RoHS exempt high reliability OEMs breathed a sign of relief for not having to go through the grind of revising their processes and material to be RoHS compliant.
However, this was short lived because of supply chain disconnects in the availability of non-RoHS devices.
Many device manufacturers are discontinuing the tin-lead option on many part numbers when unit volumes fall below a certain threshold.
Bills of materials are being transitioned to obsolete and legacy parts outside the control of the OEMs and at a rapid pace.
The end result too often is mixed reels of RoHS and non-RoHS product.
Unfortunately, exempt OEMs are many times left with only one choice and that is lead-free components.
This is clearly not optimal due to some of the reliability concerns associated with lead-free.
This paper discusses some ways to bridge the supply chain gap for exempt OEM's.
Conclusions
Proprietary processes have been developed for stripping Pb-free BGA�s mitigating inter-metallic layers & attaching Sn/Pb spheres utilizing controlled thermal profiles. Similar reliable processes have been demonstrated for the conversion of Pb free parts such as QFP, TSOP, PLCC, resistors & other types to Sn/Pb. This conversion option to Sn/Pb gives device manufacturers and high reliability users real alternatives on how to deal with the availability of Sn/Pb parts & granting the OEMs their freedom back to choose and be able to put the Sn/Pb proven reliability back in their builds.
