Rigo, The way these two test methods are written they could use either. However, when I read them, it "appears" that 2.6.3 is more for bare boards and conformal coatings and 2.6.3.7 is more for "fabrication, process or handling residues" and the body of the text for 2.6.3.7 does mention fluxes in particular. Some differences: 2.6.3 2.6.3.7 Published 2004 2007 Temp 65 40 %RH 85 90 V 100 25V/mm 2.6.3 mentions three classes (1, 2 & 3) - measure before and after for 4 days, 7 days, cycle for 160 hours, respectively. 2.6.3.7 says test at least 72 hours and measure every 20 minutes. Certainly 2.3.6.7 is more detailed. I believe there is a recent paper by a young fellow from Indium where he states that one is better for testing rosin fluxes and the other is better for testing non-rosin fluxes. I have the paper on my desk at work. I am copying my work to try and remember to get you the reference. So why did they pick 2.6.3? My guesses: 1) It is what they are used to. 2) The lack of detail gives them a lot more leeway in how they set up their test. Bev -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Garcia, Rigo (GSFC-300.0)[ARES CORP] Sent: Tuesday, June 26, 2012 3:46 PM To: [log in to unmask] Subject: [TN] SIR Testing - IPC-TM-650 - 2.6.3 vs 2.6.3.7 Hi everybody, I am reviewing a proposal for a new solvent from a supplier. When reviewing their qualification package I noted they tested the IPC-B-52 coupons to the 2.6.3 Test Method "Moisture and Insulation Resistance, Printed Boards" instead of the obvious 2.6.3.7 Test Method "Surface Insulation Resistance". Does anybody have any idea why they would've want to do this? Is 2.6.3.7 more stringent? Thanks for the help! Rigo Garcia Sr. Quality Engineer NASA, Goddard Space Flight Center Workmanship Standards, Code 300 Phone. (301) 286-6129 Fax. (301) 286-6576 ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________