Use of Soldered or Glued PCSB as Interconnection between PCB and Ceramic Package in Harsh Environment

Polymer Core Solder Balls (PCSB) have been used as interconnects between a 16 pin leadless chip carrier (LCC) ceramic package and a small FR4 board. A comparison was made between two different volumes of SnPb solder and an isotropic conductive adhesive (ICA) for the attachment of the PCSB to the board and to the package. Shear testing and electrical measurements were performed to characterize the interconnects as bonded and during thermal shock cycling (TSC) tests. No significant reductions of the measured fracture forces was observed for any of the sample groups. However, using a larger volume of solder or ICA resulted in less degradation of interconnect resistance during TSC, and the results for the solder were overall better than for ICA.