HI-REL TINNING SERVICES
Lead tinning has experienced a surge in popularity recently, even though the process has been in use for nearly 25 years.
The original need arose when the military decided that plated finishes – which are not fused – were not suitable or acceptable for Hi-Rel environments. Plated finishes were found not to be robust enough to withstand oxidation encroachment to the base lead and could result in a solder joint failure in the field. That process gradually diminished in necessity over the years, but now it has come back for that reason as well as many others.
Five Essential Reasons For Re-Tinning
Convert Sn/Pb components to RoHS
Refurbishing of “Legacy Components”: Removing the oxidized (plated) lead finish and replacing with a fused intermetallic Sn/Pb finish
Gold Embrittlement Mitigation: Removing the gold from the components leads by “solubilizing” in molten Sn/Pb solder
Tin Whisker Mitigation: Replacing the tin plating with fused alloy
Convert RoHS components to Sn/Pb
We offer quick turnaround tinning services for all types of components packages including Through-hole, SMT, LCCs, SOs, PLCCs, QFNs, DFNs, SOICs and QFPs.
The procedure for re-tinning components, from start to finish, involves the following steps:
Incoming solderability test using a wetting balance tester
Careful handling and fixturing of the components
Processing the components in a robotic lead tinning system using a double dip process.
The first dip is into a cleansing bath of molten alloy to remove the original coating, followed with a flux dip, then a final immersion into a “clean” solder bath for a pure eutectic or RoHS finish.
Post cleaning
Visual inspection
Final wetting balance test to assure best solderability
Lot report documenting the details of the process