Electric Solder Paste Dispenser Speeds Up Reflow Prep

solder paste dispenser

[Geir Andersen] of Let’s Make Robots has been venturing deeper and deeper into the wonderful world of surface mounted devices, which as you know, can be tricky to solder! Not wanting to shell out a few hundred for a professional solder paste dispenser (and air compressor), [Geir] decided to build his own.

It allows him to use a standard syringe for solder paste, which can easily be refilled using this technique. The professional dispensers use air pressure to control the flow of the paste, but [Geir] decided to go the all-electric route instead. He’s hooked up a small stepper motor to a threaded shaft which can push the plunger up and down the syringe.

Couple that with a few 3D printed parts for the housing, a nicely designed PCB, and bam you have yourself a super handy solder paste dispenser! He’s even included a small potentiometer on the board to change the speed of the motor.  It might not be quite as accurate as a professional one, but as you can see in the video after the break it seems to work great for [Geir’s] purposes.

[Thanks Jan!]

34 thoughts on “Electric Solder Paste Dispenser Speeds Up Reflow Prep

  1. This looks awesome! I’ve never heard of an electric solder paste dispenser before. What are some good expensive ones? I’d like to compare to what’s out there and would love a recommendation before I try to build this one.

    1. zephtronics has one, its expensive but i dont find it that great. the metcal one is pretty good. but honestly i find that the fastest/best way is solder paste and stencil. i have three automatic solder dispensers, never use them

      1. I’m not a big fan of small packages. To each their own I suppose. When I design things I try to bear in mind that I am going to have to put them together too. Knowing that, and knowing me, I tend to stay away from annoying niggling little things because I really don’t like that sort of thing.

        As far as devices not being offered in some outlines goes I would not call being limited in such a fashion particularly wonderful either. Perhaps you like others making decisions for you though? Some do.

      1. So you make an assumption about me, then try to be cheeky about being, informative and insightful? It is ironic that I’ve hand soldered SMT professionally in my past. So no, not too difficult, but like you just tedious.

        1. His answer was a bit provocative and sarcastic, but judging by your statement, “What is so wonderful about the world of surface mounted devices?”, either you are trying to provoke such answers or you are lying about handling SMT professionally.

          You can claim it’s harder or more tedious to work with, but the advantages are very evident.

          Personally, just by being able to fit complex circuits in considerably smaller areas is good enough for me.

    1. Size, price, availability, easy re-work, easier/faster to solder at times (drag solder 20 pins in three seconds instead of doing one pin at a time). Did I mention size?

      1. For me availability of through hole versus SMD is just the opposite. I’ve been collecting electronic components for over 40 years now. I have a trailer in my back yard loaded with vintage electronics that I scavenge parts out of. I went so far as to purchase a five pound solder pot so I could easily harvest through hole components from circuit boards. When I got my second minicomputer to scrap I really had to up my game at that point. Sitting there with a solder sucker just wasn’t cutting it anymore for me.

        I’m a dinosaur today I suppose. Oh well, at my age I ought to be. At least I’m not sitting here listing liabilities as assets like some folks are. Now quit bragging about your diminutive endowment. Some chicks do dig that though.

        1. If you ever want to use microcontrollers, really any uncommon IC, or anything other than simple analog circuits you will realize how uncommon dip packages are. SMD is tricky but opens up a world of possibilities.

          1. I’ve no desire presently to use a microcontroller. In the past whenever I thought I might have had a use for one I’ve always managed to perform the task without such a thing. This stepper drive for instance has a half stepping sequencer made out of digital logic ICs


            Most folks would have used a microcontroller today but if I did I’d have had to get involved with getting one, then programming it. These chips I just had laying around. It is a good idea to prototype some circuits, and I thought it was good idea to prototype this one myself.


            It would be a little tricky to breadboard SMD I imagine. I guess you could solder wires to all of the pads? Perhaps that is the world of possibilities that you referred to?

          2. “It would be a little tricky to breadboard SMD I imagine. I guess you could solder wires to all of the pads?”
            Crazy talk. Breakout boards. And there are proto board for surface mount devices.. solder only, but still…

            Dont make it needlessly complex just to prove your point. Bad eyes? Fine. Shaky hands? fine. Got a huge stock of parts you feel like you have to use up first? Go for it.

            But at this point, through hole parts are pretty much only made for hobbyists. And those are in limited quantity, costly, and the part selection is pretty meager these days. If someone wants to use modern parts, they will have to come to grips with surface mount.

            A lot of kit makers are still trying to find ways to avoid surface mount.. or doing all the SMDs before shipping, leaving only pin headers and connectors for the customer to ‘build’. Enough is enough. SMD is not hard, and does not require any new special tools. A decent iron, good quality solder, a pair of tweezers and a lens to check your work (if your eyes are young, and a desktop light/lens if your eyes are not so young).

          3. @MRE Today I am pretty much only a hobbyist. This is my humble electronics assembly workspace. I do so hope it meets your critical requirements.


            Because it more than adequately fulfills mine. With it I am quite capable of working with SMT, I simply choose not to for a variety of reasons that I personally find to be quite valid. More hoops does not make electronics any more fun for me. I’m not a huge fan of densely packed circuit boards either. At least not when I need to work on them. I need to take an updated picture of my electronics bench because I’ve upgraded the arm magnifier since this one was taken. Oh well, not today. I’ve garden pictures that I need to process.

            Perhaps you’d like to see some of those? I stole the Jolly Green Giants’ thumb and had it surgically attached to my hand. Ho, ho, ho… J/K but seriously my garden is kicking ass this year.

        2. ” I’ve been collecting electronic components for over 40 years now.”

          Let’s assume that you started that at age 10 at the youngest. Now it is possible you started younger (as many have, including myself), and equally possible you started doing that later.. but 10 is a good average age for the super geeks of HAD.

          That would make you about 50 years old. Again.. an average guess.

          “.Now quit bragging about your diminutive endowment. Some chicks do dig that though.”
          Everything in that statement screams “15 year old with his own dick complex”

          I dunno, maybe it is just my immature 37 years of life experience, but something tells me that by 50, you should be acting more like a role model. After all you started the conversation with what seemed like a practical question: Really, what is the deal with SMD? Ok. An excellent, somewhat rhetorical question. Here are the reasons most people can agree on as being the main reasons to get into it. You don’t like it? That’s fine. Most of us still avoid SMD when possible/practical. I know my dad will never touch SMD with a 10 foot pole. Whatever.

          But don’t shit on everyone’s opinion because they bothered to answer your question and didn’t bother to agree with you.

          1. Try 6 and yes I am turning 50 this year. I stopped giving a shit what other people thought when I was a year younger than you are. Life is too short. Die in a fire.

  2. Pretty cool…
    I see two improvements for version 2. One is an LED at the end of the circuit board to light the work surface. The second is the way the board flexes as the button is pressed makes be think about some sort of strain gauge to adjust the speed of the dispensing. Maybe a capacitive touch sensor. the harder you press the faster the dispensing.

    1. An interesting idea.
      I was also thinking the ‘back’ button (at least, I assumed it was a back up button) does not really need to be down at the tip. Could move it somewhere less in the way.
      How about a cap-touch pad array for speed control?

      Id like more detail of the gearbox too. Maybe I missed that?

  3. That’s a nice build. I am fortunate to have access to a laser cutter to create stencils. Nothing beats applying paste to all the pads at once.

    Beside that soldering individual components can be a benefit sometimes, are there other reasons to use a dispenser?

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