Servo - December 2014

Before moving on to the specific topic of soldering, it is first useful to discuss ESD. ESD — or Electrostatic Discharge — is the sudden discharge of static electricity between two objects. We routinely encounter ESD in our daily lives. It’s that shock you feel when you touch your car door in the dry winter months or when you walk across a carpet and then touch a door knob. This charge can be in excess of 20,000 volts — much more than it takes to destroy most electronic components (Figure 1).

Because of this, preventing an electrical charge from building up is important when working with electronics, since even a small potential can destroy sensitive components.

To avoid building up any excess charge, avoid loose clothing or clothing that dangles down in contact with ESD-sensitive devices, and wear materials made of cotton, rather than wool or synthetic materials. Wearing a properly grounded ESD wrist strap and/or heel straps, and making sure that it is properly grounded is also advised when working with electronics. You can find these items on the Internet at reasonable prices if you’re worried about accidentally damaging components. In general, it is also good practice to minimize handling of ESD-sensitive devices whenever possible, since the more you handle a device, the more opportunities you have to accidentally damage it with an electrical discharge. Okay, let’s move on to soldering. Soldering is the process of joining two metals together by the use of a solder alloy. It is one of the oldest known joining techniques. The successful soldering process produces a reliable solder connection — one that has both a strong physical bond and electrical connection. The solder alloy utilized is a key material used in the soldering process. Solder used in electronics is a metal alloy. A common alloy is the combination of tin and lead in different proportions for lead bearing solders, and tin, silver, and copper for the lead-free solders. When labeling or naming the different types of solder, manufacturers use the chemical symbols for each of the metals. For This series of articles will serve as a step-by-step guide to hand soldering electrical components. This first entry will be focused on the tools and materials you will need, the basics of the soldering process, and some terminology that needs to be defined before more specific topics are covered. If you already have some experience with soldering, this will be mostly review.