Agreed and well stated Bev. Ditto on my part to all you points.
The replies have confirmed my thoughts in some case and also provided some new insights.
Now have enough detail to make myself more dangerous.
Particularly useful was that no one presented details supporting high risk for low levels of Ca.
Thanks to all for the time and effort spent on my behalf.
Will indeed resurrect this thread if/when I get some useful feedback on my quest.
Rich Kraszewski
PLEXUS
(920)969-6075
-----Original Message-----
From: Bev Christian [mailto:[log in to unmask]]
Sent: Tuesday, February 11, 2014 7:47 PM
To: 'TechNet E-Mail Forum'; Richard Kraszewski
Subject: RE: [TN] Risks Associated with Calcium
All,
This thread has been, well, hilarious, exhilarating and instructive all at
once. Rich, I thought your "OK then..." was actually one of the funniest
parts. I can just see you saying something like that in an IPC meeting.
But seriously, let's look at this a bit, starting with your list.
#1 CaCl2 from deicing compounds.
I am certain that Doug said is right - go through your process and find out
where the calcium first shows up.
#2 Calcium from factory humidification misters
We had a problem with those in our lab - which crapped out a multi-hundred
thousand dollar x-ray machine by the way. We had a devil of a time tracking
down where the contamination was coming from. We had to devise a catch
system to capture the aerosol of water droplets being put out by the mister,
take samples from various points in the water delivery system and then run
IC on all the samples. In our case the offending cation was sodium although
there were smaller amounts of K, Ca and Mg also present.
#3 Talc from powdered gloves
Talc is Mg3Si4O10(OH)2 so I doubt this is your source of calcium.
#4 E-glass in the laminate
E-Glass is a low alkali glass with a typical nominal composition of SiO2
54wt%, Al 2O3 14wt%, CaO+MgO 22wt%, B2O3 10wt% and Na2O+K2O less then 2wt%.
Where is the Al and Mg?
Again, I doubt this is your source.
#5 filler in the solder mask
Yep, my first guess, IF you are finding it on the surface of virgin boards
right out of the package.
#6 DI water
???
Same situation as #2.
Doug,
You stated:
"Phil Wittmer and some of his colleagues at Delco Electronics (now Delphi)
published papers years ago where they treated cations as process
indicators."
Could you send me the references?
Rich,
Keep us posted as to the results of your investigation!
Regards,
Bev
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Richard Kraszewski
Sent: Tuesday, February 11, 2014 12:38 PM
To: [log in to unmask]
Subject: Re: [TN] Risks Associated with Calcium
OK then....
Thanks for the replies. Even the ones that turned this into a more surreal
experience than even I typically expect to have on any given workday.
My list of more bland replies (albeit it begrudgingly useful) both on and
off forum include the following:
#1 CaCl2 from deicing compounds.
#2 Calcium from factory humidification misters
#3 Talc from powdered gloves
#4 E-glass in the laminate
#5 filler in the solder mask
#6 DI water
The above list is useful from a source stand point, however am still
struggling with the effects that could be seen with low levels of Ca (i.e.
<1-2 ugm/inch). I suspect none if any.
Studies conducted by the Minzari in Denmark suggests that calcium warrants
limited concerns as only Sn, Pb, Cu and Ag present sizable ECM risk. (IEEE,
volume 9, Sept 2009).
I have a suspicion that any requirements for low levels of calcium on
assemblies have been propagated from those used in the semiconductor
industry. While those may be required in semiconductor world, they may not
have good applicability in the realm of PCA manufacture.
Any further thoughts on "RISKS" associated with low levels of calcium?
Rich Kraszewski
PLEXUS
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory
Sent: Tuesday, February 11, 2014 9:15 AM
To: [log in to unmask]
Subject: Re: [TN] Risks Associated with Calcium
Hi Steve,
You hit the nail on the head!!
http://www.youtube.com/watch?v=KX9mBaHtTrs
Steve
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Steven Creswick
Sent: Tuesday, February 11, 2014 7:22 AM
To: [log in to unmask]
Subject: Re: [TN] Risks Associated with Calcium
Doug,
Don't overlook that which is right in front of your co-ops face!
Please remember that a cow's tongue is long enough, and flexible enough to
reach inside its nostrils and extricate whatever may be resident there.
Certainly, at this time of year there may be significant 'thickening agents'
and moisture present.
Just thought you would like to know for testing!
Steve Creswick
Sr Associate - Balanced Enterprise Solutions
http://www.linkedin.com/in/stevencreswick
616 834 1883
______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
|
