Ask the Experts
June 2, 2008
Leaded Solder on ROHS Compliant Parts?
Is it a problem soldering (by hand in this case) RoHS compliant parts to a RoHS compliant PCB using leaded solder?
Expert Panel Responses
Can't really answer that unless I know if the assembly is a RoHS part or not. If this assembly is RoHS then yes it is a problem and will put the assembly out of spec. If the final assembly is not RoHS then it is not a problem and will make the job easier using Sn/Pb solder.
I assume this is PTH parts we are talking about and many of these parts are no longer available with Sn/Pb tinning or plating because it is easier to just make everything RoHS and it works in both leaded and lead-free process.
As long as your assenbly does not need to be lead-free you fine to use the leaded solder and the solder joints will be just fine also.
Senior Applications Engineer
Greg joined Electrovert in February 1984. Based out of the Electrovert applications laboratory in Camdenton Missouri, Greg has been in the process applications support role since 2000. His primary responsibilities include providing process and machine applications support for the wave soldering lines as well as process, machine and operations training. He also provides applications support for the reflow and cleaner lines. Greg is a PBET certified trainer and holds two patents on wave solder nozzle design.
No, using leaded solders on a lead free application will work just fine. You might notice a small difference in the wetting characteristics of the assembly but just remember to keep the temperatures low and if possible use a variable power soldering iron.
Regional Sales Manager
OK International Inc.
Mr. Zamborsky serves as one of OK's technology advisers to the Product Development group. Ed has authored articles and papers on topics such as; Low Volume SMT Assembly, Solder Fume Extraction, SMT Rework, BGA Rework, Lead Free Hand Soldering, Lead Free Visual Inspection and Lead Free Array Rework.
If the product is supposed to be RoHS-compliant then yes, it is a potential legal problem because it may no longer be RoHS compliant if the product can not take advantage of the exclusion for lead in solder.
Design Chain Associates, LLC
Mr. Kirschner is President of Design Chain Associates, LLC, focused on helping electronics OEMs comply with RoHS/WEEE requirements, and speeding time-to-market, reducing product cost, and increasing engineering and procurement efficiency.