leon_heller:
I buy mine from Warton Metals (UK). They make several grades.
Leon
Hi Leon,
Thanks for the info. I could not find what I was looking for.
I am in the USA and the problem with ordering from outside is that it takes longer and the whole time they need to be kept cool. So I need to order it in the US so that I can get it faster while it is still cool. Second, if I get it from outside, then I think I have pay some sort of extra taxes or tariff or whatever you call it.
I can easily get the regular paste. But the paste I have does not go through the holes of the needles I have. It needs to be small. The manufaturer of the dispensing machine told me that I require “fine pitch” soldering paste. Apparently, the fine pitch soldering paste has small size solder balls. Thanks
Google has a bunch of hits oo “solder paste” Several for companies that will sell 12 oz in a syringe. They list needles down to 30 ga which is well less than your requirement. One even has the same picture you posted. Any reason why they aren’t right?
Philba:
Google has a bunch of hits oo “solder paste” Several for companies that will sell 12 oz in a syringe. They list needles down to 30 ga which is well less than your requirement. One even has the same picture you posted. Any reason why they aren’t right?
The company that I bought my dispenser and needles sells those solder paste. But their solder paste did not go through the smaller needles. When I inquired, they said that only “fine pitch” solder paste can go through those smaller needles. They have discontinued their fine pitch solder paste. So I have to get it from somewhere else. They suggested Kester and Alpha but I could not find any vender.
I want “fine pitch” solder (they have smaller particle size and thus go through small diameter needles).
Philba:
ah, what was the finest needle it would go through?
I do not remember exactly but starting from Red (24) to smallers one (25, 26, 27, 30) it did not go through. The larger than the red needle was not a problem. See the link in my previous post. I think the fine pitch solder will do the trick but have not found it yet.
Are you trying put paste individually on close pitch pins? Why not a thin strip across all the pins?
One of my stencils (greatest thing ever!) does that rather than have cutouts for each pad. If you get the right amount, you should have minimal bridging.
I’d agree with the thin bead of solder paste method. I tried putting individual dots of paste on 0.5mm pitch pin pads, but soon gave up, far too time consuming and fiddly to get right. I also found it was very difficult to place a fine pitch part perfectly first time so you end up smudging the paste anyway as you try to get the part properly aligned on its pads.
When making a bead of paste down the pins, I still end up getting a bit too much paste on for 0.5mm TQFP and 0.4mm LQFP, but I’ve never had problems mopping it up with a bit of solder braid. For things like SOIC/SOJ I don’t even get bridging (the solder mask causes the solder to all end up on the pads once it’s all molten).
Thanks for your input. The whole idea was to avoid working with braids and cleaning up the bridges.
Normally, I use 24 guage needle and it dispenses very well. But last time, I needed to work on very fine pitch.
I like to dispense paste individualy on each pad, solder and then forget it. That is I do check my work but almost all the time they are perfect and do not need any cleaning up. I like to do it once and avoid cleaning. I do not like a lot of mess.