Electronics Forum | Mon Oct 27 20:01:00 EDT 2014 | rangarajd
Hello, We are facing solderability issues on a particular lot of board. THe Nickel thickness measured with an XRF is around 400 U inches. Spec calls out for 130 u inches Nickel and 3 - 5 U inches gold over it. Assuming there is no porosity on the g
Electronics Forum | Thu Oct 30 21:55:13 EDT 2014 | davef
Why soldering issues? I'd guess the nickel is corroded. It is very difficult to solder to oxidized nickel. Your SAC305 would get kicked all the way down the conveyor by nickel oxide. A lack of Ni-Sn-IMC formation will confirm this dewetting . What's
Electronics Forum | Thu Oct 30 18:10:19 EDT 2014 | hegemon
Rather than asking why, maybe the better response is to reject the PWBs and have them re-fabricated correctly? Of course circular reasoning tells me that the reason for your issues is that you have 3x the amount of nickel beneath the gold. I wish I
Electronics Forum | Fri Jun 07 05:19:23 EDT 2019 | gregoryyork
dont usually see this unless the Rosin hasnt been hardened due to low reflow or excessive pressure on blades squeezing flux out so you have flux rich areas. Are these boards also flow soldered?
Electronics Forum | Wed Apr 03 19:02:16 EDT 2019 | SMTA-Vikram
We still use Via as test points. so we need to paste Via. Pasting will make better contact with probes compare to test via without solder.
Electronics Forum | Fri Mar 29 07:53:12 EDT 2019 | davef
Why are you printing paste on test via? In the old days, we probed soldered pads to cushion impact force of probing. Is that still a reasonable practice?
Electronics Forum | Thu Jul 15 18:07:04 EDT 2004 | dwanzek
This has been a tough one to date. Any ideas will help. Problem definition � random QFP144 part not soldering all leads. Percentage fallout is about 1-5% of boards. Usually leads, one or more, on trailing side to the direction of travel does not wet
Electronics Forum | Tue Dec 07 16:34:54 EST 1999 | Russ
Wolfgang, I appreciate your continued feedback! The main reason that I shortened the Time Above Liquidous (TAL) was it appeared that I was burning off all of the flux from the paste. By shortening the TAL to 45 seconds and decreasing peak temp to
Electronics Forum | Wed Sep 17 13:00:25 EDT 2008 | mw_fl
For the most part there would not be a lot of change over. There are two primary boards at this time that would be run on the line that also use common components. At this point all but a couple of the pick and place machines we have looked at have t
Electronics Forum | Sat Dec 18 08:23:33 EST 2010 | remullis
I experienced warpage on a 7'x 13" long board, unfortunately my oven does not have center support. I use stiffeners on both of the short ends. It fixed my problem. Some of the things I was experiencing with the warpage on the second pass were placem
winsouce.jpg)
.gif)
