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Portland State University

Mechanical and Materials Engineering Faculty Publications and Presentations

Series

2015

Optical materials

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Full-Text Articles in Engineering

Could Application Of Column-Grid-Array (Cga) Technology Result In Inelastic-Strain-Free State-Of-Stress In Solder Material?, Ephraim Suhir, Reza Ghaffarian, Johann Nicolics Dec 2015

Could Application Of Column-Grid-Array (Cga) Technology Result In Inelastic-Strain-Free State-Of-Stress In Solder Material?, Ephraim Suhir, Reza Ghaffarian, Johann Nicolics

Mechanical and Materials Engineering Faculty Publications and Presentations

Physically meaningful and easy-to-use analytical stress model is developed for a short cylinder (beam) clamped at the ends and subjected to bending caused by the ends offset. The offset is due, in its turn, to an external lateral force that has to be determined from the known offset. It is envisioned that such a beam can adequately represent the state of stress in a column-grid-array (CGA) solder joint interconnection experiencing thermal loading due to the thermal expansion/contraction mismatch of the IC package and the printed circuit board (PCB). The CGA designs are characterized by considerably higher stand-off heights than ball-grid-array …