Whilst I wholeheartedly concur with what Doug stated, I do not agree for the need for Ion Chromatography (IC) testing. *WHAT?!!!! LIGHT THE TORCHES, BURN THE HERETIC....... (he turned me into a newt....I got better...) I must disagree with your disagreement. Iain, if you run a correct SIR test regime on your proper proposed production process, and you have acceptable results, then you can feel comfortable that you will have a reliable end product. If you have failures in this test, then you need IC to find out precisely what is present on the surface that may be causing your problem. Yes you should then use ionic extract testing (SEC/ROSE) to keep an eye on your process conditions - but make no attempt to correlate SIR with SEC/ROSE results. *Graham brings up a valid point that there is more than one tool for assessing cleanliness or quality, but I don't know that SIR would be any better than IC at this point. For both tests, you need someone to help you interpret the numbers. Having the information that your assemblies have 2.7 ppm of chloride doesn't do much good unless you know if that is a good or bad number. Having the information that your process yields a mean SIR level of 283 megohms on a B-24 doesn't mean much unless you can relate to product. The advantage of SIR is that of these two tests, it is better at showing if residues have a propensity for electrochemical failures (leakage, corrosion, metal migration), but you still have to do more extensive correlation studies on actual product to know whether the values from that lab test relate to product life in the field. Then you have to also do a correlation study with ROSE/SEC to see what levels to use as a target and upper control limit. An additional disadvantage of SIR is that it is a long test. Brian Ellis wrote a paper a few years ago that long term SIR testing could be cut down to an 8 hour test, but that is still much longer than a 2 hour IC test. Difficult to do as a process control measure. I have found it easier to correlate IC results with SEC/ROSE than with SIR. *You know, I find it really weird that after being and SIR champion for so long, I argue against it here. I guess the point being that if you are going to use ROSE/SEC as a process monitoring tool, which several companies do successfully, you have to do extensive correlation studies between product life testing (dozens of ways to do it) and any quality control measures you implement. You have to know what your monitoring signal means in order to properly set the target and upper control limits. Most existing ROSE/SEC levels in specifications are both antiquated and bogus. I would suggest that you retain the use of SIR equipment as a process/quality monitor. Taking sample coupons at each stage of the production process and running short tests will (probably) give you the necessary indicators if the process or process materials are changing. *This is possible, but I would say that you need a more focused test coupon than the B-24 and one that is fabricated with your set of materials. Additional cost in doing this, but the data is more relevant. Maybe use the **fanfare** CONCOAT TEST COUPON!!!! (Look, up in the sky, its a bird, its a plane...) To ensure that you have used the correct test protocol, I assume that you took on board the recommendations as published by the EU project partners NPL, Siemens, NMRC and Lares Cozzi. If anyone wants a copy of this work, let me know. *What a clever way to do some academic spamming <grin>. Sayyyyyyy, wasn't that the work where the particpants used **fanfare** THE CONCOAT AUTOSIR? (Notice how I very slyly slip in some gratuitous advertising for my friend across the pond. Ain't I clever?). *Graham refers to a consortia activity going on for the last three years or so looking at continous monitoring SIR vs. various flux and processing conditions. I wasn't aware that this was a published report yet. I have invited Dr. Chris Hunt of NPL in the UK to give a presentation on this work at the SIR task group meeting at the Fall IPC meeting. By the way, running IPC-TM-650 did they test to Appendix D of J-STD001 (or is it now B? Doug??) or did they run to 6.2.3. or 6.2.3.3? What was the coupon they used? What was the pitch/width they used? What was the test voltage used? *I'm sure Graham means methods 2.6.3 (cyclical environment) and 2.6.3.3 (static environment). The SIR protocol that Graham refers to was found in Appendix D of J-STD-001, Revisions A and B. Revision C is now the current version and the protocol is now Appendix B (lost two appendices somewhere). *Graham, in his last two sentences brings up another good point - there are so many possible choices in an SIR test (or IC test for that matter), that you really need a guide in selecting the best factors for any particular situation. And where would you FIND such experts? Why, at the upcoming Fall IPC meeting in Orlando, Florida. (notice the sly advertising for the IPC...) Usually you can get a few of them to guide you along if ya buy the beer (well, at least ONE such expert I know of...). Doug Pauls Rockwell Collins (Well into his third Mountain Dew of the day) --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------