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From: Crawford, John A.
To: TechNet-request
Subject: RE: Pink Poly Bags/Shipping PCB Assy's
Date:  9 Jun 95 9:39AM

Following from the EMPF HelpLine. This subject goes back about ten years to 
when Richmond Corp originally introduced the "pink poly antistat" material. 
(Who remembers Dan Anderson, the magician/salesman that made training tapes 
for ESD awareness in the early days? His jokes would never get by EEO now!) 
 Anyway, the first generations of of the pink poly material had some really 
bad problems with contamination of items put in them. Any bare board or 
components had to be cleaned after removal from the bags or they wouldn't 
wet when soldered and I believe there were some pretty bad corrosion 
problems, also.. The mfg processes for the pink poly were refined, and I 
thought contamination problems were pretty will corrected. The military got 
in the act and wanted some flame retardent in the plastic also, and there 
were a few years that it had to have a "smokey" look to it as a visual 
identifier. It is possible that (1) you have gotten some really old bags (2) 
some converter got a hold of some old  material (probably cut rate and gave 
you a great price on antistat bags) (3) something glitched in the mfg of the 
bags you are trying to use (4) some environmental thing ((sitting in the 
rail car in Yuma for two days at 250 degrees) caused the poly to break down 
and sluff off the antistat chemicals. There IS good material available on 
the market today--it's more widely used for cushioning bubble pack that 
actual electronic material contact though. Pink poly is only anti-static in 
that it does not favor generation of charge through triboelectric effect. It 
has fairly poor bleed off characteristics, and provides NO shielding. That 
is why metalized mylar/poly bags are so widely used for actual 
storage/handling of sensitive boards, and the pink poly material is used as 
over-wrap and cushioning material. If you are interested in determining what 
the actual contamination is, we can put it through our lab and find out, but 
I think you already know where it is coming from. Besides myself, we have 
several other folks here who have been long-time members of EOS/ESD 
Association and would be glad to discuss further. You can contact us 
directly at [log in to unmask] or phone to 317.226.5616. 
Jack Crawford
 ----------
From: TechNet-request
To: TECHNET
Subject: Pink Poly Bags/Shipping PCB Assy's
Date:  8 Jun 95 2:05PM

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From: [log in to unmask] (Leo Reynolds)
Subject: Pink Poly Bags/Shipping PCB Assy's
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Hello;

Our question is "Has anyone experienced a problem with shipping PCB
Assys in pink poly bags and having contamination develop on the PCB from
outgassing of the plastic bag.  The assys we've noted the problem with
have typically been air shipped, at least some of them to the Orient."

Thank You in advance for any light you might be able to shed on this
particular phenomenon.


Best Regards,


Leo