1. Placing & Soldering Components
Electronics 1
CVHS

2. What is Soldering? Solid electrical connection
Mechanically connects metal to metal
Electronic soldering
soft soldering
350° F

3. Stuffing the board
Before you begin soldering, place your components in the PCB
Slightly bend the leads to keep each component in place
Start by “stuffing” one type of component (resistors)
Once all of that type is stuffed, solder the components to the PCB

4. Equipment
Needle-nose pliers
Holding
Bending
Desoldering bulb

5. Clean Tip Tip becomes oxidized with heat
Wipe off oxidation with damp sponge before and after soldering

6. Clean Tip
Tin pencil tip
Prevents oxidation

7. Soldering Process
Step 1
Heat lead and pad
2-3 seconds
NO SOLDER

8. Soldering Process Step 2 Apply solder to pad and lead Not to tip
(bad joint)

9. Soldering Process Step 3 Remove solder Heat for 1-2 seconds
Solder flows around lead

10. Soldering Process
Step 4
Let joint cool before touching
“Cold joint”

11. Soldering Process
Step 4

12. Good Solder Joints Shinny smooth surface Filleted
No large globs of solder or charring

13. Bad solder joints Not enough solder Too much solder Too Hot
Poor connection
Component may loosen
Too much solder
May cause a solder bridge
Too Hot
Causes pads to lift from PCB
Charring

14. Bad solder joints Cold Joint Solder dripped on Poor connection
Component moved during cooling
Solder dripped on
Component may loosen

15. Component Soldering Order
Resistors
Capacitors
Diodes (Heat Sensitive)
SCR’s (Heat Sensitive)
Transistors (Heat Sensitive)
Transformers
Neon Lamps
Wired Components

16. Heat-sink -Diodes -LED’s -Transistors -SCR’s
Heat damages semiconductors
-Diodes
-LED’s
-Transistors
-SCR’s

17. Heat-sink Heat-sink clip Alligator clip
Place between joint and component
You must heat-sink each lead separately

18. Safety Solder over workbench Put pencil in stand
Treat pencil as always hot
Always wear Safety Glasses
Solder Contains Lead – Wash Hands

19. Review 1. What are the four steps for successful soldering?
2. List three types of poor solder joints
3. What is the first component you should solder into the PCB?
4. Which components are heat sensitive and need a heat sink?

20. Demonstration