Hi Mike! You are on the right page and your focus is just fine! The only portion of the test sample that you are required to evaluate is the 1 inch portion that is immersed (or "submerged" if that creates a better visual image). The portion of the test coupon above the solder bath should not be evaluated. Most folks will use a test specimen slightly larger than 1 inch square so that their test fixtures can be used without infringing on the area of interest and to avoid potential test coupon edge effects - especially if the test coupon is removed from a circuit board. The 003 specification only has a depth requirement - if your test specimen is wider than an 1 inch then you can also evaluate those regions per the 003 solderability criteria provided you don't exceed the 2"x2" maximum coupon size and ignore any test coupon edge effects. Many folks testing use a test coupon approximately 1.25"x1.25". Hope this helps. And I am curious - were you on the plunge or dip side of the discussion? Dave "Mcmaster, Michael" To: [log in to unmask] <[log in to unmask] cc: OM> Subject: Re: [TN] Solderability Test Interpretation/Guidelines Sent by: TechNet <[log in to unmask]> 01/24/2003 07:18 PM Please respond to "TechNet E-Mail Forum."; Please respond to "Mcmaster, Michael" It's starting to come into focus better but I'm still not 100% certain about the "immersion". Is the whole sample (or at least the portion to be evaluated) submerged to a depth 1" below the level of the solder? If my sample is 2" square, do I lower it so that the bottom is 1" below the surface (what I call "dip") or 3" below the surface ("submerge")? If the latter, is it equally valid to lower the sample so that the top is level with the top of the solder bath, but only evaluate the bottom 1" of the coupon since the top 1" did not meet the requisite 1" below the bath level? Mike McMaster RF Product Engineer Merix Corporation 503-992-4263 ---------- From: Dave Hillman[SMTP:[log in to unmask]] Reply To: TechNet E-Mail Forum.;[log in to unmask] Sent: Friday, January 24, 2003 4:34 PM To: [log in to unmask] Subject: Re: [TN] Solderability Test Interpretation/Guidelines Hi Mike! I believe I can clear this one up for you - see my responses within your original email. If you need additional help/clarification please give me a call and I'll assist. Dave Hillman JSTD-003 Chairman 319-295-1615 [log in to unmask] "Mcmaster, Michael" To: [log in to unmask] <[log in to unmask] cc: OM> Subject: [TN] Solderability Test Interpretation/Guidelines Sent by: TechNet <[log in to unmask]> 01/23/2003 07:47 PM Please respond to "TechNet E-Mail Forum."; Please respond to "Mcmaster, Michael" OK, I have one of those occasions where two parties disagree on the procedure outlined in a specification. In this case it's the Edge Dip Test in J-STD-003 (section 4.2.1). I'd appreciate the input of the experts on Technet on the interpretations outlined below. I'll try to do this so as not to convey among which party I reside. According to spec, the sample to be used is not to exceed 2"x2". After sample preparation, paragraph 4.2.1.4.2 says "...the specimen shall be immersed into the molten solder edgewise to a depth of 1"+/- .08". The dwell time in the molten solder shall be 3.0+/-0.3 sec minimum. Immersion and emersion rates shall be 1+/- 0.08" per second." The disagreement involves the definition of "immerse". My Webster's dictionary says that immerse can mean to dip or plunge. One party (dippers) interprets this procedure as lowering the specimen until 1" of it is in the solder bath, then withdrawing it after 3 seconds and inspecting for acceptability. The other party (plungers) says that the whole sample or at least that part which is to be inspected should be 1" below the surface of the molten solder. *** The JSTD-003 committee always wonders why we get hung-up on wording and your questions highlight exactly why "wordsmithing" is important in specifications. In you case the definition of "immerse" is simplified by the immersion requirements - per paragraph 4.2.1.4.2, the test sample shall be immersed into the solder bath at a rate of 1.0 +/- 0.08 inches per second. You can describe that motion as plunging or dipping as long as the motion meets the rate requirement. Paragraph 4.2.1.4.2 also states that the depth the test specimen needs to attain in the solder bath is 1.0 +/- 0.08 inches. You have both the immersion rate and immersion depth specified - whether the motion is a "plunge" or a "dip" is immaterial to the specification. The test has always been described as a "edge dip" test to differentiate it from the solder flow test. While I have you're attention I'd also appreciate comments on two issues around the timing. First, what does 3.0 +/- 0.3 sec minimum mean? Minimum is a minimum. To me, anything above the minimum is OK, below is not. How do I interpret the tolerance on this? *** Congratulations - you have found an error in the JSTD-003! The "3.0 +/- 0.3 seconds, minimum" should read "3.0 +/- 0.3 seconds". The committee tries to put tolerances on all values to assist in the clarity of the specification. Since a tolerance is present the word "minimum" should not be there. The new JSTD-003A specification revision does not include that error. And when do you start and stop counting the three seconds? If you're a dipper is it when the leading edge enters/exits the solder? Or the trailing edge? If a plunger, is it only once the leading (or trailing edge) reaches the depth of 1"? Depending on the answer, I can see that the trailing edge could be in the solder for as little as 1 second (start and stop when leading edge enter and exit solder) or as long as 5 seconds (start timing when sample reaches 1" depth and stop timing once retraction starts). *** The 3.0 +/- 0.3 seconds dwell time begins once the test sample has reached the minimum specified test depth (1.0 +/- 0.08 inches). And yes, that means the specimen is immersed longer than a total of 3 seconds as the 3 seconds does not include the time spent during the immersion and emersion motion. Your interpretation of "immerse, dwell, emerse" agrees with the specification. The committee also considered that thermal demanding test specimens may require additional dwell time thus the reason for having paragraph 6.4 in the specification. I look forward to your input. Mike McMaster RF Product Engineer Merix Corporation 503-992-4263 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------