Soldering: Methods, Tips, and Applications Justin T. Rucker GeoResources Institute Mississippi State ERC Mississippi State University

Equipment Soldering Iron Small Needle-Nose Pliers Solder Sucker Soldering Stand and Sponge Wire Strippers Solder Continuity tester Flux Static Safety Equipment Make sure the soldering iron is over 35 Watts, it’s best to have one that has a variable temperature. Make sure that you have a stand with a sponge. More complicated soldering stations have ESD safe Irons that make sure you don’t damage expensive CMOS parts. They even have butane soldering irons now.

Soldering Basics Know where the hot end of the iron is at all times Never leave a soldering iron plugged in Always use a table or workstation Grasp the iron like a pencil Use a pencil and paper to keep track of connections made Practice, Practice, Practice Make sure the soldering iron is over 35 Watts, it’s best to have one that has a variable temperature. Make sure that you have a stand with a sponge. More complicated soldering stations have ESD safe Irons that make sure you don’t damage expensive CMOS parts. They even have butane soldering irons now.

“Tinning” For effective soldering, the tip should be “tinned” To “tin” the tip of your iron: Melt a small bead of solder on the tip Brush of the excess solder onto a wet sponge Always “tin” a new tip immediately “Tin” periodically while soldering

Wires To join two wires together: Strip 1/4th to 1/8th inch insulation “Tin” iron Heat wire and place a small amount of solder on the tip of the wire (x2) Place a small amount of solder onto the tip of the iron and touch the two ends of wire to the iron Remove the iron and hold steady while solder cools If available, use heat shrink tubing

Through-Hole Parts Demonstration

Chips and Sockets To solder DIP sockets to project board: Insert socket so the pins come out on the side with the metal contacts, or pads Secure on the top side with tape Solder ground pin and power pin first; check to make sure DIP socket is flush Place a small dab of solder onto the remaining pins; clip any excess leads Do not melt the DIP socket or the pad

Create Power and Ground Busses Provide easy access Shorten wires Create busses: Use trimmed resistor leads Run near the power and ground side of components

Desoldering Remove soldered components: Solder sucker Desolderer Wicking wire Pliers + soldering iron Same tools are used to remove solder bridges On PCB’s ground pins take more heat to remove because of the ground plane

Using Flux Solder has a rosin core that allows solder to bond with copper. Rosin is a type of flux Flux is used to make a quick, clean solder joint Especially helpful in surface-mount applications

ESD Protection Many CMOS chips are sensitive to Electro-Static Discharge ESD protection devices: Special mats Wrist band ESD resistant soldering irons Investing in these devices will save you time and money

Safety Notes Soldering Irons are VERY hot(500-800) If you burn yourself Immediately rinse with cold water Bandage Do not puncture blisters Seek medical care if burn is 2nd or 3rd degree Again, always be mindful of where the soldering iron is