Transcript Soldering - Conestoga Valley Blog Site

Soldering &
The Tinning Process
Electronics 1
CVHS
What is Soldering?
Solid electrical connection
Mechanically connects metal to metal
Electronic soldering
soft soldering
350° F
Wave Soldering Machine
Wave- Intake
Successful Soldering
1. Correct solder and flux
2. Required equipment
3. Clean soldering pencil tip
4. Safety
Solder
Metal alloy of tin and lead
Symbol for tin - Sn
Symbol for lead - Pb
63% tin and 37% lead
Solder – 63Sn/37Pb
No mushy range
Eutectic alloy
Lowest melting solder
alloy
350°F - 600°F
Solder - 60/40
Use 60/40 in electronics because less
expensive
Standard Wire Gauge - SWG
SWG .031
Flux
Helps solder flow
Removes oxidation
Protects copper while solder melts
Flux
Rosin-based is used for electronics
Acid-based is corrosive
DO NOT USE IN ELECTRONICS
Used in stain glass lampshades
Flux
Available as a paste
Available as a liquid
Solder has a rosin flux core
Equipment
Soldering gun
Instant heat - high watts
Too hot
Copper tracks and pads come off board
Damage components
Equipment
Soldering iron (pencil)
Slower warm-up
Lower wattage - 25 watts
Tight spots
Various tips - conical best
Clean Tip
Tip becomes
oxidized with heat
Wipe off oxidation
with damp sponge
Clean Tip
File away heavy oxidation
Clean Tip
Tin pencil tip
Prevents oxidation
What is tinning?
“Tinning” means covering the tracks & pads
on your PCB with solder
PCB tracks & pads are made of copper
When exposed to air & oils on your skin,
copper oxidizes
PCB must be tinned in order to prevent
corrosion & ensure a good electrical
connection
Steps for tinning your PCB
1.Clean all tracks
2.Apply flux to all tracks
3.Heat tracks & add solder
4.Spread & add solder over all tracks
Safety
Solder over workbench
Treat pencil as always hot
Safety glasses must be worn
Solder Contains Lead – Washing hands is
recommended
Safety
Put pencil in stand
Review
1. The best ratio of solder to use in electronics
is:
2. This is because:
3. We use _______-based flux
4. What is the difference between a soldering
gun & pencil?
5. Why do we tin our PCB’s
6. What safety considerations are important to
remember when soldering?
Demonstration