Sorry to hijack this thread, but it seems that's the only way I can post
anything anymore, is by replying to a message that someone else posted.
I've been banned from posting anything for some reason. I've only been a
member for over two decades. I wonder why I've been banned?

I sent an email to [log in to unmask] and haven't heard a peep from them.

I don't know who the network administrator is anymore, it used to be Keach
Sasamori.

Steve

On Wed, Mar 13, 2024, 6:29 AM [log in to unmask] <
[log in to unmask]> wrote:

> Right on.
>
> -----Original Message-----
> From: TechNet <[log in to unmask]> On Behalf Of Pauls, Doug Collins
> Sent: Tuesday, March 12, 2024 9:03 PM
> To: [log in to unmask]
> Subject: Re: [TN] Surface energy for conformal coating
>
> ----
> External E-mail --- CAUTION: This email originated from outside GDMS. Do
> not click links or open attachments unless you recognize the sender and
> know the content is safe.
>
> Ioan,
> In general, I have used this rule of thumb:
> <30 dynes/cm - you will see problems with adhesion and wetting.
> 30-35 dynes/cm - you will still see problems with adhesion and wetting,
> but not as much as under 30.
> 35-40 dynes/cm - generally decent adhesion and wetting but occasional
> issues
> 40+ dynes/cm - good adhesion and wetting.  Collins specifies >44 dynes/cm
> for its solder mask.
>
> Douglas Pauls | Sr. Technical Fellow | Electronics AMT COLLINS AEROSPACE
> 400 Collins Road NE, MS 108-101, Cedar Rapids, IA  52498  USA
> Tel: +1 319 295 2109 | Mobile: +1 319 431 3773
>
> -----Original Message-----
> From: TechNet <[log in to unmask]> On Behalf Of Ioan Tempea
> Sent: Monday, March 11, 2024 2:42 PM
> To: [log in to unmask]
> Subject: [External] [TN] Surface energy for conformal coating
>
> Hello Technos,
>
> Some many years ago I have discovered, with help from this illustrious
> panel, the existence of the dyne pens. Have used them for a while and them
> moved to microelectronics, where I have spent 11 years without any contact
> with conformal coating. So I've kinda forgot some details.
> Where I work we have the Surface Analyst device, measuring contact angles
> and this is supposed to obsolete the use of dyne pens.
>
> The trouble is I can't remember what dyne values are related to good
> coating wetting. Or even better, which contact angles are preferred?
>
> Can anyone help?
> I'm interested in both solder masked PCBs and Au plated ceramics and the
> optimal values I believe differ from PCB to ceramics.
>
> Also, do you have any good articles or textbooks to recommend on this
> matter?
>
> Thanks,
>
> Ioan
>

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