Hi All,
 
From sad experience with ENIG.
 
Hyperactive palladium catalyst (bath used for too long) in the e-less nickel part of the process....deposits on metal, plastic,....anything.
 
Nickel frequently sticks to the palladium and immersion gold deposits over the nickel if there's enough nickel. Little tiny specks.
 
Beware that you can pick-em off with an exacto, but only where/when you can see them.
 
Gerry> Date: Wed, 28 Jan 2009 11:34:10 -0500> From: [log in to unmask]> Subject: Re: [TN] Metal particles on the PCB> To: [log in to unmask]> > Ioan,> > Pardon me if this has already been commented on. Have been falling behind> in my Techie e-mails.> > I've also seen something like this before, but it was related to> 'over-activation' prior to electroless plating. In that case, however, the> slivers and feathers were under the solder mask. These look like they are> on top of the solder mask....> > Are they on top of the mask? Or below?> > If on top - is there a slitting, routing, etc. operation somewhere along the> board fab line that is creating the debris on your boards by> transference...?> > If below the solder mask - check on plating issues.> > Steve C> > -----Original Message-----> From: TechNet [mailto:[log in to unmask]] On Behalf Of stephengregory5849> Sent: Wednesday, January 28, 2009 11:26 AM> To: [log in to unmask]> Subject: Re: [TN] Metal particles on the PCB> > Hi Ioan!> > Got your pictures finally and have them posted now, they're here:> > http://stevezeva.homestead.com/files/Photo_002.jpg> > http://stevezeva.homestead.com/files/Photo_004.jpg> > I've seen something like this before, and it was caused by overetching which> > caused plating slivers. Luckily, we found these before we populated the > boards. We rejected the boards back to the fab vendor and had them replaced > for new ones. We rejected them because of the possibilty that minimum > electrical clearances were being violated.> > Steve> > ----- Original Message ----- > From: "Ioan Tempea" <[log in to unmask]>> To: <[log in to unmask]>> Sent: Tuesday, January 27, 2009 1:48 PM> Subject: [TN] Metal particles on the PCB> > > Dear Technos,> > I have these PCB shaving a lot of small, but visible with unaided eye, Au or> > Cu particles on them, all over. I have sent Steve a couple of images, but in> > the mean time I would like to state my questions.> > As per IPC-A-610D, 10.4.2, this is a defect condition. The exceptions at > 5.2.6.1 say this would be acceptable if the particles were entrapped in > flux, which is not the case.> > Big part of the litter goes away if wiped with alcohol soaked cloth, but not> > all. Brushing will not remove the leftovers, which seem to be well attached > to the soldermask, but a solid nail scratching will.> > First of all: is this a defect?> Secondly, are there any better methods to clean than what I have tried? > Plasma and other funky methods are not an option and solvent cleaning is > probably not either, since the boards are already populated on one side with> > no-clean flux.> > Thank you,> > Ioan Tempea, ing.> Ingénieur Principal Fabrication / Sr. Manufacturing Engineer> 30 ans déjà! - Already 30 years!> 950 rue Bergar, Laval, Québec, H7L 5A1> t : 450-967-7100 ext : 244> Mtl : 514-990-5762> f : 450-967-7444> [log in to unmask]> www.digico.cc <http://www.digico.cc/>> P N'imprimer que si nécessaire - Print only if you must> > > ---------------------------------------------------> Technet Mail List provided as a service by IPC using LISTSERV 15.0> To unsubscribe, send a message to [log in to unmask] with following text in> the BODY (NOT the subject field): SIGNOFF Technet> To temporarily halt or (re-start) delivery of Technet send e-mail to > [log in to unmask]: SET Technet NOMAIL or (MAIL)> To receive ONE mailing per day of all the posts: send e-mail to > [log in to unmask]: SET Technet Digest> Search the archives of previous posts at: http://listserv.ipc.org/archives> Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 > for additional information, or contact Keach Sasamori at [log in to unmask] or > 847-615-7100 ext.2815> ----------------------------------------------------- > > ---------------------------------------------------> Technet Mail List provided as a service by IPC using LISTSERV 15.0> To unsubscribe, send a message to [log in to unmask] with following text in> the BODY (NOT the subject field): SIGNOFF Technet> To temporarily halt or (re-start) delivery of Technet send e-mail to> [log in to unmask]: SET Technet NOMAIL or (MAIL)> To receive ONE mailing per day of all the posts: send e-mail to> [log in to unmask]: SET Technet Digest> Search the archives of previous posts at: http://listserv.ipc.org/archives> Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16> for additional information, or contact Keach Sasamori at [log in to unmask] or> 847-615-7100 ext.2815> -----------------------------------------------------> > ---------------------------------------------------> Technet Mail List provided as a service by IPC using LISTSERV 15.0> To unsubscribe, send a message to [log in to unmask] with following text in> the BODY (NOT the subject field): SIGNOFF Technet> To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)> To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest> Search the archives of previous posts at: http://listserv.ipc.org/archives> Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815> -----------------------------------------------------
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