In this tutorial we are going to see how to solder a 16 pins header to a 1602A LCD display.
What we need to solder is:
1) A soldering iron or a soldering station with a very thin tip
2) Tin, for our purpose with a 0.8-1.0mm section
3) Tinning flux
4) Well sharp wire cutters
5) A magnifying glass (a 5x one should be okay)
6) Pin header strip
7) Firm hand and a lot of patience!
Step 1: Cutting the Pin Header
The first step is cutting the pin header, which are
usually sold 40 pins long.
Step 2: Tinning Tip and Pad
Brush the tip by using the tinning flux.
Note that this operation must be done when the iron soldering is powered off!
The tinning flux has duplice purpose: avoiding the oxidation of your iron soldering tip and helping tin to flow easier on the soldering point.
Step 3: Setting Up the Service Temperature
Now we can turn the iron soldering on and wait it heats itself up. We set up a temperature around 400°C. This could be a quite high temperature at the beginning so if you are new on soldering you may prefer to set up a lower one. Setting up lower temperatures allows you to spend more time on soldering without messing anything up . Keep in mind that tin melts at 200-230°C so do not set it up too low.
If you don't have a soldering station, to sold tiny parts as in this case, you should not use a soldering iron more powerful than 30 or 40W. These kind of devices reach their service temperature within 2 or 5 minutes.
When the tinning flux on the tip stops smoking, it's time to move to the next step.
Step 4: Preparing the Iron Soldering Tip
It's time to prepare the soldering iron tip.
The first thing we are going to do is cleaning the tip from dirt and remains of tin of previous soldering. For this operation a small natural sponge is required. Such sponges can be found in the Internet or specialized shops. The sponge must be wet but not drenched. So, do not overdo the water on the sponge!
Another thing that must be avoid is cleaning the tip using metal sponges (like the ones used to do the washing up) or, even worse, sand paper.
Using abrasive stuff will remove the thin layer of zinc metal from the tip. Remember that it's thanks to this zinc metal layer that the tip is able to heat itself up equally.
After the cleaning process, tinning the tip is mandatory if you want to achieve a good result.
Pick the tin up and strew the tip with a thin layer of it. Try to spread the solder equally without exceeding with. If you exceed, clean the tip by using the sponge.
Step 5: Soldering
Finally we are ready to solder!
Basically this method doesn't provide a direct contact between tin and the iron soldering tip.
Heat the display pad by using the iron soldering tip, making the tin melt indirectly. If tin doesn't melt, put it closer to the tip avoiding a direct contact between them.
Note that a part of the tin we previously put on the tip will melt, becoming a part of the material needed to solder.
Keep in mind that at this point it's better to put an insufficient amount of tin than exceeding with.
Better adding tin later than being forced to remove it from the pad! (we are preparing another tutorial on how to de-solder)
Just made the first solder, check if the pin header is perpendicular to the circuit. This is really important if you want your LCD display will fit in a breadboard.
Step 6: Quality Check
How to understand if we did a good job? That's quite simple: using a magnifying glass!
Looking through your magnifying glass, check if you have done a good job making a comparison of your joints with ours, shown in the picture above.
A good joint should cover entirely the pad and look shiny: these ones are basically the two indicators.
So, if you notice a lack of tin, add a small amount of it on pads, in order to cover them completely. And if your soldering doesn't look shiny, partially melt the joints again by using the heated tip.
Finally we have done and you are ready to connect the LCD display to your Arduino.
Thanks for your attention. Any comment and suggestion is welcome!