Electronics Forum | Tue Mar 18 17:23:40 EDT 2008 | dkntb
Any member in here has experienced of copper migration from BGA's substrate to PWB during eutectic soldering reflow process, which resulted in brittle solder joints??? We have one customer notified us that our PBGA with DSOP substrate having copper m
Electronics Forum | Mon Nov 07 12:25:32 EST 2005 | Rob
Hi CW, Larger chip caps can be susceptable to cracking, but mainly this is due to handling - flexing of boards is the main culprit (the part being mechanically joined at both ends to the board). PCB's usually flex easiest along one axis, and larger
Electronics Forum | Mon Apr 13 09:27:28 EDT 2009 | hxr6038
We had an issue with the finish, PCB manufacturer is telling that they had a problem with the Nickel rework, which resulted in 20% fall out. Please help me by providing the ENIG thickness for Flex boards, is it same as rigid boards as per IPC 4552. I
Electronics Forum | Thu May 29 14:27:04 EDT 2003 | larryk
This flex is .001" Kapton polyimide. The flex portion of this rigid flex consists of 3 layers of 1 oz copper with 5 layers of Kapton. Part of the flex is sandwiched in standard FR4 with two layer of copper on each side for a finished thickness of .
Electronics Forum | Thu May 02 07:11:10 EDT 2002 | davef
They probably the same. Most likely someone is saying immersion gold [immersion Au] as a short hand for ENIG [ Electroless Nickel - Immersion Gold]. It is very uncommon to plate gold directly on copper, because gold and copper form a brittle interm
Electronics Forum | Mon Apr 13 23:02:52 EDT 2009 | davef
Use IPC-4552 for your ENIG thickness. Typically, ENIG has nickel deposit with medium [7-9 percent by weight] phosphorus content. That's what fabs do on rigid boards. On a flex with medium-P and IPC-4552 specified ENIG, you could see brittleness and
Electronics Forum | Thu Mar 16 04:35:49 EST 2006 | vicknesh28
Paste is eutectic and it's copper based parts. Just another observation, i notice that the "flux" between the bottom foot and solidified paste is still in gluey state. Observation on good reflowed leads showed brittle type of flux residue. Can anyone
Electronics Forum | Mon Jun 25 09:59:41 EDT 2007 | slthomas
Plastic of any kind for compressed air is a code violation here. It's not just the pressure, it's the durability. PVC is pretty brittle and if you smack it with a pallet jack it's a lot more likely to shatter and generate high speed shrapnel than cop
Electronics Forum | Tue Feb 01 12:00:01 EST 2000 | K. Ckak
Hi Folks, I am looking for some info. and possibly a source on measuring inprocess copper plating thickness for Flex PCB manufacturing facilities. I have tried XRF, E-Current method but the supplier told us that it wont work with Flex material - th
Electronics Forum | Mon Mar 10 20:14:20 EDT 2008 | davef
We'd be unhappy with features that are not in copper that is at the same level as the component pads, because of difficulties the fabricator would have in maintaining registration between the copper pads and the ink used for the features not in coppe
