Stephen and Rudy,
With all due respect to the giants of TN: Have you fellows read Edgar,
Rich. "Various Applications and Production Uses of Immersion White Tin in
the Fabrication of Printed Circuit Wiring Boards," IPC Proceedings of the
Technical Conference. April 1998, S18-2-3?
My interpretation was that, after three reflow passes, 1/3 of the original
white tin remains on the surface per SERA. The rest would be intermetallic
-- one would suppose -- or gray tin converted to intermetallic under the
surface? I do not know.
The one thing I have heard from customers is a need for assemblers, OEMs,
or other end users to comment on the coating. There have been no
complaints here and also at Florida CirTech as mentioned by Stephen, but
from the work of Edgar it appears there are some limitations in multiple
thermal excursions that someone may or may not have inadvertently
experienced?
For Stephen, one might expect an exchange like the recent string over ENIG
-- in a good or bad sense -- would be the best way to obtain feedback for
other assemblers or designers to use. Comments made here can only be based
on interpretation of literature and experience with no negative feedback.
There can then be no logical conclusion of positive feed back except
indirectly.
My Opinion: With proper chemical inventory, the coating line is very easy
to control from a chemical and process standpoint -- a stark contrast in
comparison to the maintenance needs of an ENIG line (dip-to-dip).
Who on the assembly end has pushed this coating to the limits? It would
help other customers to hear even an "It works for these conditions" remark
too.
Lies? Accusations? or No information ... Maybe? Let's hear the users
view ... Many are out there.
Paul Wilson
R&D Manager / Plant Chemist
Circuit Center, Inc.
4738 Gateway Circle
Dayton, OH 45440
Phone (937) 435-2131 Fax (937) 435-7698
http://www.circuitcenter.com
-----Original Message-----
From: [log in to unmask] [SMTP:[log in to unmask]]
Sent: Friday, October 23, 1998 12:21 PM
To: [log in to unmask]
Subject: Re: [TN] pure tin surface finish requirement
Although Rudy Sedlack is very knowledgable on most subjects, I believe
he
falls a little short in the Tin Immersion department. I'm not sure what he
means by stating "depending on who's lies you believe" can give you 30 -100
microinches. Normally I wouldn't mention the fact that I sell OMIKRON
White
Tin Immersion, I wouldn't mention the fact that it will not grow
whiskers/dendrites, I wouldn't mention the fact that in the last year of
production at MANY shops I haven't recieved a single complaint, I wouldn't
mention the fact it's very easy to run and unlike what Mr. Sedlack stated,
can
be measured very accurately using a SERA unit (as advertised in CircuitTree
Magazine. I wouldn't mention that I believe this is the best alternative
finish on the market, and I can show you why.
I know this forum is not to be used as a sales tool, but it should
work
both ways, if your going to slam my product online, I'm going to defend it
online, and if you don't know what you're talking about maybe you should
reserve your comments to the bathroom.
Rudy I am NOT A LIAR and have all the technical data and test data to
back up my statements. I think White Tin happens to be one of the products
YOU don't sell, maybe that's got something to do with your negative
opinion.
AAAAAAhhhhhhh... I feel much better now!!!
Stephen M. Wentz
Florida CirTech Inc.
p.s. anyone want some info?
################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following
text in the body:
To subscribe: SUBSCRIBE TechNet <your full name>
To unsubscribe: SIGNOFF TechNet
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section
for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or
847-509-9700 ext.312
################################################################
################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe: SUBSCRIBE TechNet <your full name>
To unsubscribe: SIGNOFF TechNet
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################
|
