Hi guys,
I've been playing around with reflowing LEDs, and as some have pointed out, the volume of solder needed is quite small for such an operation.
I'm thinking that paste would be less frustrating to use, but I see a ton of options for sale.
Can the reflow-gurus please chime in to suggest the correct product to purchase?
Thanks !!!
I’d like to know what to buy as well.
I’ve been using straight 63/37 solder, but it’s not as suited to reflow work as solder paste.
Kester makes good solder paste, but they make several types. You could google kester solder paste. I cannot tell you which exact one. I know some of the guru's here will know more.
I’m using Chipquick low temp solder paste I ordered from Amazon.com.
It seems to work and has a low enough melting point that my soldering iron can reflow it.
I squirt out a bit of paste, then use a toothpick to scrape up any excess and make sure the paste is even across the contacts. Then I use a wooden clothespin to hold the star with the soldering iron held underneath.
So let me get this straight. The solder paste applied to the contacts eliminates the need for any solder? Just apply paste to contacts…heat…and reflow?
Some bases (stars) come pre-tinned (already have lead on the contacts). Those you just use paste. I got some stars recently from Mouser that had bare gold coated contacts. I had to a solder to those. I just used a generic rosen-core solder and no paste with good results.
I can’t recommend a paste as I haven’t really liked anything that I have used to date.
Yep! You generally apply paste to the pads on the board and then put the component down the past is sticky enough to hold it in place.
This vide is a very good intro to surface mount soldering: http://www.youtube.com/watch?v=3NN7UGWYmBY
When you move beyond the one-off stage, the paste is either applied by robot (same as the parts) or with a stencil and squeegee. Makes it very fast.
I’ve used the cheap solder paste that DX has for sale and it works pretty well. Hard to apply quickly as it is in a tub not syringe.
I've used this exclusively since I first discovered it on DX:
http://www.manafont.com/product_info.php/lodestar-soldering-paste-50g-p-599
It's much cheaper than buying the tiny syringes locally and works just as well. I've used it to successfully reflow a couple of emitter now so I'm no guru, but it does work. It thickens with age; I typically end up throwing out more than I use when it gets too thick to apply easily. Keep it refrigerated and it should last longer.
That’s what you want. Kester No-Clean (Doesn’t need to be washed) Sn63Pb37 Solder Paste.
This is Solder and Flux paste. You do NOT need to add solder to this. Spread a small amount on each pad, set the emitter in the paste, heat. Done.
PPtk
Thanks, PPTK; ordered.
I've said it a thousand times ... flux flux flux ..same thing as soldering paste ..it will make your life a million times easier .
The only thing you don't want is acid based flux as it's not good for electronics but I bet you could still get away with it depending on if you clean up your work afterwards with alcohol .flux has a tendancy to spit a bit i was wondering if anyone covers their emitters when soldering ..nichias on a 10 mm star have contacts very close to the emitter
I use Burnleys .. old tin .. works fine
http://store.curiousinventor.com/guides/how_to_solder/kind_of_solder/
I have this. https://www.fasttech.com/products/0/10002129/1153800-amt-amtech-professional-soldering-flux-10ml
Will that work on a reflow? No solder needed?
I have this and it works great. I bought it about a year ago and it still works great. Less than $3.5 you can't go wrong. I can't believe it took me until a couple days ago to get around to using it. Works great.
That is only paste flux. It doesn’t contain any solder. You need paste solder to reflow, or solder pads lightly with regular stuff, than add some flux on it and put the led on top of it. Reflow and they’ll become as one.
I use Lodestar paste I got from DX as paste solder. I keep it refrigerated and it lasts longer than a year. I recently added some liquid flux to it and it became a syringe friendly thinner paste instantly. Reflowed two Nichia emitters with this and worked really well.
Just add tiny amounts of solder paste and you’ll get a good enough connection.
I couldnt decide on which flux to buy so I didnt buy any at all. Any hints for me being in Germany? :D
Well, the label does, for one.
So I can assume that this is what is needed for reflowing and stuff like that. Just wanted to be sure that it is what I would want to perform that task?
Probably need to get some flux like boaz recommends so that some of my soldering jobs could become easier.
Flux and solder paste are not the same thing. Solder paste is a mixture of flux and solder.
