Separation of the bar: Systemic solution of runner bar cull remain problem through leadframe design change

With the drive to enhance Moisture Sensitivity Level for TSSOP-48L package in OSPI, plating type for this package was converted to roughened treated upgraded Pre-Plated Nickel Palladium Gold(RT-UPG PPF). The enhanced property of this plating type to adhere to the epoxy molding compound, results in processing difficulty for the runner bars to be removed from the strip. This paper will discuss in detail the systematic approach taken to resolve the problem, the design changes implemented both on the material and the tool parts. It closes on the point that with the new leadframe design a more robust process is achieved without compromising the integrity of the package and processes involved.