Good to hear, Rainer,
y're quite right, but that was the recipe 20 years ago, and many humidizers were installed, now included in the AC system. We also use ionizers, but even these countermeasures may be unsufficient. In one of our plants people found that a small number of the tiny chips disappeared on the way from tape to board. Where on earth were they? After some time they were found on inside of the P-P! Sitting here and there like butterflies on a flower. And we thought ESD was under full control! OK, this was some years ago, but we do never underestimate ESD risks after that.
Ingemar
-----Original Message-----
From: Blomberg, Rainer (FL51) [mailto:[log in to unmask]]
Sent: den 7 september 1999 18:14
To: [log in to unmask]
Subject: Re: [TN] ESD and SMT Tape/Reels - Concern
I would say not. Even here in Florida we use them in certain build areas to
increase humidity to reduce the build-up during the dry winter months. But
I hope you realize, higher humidity does not eliminate ESD build-up, it only
allows faster, natural dissipation.
Rainer Blomberg
-----Original Message-----
From: Ingemar Hernefjord (EMW)
[mailto:[log in to unmask]]
Sent: Friday, September 03, 1999 4:36 AM
To: [log in to unmask]
Subject: Re: [TN] ESD and SMT Tape/Reels - Concern
Are humidizers unfashionable today for eliminating ESD buildup? Ours are
still on day and night.
Ingemar Hernefjord
Ericsson Microwave Systems
-----Original Message-----
From: Clive ffitch [mailto:[log in to unmask]]
Sent: den 2 september 1999 17:21
To: [log in to unmask]
Subject: [TN] ESD and SMT Tape/Reels - Concern
All,
I know this has been raised before, but the picture does not seem all
that clear. So here goes.
We have an issue with some SMT part tapes and reels being supplied using
non-ESD compatible materials, where we have measured up to around 1000V
on the plastic reels, or as measured on the tapes themselves when peeled
back. Some plastics used do appear to be static dissipative/conductive,
as do some of the black tapes, but not all. The tape/reels in question
are for resistor/capacitor parts, and some SOT23s etc.
When challenged, some suppliers have said this is not an issue for other
people, and to re-package the parts would cost +300%, but we can have it
if we pay. We assemble resistors/capacitors/discretes on the same
equipment as more sensitive ESDSs, and feel sure we are not the only
people with these concerns; what we want are parts supplied using
ESD-safe tape and reel packaging. For the assembly of high reliability
equipment, we do not want to have to resort to installing ioniser farms.
However, we do not have any leverage in the market place on our own, and
our order quantities are small - even insignificant - so the question
is, ARE we alone?
Is the rest of industry getting what it wants, or do we have to adapt
our own practices to accommodate resistors and capacitors being
delivered in the packaging that suppliers say we can have them in?
All comments to TechNet most welcome.
Clive ffitch
MBUK
Stevenage, England
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