1. Placing & Soldering Components Electronics 1 CVHS

2. What is Soldering? 4 Solid electrical connection 4 Mechanically connects metal to metal 4 Electronic soldering –soft soldering –350° F

3. Stuffing the board 4 Before you begin soldering, place your components in the PCB 4 Slightly bend the leads to keep each component in place 4 Start by “stuffing” one type of component (resistors) 4 Once all of that type is stuffed, solder the components to the PCB

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

5. Clean Tip 4 Tip becomes oxidized with heat 4 Wipe off oxidation with damp sponge before and after soldering

6. Clean Tip 4 Tin pencil tip 4 Prevents oxidation

7. Soldering Process 4 Step 1 –Heat lead and pad –2-3 seconds –NO SOLDER

8. Soldering Process 4 Step 2 –Apply solder to pad and lead –Not to tip (bad joint)

9. Soldering Process 4 Step 3 –Remove solder –Heat for 1-2 seconds –Solder flows around lead

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

11. Soldering Process 4 Step 4

12. Good Solder Joints 4 Shinny smooth surface 4 Filleted 4 No large globs of solder or charring

13. Bad solder joints 4 Not enough solder –Poor connection –Component may loosen 4 Too much solder –May cause a solder bridge 4 Too Hot –Causes pads to lift from PCB –Charring

14. Bad solder joints 4 Cold Joint –Poor connection –Component moved during cooling 4 Solder dripped on –Poor connection –Component may loosen

15. Component Soldering Order 4 Resistors 4 Capacitors 4 Diodes (Heat Sensitive) 4 SCR’s (Heat Sensitive) 4 Transistors (Heat Sensitive) 4 Transformers 4 Neon Lamps 4 Wired Components

16. Heat-sink 4 Heat damages semiconductors -Diodes -LED’s -Transistors -SCR’s

17. Heat-sink 4 Heat-sink clip 4 Alligator clip 4 Place between joint and component 4 You must heat-sink each lead separately

18. Safety 4 Solder over workbench 4 Put pencil in stand 4 Treat pencil as always hot 4 Always wear Safety Glasses 4 Solder Contains Lead – Wash Hands

19. Demonstration

20. 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?