7.2.1 Soldering Through Hole Components, Point To Point Method

Procedure

1. If needed, form the component and clean the area.
2. Insert the component into the plated hole. If needed, secure in place by bending leads or other mechanical means.
3. If needed, apply liquid flux to the plated holes and pads.
4. Place the soldering iron tip at the pad and component lead junction. Apply a small amount of solder at the junction of the soldering iron tip and lead to make a solder bridge. (See Figure 1)
   Note: The size of the solder is important when soldering small components. If the solder is too large, it is easy to melt too much solder into the joint. If the solder is too small, it can take too long to melt the optimum amount into the joint.
   Caution: Avoid exerting any pressure on the pad.
5. Immediately feed the solder into the joint from the side opposite of the soldering iron tip until the proper fillet is achieved. Remove the solder, then remove the iron. The iron may be swept over the end of the component lead to cover it with solder. (See Figure 2)
   Note: Apply the solder to the side opposite of the soldering iron tip so that the work surfaces and not the iron will melt the solder.
6. On multiple lead components, solder the opposite corners first to stabilize the component. Followed by soldering the remaining leads in a random pattern to reduce excessive heat buildup in one area.
7. Clean the flux residue, if required, and inspect.