Assembly and Rework of Lead Free Package on Package Technology

Abstract
Miniaturization continues to be a driving force in both integrated circuit packaging and printed circuit board laminate technology. In addition to decreasing component pitch (lead to lead spacing), utilization of the vertical space by stacking packages has found wide acceptance by both designers and manufactures of electronics alike. Lead free Package on Package (PoP) technology represents one of the latest advancements in vertical electronics packaging integration and has become the preferred technology for mobile hand held electronics applications. TT Electronics in Perry, Ohio has developed the capability to  assemble and rework numerous “state of the art” packaging technologies. This paper will focus on the essential engineering development activities performed to demonstrate TT Electronics’ ability to both assemble and rework PoP components.

• Background
• Test Vehicle and Components
• Package on Package Assembly Considerations
• Test Vehicle Assembly
• Forced Rework Process
• Transfer Fluxing Process
• Rework of Under-­‐filled PoP Packages
• Under-­‐filled Options for PoP Packages
• Assembly Result
• Conclusions
• Acknowledgments
• References

By: Raymond G. Clark and Joseph D. Poole, TT Electronics – IMS Perry, Ohio