 
| Received: |
by ipc.org (Smail3.1.28.1 #2)
id m0t7OR8-0000GqC; Mon, 23 Oct 95 10:05 CDT |
| Old-Return-Path: |
<miso!aol.com!SIRGuru> |
| Date: |
Mon, 23 Oct 1995 10:48:12 -0400 |
| Precedence: |
list |
| Resent-From: |
|
| Message-ID: |
|
| X-Status: |
|
| Status: |
O |
| X-Mailing-List: |
|
| From [log in to unmask] Sat Apr 27 15: |
11:10 1996 |
| TO: |
|
| Return-Path: |
|
| Resent-Message-ID: |
<"wNPa9.0.9T6.dywYm"@ipc> |
| Subject: |
|
| From: |
|
| Resent-Sender: |
|
| X-Loop: |
|
| cc: |
|
| Parts/Attachments: |
|
|
Mr. Reynolds,
You neglect to provide some critical information: What flux chemistry are
you using? OA, WSF, RA? The validity of Omegameter testing is closely tied
to flux chemistry.
A few days ago, Tim Crawford, EMPF, gave a good overview of the uses of ionic
cleanliness testers (e.g. Omegameter) and some of the associated problems.
Tim was the primary author of EMPF report RR0013 "An In-Depth Look At Ionic
Cleanliness Testing". I highly recommend reading that report when you look
for the answers you pose.
The report summarizes that the instruments should only be used for their
designed purpose, as a process monitoring tool. Not as an analytical
instrument.
It is critical that you understand the information that the Omegameter (or
similar) is telling you. For this reason, our lab recommends that all such
cleanliness monitoring be baselined, with a more analytical and sensitive
method for measuring ionic cleanliness. We use ion chromatography per
IPC-TM-650, method 2.3.28. IC will tell you specifically what ions you have
present. You can then tell what an Omegameter reading of 4.0 means for your
technology.
This is a very complex issue and cannot be adequately covered in such a
forum. If you, or anyone on technet, have questions regarding bulk ionic
cleanliness testing vs. ion chromatography, please call myself (Doug Pauls)
or Terry Munson at 317-457-8095.
Doug Pauls
Contamination Studies Laboratories.
|
|
|
