Transcript What is solder?

Introduction to Soldering
The Basics
Learning Objectives
• To know how to use a soldering iron to achieve
perfect soldered joints;
• To understand and put into practice all safety rules
when using a soldering iron.
What is soldering?
Soldering is a
method of
joining metals
using heat to
melt a filler
metal with a
lower melting
point.
What is solder?
• Solder is an alloy
• It used to be tin and lead, but lead is
poisonous
• It is now tin and copper (sometimes also
silver or nickel or antimony)
• Melting point 210 – 2300C
• Has a hollow core filled with FLUX - a
chemical cleaning agent
The quick guide to perfect
soldering
•The parts must be clean and grease free.
•Hold the parts securely in a clamp.
•Clean the tip of the iron.
•Heat both parts of the joint equally.
•Apply just enough solder to make the joint.
•Remove and return the iron to the safety stand.
•Do not move the joint until cooled.
THINK SAFE
•Soldering irons work at 350°C. This is
very hot (boiling water is 100°C). The
soldering iron will give you a severe burn if
touched.
•Wear goggles when soldering.
•Never fool around with the soldering iron.
•Store the soldering iron in the stand when
in use.
WORK SAFE
Basics One - Begin
• Plug in and switch on the
soldering iron. It will now
begin to heating up
• Lightly wet the sponge
Basics Two – Stripping the wire
• Use the side cutters
to lightly grip the wire
• Twist the side cutters
and the wire gently in
opposite directions.
Until…
• …you begin to see a
gap in the rubber
insulation and bare
silver wire appears.
• Now use the wire
strippers to remove
the rubber insulation
from the wire.
Basics Three - Twisting
• Twist the bare wire strands together
• The wire will look like this
• Now twist the
wire around one
of the L.E.D light
legs
Basics Four – STOP HOT!!!
• REMEMBER: The
soldering iron is
extremely HOT. It has
been on for the entire
time you have been
preparing to solder. So
make sure you ONLY
handle it by the
HANDLE and not by
the metal areas.
Basics Five – Soldering
• Safely handle the soldering iron.
Place a small amount of solder on
the tip of the soldering iron until it
begins to melt.
This is called tinning and helps the
transfer of heat from the soldering iron
to the components.
• Place the soldering iron against the
wire and leg of the LED light - hold it
there for a few seconds.
•Touch the solder against the heated
area, so that just enough solder runs
onto both. Then remove.
Basics Six - Good and Bad Soldering
Poor soldering
(dry joint)
Correctly soldered
Solder
Components
Poor joints are usually the result of one of the following:
• Not heating the joint for long enough
• Not cleaning the soldering iron and tinning
• Poor soldering iron contact
• Moving the components before the joint has cooled
Twist the LED short wires
together
LED - long wire is positive,
short wire is negative
Put LEDs in wooden mounting blocks
Twist long legs together with the resistor
Resistor
Solder the long leads and resistor together
Cut off the small connector
Solder the red wire to the resistor
Solder the black wire to the short legs
Tips and Tricks
1. Keep the iron tip clean. A clean iron tip means
better heat conduction and a better joint. Use a
wet sponge to clean the tip between joints.
2. Double check joints. It is a good idea to check
all soldered joints before moving on.
3. Use the iron properly. This will ensure that you
are safe.
Plenary
1.
2.
3.
4.
5.
6.
At what temperature does water boil at?
What is the temperature of the soldering iron?
What is an alloy?
3 safety rules when soldering
What two things, other than the solder, must the
soldering iron touch when you are soldering?
What makes a bad soldered joint?