Introduction to Soldering The Soldering Iron American Standard Wire Gage (AWG) Solder The Soldering Process Stripping & Tinning Wire Connecting/Soldering Wire Component Soldering De-Soldering Lab Exercise 3/1/2012 1
The Soldering Iron Handle Heating Element Soldering Tip Power Cord Plug Tip Set Screw 3/1/2012 2
The Soldering Iron Power Plug 120 vac 5-15 receptacle Hold by plug to plug-in or to unplug the Soldering Iron Power Cord Always verify insulation before using Never unplug iron with it. Handle Verify it is not burned or damaged before using iron Heating Element Selected by what size work is being Soldered Rated in Watts i.e. 40 watts, etc. Keep it Clean, especially around the Tip Set Screw. Burned Flux will lock the set screw. Soldering Tip Tip selected for the work. Tips are particular to a model of soldering iron heating element. Different Shapes Chisel Pointed Rounded 3/1/2012 3
Soldering Iron Care Tinning the Tip Each time a new tip is installed or an old tip has been burned, the tip must be properly prepared for soldering. Old Tip Care: An old tip that has not been properly maintained must be reconditioned to solder properly. Sandpaper and/or file off burns and rust. Heat up the tip to operating temperature Dip tip into rosin core flux Immediately apply rosin core solder to the tip and tin it. Use 60/40 Solder for tinning. Allow a generous amount of solder to stay on the tip when not soldering or when turning the iron off and letting it cool down. New Tip Care: Start out by by cleaning the new tip with steel wool lightly and alcohol. Get all oils (from hands) off the new tip. heat the new tip up to the operating temperature. Immediately as it is heating, apply 60/40 Rosin Flux Core Solder to the iron generously to tin the tip. Between Soldering Sessions, retin the tip and leave generous amounts of solder on the tip to keep it sealed from oxygen induced heat corrosion. When shutting off the iron, always have a generous amount of solder on the tip of the iron to protect it from corrosion. 3/1/2012 4
American Standard Wire Gage (AWG) Stranded Wire or Solid Wire (Measurement does not include the insulation) 6/0 =.5800 5/0 =.5165 4/0 =.4600 3/0 =.4096 2/0 =.3648 1/0 =.3249 1 =.2893 2 =.2576 3 =.2294 4 =.2043 5 =.1819 6 =.1620 7 =.1442 8 =.1284 9 =.1144 10 =.1018 11 =.0907 12 =.0808 13 =.0719 14 =.0640 15 =.0570 16 =.0508 17 =.0452 18 =.0403 19 =.0358 20 =.0319 21 =.0284 22 =.0253 23 =.0225 24 =.0201 25 =.0179 26 =.0159 27 =.0141 28 =.0126 29 =.0012 30 =.0100 31 =.0089 32 =.0079 33 =.0070 34 =.0063 35 =.0056 36 =.0050 37 =.0044 38 =.0039 39 =.0035 40 =.0031 41 =.0028 42 =.00249 43 =.00222 44 =.00198 3/1/2012 5
Solder 60/40 Rosin Core Solder 60% Tin, 40% Lead Solder Metal Mixture / Alloy American Standard Wire Gage (AWG) used to size the Solder. Solder has a fixed ratio of Solder to Flux That ratio can be disturbed by distorting the shape of the solder by stretching it or flattening it. Rosin Flux Core 3/1/2012 6
Solder Solder can be purchased with many different properties: Acid Core Solder (Tin/Lead) Used on Plumbing to Solder Copper Pipes together. Never use if in Electronics Wiring or Electronic Circuits. Rosin Core Solder(Tin/Lead) Used in Electronics Many different sizes (diameter)(12 gage, 16 gage, 22 gage etc.) Many different mixtures. Most common mixture is 60/40. Lowest melting point is a 63/37 mixture (Under 400 o F) Silver Solder (Silver Alloy) Used in Electronics Used for high conductivity Higher Melting Temperature than tin/lead mixtures. 3/1/2012 7
The Soldering Process Heat Source The Soldering Iron Butane or Propane Torch 2 Soldering Surfaces Materials Cleaned Materials Tinned Solder Solder Type Selected Solder Cleaned Flux Typically Rosin Flux used with Electronic Circuits and applied to remove oxides from the Soldering Surfaces Application of Heat to the 2 Soldering Surfaces The Iron is placed in contact with both surfaces simultaneously. Application of Solder to the 2 Soldering Surfaces Solder is applied to the heated surfaces at the junction to be soldered together. Solder should flow into the junction when sufficient heat is applied. Time of the Process 2 Seconds for Electronic Connections 3/1/2012 8
Stripping and Tinning the Wire Strip the wire with the correct size wire strippers Do not nick or break the strands Clean the stripped wire with a pencil type eraser Clean the wire with Alcohol Clean a Piece of Solder Do not touch the wire. Hold by the insulation only. Heat the wire with the iron by placing the wire on the tip of the iron. Apply the Solder to the junction of the iron and the wire being tinned. As soon as the Solder melts to form a solder bridge between the soldering iron and the wire, feed solder from the insulation out to tip of the wire in a smooth stroke. The shape of the strands of the wire should be visible yet completely coated with solder. 3/1/2012 9
Stripping & Tinning Wire Solder 3/1/2012 10
Strip, Tin, and Shape Wire ` 1 to 2 Lead Diameters 180 degree wire wrap 3/1/2012 11
Connecting Wire Solder 3/1/2012 12
Component Soldering Clean leads with eraser and then with alcohol get all oil and oxides off leads. 3/1/2012 13
Form leads to fit Circuit Pads in the Board 3/1/2012 14
Solder Component into the Board Solder Surface shines like a diamond. If it is dull, it is a cold solder joint and must be fluxed and reheated. Solder 3/1/2012 15
Soldering Summary Clean & Tinned Tip for your Soldering Iron Clean & Undistorted 60/40 Rosin Core Solder Cleaned (Using an Eraser or Steel Wool and Alcohol) Soldering Surfaces, Terminals, Wires, etc. After Cleaning - Tinning Soldering Surfaces, Terminals, Wires, etc. Sufficient Heat to make the connection in 2 seconds (40 watt, 100 watt iron etc.) Shape Component leads or wires and physically connect to Soldering Surfaces. Flux Soldering area lightly with Rosin Flux (Never Acid Flux). Place fully heated iron on junction of solder connection for the materials to be soldered. Apply Solder first to the junction of the iron and the surfaces to obtain a solder bridge. Apply Solder in a smooth sweep over the entire junction to be soldered. The solder should flow and form smooth and concave solder fillets yet not removing the shape of the soldered surfaces. The Solder and the Soldering Iron should be removed together. The Connection should not require heating longer than 2 seconds. The connection should be cleaned with a Flux Remover after Soldering. The connection should be shine and sparkle like a diamond and reveal shape of parts. To reheat a cold solder joint clean and apply flux then reheat then clean again. In Soldering Remember Cleanliness is next to Godliness for outstanding results. 3/1/2012 16
De-Soldering De-Soldering The process of removing the solder from the soldered connection or solder joint. De-Soldering Methods Solder Wicking with Braided Copper Wire Vacuum Extraction (Using) Spring Loaded, Teflon Tip, Vacuum Extractor Spring Loaded, Heated Hollow Tip, Vacuum Extractor Vacuum Pump Generated Vacuum, Heated Hollow Tip, Vacuum Extractor. 3/1/2012 17
De-Soldering with Braided Copper Wire Braid Place the Braid on Soldered Connection. Place Hot Iron on the Braid. Slide braid across the connection and under the hot iron maintaining contact with both. The braid picks up the solder and removes it from the soldered connection. After removing the solder, break the film loose with needle nose pliers by moving the lead that goes through the pad on the circuit board. Remove the component. 3/1/2012 18
Spring Loaded Vacuum Solder Extraction Press the Spring Loaded Plunger Down and Load the Spring for the Extractor. Place the Iron on the Soldered Connection and heat it up until the solder melts. Place the teflon tip of the extractor against the molten solder and initiate the vacuum by pressing the spring release on the extractor. Load the Spring and vacuum again if necessary. Break the component loose with needle nose pliers and remove the component. 3/1/2012 19
Heated Tip Extraction with Either Spring Loaded Vacuum or Motorized Vacuum Heat up the tip to the solder melting temperature. Place tip over the lead and press it down into the solder on the circuit board pad and over the component lead. Watch the solder and wait until it becomes completely molten. Release the vacuum (Either Spring Loaded or Vacuum Pump Generated) and extract the solder from the circuit board pad and the component. Repeat extraction process for the other component lead and printed circuit board pad. Break the component leads loose from both pads with a wriggling action using Needle Nose Pliers. Remove the component from the printed circuit board. Hollow Metal Tip 3/1/2012 20
Things to Remember Keep everything as clean as possible! Don t over heat the components, wire insulation, or printed circuit board by staying on a connection longer than 3 seconds. You can lift the pads on a printed circuit board by applying heat longer than 3 seconds. When not using your iron keep it coated with solder be generous. Always clean every surface before soldering it! Clean your printed circuit board pads, clean your component leads, clean your wire, clean your solder. Don t distort the shape of your solder it has just the right mixture of flux to solder don t change that mixture by stretching or bending your solder. Wipe off the excess solder on the tip of the iron just before soldering or desoldering. From time to time, shock your iron tip by pressing it into a wet sponge. Wipe off broken free rust/oxides from the tip. Re-tin the tip. Use just enough solder to coat the object don t lose the shape of the soldered object with to much solder. Remember it is not The bigger the glob the better the job It is use only what is necessary to concave fillet & bond. 3/1/2012 21
LAB Exercises Prepare a Soldering Iron for Soldering Exercises. Clean the Tip Tin the Tip Wire Preparation & Wire Splicing Strip 2 wires, Clean both wires, Flux both wires, Tin both wires Form both tinned wires into hooks, hook together, and Solder them together. Use your Weighted Base Vise to hold the wires straight and then Solder them. Component Preparation & Installation in the Circuit Clean the leads on a Resistor and a Capacitor, and the pads on the circuit board. Measure the spacing on the pads where the parts are to be installed. Form the leads on the Resistor and the Capacitor to fit through the Pads. Place the components in the board, tape them down, and trim the leads. Solder the leads to the pads. Be sure you have shining, smooth, concave fillets. Component Extraction Use Wicking wire and remove Solder from all component leads and pads. Use Needle Nose Pliers, wriggle the Component leads free from the pads. Use Needle Nose Pliers to extract the components. 3/1/2012 22