Ioan,

Been there, done that, got the tee shirt.

What I've used successfully to diffuse these types is the paint lead test available from hardware stores. It's capable of detecting very low levels and is quite convincing, especially if you do a "side by side" comparison.

http://www.homedepot.com/p/LeadCheck-Instant-Test-Swabs-2-Pack-LC-2SDC/203313743


Ed Popielarski
Engineering Manager


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-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Ioan TEMPEA
Sent: Friday, March 07, 2014 8:06 AM
To: [log in to unmask]
Subject: Re: [TN] Cleaning Tester for RoHS Product

I'm all with you, Brian!

I raised a little flag, since Tuyen will most likely be audited and will have to prove they have a plan to avoiding cross-contamination. Unfortunately, most auditors don't have your knowledge and are only looking for hard evidence that more than due diligence measures are in place to avoid getting Pb on RoHS product, bla, bla, bla...

Ioan

-----Original Message-----
From: Brian Ellis [mailto:[log in to unmask]]
Sent: March-07-14 10:55 AM
To: TechNet E-Mail Forum; Ioan TEMPEA
Subject: Re: [TN] Cleaning Tester for RoHS Product

Ioan

I think your concern is not consequential. Solder balls, if they are fine enough to be suspended and not just sink to the bottom of the tank, they will almost certainly be mechanically trapped in the resin column as is dust and other particulate matter, during regeneration. Of more concern may be the metal/flux reaction products; these will be mostly ionic tin (possibly copper) salts and will be captured during regeneration. Most lead organics (or inorganics) are almost insoluble (except lead formate and acetate, which I would be surprised to find on an assembly) but their ionic polarity is so weak that they may not be removed entirely during regeneration if any should happen to be present (very unlikely, especially if your cleaning process is reasonably good).

Frankly, it is my belief that cross-contamination is a red herring and nothing to worry about.

Brian

On 07.03.2014 17:29, Ioan TEMPEA wrote:
> Tuyen,
>
> Cross contamination between RoHS and non-RoHS means you cannot mix metals, so you end up with Pb on RoHS assemblies. I assume your concern is this cross-contamination. Please note dissolved fluxes are no concern, as they are not contaminants, RoHS wise.

>
> If the assemblies are properly soldered, meaning all solder properly melted, and free of solder balls, there is no concern of having SnPb in suspension in the alcohol bath, otherwise said, water/alcohol mixture won't dissolve solder joints. But, as solder balls appear where you expect them less, you might end up with some Pb in the bath.
> Realistically, even if some SnPb solder balls end up on your RoHS boards, the probability of them actually staying there and being detected during RoHS validation is so small that you will normally get away with it. But, as everybody freaks about cross-contamination, you might want to take certain precautions, like emptying and cleaning the alcohol bath when switching from RoHS to non-RoHS (to keep it efficient, you might want to group boards and properly schedule ionic testing).
>
> Ioan Tempea
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Douglas Pauls
> Sent: March-07-14 8:07 AM
> To: [log in to unmask]
> Subject: Re: [TN] Cleaning Tester for RoHS Product
>
> Tuyen,
> The ionic contamination testers work equally on RoHS and non-ROHS assemblies.  You may find that the residues from RoHS-compliant boards do not dissolve as readily and so your boards may appear cleaner than they really are.  I would suggest using ion chromatography per IPC-TM-650, method 2.3.28, to get a truer representation of how clean your assemblies are.
>
> Doug Pauls
> Rockwell Collins
>
>
>
> From:   Tuyen Tran <[log in to unmask]>
> To:     <[log in to unmask]>
> Date:   03/07/2014 07:00 AM
> Subject:        [TN] Cleaning Tester for RoHS Product
> Sent by:        TechNet <[log in to unmask]>
>
>
>
> Dear Technet
>
> I'm new here and I would like to ask question.
> We are manufacturing PCBA. Our challenge is the problem on testing clean.
> Our customer requested cleaning and testing ionic contamination for RoHS products, but we had only a cleaning tester (OMEGA METER SMD 600) which does work well for Non-RoHS product.
> Our question: Can we use the cleaning tester (OMEGA METER SMD 600) to test ionic contamination for RoHS product? is it compliant with RoHS regulation?
>
> We would dearly love to find a more elegant solution.
>
> Thanks you and Best regards
> Tuyen Tran (Ms.) - QAE
> Spartronics Vietnam Co.,Ltd
>
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