Hi George! Yep, you summarized the flux change right on the money, in fact, here is an equation for what you said: "...allow a known about of activators, which would tend for the sample under test to show a little better solderability than if just water white rosin was used = consistency and repeatability"! The use of water white rosin served the industry well for many years but as we changed to new component and printed circuit board surface finishes, the WW rosin had too large of a safety factor and would sometimes results in "false negative" solderability tests. The new test flux formulation is better matched to the material sets the industry is now using. Graham will have to let us know if it was a soldering process variable or solderability test inconsistency that is causing the problem. A wetting balance test would provide a dynamic wetting measurement that could be helpful too. Dave "Wenger, George M." <[log in to unmask]> 02/09/2009 08:15 AM To "TechNet E-Mail Forum" <[log in to unmask]>, <[log in to unmask]> cc Subject RE: [TN] Part solderability Dave, Sorry but I just couldn't resist the opportunity to throw out my 2 cents. "Nothing tests soldering better than soldering". It is my general understanding that the change to the flux in Revision B was to allow a known about of activators, which would tend for the sample under test to show a little better solderability than if just water white rosin was used. If Graham's component supplier indicates the components pass 002 using the old flux they should certainly pass using the Rev. B flux but since he's having soldering problems there is either something wrong with his soldering process or there really is a solderability problem that 002 isn't detecting. My guess is the later and Graham is finding out that Nothing tests soldering better than soldering". Regards, George George M. Wenger Andrew Wireless Solutions Senior Principal FMA/Reliability Engineer 40 Technology Drive, Warren, NJ 07059 (908) 546-4531 (Office) (732) 309-8964 (cell) [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman Sent: Monday, February 09, 2009 8:47 AM To: [log in to unmask] Subject: Re: [TN] Part solderability Hi Graham - yep, that's what I suspected. If they are following the IPC/EIA JSTD-002C, they should be using a flux in accordance with paragraph 3.2.2. which is a rosin type flux but has a very specific recipe. The 002C committee changed the flux at Revision B and some folks haven't noticed the change yet (hummm, if you are running a solderability test, shouldn't you read the method!). The 002 committee made the flux change based on an industry round robin test and the new flux formulation provides better testing consistency and reproducibility. There's nothing wrong with your soldering iron/RMA flux test - it would defined as a soldering-ability test. The objective of the JSTD-002C test protocols is to provide a common baseline measure of the solderability of a component finish and your soldering iron test is the same measurement but includes specific attributes reflective of your soldering process. In 002C Appendix E, there is a listing of the test flux products that were submitted to the 002 committee - see if the flux being used is on that list. Dave [log in to unmask] 02/09/2009 05:39 AM To "TechNet E-Mail Forum" <[log in to unmask]>, <[log in to unmask]> cc Subject RE: [TN] Part solderability Hi David When I talked with them on Friday they told me they were using a rosin flux and following J-STD-002. I didn't ask brand. The one thing I asked them to do is to put a soldering iron on a few leads (one at a time) and reflow the dip coating. We have found that we can dip tin these parts here with RMA flux, and have them look great, but when we try to install them in CCAs it's a disaster. We found that applying a soldering iron on the lead we would find the solder would dewet. (Not sure dewet is the right term, but hopefully you see what I mean) I'm sure my test is not J-STD-002 compliant, but it works for me... regards, - Graham -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman Sent: Friday, February 06, 2009 8:03 PM To: [log in to unmask] Subject: Re: [TN] Part solderability Hi Graham - Please find out what flux (i.e. product name: Kester XXX or Alpha YYY or Indium ZZZ, etc.) the component fabricator used in his test. Also find out which solderability specification did they use (IPC-JSTD-002C or MIL-STD-XXX) and which solderability test method did they use (Method A or B or...). If you can get those facts, I can tell you if they followed the specification requirements. My guess is that they used an incorrect flux. Dave Hillman JSTD-002 specification Chairman [log in to unmask] Graham Collins <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 02/06/2009 08:12 AM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to [log in to unmask] To [log in to unmask] cc Subject [TN] Part solderability Hi guys. A while back I rejected a bunch of parts due to non wetting when we went to solder them. The manufacturer has come back with a response to our guys, saying that they did a steam aging test on them and they passed fine. He wants to discuss it with us. Obviously this is not good - they pass his test but I can't solder the things. Which makes me suspect his test... but makes him suspect my process. I don't know enough about steam aging tests to discuss this well. Obviously I need to ask what kind of flux he is using, but anything else? Our process is SnPb, we use RMA flux, and the wave soldering machine runs at 500F for the pot. This is on an assembly that we have happily built for about 7 years, with the same manufacturer of part, and no process changes that I can identify as significant. The part is what I would call marginally solderable, if we hand solder it and put a fair bit of heat to the lead we can get it to solder, but not well or easily. No previous soldering issues with the part. regards, Graham Collins Halifax Production Engineering L-3 communications Electronic Systems (902) 873-2000 ext. 6215 --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ------------------------------------------------------------------------------------------------ This message is for the designated recipient only and may contain privileged, proprietary, or otherwise private information. 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