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About two months back I was browsing digikey and I came across this strage solder paste
- strange beacuse it says low temp. I looked down below and it is in fact RoHS! It's actually
got tin and bismuth of all things. And, it's pretty cheap, so I figured I would go buy
some and with a data sheet like this "New Product" "This thing is liquidous" well, where
could I go wrong? So I bought some, it comes in these nice little 5ml syringes. It comes
with a syringe head, which I tried, it didn't really pan out for me. So I am gonna go and
use the old technique of good old trusty toothpic and board and I'm going to show you just how
awesome this stuff is.
Ordinarily, when dealing with solder paste you have to have fairly tight temperature
controls to make the solder paste melt and not cause damage to your parts. Especially
temperature sensitive parts. Not true with this stuff! Generally, as long you get it
just hot enough to melt, you're probably not going to toast your board. At home, I use
a toaster oven, and watch it and wait for it to melt, and with this stuff I have yet
to toast any parts. I don't have a PID controller or anything. Unforuantely, right now I am
at Unit-E studios and I don't get that luxury. So, I found in the back of my truck this 250
watt halogen light from harbor freight, and I put a little piece of sheet metal on top.
This is going to be my reflow station for today. And because this is going to be some
very bright light, uuh... Definately borrow some sunglasses even if you have to borrow
them from some dude's girlfriend.
I'm just going to take this board and place it on this light and try not to knock the
parts around too much, and I'm turning down the exposure so you can see what's going on.
Let's just give it a moment and it's going to slow melt the solder paste.
[ratchet sound in background]
It's been a very small amout of time and it's already melted basically the entire board.
Just wanted to show you guys how easy it is to fix solder bridges. So I am just going
to do it with this - one handed, looking through the camera - just pull it out - blamo - solder
bridge is gone. Wasn't that easy?
And now, we play the game "does it program?"
Maybe I have the programming header in backwards?
Okay let's try that.
Indeed! It does program!
And now, the light is just barely on, it means everything is A-Okay!