Hey folks,
I just thought I'd salvage some parts from a dead mainboard, but I was pretty surpried to see that my 60w soldering iron has no chance of melting that solder!
I managed to get the toroids by snapping their wires, but it would be nice to have some other parts like fan connectors or the battery holder as well.
Any directions for me? Thanks...
AFAIK almost all modern electronics have switched to “environmentally friendly” lead free solder. I had no idea the melting temp was so much higher though. I would have thought a 60 Watter would melt anything on a circuit board.
I was recently looking at irons in the local electronics parts suppliers, Jaycar. The guys unanimously told me to bin the lead free solder provided in the packaged kits, they thoroughly hate it.
They all use “silver” non leaded solder for RoHS compliance. Wikipedia says 5-20 degrees Celsius higher (220+ decrees C), but another pal of mine says that 400 degrees C is when you can get the shiny surface like with lead solder, but that seems a bit high to me. Maybe that’s only the solder iron tip temperature.
Most new soldering materials are lead free solder. as gunner said, their melting point bit higher than leaded solder.
but practically (form my experience) lead free solder require much more heat than leaded solder.
Some pre-heat also require
OK, so I finally managed to get some things off the board! I put a good amount of fresh, lead-based solder on top of the solder joints and applied massive heat.
The battery holder came off very quick, but the fan connectors were kind of tough. At one point, the board was too hot to touch even two inches away from where I heated it.
BTW, I also found out what "ASUS stack cool 2" means: They basically embedded a layer of thermally conductive material (copper?) throughout the ENTIRE board, which may be a big part of the problem I experienced.
Anyway, thanks for the hints guys!
Is there still "good" solder up for sale?
I just checked it, you can still buy lead-based solder. But I think its use is limited to hobby-purpose only.
You can still get it from the hardware store and I think even Radio Shack still sells it.
Radioshack still sells it, I bought a spool of it there recently.
Great, now I'll go find a Radio Shack in Germany. :P
They sell it at conrad 
63/37 is the most common tin/lead solder for electronics and has the lowest melting temp. of any tin/lead solder.
All I have ever seen is 60/40.
I use 63/37, and I agree, lead-free solder is SO hard to remove.
DX also have lead solder
You can find lot of sources from ebay too
Before I can respond, “how old is this motherboard”?
About seven years (AMD Socket 939)
Wikipedia is correct, and yes, 400C is a pretty reasonable tip-temperature for working with lead-free solders.
The most commonly used lead-free solder wets at 217C. Leaded 63/37 about 35 degrees lower than that. A typical lead-free solder profile doesn’t take a PCB past 240C.
PPtk
The copper plane layers in the circuit board are what make component removal so difficult. The copper wicks the heat away from where you’re trying to put it with amazing efficiency.
Here’s what you do… Put the circuit board in your oven at 212F (100C) and let it sit there for about 15 minutes. Some of the REALLY cheap plastic parts might metl, but who cares… They won’t explode into flames, they’ll just turn soft and sag a bit.
Now, take the circuit board out, and (BEING VERY CAREFUL), immediately start removing what you want. You’ll be absolutely amazed how easy things will come off when you only have to introduce a 100C Delta-T rather than a 175C Delta…
Just be darn careful - a 2 pound hunk of metal at 100C is capable of doing an awful lot of damage. Make sure your work surface can tolerate that temperature.
PPtk
wow battery holder & fan connector? never thought of that. Would you provide pics?