That's me, the Emperor of Effluvium, Duke of Dirt, Sultan of Schmutz, the
Marquis of Mud ...........
As Joe indicated, cleanliness at the component level, or at least very
small sub-assembly is being examined. Once IPC as an organization gets
its hands around how do you determine cleanliness at that level and give
some guidelines on what is desirable, then it can go into larger
specifications like J-STD-001.
Doug Pauls
From: "Stadem, Richard D." <[log in to unmask]>
To: <[log in to unmask]>
Date: 02/18/2014 02:34 PM
Subject: Re: [TN] Cleanliness testing at component level
Sent by: TechNet <[log in to unmask]>
Yes, the lack of component cleanliness requirements in IPC documents is
lacking. Are they covered in JEDEC standards? If so, I think there should
be a reference within the IPC documents, especially those standards
dealing with cleanliness and contamination issues to the next level
(contagion). And no, I am not going to be a part of that committee, as I
am suffering sufficient filth unto today to keep me busy thereof. Maybe
Doug Pauls and Terry Munson? Those guys know dirt like nobody else.
-----Original Message-----
From: [log in to unmask] [mailto:[log in to unmask]]
Sent: Tuesday, February 18, 2014 1:56 PM
To: Stadem, Richard D.; [log in to unmask]
Subject: RE: Cleanliness testing at component level
Dean,
No, I agree with you completely. I just don't see the specification
addressing component level. I would like to see the words "component
level" added so that everyone sees it the way we do.
In my case, the pre-tinned component may be shipped back to me and sit in
stock for a year before it is assembled onto a PWA which is subsequently
tested for cleanliness.
Phil
-----Original Message-----
From: Stadem, Richard D. [mailto:[log in to unmask]]
Sent: Tuesday, February 18, 2014 9:00 AM
To: TechNet E-Mail Forum; Bavaro, Phillip @ MWG - TW
Subject: RE: Cleanliness testing at component level
For me, the difference between components and assemblies is becoming so
blurred that it is very difficult to determine where the spec applies and
where it doesn't.
Can you tell me that a PoP component consisting of 4 stacked miniature
pwbs that is soldered together using a special flux and laser as well as
standard solder and flux and touched up and cleaned in an in-line cleaner
does not require the same treatment by the specification as the 36" by 24"
supercomputer CCA that has 24 layers, 36 miles of copper traces, weighs 45
lbs when populated with just 24 sockets?
Why?
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Phil Bavaro
Sent: Tuesday, February 18, 2014 10:31 AM
To: [log in to unmask]
Subject: [TN] Cleanliness testing at component level
I have reviewed the J-STD-001 several times but still have a question
regarding a subcontractor who performs component level soldering
operations for Class 3 hardware.
If the subcontractor is performing a soldering operation, then cleaning is
required to remove flux residues (this is not a no clean flux situation).
If the subcontractor is cleaning, then cleanliness testing is required.
The J-STD-001 does not really address the component level when it comes to
the Post Soldering Cleanliness Designator (PSCD).
If a component is having its leads pre-tinned or a BGA being re-balled,
then is it defaulted to a C-22 PSCD?
My position is yes but I can see where there might be arguments against
this since the designator codes seem to speak to the assembly level and
not the component level.
My concern is that there is considerable time lag between when component
soldering operations are performed relative to the actual PWA process
which does get checked for cleanliness.
Any input is appreciated.
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