This is an established test, not for reliability, but to determine whether solder mask or conformal coating will vesicate. It has been in use for decades and is well established in literature. For ex., Tautscher mentions it on p. 10-31 of his book (1976) and cites MIL-STD-810 method 507 procedure 1: 2 hours at 115°C ±5°C, 15 psi ±5 psi followed by 1 hour at 125°C ±5°C, 25 psi ±5 psi. He calls it the "autoclave test". In my book (1986), on p. 290, section 26.2, I suggest using a domestic pressure cooker for 2 - 4 hours and examining it with a 10x magnifier for signs of vesication. On p. 138, I explain the mechanism of vesication, with a photo of a circuit on p. 140 (Fig. 13.5) with bad vesication after a pressure-cooker test. So, yes, this test has been around for a long time and is very useful to determine that the adhesion of coatings is good, having been put over poorly cleaned products. I would say that this test is an absolute must when applying conformal coatings over "no-clean" flux residues. That having been said, 72 hours seems somewhat exaggerated, unless you are seeking potential delamination of inner layers. Brian Glynn Shaw wrote: > Customer is taking fully loaded, tested assemblies and cooking them: > > 2 atmospheres, absolute > 121 deg C > 100% humidity > 72 hours > > > Pass-fail criteria: boards must appear cosmetically identical, before and > after cooking. > > They don't... but the circuits aren't falling off the bones and the boards > still function electrically after drying :-) > > Question: is this a valid/known Jedec, IPC, or Telecom test or is customer > using grandma's recipe? End use is cell phones. > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 1.8e > 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 1.8e 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 -----------------------------------------------------