By:– Brian Ambrosini– Matt Spence– Waldon Wong

Engineering 45Younes AtaiiyanSanta Rosa Junior

College12/06/04

ApplicationsApplications

Circuit BoardsCircuit Boards Connecting copper pipesConnecting copper pipes Light bulbsLight bulbs AlternatorsAlternators11

Stained GlassStained Glass

Soldering Techniques Soldering Techniques & Future Products& Future Products Soldering IronSoldering Iron Blow TorchBlow Torch Solder Wave MachineSolder Wave Machine Cold HeatCold Heat22

ExperimentExperiment Procedure Procedure

Cut up solderCut up solder Heat solder in crucibleHeat solder in crucible CoolCool

– Slowly cool in furnace (100°F/20 Slowly cool in furnace (100°F/20 min)min)

– Air CooledAir Cooled– Ice cooledIce cooled

Procedure ContinuedProcedure Continued

Cast the cooled solder in plasticCast the cooled solder in plastic– Bakelite would melt the solder Bakelite would melt the solder

(thanks Younes)(thanks Younes) Sand and Polish sampleSand and Polish sample Etch with Nitric acidEtch with Nitric acid View/compare microstructureView/compare microstructure

Lead-Tin Phase Lead-Tin Phase DiagramDiagram33

Results – Ice CooledResults – Ice Cooled

Small eutectic Small eutectic structures (dark structures (dark areas)areas)

Less ductile then Less ductile then the other the other specimensspecimens44

Most susceptible Most susceptible to fatigueto fatigue– Possible Possible

reduction in lifereduction in life

Results – Air CooledResults – Air Cooled

Standard sized Standard sized eutectic structure eutectic structure (dark areas)(dark areas)

Results – Slow CooledResults – Slow Cooled

Large eutectoid Large eutectoid structures (dark structures (dark areas)areas)– By cooling the By cooling the

sample slowly, it sample slowly, it looks similar to looks similar to steelsteel

Most ductile Most ductile samplesample– Best commercial Best commercial

useuse– Not cost Not cost

effectiveeffective

ConclusionsConclusions

Air cooled specimen Air cooled specimen had a medium had a medium amount of eutectic amount of eutectic structuresstructures

The furnace cooled The furnace cooled specimen had large specimen had large eutectic structureseutectic structures– More ductileMore ductile– Not as strongNot as strong

Ice cooled specimen Ice cooled specimen had very small had very small eutectic structureseutectic structures– Less ductile (more Less ductile (more

brittle)brittle) All three samples All three samples

have the same have the same compositioncomposition– Electrical properties Electrical properties

are similarare similar

ReferencesReferences

1: 1: http://www.seas.ucla.edu/eThinFilm/Pb-freeWorkshop/http://www.seas.ucla.edu/eThinFilm/Pb-freeWorkshop/abs/pan.htmlabs/pan.html

2: 2: http://www.coldheat.com/http://www.coldheat.com/ 3: 3:

http://www2.umist.ac.uk/material/research/intmic/phahttp://www2.umist.ac.uk/material/research/intmic/phase/pbsndiag.htmse/pbsndiag.htm

4: 4: http://technology.open.ac.uk/emsuite/prj7.htmlhttp://technology.open.ac.uk/emsuite/prj7.html