Hi folks! Just an echo George's comments - Rockwell Collins has used
TetraEtch on PTFE and Duriod printed wiring assemblies for a number of
years to improve the bondability of the pwb surface on specific
applications. The TetraEtch does not create a significant impact on circuit
performance unless you are dealing with a very hairy RF or Microwave type
of circuit design. However, the TetraEtch process involves some very nasty
chemicals and I wouldn't recommend anyone integrate the process on a
"standard" basis without a fair amount of consideration of the other
possible alternative processes. There have also been a number of studies
(unpublished efforts) which have shown that the TetraEtch process does not
result in a bondability improvement in some use applications. I recommend
you look at other alternatives before implementing a TetraEtch process.
Good Luck.
Dave Hillman
Rockwell Collins
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"Franck, George" <[log in to unmask]>@ipc.org> on 06/03/2002
06:55:20 AM
Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond
to "Franck, George" <[log in to unmask]>
Sent by: TechNet <[log in to unmask]>
To: [log in to unmask]
cc:
Subject: Re: [TN] Tetra treatment
The creator of Teflon was overjoyed and proud after creating a material
that NOTHING would stick to. Of course, he became somewhat depressed when
the first set of engineering questions everyone asked him was, "How do I
get stuff to stick to your Teflon?"
I can not think of any reason the Tetra-Etch (W.L. Gore?) would mess up
your circuit performance. Even if the material is degraded, it is not the
material under the circuit traces, where the Teflon is electrically
functional, that will be in contact with the Tetra-etch.
On the other hand, I never let my designers put any silkscreen marking on
Teflon, so I have no direct experience. I would recommend you not mark the
boards. Most designers hate creating the marking files for Silkscreen, so
you would hear any complaints from them. Any required marking is placed on
the artwork and etched in copper. (driving the AOI machines crazy)
Tetra-Etch is a nasty chemical. (the smell of moth balls is the nicest
thing about it.) If something COULD go wrong, Tetra-Etching at the final
step of the process probably would help push any potential problem into the
realm of reality.
Tetra-Etch has been used for, shez... 30+ years on Teflon PWBs, and is
primarily used to condition the drilled hole walls, a smear removal and
surface preparation step, to allow electroless copper to adhere. Other
process have been developed in the last 5 - 10 years to do the same thing.
George Franck
"My opinions are just that."
-----Original Message-----
From: Goh Guan Chye [mailto:[log in to unmask]]
Sent: Monday, June 03, 2002 5:53 AM
To: [log in to unmask]
Subject: [TN] Tetra treatment
Hi all,
Does anyone know what is Tetra treatment ? According to my board maker, it
is used to treat the surface of the PCB for better adhesion of the
silkcscreen printing. Will it affect the characteristic of the PCB
dielectric laminates, especially for Roger's Teflon board.
Appreciate anyone could advise please.
Regards,
Guan Chye
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