Solder Paste - 40g (Lead Free)

Solder Paste Stenciling is the easiest and quickest way to solder some of the trickier SMD components. Here at SparkFun, we use solder paste stenciling on pretty much all of our boards. It saves us a lot of time. But stenciling takes more than just a stencil and a dream... you're going to need some paste.

We wanted 50g of unleaded solder paste, as the perfect amount to keep around for prototyping and hobby projects. Unfortunately, though these small tubs are labelled as 50g, they actually weigh in at closer to 40g, so only almost the perfect amount.

The composition of this paste is Sn:90%, Ag:3%, Cu:7%

Check out the Solder Paste Stenciling tutorial (and the video below), if you haven't already.

Note: These tubs are labeled as 50g but lately we've measured closer to 30g of solder paste in each container.

Solder Paste - 40g (Lead Free) Product Help and Resources

Core Skill: Soldering

This skill defines how difficult the soldering is on a particular product. It might be a couple simple solder joints, or require special reflow tools.

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Skill Level: Experienced - You might be required to do some reflow or basic rework with SMD components. A heat gun, Heaterizer or other tools might be required, and a good understanding of SMD soldering as well as PTH soldering are required.
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Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

  • FelixR / about 11 years ago / 3

    Here's my review of this paste:

  • Jeff_M / about 11 years ago / 2

    Bought some of this paste and it's absolutely horrible. I'm having the same issue as others where the solder doesn't pull together as it should, doesn't reflow properly, and generally looks like crap.

  • machadolab / about 10 years ago / 1

    Got the paste earlier this week and did some reflowing today. It is indeed horrible. The top layer of the paste when I first opened the jar was this thick rubbery layer, like the paste is quite old!

    My results were very similar to FelixR's, having little splatters all over between pads!

  • Member #399726 / about 10 years ago / 1

    Is this product "no clean"?

  • Member #344403 / about 10 years ago / 1

    Chip Quik sells a tin+bismuth paste with a very low m.p. See CN Lohr's you tube vids about this. With this stuff, he solders his boards over a 250W halogen work lamp, or uses a hot-air gun.

  • Rocky3 / about 11 years ago / 1

    Hello, I have recently bought this solder paste and I haven't been having much sucess with it. I use hot air for heating, the paste starts melting while forming micro sized spheres around the pad perimeter that eventually break away from the pad and start floating around. Here is a snap shot of the metled solder paste :

    • Jake0313 / about 11 years ago / 1

      Have you tried cleaning the pads with flux (flux pen) before applying the solder paste.

    • Jose Luis2 / about 11 years ago / 1

      I have the same issue with this paste.

  • Qtechknow / about 11 years ago / 1

    Do you know the melting point of this solder paste? I'm trying to make a toaster reflow oven using this soldering paste.

    Thanks, Quin

    • MikeGrusin / about 11 years ago / 2

      Hey Quin! Good question; I spent some time (as I'm sure you did) looking for a reference and didn't find one; a very close formula has a melting point of 231C so I'd start with that and do some tests on either side (we do this at SFE as well). Let us know how it goes, and great job at Maker Faire!

    • Kamiquasi / about 11 years ago / 1

      Might be one for techsupport@ - the datasheet doesn't mention, other vendors don't mention, and the composition is different enough that I wouldn't want to make an assumption based on other Tin/Silver or Tin/Copper compositions (if forced to: between 217°C and 230°C). If you have this paste (looks like it's out of stock right now), you can always try and find the ideal temperature / profile for your workflow directly.

  • Member #344403 / about 11 years ago / 1

    30g is just 2g over an oz. Maybe someone got confused about the quantities.

  • Member #143483 / about 11 years ago / 1

    What's the best way to apply this if you don't have a stencil?

  • JerZ / about 11 years ago * / 1

    "The label says 50g, but they actually weigh closer to 40g. NOTE: But lately we've measured closer to 30g in each container." WTF?

    It's nice these are back in stock, but how much is in it when I open the box?

    • Lion XL / about 11 years ago / 1

      Sounds to me like the manufacturer needs to do better QUA control on their products, but that has nothing to of with SF. They have no way of knowing EXACTLY how much is each, but at least they are telling us, and they also compensated for the difference (look at the other product listing for the price!). Other shops probably wouldn't have bothered....

      take breath...release...wusaaaa..

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