RE>>OSP Coating 11/4/96
Our experience with the need to completely dry prior to packaging is the same as yours, but our experience with dip tanks vs. in-line processes differs. We've had much better success with the former.
Some general comments:
-We've used multiple reflow OSPs (several types) for nearly 3 years now with considerable success. We adopted them because of soldering process problems with CBGA devices, and this change was instrumental to the success of a major program.
-The implementation of bare copper boards wasn't a drop-in process for us. We had to work on learning about storage, handling, processing, workmanship standards, and inspection issues. (As with all technologies, I suppose, the advertised claims tend to "stretch" the truth in areas!)
-I firmly believe that OSPs provide for a more reliable product, mainly because of the elimination of HASL thermal shocks and reduced amounts of ionic contamination.
-We've only had one customer acceptance issue, and that customer was receptive to the change after learning more about the technology.
For what it's worth: our products are generally double-sided SMT or mixed technology, they're assembled with water soluble chemistries, and the final applications are mainly in high performance defense and medical markets.
Regards,
Greg Bartlett
Mercury Computer Systems
Chelmsford, MA
[log in to unmask]
--------------------------------------
Date: 11/1/96 10:50 PM
To: Greg Bartlett
From: Jeffrey Harry/HQ/3Com
If you use Entec 106, make sure that the PCB supplier has an in-line process.
Dip tanks will cause major problems. Also the PCBS need to be thoroughly dried
before packaging. If not, you will have solderability problems.
Jeffrey_Harry @ 3mail.3com.com@ ugate
----- Previous Message ----------------------------------------------------
To: Technet @ ipc.org @ UGATE
cc:
From: EHolton @ vines.etn.com @ UGATE
Date: Thursday October 31, 1996 02:40 PM
Subject: OSP Coating
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Fellow technetters:
My company is beginning its research into the wonderful world of organic
solderability preservative coatings. Our goal being to implement this on
the circuit boards in the near future. I am looking for any and all
information that anyone may have(I have a pile of articles 12" high) with
use in production. I am especially interested in:
What type of coating is on the board
Number of heat excursions you have and does the coating live up to its
published cycles
Special handling procedures(operators) Board storage, time in
production
How you flux/profile/anything you did to get the topside fillet
Use of nitrogen?
Have you had solderability problems and how were they handled
Do you specify board cleanliness, coating brand, thickness on the
print and how is it verified.
Thru-hole components scrap the inside of the barrel when inserted, any
problems here with soldering
Any special tricks done at the wavesolder
Any and all information is appreciated
Thanks
Ed Holton
[log in to unmask]
***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To unsubscribe from this list at any time, send a message to: *
* [log in to unmask] with <subject: unsubscribe> and no text. *
***************************************************************************
***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To unsubscribe from this list at any time, send a message to: *
* [log in to unmask] with <subject: unsubscribe> and no text. *
***************************************************************************
------------------ RFC822 Header Follows ------------------
Received: by mailgate.mc.com with SMTP;1 Nov 1996 22:44:45 -0400
Received: from firewall.mc.com (firewall [192.148.197.15]) by jericho (8.6.11/8.6.11) with SMTP id VAA00247 for <[log in to unmask]>; Fri, 1 Nov 1996 21:44:40 -0500
Received: by firewall.mc.com id AA03352
(5.65c/IDA-1.4.4 for <[log in to unmask]>); Fri, 1 Nov 1996 21:44:37 -0500
Received: from ipc.org(168.113.24.64) by firewall via smap (V1.3)
id sma003347; Fri Nov 1 21:44:34 1996
Received: from ipc.org by simon.ipc.org via SMTP (940816.SGI.8.6.9/940406.SGI)
id UAA24529; Fri, 1 Nov 1996 20:27:18 -0800
Resent-Date: Fri, 1 Nov 1996 20:27:18 -0800
Received: by ipc.org (Smail3.1.28.1 #2)
id m0vJVGh-0000S7C; Fri, 1 Nov 96 19:53 CST
Resent-Sender: [log in to unmask]
Old-Return-Path: <[log in to unmask]>
Message-Id: <[log in to unmask]>
To: EHolton <[log in to unmask]>
Cc: Technet <[log in to unmask]>
From: Jeffrey Harry/HQ/3Com
<[log in to unmask]>
Date: 1 Nov 96 17:06:22 EDT
Subject: Re: OSP Coating
Mime-Version: 1.0
Content-Type: Text/Plain
Resent-Message-Id: <"KhMhI1.0.kRJ.xbgUo"@ipc>
Resent-From: [log in to unmask]
X-Mailing-List: <[log in to unmask]> archive/latest/7344
X-Loop: [log in to unmask]
Precedence: list
Resent-Sender: [log in to unmask]
***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To unsubscribe from this list at any time, send a message to: *
* [log in to unmask] with <subject: unsubscribe> and no text. *
***************************************************************************
|
