Re: OT: RoHS and Lead?

Al Clark wrote:

"Martin" <0_0_0_0_@xxxxxxxxxxx> wrote in
news:XiBxf.287$or4.4@xxxxxxxxxxxxxxxxxxxxxxxxxx: 


Excuse the OT post, but I figured people in this group may have an
answer for this odd question:

In transitioning to RoHS, can you mix Lead-free parts into a standard
PbSn process?  The idea is to start buying RoHS parts while depleting
the existing stock of PbSn components.

Good? Bad? Ugly?

Thanks,



You are going to have no real problems soldering leadfree parts with tin-
lead solder. The big exception to this are BGAs. The ball of a BGA is solder. If it is leadfree, it will need to be soldered at a higher temperature. You CM will need to know this.

Many parts have been supplied leadfree for several years. This includes many of the passives that you probably are already using. They might not have been labeled as such.

We have started using lead free pcbs as well. In our case we have opted for ENIG (electroless nickel/immersion gold). They are easy to solder with PbSn

No one really knows the long term effects of moving to RoHS. I am hoping that the EU decides that July is too soon since industry is not really ready. Nevertheless, I think it is prudent to plan for it to happen. For example, try buying Altera PLDs. They seem to be readily available in lead but not available in the lead free versions (of course, Altera claims they have both). Part of this situation is caused because everyone (distributors, manufacturers, etc) wants to get rid of their non RoHs inventory. It's hardest on those of us on the end of the chain, since we have the least amount of time to transition.

I think one of the biggest problems will be for products that have relatively long lives and small volume. I have already seen parts that were discontinued just because the mfr didn't want to change to a lead free process. How many designs will have to be completely redone, just to deal with a part that has been obsoleted prematurely. Even if you could buy enough existing material, you still couldn't ship the existing design because there it will never be a RoHS compliant part. 

 I think there are enough escape clauses in the RoHS, that you do not
have to terminate and dump a product line, due to one non complying part.
 If you can prove that there IS no lead free alternative (yet), ( and
that you are diligent in using lead Free, where avaialable) then
that's one path.

 Another is that a single part, in a Lead-free flow, is unlikely to
trigger lead threshold alarms.
 Product reliability is a different question....

-jg


.

Relevant Pages

  • Re: OT: RoHS and Lead?
    ... >>>the existing stock of PbSn components. ... >> tin- lead solder. ... >> We have started using lead free pcbs as well. ... >> No one really knows the long term effects of moving to RoHS. ...
    (comp.arch.fpga)
  • Re: Future: 0603 versus 0402 parts
    ... RoHS should have only been implemented on short lived disposable consumer ... quality manufacture where they used lead free solder with a HASL finish. ... Lead free solders also corrode much more then leaded solders. ...
    (sci.electronics.design)
  • Re: OT: RoHS and Lead?
    ... > In transitioning to RoHS, can you mix Lead-free parts into a standard ... The idea is to start buying RoHS parts while depleting ... lead solder. ... We have started using lead free pcbs as well. ...
    (comp.arch.fpga)
  • Re: english solder
    ... All of the solder is going lead-free ... years ago, a tried, tested, reliable and mature technology. ... There are also issues with mixing leaded and lead free solders. ... into solder, and again, new recycling mandates for end of life electronic ...
    (sci.electronics.repair)
  • Re: Future: 0603 versus 0402 parts
    ... horrendously expensive fab costs, and it was a 5v design which limited ... RoHS should have only been implemented on short lived disposable consumer ... quality manufacture where they used lead free solder with a HASL finish. ... Lead free solders also corrode much more then leaded solders. ...
    (sci.electronics.design)