5 Replies Latest reply on Oct 24, 2014 7:44 AM by Andy Clark (Workshopshed)

    Essencial tools for SMT

    Andy Clark (Workshopshed)

      I'm planning to make a small batch of 10 boards with 12 components each, including one SOIC chip. I currently have an old Antex 40W soldering iron which has no temperature control. I have successfully soldered up a couple of kits with that but I also managed to melt one of the legs off a TSSOP chip.

       

      I've read some of the other posts and light and magnification are already on my need to have list (for assembly or inspection).

       

      Should I go for a temperature controlled iron or would a reflow approach be a better start?

      I am on quite a tight budget at the moment so is a toaster oven reflow a reasonable solution or is that a false econnomy?

      What else might I need?

        • Re: Essencial tools for SMT
          shabaz

          Hi Andy!

           

          Perhaps it may be a borderline volume between hand-soldering or oven. I've never used a reflow oven : ( (am building one though) but hopefully others have some experience here.

          I'd say get the temp controlled iron : ) since it will always get used. Antex do have a low-cost small handheld temp-controlled 50W one, it is quite basic but lasted me for years doing SMT. Also, ultra-fine solder and a small tip. My favourite is this style in the image below, 1mm dia gets used most often. Smaller tips than 1mm are possible too, for the ultra tiny stuff (or use the drag type soldering or just cover TQFP's with lots of solder, then remove it with desoldering wick.

          iron-tip.png

          However, Antex do not have such a small tip, but the 1.8mm one they had was usable too just about, although with TSSOP you'd have to resort to the desoldering wick method. So ideally if you can spend a bit more, then it would be worth spending it on the iron and get one that does have 1mm and smaller tips.

           

          You'll need the light and magnifier anyway (regardless of oven or iron) for inspection, so that is useful too. To save cost, inspect the magnifier in a store if possible - some I've bought have not been great, and the one I regularly use is a cheap handheld one with built-in LED for about $6 (a microscope is nice but not essential).

           

          Also a brush (anti-static) and cleaner to scrub the board.

           

          So, to summarize, perhaps £80 of cost with an Antex iron, or a bit more for another model.

          • Re: Essencial tools for SMT

            Normal electronics tools will work (as long as you have some tweezers.) Also, when your desoldering try not to suck up the component your desoldering.

             

            img1.jpg

            • Re: Essencial tools for SMT
              michaelwylie

              Andy Clark wrote:

               

              I'm planning to make a small batch of 10 boards with 12 components each, including one SOIC chip. I currently have an old Antex 40W soldering iron which has no temperature control. I have successfully soldered up a couple of kits with that but I also managed to melt one of the legs off a TSSOP chip.

               

              I've read some of the other posts and light and magnification are already on my need to have list (for assembly or inspection).

               

              Should I go for a temperature controlled iron or would a reflow approach be a better start?

              I am on quite a tight budget at the moment so is a toaster oven reflow a reasonable solution or is that a false econnomy?

              What else might I need?

               

              120 components total, I would use a hot air gun (very low air speed) and solder paste. If you don't have a hot air station, then you could probably hand solder it all in less than an hour once you got going. A SOIC has pretty sparse leads compared to other devices, the 40 Watt iron will suffice. I had a 30 Watt that could do soldering of SMT. Melted the leg on a TSSOP? Do you mean the leg moved sideways while you were soldering? If that's the case, you are pushing on the device when soldering. Try not to do that, you just have to make contact between the leg and pad. Also, I agree you will need some tweezers.

              • Re: Essencial tools for SMT
                Andy Clark (Workshopshed)

                Thanks again for all your suggestions, I'm going to try hand soldering for the first board. I've got my SOIC chips for $0.25 each so I can afford to melt some.

                I'll keep you posted of results and what kit I ended up using.