FR4 - CERAMIC ''Z'' AXIS SOLDER INTERCONNECTION

Josef Šandera - Ivan Szendiuch

   Special FR4-ceramic Z-axis connection was designed and realised which allows to decrease thermomechanical stress. Fatigue life measurement was performed on a special specimen. Temperature cycles with a period of 9 minutes and temperature amplitude from 20 to 95°C were applied. The solder joint fatigue was measured for eutectic Sn/Pb and LF solders. Practical results were compared with the results from FEA. Viscoplastic, plastic strain, and dissipated strain energy density per cycle ΔW were computed and used as failure indicators for fatigue analysis. Darveaux's energy density model was used for solder joint fatigue calculation.

Keywords: 3D system, SMVPH (Special Modified Via Plated Hole), FR4 frame, fatigue life, Sn/Pb, LF solder, FEM simulation, thermo-mechanical stress, plastic work, Darveaux's theory

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