We have certainly all had our moments with solder paste. Some of us hate it; it’s sticky and gooey, and it gets everywhere. That is, unless you have a solder paste dispenser. The trouble with these is that they typically require the use of an air compressor, which can be cumbersome to haul around in certain situations. If you need a solder paste dispenser that fits conveniently where air compressors won’t, take a look at this small one from [Nuri Engineer] called the solderocket.
This design foregoes the traditional compressor in favor of pressurized carbon dioxide canisters. These are common enough and used for things like rapidly inflating bicycle tires, but for this more delicate procedure the pressurized gas needs to be handled more daintily. A rotary knob is attached to the canister to regulate pressure, and a second knob attached to a microcontroller adjusts the amount of time the air pressure is applied to the solder paste. With this small compact setup, any type of paste can be delivered to a PCB without needing to use messy stencils or needing larger hardware like a compressor.
This could be just the tool that you need if you regularly work with surface-mount components. Of course there are other methods of dispensing solder paste that don’t require any compressed gas of any kind, but as long as something is around that gets the job done, we can’t really argue with either method.
Beautiful industrial design. Love it!
Thanks Mansour!
Thanks Mansour!
Interesting, but seems pretty wasteful, how many “shots” do you get out of a cartridge before it becomes recycling trash?
Also there’s no retraction (normal compressor ones use a venturi to suck it back slightly).
Hi James,
You can get more than 500 shots with 20g Co2 cartridges. There are refillable versions that you can refill when it finished
Hi James,
You can get more than 500 shots with 20g Co2 cartridges. There are refillable versions that you can refill when it finished .
https://twitter.com/robin7331/status/1464272409440227335?s=21
Using stencils throw out more trash
The idea of a using a chamber to control pressure is at least as old as… bagpipes.
Even my refillable bottle for spraying weeds would qualify.
This seems a bit like overkill.
To be fair, if one owns a laser cutter and regular printer paper, then one can cut out solder paste stencils quite quickly and trivially. And regular 80 gram paper is suitably thick for a lot of footprints and sturdy enough to last for a handful of boards.
I have never used a solder paste dispenser and been happy with the results. Stencils are the far superior option.
For those that don’t have a laser cutter, then cutting solder stencils is a rather large reason to get one. Among its numerous other applications.
I use a vinyl cutter, bought a used one off ebay for 30 bucks
Vinyl cutters are also a nice solution for making stencils. Not to mention having their own slew of applications.
If one has easy access to a method of cutting thin sheets of vinyl, plastic or paper, then one can make stencils at home fairly trivially. And get very fast application of a lot of pads without the tediousness of having to dose it all out individually. Placing the components is tedious enough…
Hi Alexander
I am using stencils for my regular productions and I really do not like to touch solder with my hands or with my tools. It is also very hard to clean all the dirt from the stencil itself. Solderocket is always ready and It is clean.
Get some nitrile or vinyl gloves, they work fine for preventing it getting on your hands. (Wash the gloves under water and you can use them again, and again for quite a while.)
In regards to tools, just clean them… IPA and water takes it off in seconds. Even if one dedicates a putty knife to the task one still needs to clean it. (The flux in most solder pastes are really good at eating up metal long term. So clean them.)
Secondly, most solder paste doesn’t really last all that well in room temperature. The flux tends to evaporate away and leave the paste a bit stale. Ie, the solder joints gets progressively worse over time. So the “Solderocket is always ready” is partly stupid… (Unless you leave the syringe in a sealed bag in the fridge. And then you still need to wait for it to heat up before use. Time where you could prepare the stencil.)
Old semi dry paste is honestly not fun to work with, it tends to leave a noticeable amount more solder bridges, tombstones and sometimes open connections that looks fine on first glance.
In the time it takes to dispense paste onto a board one could have just populated the components. Smearing paste with a solder stencil is a lot faster. And cutting the paper stencil takes less than a minute or two if one keeps the appropriate laser settings saved. Not to mention that the stencil always gives the correct amount of paste, giving a more uniform result.
If one however needs to place in some odd component in some odd place surrounded by tall “immovable” components making it unreachable by an iron and regular solder, then yes the paste dispenser comes in handy. But that is a very rare situation.
In the end.
I solder SMD components in 2 ways, stencils or regular solder and an iron. SMDs don’t require solder paste when hand reworking stuff after all.
“I have never used a solder paste dispenser and been happy with the results. Stencils are the far superior option.”
I just shake my head at people who are absolutely certain they know the far superior way to do something when they have never even tried an alternative.
“I have never used a solder paste dispenser and been happy with the results.” literally states that I have used dispensers before for the application, but that I have never been happy with the results.
I consider stencils a better option since they are:
1. Trivial to make for any board that one has the design files for. (If one doesn’t have the design files, a photo and some editing can get one reasonably close.) This is of course if one has a suitable cutting machine for making the stencil.
2. They apply paste to all pads in one go.
3. They have better consistency, leading to fewer solder bridges and other related issues.
I simply value my time and consistent quality.
If one however doesn’t have access to a suitable cutting machine, be it a vinyl cutter or laser, then yes, dispensing is fairly decent for some components.
Ok, I was confused too by the wording haha
I also understood that you never used a solder dispenser and were happy with the results you got from other techniques.
When instead you meant that everytime you used a solder dispenser you weren’t happy with the results.
I just wanted to clarify (in a different way) for people like me for whom English is a second language.
Have a nice day!
I can see that way of interpreting the sentence.
I should likely have been more clear, though it is a fairly common way of expressing things in English and a fair few other languages too, therefor I didn’t think anyone could misinterpret it at the time.
I end up using solder paste dispensers every now and then, some things they do work for. Primarily larger pads.
Though, adding regular solder to the pads and simply using hot air and plenty of flux works fine as well and can be quicker. (It isn’t like Louis Rossmann does that all the time.)
This is brilliant! I am curious exactly how precise this can be if you were to put it on a three axis system to paste up a board.
Thanks Gravis! You can adjust both the pressure and the time to get really precise drops.
Solder dispensers seem to always use compressed air/gas. Doesn’t this make the volume dispensed dependent upon the viscosity of the paste; if pressure and duration are being controlled?
I always thought it would be better to use a screw actuator; that way the paste volume would be a function of the number of turns and nothing else.
That would indeed be a nice implementation.
Solder paste is after all fairly non compressible, though doesn’t stop the syringe itself from bulging a bit, giving back some of that uncertainty.
Though, solder paste tends to be somewhat sticky and hard to properly smear onto boards from a dispenser regardless. Making it somewhat impractical for more fin pitched components.
like this? https://www.thingiverse.com/thing:384680
i wanted to build one, but never did need it that much.
I want one. Take my money!
https://youtu.be/J5Sh9EA8GL0
Here is the video of the device
Interesting project! I don’t make PCBs, but I do have an upcoming project (controlled deposition of cellulose nanocrystal gel) that will need air pressure in a location where supply is difficult. This looks like I’ll be able to leverage ideas from your project to speed up mine. Thanks for sharing!