CABLE, LEADS, CONNECTS
RESOURCES

SOLDERING:

Soldering Rules

 

Soldering is actually quite simple if you observe a few rules:

 

1. Keep the solder tip clean (hopefully you have purchased a chrome plated tip). "Tin" it by wiping it clean with a wet sponge and then applying a small bit of solder so it just looks shiny. Immediately before you use it, wipe it clean. After use place it in the holder - the solder from the soldering operation should keep the tip tinned.

 

2. It is also imperative that the elements being soldered be relatively clean. (You should be getting the idea by now that cleanliness is a good thing.) Rosin based solder has powerful chemicals that when heated do a pretty good job of cutting through component and pc board oxides. But this takes time and heat. And the longer you are required to heat the junction to dissolve oxides the more the risk that you will physically damage the PC board foil or melt the insulation on the wire. (By the way if you use teflon insulation this latter problem is eliminated.) So to simply minimize these problems, it is recommend that you apply a simple cleaning step with the leads of components. This involves using your mini long nose pliers (should have serrated tips) to scrape off the thin layer of oxide. Place the component lead at the body of the part in the jaws of your mini long nose pliers and with a little force pull the pliers away from the component body (with a little practice this will become second nature). Do this two or three times, to make sure that you cover the entire circumference the lead.

 

3. Place the items being soldered in a relatively stable position such that once competed there is no possibility of jarring or relative movement between the soldered elements

 

4. Now, for eyelet connections using your needle nose pliers make a good mechanical connection. For printed circuit boards, simply bend the leads with a slight radius and inset into the board.

 

5. Hold the component in place so it remains undisturbed. Apply heat to the junction with the bright shiny tip of the iron.

 

6. After a few second the junction temperature will rise and you can then apply solder to the other side of the junction (not the solder iron). It should melt immediately and flow smoothly into the junction. You will note that the solder seems to fuse with the two elements.

 

7. Allow this to cool undisturbed.

 

8. Examine the joint - it should appear clean and shiny - not dull or pitted.

 

On printed circuit boards, and especially neat high density IC components, it is very common to accidentally form a solder bridge. This is when a connection of solder forms between two adjacent pins. Many hours have been dedicated to troubleshooting and many components destroyed as well as a result of this "minor" error. I would suggest that at the end of each component connection you stop to visually inspect each connection. Look for both dry joints and bridges, and don't be shy about using a magnifying glass to examine each connection in detail. This is a valuable investment with a payback in both trouble free start up and long term reliability.

 

OK, that's it. The process is actually much simpler that it sounds. If you are new to this, take the time to practice on some scrap cables, PC boards and terminals until you feel confident.