Tab Electronics Guide to Understanding Electricity ... - Sciences Club

98 Chapter Three
Soldering Overview
Soldering is a process by which conductive materials are electrically and
mechanically bonded together with a tin-lead alloy by the application of
heat. For the bonding process to occur properly, the solder and the materials
being soldered must be of sufficient temperature. The materials
being soldered must also be clean and free of corrosion, oil, and dirt.
During the actual soldering process, the soldering iron is used to heat
the material to be soldered (such as a component lead, bare wire, or the
copper “artwork” on a printed circuit board) until it reaches a temperature
above the melting point of the solder. Rosin-core solder is then placed on
the material to be soldered and allowed to melt. As it melts, it will flow
outward (called wetting) toward the soldering iron tip. When sufficient
solder has flowed for a good electrical and mechanical bond, the soldering
iron tip and the unused solder are removed simultaneously. The
newly formed solder connection is given time to cool and solidify. After
cooling, it should appear bright, shiny, and smooth. A rough or grainylooking
joint (a cold joint) is questionable, and should be redone.
Soldering for the First Time
If you have never tried soldering, I’m sure you probably think it is more
difficult than it is. My experience in working with beginning students
has taught me that if I just give them a few pointers and leave them
alone, they will quickly get the hang of it.
Safety note: Wear safety glasses or goggles to protect your eyes when
soldering. Also, work in a well-ventilated area, and don’t inhale the
smoke.
To begin, you will need something to practice on. I recommend a
scrap of printed circuit board. Printed circuit boards (commonly called PC
boards) are thin sheets of phenolic or fiberglass material with electronic
components mounted on them. The electronic components interconnect
on the board by means of copper foil “artwork,” called traces, glued
to the PC board. These are easy to come by. Virtually any kind of junk
electronic equipment will contain at least one PC board. If it is difficult
to obtain a scrap PC board, you can purchase a general-purpose “grid
board” from your local electronics supply store, together with a bag of
miscellaneous electronic components. Buy the cheapest you can find;