The special performance requirements of chip attach in the growing market of mobile electronics such as mobile phones, laptops, PDA's and smartlabels necessitate a re-examination of cost and reliability of assembly technologies used to mount flip chip dice on flex substrates. This paper reports a design-of-experiment (DOE) matrix that was constructed to identify significant factors to electric performance and comprehensive reliability tests of NanoPierce Connection System (NCS) for the assembly of dice in a unique flip chip technology. These tests were adapted to emphasize the reliability of flip chip application using NCS on ultra-thin flex substrates. An optimized manufacturing process window was determined from the results obtained in the DOE study. In addition, the results from the reliability tests showed that the NCS technology has great stability and reliability during all the tests, and performs better than conventional flip chip technologies and well beyond the manufacturer specifications.
