A new innovative model for green QFN qualification

QFN (Quad flat no-lead) package has become a necessary IC package type covering low cost and high performance needs throughout consumer, telecommunication (wireless handset, power management, analog baseband and Bluetooth) to high end electronics product application due to its small form factor and excellent thermal and electrical performance compared to similar size IC package [1]. With more and more requirements, the QFN package is developed toward multi-row, thinner, large package size, high I/O around 100~400, fine pitch <;0.4mm, larger die supporting, Green compliance and so on. Compared with the FBGA, QFN can reduce IC package dimension to half due to substrate elimination, as well the entire packaging assembly cost can be reduce 25% [2, 3]. From the perspective of IC package designer and assembler, it will be more difficult to consider further the compatibility with the users like SMT assembler and PCB fabricator to well use the developing and innovative QFN package. Therefore, one new business model will be suggested to overcome the above issue [4]. In the paper, the real examples from the collaboration of supply chain on the green QFN package qualification through board level acceleration temperature cycling testing (ATC) will be taken to explain how to address the package verification from the design of package and PCB, PCB assembly, reliability test and failure analysis. The 3 key factors on the QFN package, PCB and PCBA must be incorporated for design consideration to conclude a total QFN package solution for end product application. Furthermore, the actual benefit in the supply chain will be also discussed in terms of collaboration working model.