Here is the abstract you requested from the IMAPS_2008d 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.
|A Study of Lead-Free BGA Backward Compatibility Through Solderability Testing at Component Level|
|Keywords: Lead-free IC Packaging, Backward Compatibility, Solderability|
|As the IC electronic packaging converts into lead-free for RoHS compliance, one of the main lead-free transition issues at SMT assembly is backward compatibility. This refers to SnPb soldering with lead-free components. Such issue is especially real for most of the storage array systems, network infrastructure equipment for switching, transmission, signaling as well as network management for telecommunication products. This is because these products are exempted from lead-free by the RoHS directive, hence there is no urgency for these products to be converted from SnPb soldering to lead-free soldering. However, since the electronics industry is transitioning to lead-free, some of the necessary SnPb components may have been converted into lead-free, and therefore the backward compatibility issue arises. A study was conducted to assess the backward compatibility of three different lead-free BGA components using Jedec Solderability testing method at the component level. The three components tested were the 29x29mm Thermally Enhanced PBGA (TePBGA-II) and 35x35mm Tape BGA (TBGA) with SAC387 and Sn3.5Ag solder balls, and 33x33mm Flip Chip HiCTE BGA with only Sn3.5Ag solder balls. Four units from each of the three component types were used to prepare the profiling pallet. These pallets were used to obtain a Low Solderability Profile and a High Solderability Profile to encompass the low and high end of the Jedec SnPb Solderability Test Conditions. Before solderability testing, 15 units per cell were subjected to 8hrs of steamaging and followed by 1hr baking at 100 degree C per Jedec method. This is followed by solderability testing using SnPb solder paste. The solderability testing result showed that all the three BGA component types passed without any solderability failure with both the Low and High SnPb Solderability Profiles. This result showed that backward compatibility is NOT an issue for lead-free BGA components with SAC387 and Sn3.5Ag solder balls from solderability point of view.|
|Eu Poh Leng, Senior Staff Engineer (R&D Engineer III)
Freescale Semiconductors Malaysia Sdn Bhd
Petaling Jaya, Selangor 47300,