Here is the abstract you requested from the automotive_2015 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Improved QFN Reliability by Flank Tin Plating Process after Singulation|
|Keywords: QFN, Reliability, Flank solderability|
|Improved QFN Reliability Process The process of singulating IC packages such as QFNs by either a sawing or punching operation results in exposed copper on the sidewalls. This exposed copper surface can oxidize leading to poor or no solder wetting up the sidewall during the assembly operation. The consequence of this oxidized copper surface is either incomplete or no solder fillet formation during the PCB mounting operation resulting in solder joint reliability concerns. Several component manufacturers have requested a toe fillet solderability process which would improve current QFN reliability by ensuring toe fillet solder coverage. A process whereby immersion tin is plated on the copper sidewall of the QFN after singulation has been developed to improve toe fillet solderability. Several assembly studies have been conducted which demonstrate improved QFN reliability due to the use of this toe fillet solderability process.|
|John Ganjei, Technology Manager