Electronics Forum | Fri Aug 29 10:18:31 EDT 2008 | rrpowers
We saw this one time when we were trying to develop some lead-free product. It ended up being copper migration. Some of the pads had a brown discoloration and those that did would not wet very well. Your elemental analysis would have shown if ther
Electronics Forum | Thu Aug 28 21:39:47 EDT 2008 | davef
Shelf life numbers don't mean dip. Are the parts solderable per ANSI/J-STD-002, Solderability Tests for Component Leads, Terminations, Lugs, Terminals, and Wires? If yes, go solder the parts. If no, get better parts from your supplier.
Electronics Forum | Tue Sep 02 22:21:26 EDT 2008 | davef
IPC-6012 Table 3-2. States "Fused tin-lead or solder coat - Coverage and Solderable". The lack of any specific dimension criteria doesn't make this any less a requirement. There must be complete coverage of solder on the land, and it must be wettable
Electronics Forum | Wed Sep 03 07:43:13 EDT 2008 | davef
What do you mean by a "few micron thick"? IMC thickness pre-cycling (NEMI Lead-free) * Cu3Sn: 3um [118 uin] * Cu6Sn5: 1um [40 uin]
Electronics Forum | Wed Sep 10 16:53:46 EDT 2008 | realchunks
Actually it's not rare. I use several pastes from various manufacturers that add 2% silver in their leaded pastes. I would bet it's 2% silver.
Electronics Forum | Thu Sep 25 16:50:50 EDT 2008 | glennster
Ditto here, also. This is generally referred to as �cratering,� and is associated with stress on boards from operations such as ICT, installation of compliant pin connectors, and depanelization. It is more common on PCBs designed for Lead-free proc
Electronics Forum | Fri Sep 26 01:15:05 EDT 2008 | scauter
Can anyone take a look on the cross sectional diagram of this reflowed BGA ball? Any idea on what has happened to this? The PCB surface finsihing is OSP with regular lead-free 305/405 solder paste. Thanks SC
Electronics Forum | Mon Sep 29 10:04:40 EDT 2008 | illheader
Has anyone used lead free 99C bar solder/paste? Looking for more information other than what the manufacturers give you. Thanks
Electronics Forum | Mon Sep 29 11:44:39 EDT 2008 | manishc
We r facing less soder problem with qfp,using 4 mil tencil and lead free paste,tried out different combinations of reflow profile,can anybody suggest?
Electronics Forum | Fri Oct 03 17:27:05 EDT 2008 | davef
Steve, you're correct. Placing and dragging 20 pitch is tedious and easily leaves bridges behind the heels of leads that can be difficult see.
