This article focuses mainly on the tinning of components on printed circuit boards (PCBs). Circuit board components are those that have terminals (i.e. wires or tabs) that pass through a hole on a board and are then soldered to the surrounding metal plating. The hole may or may not be plated as well.
To tin other types of electrical components, such as cables and others, different steps must be followed, but the general principles are the same.
Steps
Step 1. Choose the right components
Many components look similar, so read the labels carefully or check the meaning of the different colors.
Step 2. If necessary, bend the terminals
Be careful not to damage them.
Step 3. Put the terminals in a vice
To do this you will first have to think about whether or not to shorten the terminals, and this depends on whether or not you want to achieve a heat dissipation effect.
Step 4. Dissolve some of the solder on the tip of the soldering iron
It will serve to improve heat transfer during tin plating.
Step 5. Carefully place the tip of the soldering iron (which will have the newly melted tin on top of it) on the component terminal and on the metal plating surrounding the PCB hole
The tip, or the tin spot, will need to touch both the terminal and the plating at the same time. Avoid touching the non-metallic area of the PCB, as the heat could damage it. At this point, the work area will begin to heat up.
Step 6. Put the tin wire in the area between the terminal and the PCB plating
Do not pass the tin at the tip of the tinner! The terminal and the plating around the hole should be hot enough for the tin to melt. If the pond does not melt on that area, the heat is most likely not enough. Loose tin should "cling" to the plating and terminal due to surface tension. This phenomenon is called wetting.
- With experience you will learn how to heat the joint between the plating and the terminal more efficiently by varying the way the tip of the soldering iron contacts that area.
- The flux of the tin wire is only effective for about 1 second after melting, as the heat tends to burn it away.
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The pond will be able to wet a surface alone self:
- The surface is warm enough and
- There is enough flux to remove the oxide from the surface as well
- The surface is clean and free from grease, dirt, etc.
Solder (Electronics) Step 7 Step 7. The tin should be able on its own to "go around" the point of contact between the terminal and the cladding and fill that area
Avoid adding more pond if you have already provided all the necessary pond at the junction. The amount of tin needed depends on:
- For PCBs that do not have plating inside the hole as well (non-PTH - many home-made PCBs are of this type): tin is sufficient when forming a flat joint.
- For PCBs with plating also inside the photo (PTH - many commercial PCBs are of this type): tin is sufficient when forming a concave junction.
- Too much tin would form a convex, "bulb" junction.
- Too little tin would form a "very concave" junction.
Advice
- Most tiners have an interchangeable tip. The tips of the tiners have a limited life, and there are different shapes and sizes in order to meet different needs.
- Have a blower or other type of vacuum tool to remove the tin, or a spool of desoldering braid (a braid made up of thin copper wires that serves to absorb the molten tin), in case you make a mistake and need to desolder something or to remove excess tin from a joint.
- It is easy to damage a component due to too much heat. Some components (diodes, transistors, etc.) are quite sensitive to damage caused by heat, and must therefore have a heatsink (in the form of an aluminum clip) connected to the terminal on the side of the PCB opposite the one where the tin plating will be carried out. Use a 30-watt soldering iron and practice soldering quickly to avoid overheating the components.
- The tip of a soldering iron tends to get stuck over time (if used frequently, of course), due to the oxides that form between the copper tip and the underlying iron. Plated tips usually do not have these problems. If you don't remove the copper tips from time to time, they will stay stuck to the tinplate forever! At that point it would be thrown away. For this reason, every 20-50 hours of use, when it is cold, remove the tip from your soldering iron and move it a little so that the oxides can escape, before reassembling it. Now your tinker is ready to last for years and years!
Warnings
- Ponds, especially lead-based ones, contend with hazardous materials. Wash your hands after tinning, and keep in mind that tin-containing items may need to be disposed of properly if you decide to discard them.
- The tiners reach very high temperatures. Never touch the tip of the soldering iron. Always use a support to be able to rest the tip of the soldering iron up and away from your work surface.
