Electronics Forum | Mon Oct 20 15:24:52 EDT 2008 | davef
During reflow soldering, sometimes via fill with solder leaving the solder connection starved. Questions are: * Specifically, what is the problem you see? * Do the defective pads show that solder has melted in a uniform fashion? * How do the tempera
Electronics Forum | Mon Oct 20 21:57:58 EDT 2008 | jdt13
The problem that I see is the pads not soldered and I can see on the X-Ray the solder on the pad after reflow, and yes the solder has melted in a uniform fashion, I have not measured the diference of temperatures in each pad of the PCB, the size is a
Electronics Forum | Mon Oct 20 07:29:17 EDT 2008 | hussman
I assume you mean soldered and not welded. If the one pad that is having problems has a via hole next to it, it probably has more copper around it. Try running a hotter profile.
Electronics Forum | Sun Oct 19 15:02:10 EDT 2008 | Jdt13
We are having some issues with a RF PCB aprox 1" x 1". The pads are in the bottom of the PCB and it goes on the Top side of the mother board the pads of the RF board are like a BGA (square pads)and we have troubles to make the proper welding in the
Electronics Forum | Thu Feb 18 21:20:13 EST 1999 | Ernie Flamont
During inspection and test we find leads which do not get soldered. Some are because of insufficient paste, but with others everything looks right. This will only happen on 1 to 2 pins, and it is not isolated to a specific type of ic or location on
Electronics Forum | Thu Mar 29 08:52:59 EDT 2007 | realchunks
Hi George, Depending on your product, wave soldering twice is not all that bad. Residues will be higher, but should only be cosmetic unless your product is sensitive to ionic contamination. You can set-up an alternate profile on your wave for 're-
Electronics Forum | Thu Mar 29 08:41:29 EDT 2007 | george
Hello everybody, I had not noticed until yesterday this situation. Whenever the wave operator has a problem with a PCB (i.e. lifted parts, misprayed flux, etc.) they wave solder the PCB again "to fix it". The problem is that PCBs do not look pretty
Electronics Forum | Mon Jun 03 16:21:11 EDT 2013 | stefgaudreau
Hi, I have a design were power supply multi strand wire (AWG18) are soldered directly on the pcb (thru-hole) by wave soldering process. I don't have any ferrule on the wire. I would like to know if the IPC standard allow this for class 3 assembly
Electronics Forum | Thu Sep 29 19:18:24 EDT 2005 | HLy
Hi, I noticed that the solder joints on my BGAs end up with a lot of wrinkles after reflow. See picture at: http://pstr-r02.ygpweb.aol.com/data/pictures/02/01A/17/DD/E3/9E/n8BhepQLFDs6GMSwaRNxPCTWR5NdpUJZ0300.jpg Does anybody have any ideas what cau
Electronics Forum | Fri Oct 07 09:19:54 EDT 2005 | Kris
the direction in which the solders cool in a BGA are also different than the rest of the boards as the joints " hidden" to ambient. Refer to an analogus phenomenon in the cookson application note. http://www.cooksonsemi.com/pdfs/How%20&%20Why%20Bum
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