroless Ni-P under bump metallization (UBM) is used. Lead-free solders will replace Sn-37Pb in all electronic packaging in near future because of the environmental and healthy concerns. However, it offers a challenge to apply lead-free solders for flip chip interconnect in electronic packaging, due to the higher re flow temperatures and the higher Sn content associated with the lead-free solders, resulting a faster rate of dissolution and severe interfacial reactions between solder and the thin-film UBM.Furthermore, this application is also under the pressure of continuously growing demand of higher density, smaller size and higher performance of chip technology. 0 Immersion solder bumping of lead-free solders is a good, flexible approach to meet ultra-fine pitch and volume production requirements. The study focuses on metallurgical interface reactions, dissolution rate of Ni-P into solders, electro-migration, mechanical properties and reliability issues of solder joints and identify failure mechanisms of ultra-fine pitch lead-free solder joints. The study is expected benefits for successful application of lead-free solders for future realistic" ultra-fine pitch flip chip interconnects."

Original text from CORDIS.

Participants

• FRAUNHOFER INSTITUTE FOR RELIABILITY AND MICROINTEGRATIONCoordinatorCity levelGermany

Links

• View on CORDIS