Electronics Forum | Thu Jul 31 15:41:23 EDT 2003 | davef
Q: Could any of you guys tell me what exactly is this greenish thing ? A: No, but is not copper oxide. Copper oxide is brown, the color of a penny [here in the US] or an untreated copper laminated trace on a board. Many copper salts are greenish in
Electronics Forum | Fri Aug 01 23:43:52 EDT 2003 | Yngwie
Thanks Dave, the residue appeared to be similar to fungus. First, I thought it could come from water soluble flux but, our plant only runs no-clean. So, can I concluded that this greenish "fungus" looking staff is not initiated from high hot air temp
Electronics Forum | Thu Jul 31 11:33:51 EDT 2003 | yngwie
I faced problem over connecter's pin that were hot air soldered. This connector has 168 pins ( similar to the straddle connector ). The process is to apply the flux onto the connector's J-leads, and the hot air pencil were then ran thru' the leads to
Electronics Forum | Sat Aug 02 08:12:05 EDT 2003 | davef
Q: So, can I concluded that this greenish "fungus" looking staff is not initiated from high hot air temperature setting ? A: Your temperature setting could have increased the growth rate of this crunchy looking stuff, but we wouldn't start there to
Electronics Forum | Thu Apr 15 11:15:30 EDT 2004 | patrickbruneel
Pure (red) copper oxide is green, its not a residue its just oxidation. In your case water and heat will accelerate the oxidation process of unplated or unprotected pure copper. The best way to avoid this from happening is use a socket with tin or n
Electronics Forum | Wed Dec 08 04:19:16 EST 1999 | pascal MATHIEU
I am working in electronic automotive industry and today we are facing to a very serious problem : if we want to use a PCBoard with a copper thickness of 90�m + fine pitch circuit (0.65mm, 0.5mm) the supplier(several) of the PCB has some trouble t
Electronics Forum | Mon Nov 07 16:34:55 EST 2005 | CW
If I am putting chip capacitors on a .063 FR4 board, what size package should we stay away from to avoid cracking? If I use 2 mil copper on the outside layers of a PCB, am I limited to what pitch of parts I can use? Specifically, will using 0603
Electronics Forum | Mon Nov 07 11:26:23 EST 2005 | CW
How large of chip capacitor can we use reliably? I��ve heard they tend to crack. I��ve also heard if you pre heat the larger chip caps (1812 and above) before vapor phase reflow, they won��t crack. If I use 2 mil copper for a power supply board, a
Electronics Forum | Mon Nov 14 12:10:05 EST 2005 | davef
Ceramic capacitors larger then EIA size 1812 are known to be very susceptible to thermal shock damage due to their large ceramic mass.
Electronics Forum | Mon Nov 07 16:31:47 EST 2005 | CW
hi Bob, Thanks for the info. I understand your comments, but I am looking for specific guidance, If I am putting chip capacitors on a .063 FR4 board, what size package should we stay away from to avoid cracking? (I realize this is dependent on h
