They are just normal jumpers, called as “pin jumper” 2.54mm, like this:
(short jumper)
or this (long jumper)
Both are the same and do the same function. But that is for stethic, if you can’t get one just solder one line with the other with a piece of wire and you’re done, but have in mind that it also acts as a switch in case you want to power off without unplug the whole device or removing the board.
About the soldering is just an acquired skill, more you solder, best results you will get. It’s hard to explain here, because its more practical than theorical, so i suggest to watch some videos in youtube about how to soldering tht (through hole components) and smd (surface mount components). That will help you to do it like a profesional.
Other suggestions that i can give you and some videos doesn’t even mention is: safety first, have clear what you are doing, work on a clean area and do not inhale toxic vapour from the soldering, some people likes the smell of flux, but what they are doing is to smell heavy metals.
If you are using the soldering iron, use an apropiate tip, keep it clean by cleaning with an sponge (dont forget wet the sponge, but dont use water in excess, when you compress the sponge it should drop at least one drop).
If you are using a heat gun, first all this is the most difficult soldering method but there are the best results if you know how to using, so i’ll give you some tips:
- This method is not usefull for tht componets, so use a soldering iron in stead. Do not try it, because the results will not be the best on this kind of componets.
- This method is the best for SMD componens, but you need soldering paste (is not flux, soldering paste is a compound of thiny balls of tin element + flux)
- if you cant regulate the temperature, do not try it, because heat guns usually does 450-600°C and for sensible components you could burn them if you expose for long periods, usually no more than 10 seconds (more time you will cook the PCB and components and then burn them).
If you can regulate the temperature, you need to know the datasheet of the soldering paste you’re using, most common the range to melt it is arround 280-320°C, you can hold this temperature for arround 1-2minutes, more time you will cook the PCB and components. The procedure is to pre-heat the board, and then apply heat to the zone you want to melt, use a low flow of air and place the tip of the gun closer to that zone 0.5-1 cm depending.
So… back to the question: What is the best way to solder the LM2596 onto the board?
Many methods but i will give you two ways to do it:
- And i recomend this: Take a header pin (just remove the plastic holder) or a pice of wire and pass it through the LM2596 and the boards holes. Headers must stand out so you can solder each ends on the top and the bottom with an soldering iron.
- If you want to use a heat gun, just put soldering paste on the pads, and apply heat with the airgun on the bottom of the board. You will notice that you melt the paste when you see some bubbles on the sides of the pads and also both boards will stick with each other.
Hope it helps to you and maybe others