Lead-free Solder Alloys: Enthalpies of Lead-free Solder Alloys: Enthalpies of formation of (Ag,Cu,Ni)-Sn formation of (Ag,Cu,Ni)-Sn

binary alloysbinary alloys

U. Saeed, H. Flandorfer, H. Ipser

Institute of Inorganic Chemistry / Materials Chemistry

University of Vienna

Introduction

Experimental technique

Enthalpy of solution

Enthalpy of formation

Summary

Contents

Estimation of phase stability

Optimization of Thermodynamic datasets for CALPHAD

Theoretical calculations of physical properties

Introduction

Enthalpy of formation

Binary IMCs in Ag-Sn, Cu-Sn, Ni-Sn systems

Extended ternary solubilities in Cu-Ni-Sn system

No ternary or quaternary IMCs formation

Six binaries & four ternaries in Ag-Cu-Ni-Sn system

Cu-Sn

Cu41Sn11

Cu6Sn5

Cu3Sn

Ni-Sn

Ni3Sn4

Ni3Sn2

Ni3Sn

Ag-Sn

Ag4SnAg3Sn

Intermetallics in binary systems

Cu-Ni-Sn

600 °C

Cu0 10 20 30 40 50 60 70 80 90 100

Sn

0

10

20

30

40

50

60

70

80

90

100

Ni

0

10

20

30

40

50

60

70

80

90

100

Single Phase Multiphase

Cu3Sn ()

Ni3Sn4

Ni3Sn2-HT

Ni3Sn LT

Cu3Sn- HT

Schematic of Calvet type HT1000 Calorimeter

Automatic drop device

xA(solid) + yB (solid) AXBy (Solid) DT

fH298(AxBy) = x∙solH(A) + y∙solH(B) - solH(AxBy)

Solution calorimetrySolution calorimetry

=

Sol

mixfus

MT

DTp dTC=

liquid solvent MT

Heating

Melting

Mixing

Enthalpy of solution

xCu0.36Ni0.24Sn0.40

0.00 0.01 0.02 0.03 0.04 0.05 0.06 so

lH

kJ

/mo

l

18

20

22

24

26

28

30

32

mol/Jk 27.29sol

xAg

0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28

fH

k

J/m

ol

-5.5

-5.0

-4.5

-4.0

-3.5

-3.0

-2.5

-2.0

-1.5

Experimental results KleppaLauri

Ag4Sn

Ag3Sn

xCu

0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85

fH

kJ/m

ol

-10

-9

-8

-7

-6

-5

-4

Expeimental resultsGanguleeKleppaBiltzCohen (Cu3Sn)

Cu41Sn11

Cu3Sn

Cu6Sn5

fH of Ag-Sn & Cu-Sn IMCs

Reference state: Solid

fH of NiSn IMCs

xNi

0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80

fH

kJ

/mo

l

-45

-40

-35

-30

-25

-20

-15

Experimental resultsKoerberDannöhlPredelTorgersenVassilev

Ni3Sn4

Ni3Sn2(HT)

Ni3Sn(LT)

Reference state: Solid

fH of ternary solubilities

(Cu,Ni)3Sn2- HT (Cu,Ni)3Sn4

xCu

0.00 0.10 0.20 0.30 0.40

fH

k

J/m

ol

-40

-35

-30

-25

-20

-15

xSn=0.40

Reference state: Solid

xCu

0.00 0.01 0.02 0.03 0.04 0.05 0.06 fH

J

/mo

l

-30

-28

-26

-24

-22

-20

xSn= 0.58

fH of ternary solubilities

(Cu,Ni)3Sn

xCu

0.0 0.2 0.4 0.6 0.8

fH

kJ/m

ol

-35

-30

-25

-20

-15

-10

-5

xSn = 0.25

Reference state: Solid

Summary

Solution calorimetery technique was used

Reinvesitigation of enthalpy of formation of binary intermetallic compounds

Agreement with the previously presented of data

Enthalpy of formation of extended ternary solubilities in Cu-Ni-Sn system

Thanks for paying attention