Authored By:
Brian Roggeman, Michael Meilunas
Unovis Solutions
Binghamton, NY USA
Transcript
This paper discusses the results of several independent experiments designed to address the many aspects of successful package on package integration. Assembly through the use of inline stacking and prestacking was evaluated. Top package soldering was performed by dipping in either flux or paste. The warpage behavior of each level as well as the full module was characterized through simulated reflow using Shadow-Moire analysis. Warpage behavior was found to be a limiting factor in assembly yields.
Reliability of package on package assemblies was evaluated using drop shock, vibration and thermal cycling.
The level at which failure occurred depended on the location of the module on the PCB. Underfill was found to greatly enhance mechanical reliability. However thermal cycling reliability was decreased.
Summary
This paper discusses the results of several independent experiments designed to address the many aspects of successful PoP integration. Assembly through the use of in-line stacking and pre-stacking was evaluated. Top package soldering was performed by dipping in either flux or paste. The warpage behavior of each level, as well as the full module was characterized through simulated reflow using Shadow-Moire analysis.
Warpage behavior was found to be a limiting factor in assembly yields. Reliability of PoP assemblies was evaluated using drop/shock, vibration and thermal cycling. The level at which failure occurred depended on the location of the module on the PCB. Underfill was found to greatly enhance mechanical reliability, however thermal cycling reliability was decreased.
Conclusions
The preceding summarizes several experiments meant to address both the assembly and reliability concerns of Package-on-Package technology. Because the experiments were based on specified test vehicles, direct comparisons between each are not possible. However, general conclusions can be made by observing the trends
Initially Published in the IPC Proceedings
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