Also, even with a high-power spray wash, you may not get all of the
leaded solder paste out of the stencil apertures. If some of the solder
paste fines remain in the apertures, you may get enough lead in a single
solder joint to fail an audit by the RoHS police. Your product would
then be the subject of investigative reporters such as Geraldo Rivera.
You will appear on the Jerry Springer show desperately trying to prove
that the assembly was fathered by someone else, and you were being
framed. After conviction in the EU court system, you can appear on
Oprah, in the category "This Happened to Me".
Buy another stencil. I suppose by now someone has thought of
manufacturing green "RoHS Compliant" stencils that cost twice as much as
the original. Make sure the stencil is not made of non-homogenized
hexavalent chromium alloys, or finished using polynylated
hyperglycerides or un-neutered cadmiatic acids.
The RoHS police are keeping a close eye on you.
Good luck.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Kathy Jenczewski
Sent: Thursday, November 30, 2006 11:39 AM
To: [log in to unmask]
Subject: Re: [TN] Stencils
Tom,
Most people that I talk to do not use the same stencil. How clean is
clean? If you are using an automated cleaning machine, the
contaminants from
the leaded can get into the Pb free stencil. Also, depending on the
paste
you are using, the Pb Free stencil may be made 1:1 solder pads to your
board while the stencil for tin/lead may have reductions (the tin/lead
solder alloys tend to have better wetting than most Pb free alloys).
Kathy Jenczewski
MicroScreen
At 12:22 PM 11/30/2006 -0500, you wrote:
>Hello all,
>
>SMT Stencils - Can we use the same stencil that was used for leaded
>paste, for no-lead paste if they are properly cleaned? What's your
>thoughts on this?
>
>Thanks
>
>Tom Parkinson
>Quality System Manager - CIT
>WinTronics, Inc.
>Phone: 724-981-5770 - extension 235
>
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