[tinwhiskers] Re: New study on coating to mitigate whiskers
- From: Steve Smith <steve@xxxxxxxxxxxxxxxxxxxxxx>
- To: engelmaier@xxxxxxx
- Date: Fri, 15 May 2009 15:19:34 -0700
Nothing grows in a vacuum.
Steve Smith
eac> How can you study something that is non-existent—"brains of the
eac> EU politicians"? the good news, there is lots of room for growth.
eac> Werner
eac>
eac>
eac> -----Original Message-----
eac> From: Norman Dancer <ndancer@xxxxxxxxxxxxxxxxxxx>
eac> To: tinwhiskers@xxxxxxxxxxxxx <tinwhiskers@xxxxxxxxxxxxx>
eac> Sent: Fri, 15 May 2009 4:43 pm
eac> Subject: [tinwhiskers] Re: New study on coating to mitigate whiskers
eac> Be
eac> sure to test the brains of the EU politicians. They’ve definitely
eac> got something growing there. J
eac>
eac> (OK,
eac> I’ll behave myself now).
eac>
eac> From:
eac> tinwhiskers-bounce@xxxxxxxxxxxxx
eac> [mailto:tinwhiskers-bounce@xxxxxxxxxxxxx] On
eac> Behalf Of Fritz, Dennis D.
eac> Sent: Friday, May 15, 2009 11:41 AM
eac> To: tinwhiskers@xxxxxxxxxxxxx; tinwhiskers@xxxxxxxxxxxxx
eac> Subject: [tinwhiskers] Re: New study on coating to mitigate whiskers
eac>
eac> What is your whiskers inspection methodology?
eac>
eac> I
eac> am getting ready to do a study with Purdue undergraduate interns (who work
for
eac> a VERY attractive price for our program). We will determine
eac> both the extent of whiskers growth on commercial boards - scrap cell
phones and
eac> laptops, and the ease of measurement by "semi-skilled"
eac> operators. We will be using optical microscope, enhanced di
eac> gital
eac> microscope, and simple SEM.
eac>
eac> Can
eac> you share your proceedures?
eac>
eac> Denny
eac> Fritz
eac> SAIC
eac> - Merrillville, IN
eac>
eac> From: tinwhiskers-bounce@xxxxxxxxxxxxx on behalf
eac> of Jim Bunn
eac> Sent: Fri 5/15/2009 10:55 AM
eac> To: tinwhiskers@xxxxxxxxxxxxx
eac> Subject: [tinwhiskers] Re: New study on coating to mitigate whiskers
eac> I think they are
eac> saying it works if the thickness is at least 2mils. Or maybe that the
coating
eac> is better than nothing.
eac> We have a lot of uncoated stuff out there running a test right now. And
it's
eac> pretty comprensive considering the voltage levels that we are using in the
eac> PCUs. I'm suprised that we have not had some kind of problem.
eac> ________________________________
eac> From: tinwhiskers-bounce@xxxxxxxxxxxxx on behalf of Pedro Tort
eac> Sent: Thu 5/14/2009 7:48 AM
eac> To: tinwhiskers@xxxxxxxxxxxxx
eac> Subject: [tinwhiskers] New study on coating to mitigate whiskers
eac> The National Physics Laboratory in UK has undertaken a study on the
capability
eac> of different coatings to mitigate tin whiskers growth. The results of this
eac> investigation reinforces the findings of Jay Bruse and Dr. Henning
Leidecker
eac> who back in 2007 found the Uralane 5750 Polyurethane was an effective
eac> mitigation strategy for tin whiskers provided the nominal coating
thickness was
eac> 2mils.
eac> I quote from the first issue of the NPL Electronics Interconne
eac> ction Newsletter:
eac> "The use of conformal coatings is seen as the only practical means of
eac> controlling whisker growths shorting adjacent conductors on a PCB. NPL has
eac> studied three types of coating, to assess their effectiveness for
inhibiting
eac> whisker growth.
eac> Two coatings, polyurethane and paraxylene both were found to reduce the
growth
eac> of whiskers for up to 150 days of testing, compared with failure of 14
days for
eac> uncoated samples. The acrylic coating was found not to perform as well as
the
eac> others in parallel tests. All coatings failed to provide sufficient
protection
eac> in areas of insufficient coating coverage, at corners and sides of the test
eac> samples."
eac> Pedro Tort
eac> Quality Manager
eac> DigiProces, S.A.
eac> Solsones, 87 - P.I. Pla de la Bruguera
eac> P.O. Box 127
eac> E-08211 CASTELLAR DEL VALLES
eac> TEL. +34 937 142 132
eac> FAX. +34 937 142 072
eac> www.digiproces.com
eac> This email and any files contained therein is confidential and may contain
eac> privileged information. If you are not the named addressee(s) or you have
eac> otherwise received this in error, you should not distribute or copy this
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eac> or use any of its content for any purpose. Please notify the sender
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eac>
--
Best regards,
Steve mailto:steve@xxxxxxxxxxxxxxxxxxxxxx
www.consultingscientist.us
http://www.pickensplan.com/
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