And what about the effect of just plain old physical surface roughness? Bev -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Victor Hernandez Sent: Wednesday, February 12, 2014 3:27 PM To: [log in to unmask] Subject: Re: [TN] [COM] Solder Mask Surface Tension for Conformal Coating Adhesion Check the insulation black material for elements and adhesive which will attract dust and what not. Victor, -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Ed Popielarski Sent: Wednesday, February 12, 2014 11:26 AM To: [log in to unmask] Subject: Re: [TN] [COM] Solder Mask Surface Tension for Conformal Coating Adhesion Good point, thanks! Ed Popielarski Engineering Manager [Description: FullLogo] 970 NE 21st Ct. Oak Harbor, Wa. 98277 Ph: 360-675-1322 Fx: 206-624-0695 Cl: 949-581-6601 https://maps.google.com/maps/myplaces?hl=en&ll=48.315753,-122.643578&spn=0.0 11188,0.033023&ctz=420&t=m&z=16&iwloc=A From: [log in to unmask] [mailto:[log in to unmask]] Sent: Wednesday, February 12, 2014 8:49 AM To: TechNet E-Mail Forum; Ed Popielarski Subject: Re: [TN] [COM] Solder Mask Surface Tension for Conformal Coating Adhesion Ed, In your study, make note of whether the surface you are testing rested against any packing material (like polyethylene shrink wrap) or interleave material (like paper or Silver Saver). I have found that boards from the center of the pack of boards can sometimes have different energy than those that are at the top or bottom. Doug Pauls From: Ed Popielarski <[log in to unmask]<mailto:[log in to unmask]>> To: <[log in to unmask]<mailto:[log in to unmask]>> Date: 02/12/2014 09:57 AM Subject: Re: [TN] [COM] Solder Mask Surface Tension for Conformal Coating Adhesion Sent by: TechNet <[log in to unmask]<mailto:[log in to unmask]>> ________________________________ I'm launching a study here to try to correlate variation in solder mask surface activity measured with Dyne Pens vs. "spotty" defects we see from time to time. My theory is that the "out of the box" surface activity may be marginal in some cases, and wetting problems exacerbated by environmental (handling, atmosphere, etc.) influences that would have negligible effect if the activity were otherwise better. I've selected 5 Dyne "classes" as a sorting mechanism, 46+, 42+, 36+,30+, 30- and will test one board per "batch", i.e., P/N & Job No. & record measured value. I will have inspection scrutinize for dewetted spots and advise before touchup so I can record the defect in its appropriate entry. I'll let y'all know if there are any interesting results. Ed Popielarski Engineering Manager 970 NE 21st Ct. Oak Harbor, Wa. 98277 Ph: 360-675-1322 Fx: 206-624-0695 Cl: 949-581-6601 https://maps.google.com/maps/myplaces?hl=en&ll=48.315753,-122.643578&spn=0.0 11188,0.033023&ctz=420&t=m&z=16&iwloc=A -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Braddock, Iain (UK) Sent: Wednesday, February 12, 2014 7:41 AM To: [log in to unmask] Subject: Re: [TN] [COM] Solder Mask Surface Tension for Conformal Coating Adhesion Doug, Hmm....now why did I not think of that? The trouble is I am working on a special project that requires expensive complicated processing so I was hoping to steal a lead from someone with experience in this area - not being one for reinventing the wheel. Iain From: [log in to unmask]<mailto:[log in to unmask]> [mailto:[log in to unmask]] Sent: 12 February 2014 13:39 To: TechNet E-Mail Forum; Braddock, Iain (UK) Subject: Re: [TN] [COM] Solder Mask Surface Tension for Conformal Coating Adhesion *** WARNING *** This mail has originated outside your organization, either from an external partner or the Global Internet. Keep this in mind if you answer this message. Iain, quite simple. Start with a bad level for the material then improve it until it is not bad anymore. That will be your good level. I love being helpful. Doug Pauls From: "Braddock, Iain (UK)" <[log in to unmask]<mailto:[log in to unmask]>> To: <[log in to unmask]<mailto:[log in to unmask]>> Date: 02/12/2014 04:24 AM Subject: Re: [TN] [COM] Solder Mask Surface Tension for Conformal Coating Adhesion Sent by: TechNet <[log in to unmask]<mailto:[log in to unmask]>> ________________________________ Hi all, On the Dyne pens theme, does anyone had an idea what would be a good value for a Taconic TLY3 double sided laminate that has had one side of Cu etched away. Regards, Iain -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of GRIVON Arnaud Sent: 11 February 2014 08:05 To: [log in to unmask]<mailto:[log in to unmask]> Subject: Re: [TN] [COM] Solder Mask Surface Tension for Conformal Coating Adhesion *** WARNING *** This mail has originated outside your organization, either from an external partner or the Global Internet. Keep this in mind if you answer this message. Hello, Thank you for the clear information provided. As a supplement, I would be interested in someone could give the reference of the mentioned ASTM standard for surface energy measurement by Dyne Pens. Also wondering why there is no IPC standard or guideline on this topic, as conformal coating adhesion on solder mask is a quite common concern within the industry. It looks like indications given by Doug are acknowledged as good practice and therefore could be introduced within IPC standards. Best regards, Arnaud Grivon -----Message d'origine----- De : TechNet [mailto:[log in to unmask]] De la part de Lee Hitchens Envoyé : mardi 4 février 2014 07:26 À : [log in to unmask]<mailto:[log in to unmask]> Objet : Re: [TN] [COM] Solder Mask Surface Tension for Conformal Coating Adhesion Hi Arnaud I agree with Doug on this on using Dyne Pens although with no clean processing generally you are lucky if you can get close to the range of 35-40! We tend to be working in the lower range of this. It's also solder resist / coating dependent. Don't dismiss the energy value out of hand immediately. There is no logic sometimes to selection. We found one case where we tried absolutely any coating we could find to stick to a solder resist and only one did. No idea why and none of the chemists could explain. Best Regards Lee Hitchens -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Douglas Pauls Sent: 03 February 2014 17:01 To: [log in to unmask]<mailto:[log in to unmask]> Subject: Re: [TN] [COM] Solder Mask Surface Tension for Conformal Coating Adhesion Arnaud, I think you are asking about surface energy rather than surface tension. We use the readily available Dyne Pens which have solutions calibrated back to an ASTM standard. I generally use this rule of thumb regardless of the coating used. Under 30 dynes/cm: Coating adhesion will be poor 30-35 dynes/cm: Coating adhesion will be slightly better, but you can expect more frequent cases of delamination. 35-40 dynes/cm: Coating adhesion generally good, but can have some periodic delamination or adhesion issues. 40-45 dynes/cm: Coating adhesion is good and only rarely will you see delamination problems 45+ dynes.cm: Good adhesion. Of course, there will always be special cases but this is a good starting point. Doug Pauls From: GRIVON Arnaud <[log in to unmask]<mailto:[log in to unmask]>> To: <[log in to unmask]<mailto:[log in to unmask]>> Date: 02/03/2014 10:48 AM Subject: [TN] [COM] Solder Mask Surface Tension for Conformal Coating Adhesion Sent by: TechNet <[log in to unmask]<mailto:[log in to unmask]>> Hello TechNet, I would like to sense the best practices in terms of solder mask surface tension with respect to conformal coating adhesion : - Which standard/test method are you using? - Which requirement (e.g. minimum value in dyn/cm²) would you accept for the various CC types (acrylics, urethanes, silicone, parylene)? Thanks in advance for the insights. Best regards, Arnaud Grivon ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. 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