Answer below: Bev Christian wrote: > Brian, Ingemar, Greg, George, Dave, Graham and others, > > Brian's first sentence contains a very important word - "carefully". > Most dip tests I have seen are certainly not that. Certainly people are > generally not using a wetting balance as the dipping apparatus! And > Brian's dip test replaces forces measurements with distance > measurements, if I read one of your previous e-mails correctly, Brian. Yes, but under perfectly repeatable conditions (see the description of the apparatus I "invented" nearly 40 years ago, which does automatically ensure repeatability between fluxing and dipping AND a freshly-skimmed bath. > > If there is variation in the time between fluxing and dipping then your > procedure is not tight enough. And wouldn't this also affect a dip and > look test, if it really were critical enough? This is difficult to automate with many WBs, but easy with dipping. > > I wish I had a dictionary and the time to debate the philosophy of > "subjective" vs. "objective", but I will only say I am a little > uncomfortable in how you use those words in this context, Brian. > > I do not understand why you say the test piece from a wetting balance is > useless for archiving. You still have the piece that was being tested. > You can see if the solder wetted. You can see how far the solder front > advanced. You can see if dewetting took place. How is this any > different from a piece that was tested using a dip and look test? I am > confused. Because, in the dip test I described, you can see the reaction of the solder on the test piece for times from 0 to 10 seconds, clearly defined, with no equivocation because of the buoyancy of the insulation. I should perhaps say that my machine was developed when I was studying wetting of PCBs. A WB will give different answers depending on the conductor widths: a dip test won't. > > I agree both serve a purpose. > I would say both do not give a completely correct answer - to avoid the > use of subjective or objective. Let's not get into semantics. > > And, Brian, you make a very important statement at the last I completely > agree with "the dip test is useless for SMDs" - certainly for the small > sized parts we are dealing with. In our company we only have one > through hole component! 0402's are the size of choice for chip > components. Agreed 100% I defy any supplier to tell me that their workers can meet > IPC or MIL Spec parameters for dipping by doing it by hand. I NEVER mentioned hand dipping. And I defy a supplier and a client to get the same results with a globule test on a 0402 component!!!!! (even if they each have identical apparati) Brian Please note new e-mail address [log in to unmask] --------------------------------------------------- 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 -----------------------------------------------------