EEVblog Electronics Community Forum

Electronics => Beginners => Topic started by: jgalak on December 07, 2017, 02:50:51 pm

Title: Solder paste recommendations.
Post by: jgalak on December 07, 2017, 02:50:51 pm
I'm going to try my first reflow project, and looking for advice on solder paste.  Small board, just a few parts (QFN20, 0402, and a weird custom one, but larger pitch than those).  Stainless stencil.  Going to use a hot air station since I don't have an oven yet.  Strictly hobby use.

So.  Leaded or lead-free?  I'm not super concerned about lead, since I don't think it's a health hazard in hobbyist levels.  Of course less is better, but for hand soldering I use 63/37 or 60/40, they just work better.  As this is my first attempt, would leaded be easier?

Particular brands?  The stencil manufacturer is offering Kester NXG1 (lead free) or Kester EP256 (leaded), are these any good?  Other specific brands you'd recommend?  Ideally things easily available in the US in very small quantities.
Title: Re: Solder paste recommendations.
Post by: ovnr on December 07, 2017, 03:59:42 pm
Leaded.

Really, most pastes work fine for hobby use. Even something like Chipquik SMD291 (https://www.digikey.com/product-detail/en/chip-quik-inc/SMD291AX/SMD291AX-ND/1160002) works perfectly well.

For smaller pitch stuff, you will want a paste with finer balls. But at that point, the stencil and pad geometry start to actually matter a fair bit too.
Title: Re: Solder paste recommendations.
Post by: bson on December 08, 2017, 10:03:59 am
Leaded, without doubt!
Title: Re: Solder paste recommendations.
Post by: AllTheGearNoIdea on December 09, 2017, 11:14:36 am
I recommend you don’t eat it. 

Leaded and don’t buy to much as it has a relatively short shelf life. I hide it at the back of the fridge behind all the greens that don’t get eaten.  This may extend the shelf life one of my pots it’s year out of date but performs the same. I only use small amount for repair usually end up chucking it away.

Chris
Title: Re: Solder paste recommendations.
Post by: Azu on December 19, 2017, 01:23:29 am
Leaded. Gem to work with compared to lead free.
Title: Re: Solder paste recommendations.
Post by: nanofrog on December 19, 2017, 03:33:13 am
Kester's products work extremely well IME.   :)

Between lead and lead-free, go with the lead based EP256 (https://www.cmlsupply.com/solder-paste/) (35g syringe & 150g jar). If you need/want to buy some yourself, CML Supply (https://www.cmlsupply.com/electronics-materials/) repackages other Kester products as into hobbyist/repair tech friendly sizes.   :-+

They also sell on eBay if you'd prefer the obfuscation that PayPal offers/use funds already available. Just note that international shipments are only available directly from their own website for those not in NA and would like to try it (though I'm not sure how competitive it would be price-wise vs. say Multicore/Loctite  :-//).

For disclosure, the only affiliation I have with CML is as a customer.  ;D