Soldering Basics 2 Overview Introduction Definition Equipment Procedure Preparation Execution Finishing Specific Techniques Desoldering Tinning Conclusion References 3 Introduction 3 Definition Unite two base metal items Add filler metal ( solder ) Typ. < 842°F (450°C) melting point Metal flows via capillary action Metal bonds via wetting action Metallurgical joint exhibits Fair mechanical strength Excellent electrical conductivity Watertightness 4 Introduction 3 Common Usage Electronics Plumbing Stained glasswork Jewelry Orthodontics 5 Introduction 3 Equipment Solder Joint filler metal Metallic alloy Sn/Pb Typ. 60/40 or 63/37 mix 60/40 melts @ 374°F (190°C) 60/40 melts @ 364°F (183°C) Pb-free EU RoHS compliance Typ.
Sn/Ag/Cu alloy Melts @ 422 3433°F (217 3223°C) 6 Introduction 3 Equipment Flux Removes base, filler metal oxides Aids wetting process Rosin-based flux Availability Separate paste Flux-in-core solder Primary fume component& 7 Introduction 3 Equipment Soldering Iron Solder melting heat source Power rating Higher power ` higher tip temp Higher power ? heat larger joints 15-35W for electronic work Various tips available Conical, chisel types Tip width ~ 70-90% contact width Never use 8cold heat 9 irons on electronics! 8 Introduction 3 Equipment Solder wick Braided copper strands Flux impregnated Absorbs solder when heated Remove excess solder Desolder components Solder stand ... more. less.
+ sponge Always return iron when unused Always clean tip Remove burnt flux Remove excess solder 9 Introduction 3 Equipment Heat sink Protect heat sensitive components Clip between component body and iron Substitution alligator clips Hemostat 99% alcohol + brush Clean joint residual flux Purity important 10 Procedure 3 Preparation Clean components Remove dirt, grease, oxidation Causes unwettability Solder tend to bead up Component leads bright, shiny Solder pads bright copper color Fine steel wool, emery cloth 11 Procedure 3 Preparation Prepare iron Plug in iron Dampen sponge Clean tip w/ sponge Apply solder to iron tip (tinning) Wipe excess solder Tip should be have silvery sheen 12 Procedure 3 Execution Place component Bend leads to fit hole pattern Insert component through correct holes Clinch leads slightly outward to hold in place Attach heat sink if needed 13 Procedure 3 Execution Solder component Wipe iron w/ sponge Apply tiny solder amount to iron tip Not solder to form joint Helps conduct heat properly Touch tip side to BOTH pad and lead Add bit more solder to form heat bridge Wait for joint to be heated (~1-2 sec) 14 Procedure 3 Execution Solder component (cont.) Feed small solder amount from opposite side Molten solder should spread and fill joint Move solder away first Move iron away quickly Return iron to stand Entire process d 5 sec Wait additional 3-5 sec for joint cooling 15 Procedure 3 Inspection Inspect joint quality Good joint Shiny Bright Smooth Concave solder fillet Good wetting 16 Procedure 3 Inspection Inspect joint quality (cont.) Bad joints Balled up or spiked Dull color Crystalline or grainy looking Convex solder fillet Dewetted Causes Dirty leads, pads Movement during cooling Overheating 17 Procedure 3 Finishing Return iron to stand Cut excess lead length Clean residual flux w/ alcohol Prevent future oxidation Prevent unwanted electrical shorts 18 Techniques - Desoldering Repair bad joints Remove solder bridges Excess solder connects two pads, leads Unwanted electrical connection formed Remove components Both require old solder removal Place solder wick against solder joint Heat wick opposite side from joint Solder should wick up braid Remove braid first Remove and return iron to stand 19 Techniques 3 Wire Tinning Must tin wires before soldering to components, board Attach heat sink just below insulation Heat wire end Touch solder to wire opposite iron tip Solder should wick up wire Too much heat damages wire insulation 20 Conclusion Introduction Definition Equipment Procedure Preparation Execution Finishing Specific Techniques Desoldering Tinning 21 References www.curiousinventor.com/guides/How_To_Solder www.aaroncake.net/electronics/solder.htm www.qsl.net/n9zia/solder.html www.solderinguide.com itp.nyu.edu/physcomp/Tutorials/SolderingAPerfBoard www.modchipworld.co.uk www.drmsmetals.com/data/electronic/erzin.html www.hsl.gov.uk/capabilities/rosin.htm www.sparkfun.com www.howardelectronics.com www.ladyada.net www.uelectronics.info us.geocities.com/steves_workshop www.theavenuestaineglass.com<br><br>