7 Replies Latest reply on Apr 23, 2019 9:31 AM by mahmood.hassan

    which are the best smd welding techniques?


      Good morning everyone, this is my first discussion, so be kind with me


      I'm starting to weld smd for a PCB in a formula student aplication, and the first approach was this:

      wlding example


      This was welded with a basic JBC soldering station and smd tweezers, and with some patience and time the result was functional, but not professional.


      What are your tips?


      Thanks for your time.

        • Re: which are the best smd welding techniques?

          Hi Marti,


          A little more information would be useful- e.g. did you use lead free solder, rosin core solder or paste, iron temperature, flux, etc.  what concerns you most about the results?   Did you have bridging?


          it looks like some of the pads did not get enough solder, some too much.  The best way to solve this problem is with a stencil and paste.  But with practice manual paste application improves or try small diameter (less than 0.5 mm) rosin core solder.


          Some of the joints look more like blobs than concave joints.  This may be due to temperature as well as excess solder.  Make sure joints are heated long enough to flow and wick away excess solder if necessary.


          Soldering SMD manually improves with practice so don’t be discouraged. If the result is functional it is better than some of my attempts.  There are some good videos online but you will notice they all seem to differ somewhat. Try different methods until you find the one that suits you.  Find a video or tutorial that demonstrates good and bad results and you will soon learn to recognize them.


          There are good tips in this recent thread: https://www.element14.com/community/message/274031/l/re-first-attempt-at-smd-soldering#274031


          Finally, you can always use an inexpensive toaster oven which is now my preferred method: IOT Reflow Oven with Arduino MKR WiFi 1010   The IOT aspect is optional.



          7 of 7 people found this helpful
          • Re: which are the best smd welding techniques?

            Hi Marti,


            The first thing to keep in mind is that soldering is a skill that is perfected with repeated attempts.  Nobody starts as an expert.  I have been soldering (on and off) for more than 50 years, but I am still learning.  Equipment is changing, materials are changing and geometries are changing.  You need to find the right equipment and supplies and then use them will the proper techniques.


            Frank has offered some great advice and asked some great questions.  Watch videos, practice your skill and keep trying/learning.  While your first attempts look good, they will improve over time.


            Good luck.


            1 of 1 people found this helpful
            • Re: which are the best smd welding techniques?

              What I get from ur post is you dont have a reflow oven. If that true then no need to worry about smd soldering.


              Using standard soldering wire:

              1- Apply a soldering flux (very important) on solderable SMD part.

              2- Place smd component on it

              3- solder it and DONE;

              Using Solder paste (Better option and step 2 & 3 are interchangeable)

              1- Apply a soldering flux (very important) on solderable SMD part.

              2- Place smd component on it

              3- Apply solder paste on SMD pins

              4- solder it and DONE;


              You can easily find lots of tips and trick on youtube

              • Re: which are the best smd welding techniques?


                Let us try this again and maybe finish the sentence.


                The following article First attempt at SMD soldering  I took formal training in electronics some 38 years ago. SMD was very much in its infancy.


                The author points are well presented in learning to master the SMD art.



                2 of 2 people found this helpful
                • Re: which are the best smd welding techniques?

                  Hi Marti,


                  You've got great tips from everyone, especially the point that the preferred method may vary from person to person depending on tools/materials and what they are comfortable with.

                  I like holding the solder and tweezer in one hand, others like putting solder on a pad first, or using flux paste, and so on.

                  The photo isn't detailed enough, but if it functions as you say, you're 90% there. All prototype boards look untidy to a degree with manual methods, you can optionally scrub it clean with a brush and cleaner or IPA for a one-off project. The resistors at the top look like the flux wasn't sufficient, or the iron temp was too low or the iron was reapplied many times. The blobs where there is too much solder, are sometimes inevitable, because wire solder is nearly always too thick. It doesn't affect function if you're not getting shorts.

                  2 of 2 people found this helpful