Soldering By: Sam Eaton, Dhiman Sengupta, Cindy Wan March 26, 2013 EECS 373 Winter PCB Soldering Example ( Soldering Station Example (

Agenda: Why Solder?!? Safety & Tools How to Solder Resources Questions?? 2

Why Solder?!? Connect components to board Add electrical connections on board Permanent connections Super glue doesn't work Woman soldering ( 3 Taken by Jonathan Kurzer

Safety & Tools 4

Safety First: Remove all jewelry and loose articles Wear safety glasses Tie back long hair Wash hands afterwards 5 Jewelry Sign ( Safety Eggineer (

"Radio Shack Fire Starter": Cheap and simple 15 to 35 watts power watts Uncontrolled temperature 6 Radio Shack Solder Iron (

Soldering Stations: Costly but practical 40 to 200 watts power watts Temperature-controlled 7 Soldering Station (

Hot Air Rework Station: Blows hot air Melt multiple pads Mainly for SMD components 8 Hot Air Rework Station (

Solder: Solder Available Lead-based solder o o non-Lead-based solder Why? o cold joints o whiskering o better bonds 9 Solder Wire ( Whiskering ( Solder Cold Joint (

Magnifier: Large Laboratory Magnifier ( good for checking work afterwards, especially for fine pitch components available in EECS 373 lab 10 Taken by Jonathan Kurzer

Flux: a substance that promotes the fusion of two substances or surfaces. Use: soldering, welding.* the rate of flow of something such as energy, particles, or fluid volume across or onto a given area* a substance added to molten ore that combines with impurities to form slag for extraction* * Flux paste ( 11

How to Solder 12

Preparation: Clean all parts using flux o use a clean cloth to wipe off the metal until thin layer is gone o use a cotton swab to rub of fast evaporating electronic solvent to eliminate oils Set up holding stands Heat up iron 13 Solder Cleaner (

Time to Solder! Through-Hole Components 14 Through-hole Soldering Example (

1) Insert the component into the circuit board 2) Bend excess metal tips to prevent movement 15 Taken by Jonathan Kurzer

16 3) Tin the tip of the iron 4) Apply little solder on the pad 5) Feed solder to fill wanted area 6) Cut any excess metal tips

17

Time to Solder Continued: Surface Mount Soldering 18 Taken by Jonathan Kurzer

shtml 1) Apply Flux to pads 2) Pre-fill a pad with a little solder 3) Tack the component 4) Apply solder to the other side 5) Clean up if needed

Time to Solder Continued: Stencil Soldering 20

1) Clean pads with flux 2) Secure stencil on to PCB 3) Put generous amount of solder paste Taken by Jonathan Kurzer 21

Taken by Jonathan Kurzer 22 4) Spread solder over stencil 5) Lift stencil carefully 6) Populate smaller components first

23 Taken by Jonathan Kurzer 7) Populate the rest of the components 8) Heat on hot plate to 150 Celcius 9) Reflow solder paste using Hot Air

24 Reflow Oven china.com/product/YeDxpKtMJbUH/China-Infrared- IC-Heater-Reflow-Oven-T-962-.html

Make a Mistake??!? Best Advice: Don't. But you will, so... Desoldering vacuum pump Desoldering wick Hot air rework 25 Soldering Wick Example ( Soldering Vacuum Example ( Soldering Wick Example (

Bridging 26 Taken by Jonathan Kurzer

Damage Control 27 Taken by Jonathan Kurzer

More Possible Problems: Overheating chips Burning board 28 Burnt Board (

Clean Up: Clean out desoldering vacuum Put everything away Do not remove safety glasses until all tools unplugged and stored safely Wash hands 29 Clean Up (

Appendix: Additional Tools Pliers Strippers Wire cutters Tweezers Solder wick Vacuum pump 30

Resources: Basic Soldering for Idiots soldering-and-how-do-you-use-solder-tools.html How To Do It: Basic Soldering EPE Basic Desoldering Guide EPE "Basic Soldering Guide" SMD Soldering KitCard-SolderingSMD-ReaderSpreads.pdf Umich MESH lab (CSE(BBB) 1625) 31