But Dean, it's on the internet. They can't put anything on the internet
that isn't true. I heard that on the internet......
Doug Pauls
Principal Materials and Process Engineer
Rockwell Collins
On Wed, May 17, 2017 at 9:14 AM, Stadem, Richard D. <
[log in to unmask]> wrote:
> Steve, please don’t bandy that stuff about. If my operators see that
> they’ll all want some ASAP. Imagine not having those pesky cords that are
> always knocking over their pop cup on the ESD bench, LOL!
>
> From: Steve Gregory [mailto:[log in to unmask]]
> Sent: Wednesday, May 17, 2017 9:07 AM
> To: TechNet E-Mail Forum; Stadem, Richard D.
> Subject: Re: [TN] IMC Formation Thickness in OSP
>
> Hey Dean,
> You liked those ROHS compliant foot straps so much, I know you'll just
> love the wireless wrist straps! At least they're only $4.00.
>
> http://www.batteryspace.com/cordlesswriststrap--
> staticdissipativewithoutgroundingcord.aspx
> Steve
>
> On Wed, May 17, 2017 at 7:44 AM, Stadem, Richard D. <
> [log in to unmask]<mailto:[log in to unmask]>> wrote:
> I could not agree with you more, Dave!
> What a lot of people do not understand also is that IMC formation is
> self-limiting. Rework temperatures do NOT “double the thickness of the IMC
> and therefore reduces reliability by half” as one solder company’s PhD
> stated recently when attempting to sell low-melting –point solder alloys.
> IMC thickness normally has little effect on reliability.
>
> We in the electronics industry have to constantly beware of hucksters
> trying to make a buck with “easy” technical solutions, only to find you
> never get something for nothing, and sometimes you get nothing for
> something more, such as those green RoHS-compliant ESD footstraps for $49
> per pair (still laughing and stepping down from soapbox also).
> Odin
>
> From: David Hillman [mailto:[log in to unmask]<mailto:dav
> [log in to unmask]>]
> Sent: Wednesday, May 17, 2017 8:21 AM
> To: Stadem, Richard D.
> Cc: TechNet E-Mail Forum
> Subject: Re: [TN] IMC Formation Thickness in OSP
>
> Hi Dean - good summary! There is currently a soldering iron manufacturer
> (who shall remain nameless) who is claiming their system manages the solder
> joint creation making the "ideal" IMC for a reliable joint. I have
> requested a copy of the data or research conducted on how the "ideal" IMC
> for solder joint integrity was derived and am still awaiting the
> information. I think we are causing some unnecessary waste of industry
> resources many times with the topic of IMC comes up. Ok, I'll get off my
> soap box!
>
> Dave
>
> On Wed, May 17, 2017 at 7:29 AM, Stadem, Richard D. <
> [log in to unmask]<mailto:[log in to unmask]><mailto:
> [log in to unmask]<mailto:[log in to unmask]>>> wrote:
> Most IMC failures are actually design issues related to delta CTEs between
> components and substrates, and to varying degrees. I respect the challenge
> you have of summarizing the perfect storm of these design issues, alloy
> factors (including nucleation and brittleness), aging, and incorrect or
> abusive solder joint processes (including rework) that could contribute or
> lead to catastrophic SJ failure.
>
> And yet, we all manage to do this every day in this industry.
> Dean
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]<mailto:[log in to unmask]><mailto:
> [log in to unmask]<mailto:[log in to unmask]>>] On Behalf Of David Hillman
> Sent: Wednesday, May 17, 2017 7:16 AM
> To: [log in to unmask]<mailto:[log in to unmask]><mailto:[log in to unmask]<mailto:
> [log in to unmask]>>
> Subject: Re: [TN] IMC Formation Thickness in OSP
>
> Hi TechNet! I was holding off to see what folks posted. My question is
> "why does it matter?". An industry colleague and I are collaborating on a
> paper that covers "industry soldering myths" and intermetallic compound
> (IMC) failure is right at the top of the list. Its a true statement that
> IMCs are brittle but, as an industry, we seem to translate/proliferate that
> statement into a solder joint defect. There are very very very few industry
> reports/publications of solder joint integrity failures due to IMC in
> product use environments. There are tons of reports of IMC failures created
> because of grossly incorrect or abusive solder joint processes which isn't
> the same thing. Victor - my suggestion is to focus on having a correct
> soldering process using acceptable time/temperature parameters regardless
> if its the initial soldering process or a rework activity. If the solder
> process is correct, whatever the IMC thickness turns out to be, it will be
> acceptable.
>
> Dave Hillman
> Rockwell Collins
> [log in to unmask]<mailto:[log in to unmask]
> ><mailto:[log in to unmask]<mailto:david.hillman@
> rockwellcollins.com>>
>
> On Tue, May 16, 2017 at 4:58 PM, George Wenger <[log in to unmask]<
> mailto:[log in to unmask]><mailto:[log in to unmask]<mailto:
> [log in to unmask]>>>
> wrote:
>
> > Victor,
> >
> > I haven't seen and TechNetter responses but I'll give you my two cents.
> > The
> > IMC thickness numbers you heard sound much too high. I think the IMC
> > thickness should be half as thick as those numbers.
> >
> >
> > Regards,
> > George Wenger
> >
> >
> >
> > -----Original Message-----
> > From: TechNet [mailto:[log in to unmask]<mailto:[log in to unmask]><mailto:
> [log in to unmask]<mailto:[log in to unmask]>>] On Behalf Of
> > [log in to unmask]<mailto:[log in to unmask]><mailto:
> [log in to unmask]<mailto:[log in to unmask]>>
> > Sent: Tuesday, May 16, 2017 8:35 AM
> > To: [log in to unmask]<mailto:[log in to unmask]><mailto:[log in to unmask]
> <mailto:[log in to unmask]>>
> > Subject: [TN] IMC Formation Thickness in OSP
> >
> > Fellow TechNetters:
> >
> > What is the acceptable guideline for IMC Formation thickness on OSP
> > after
> > 2x rework.. IPC-4555 is still pending. I've heard of 3-5 microns on
> > first
> > pass and 5-10 microns on 2x RW. All comments/suggestions welcomed.
> >
> > Victor,
> >
>
>
>
> --
> Steve Gregory
> Kimco Design and Manufacturing
> Process Engineer
> (208) 322-0500 Ext. -3133
>
> [http://fileserver1.kimco.net/PublicDocs/KDMsig200.png]
>
> This email and any attachments are only for use by the intended
> recipient(s) and may contain legally privileged, confidential, proprietary
> or otherwise private information. Any unauthorized use, reproduction,
> dissemination, distribution or other disclosure of the contents of this
> e-mail or its attachments is strictly prohibited. If you have received this
> email in error, please notify the sender immediately and delete the
> original.
>
|
