„CONTROLDER“ (Control of microstructure in solders)

G.J.Schmitz

presented at the COST 531 WG6 meeting

Berlin , January 14th 2003

ACCESS Materials&Processes

Intzestr 5

D-52072 Aachen, Germany

www.access.rwth-aachen.de

• private,non-profit research association, • originated from Foundry Institute of RWTH Aachen in 1986• annual turnover 2001 approx 5 million €• actually approx. 60 employees (35 scientists, > 7 disciplines)• interests in materials& processes :

„anything related to solidfication“

Materials

Processes

and

MICRESS

active:

M. Apel

B. Böttger

H.-J. Diepers

J. Eiken (Tiaden)

P. Schaffnit

I. Steinbach

N. Warnken

former (or less active)

S.G.Fries

U. Grafe

U.Hecht

B. Nestler

F. Pezzolla

G.J.Schmitz

M. Seeßelberg

V.Vitusewych

The "Aachen" Phase Field Model

real system thermodynamics interfaces

diffusion

= +

+

Results of H.J.Diepers

Directional Growth of a 3-D Dendrite in Al-Si7

200 m

r = 3 m

T = 20 K/mmv = 5 mm/sanisotropy 30% in kinetics

.Model Description: Schematic View on Thermodynamic Coupling

Results of B.Böttger

Coupling with Thermodynamic Databases (II)

IN706

dT/dt =

-0,5K/s

=

200 m

x(Nb) %

Results of B.Böttger

Coupling with Thermodynamic Databases (III)

IN706

Results of M.Apel

Ternary Eutectics

Eutectic compositon:

Liquid: Al, at% = 69,9647

Ag, at% = 16,9674

Cu, at% = 13,0679

Te = 775,71 K

System Al-Ag-Cu

fcc + hcp + Cu Ag

Results of M.Apel

Ternary eutectics: EXPERIMENTAL example: Ag-Cu-Zn

• former and present areas of activity related to solders

– melt atomization of BiSn powders

– solder contacts to superconductors

– solder contacts to solar cells

– soldering of single crystalline superalloys

– laser surface welding

– directional solidification studies Bi-In-Sn system

• future activities– „CONTROLDER“ : Experiments, Analytics, Microsimulation

– „NOPLEES“ :Thermodynamics

•macroscopic issues of solder joints

• sessile drop experiments/wetting

• mesoscopic self-assembly

• solidification in confined geometries

• microstructure formation in solder alloys

• directional solidification

• thermal cycling

• doping effects

• interaction with solder pads

• generation/avoidance of precipitates

• others.....

• numerical simulations

•microstructure evolution

•thermoelectric aging

„Controlder“ OBJECTIVES

To propose

and to develop

effective means

to control

microstructure formation

in solder joints

NOPLEES- No Plumbum Equilibrium and Environment Search

Ag-Al-Cu, Ag-Al-Zn, Ag-Cu-Zn, Al-Cu-ZnTernary

Ag-Al, Ag-Cu, Ag-Zn, Al-Cu, Al-Zn, Cu-ZnBinary

Systems with Cu Relevant for Soldes and Substrate, Ag - Al - Cu - Zn

Ag-Al-Mg, Ag-Al-Sn, Ag-Al-Zn, Ag-Mg-Sn, Ag-Mg-Zn, Ag-Sn-Zn, Al-Mg-Sn, Al-Mg-Zn, Al-Sn-Zn, Mg-Sn-Zn

Ternary

Ag-Al, Ag-Mg, Ag-Sn, Ag-Zn, Al-Mg, Al-Sn, Al-Zn, Mg-Sn, Mg-Zn, Sn-ZnBinary

Additional Set to Investigate New Solder Alloys, Ag - Al - Mg - Sn - Zn

Ag-Bi-Pb, Ag-Bi-Tl, Ag-Pb-Tl, Bi-Pb-TlTernary

Ag-Bi, Ag-Cu, Ag-Pb, Ag-Tl, Bi-Cu, Bi-Pb, Bi-TlBinary

Updated Systems (Zimmermann 1976) Relevant for Solders: Ag - Bi - Cu - Pb - Tl

Ag-Bi-Cu, Ag-Bi-Sn, Ag-Cu-Sn, Bi-Cu-Pb, Bi-Pb-Sn, Ag-Bi-Pb, Ag-Cu-Pb, Ag-Pb-Sn, Bi-Cu-Sn, Cu-Pb-Sn

Ternary

Ag-Bi, Ag-Pb, Bi-Cu, Bi-Sn, Cu-Sn, Ag-Cu, Ag-Sn, Bi-Pb, Cu-Pb, Sn-PbBinary

NIST Solder Database: Ag - Bi - Cu - Sn - Pb

http://www.lpmc.univ-montp2.fr/

http://aldix.mpi-stuttgart.mpg.de/D_head.html

http://www.sgte.org/

NOPLEES Coordination:

Suzana G. Fries

Partners:Finacial and ScientificSupport Agencies

Dr. Matsvei Zinkevich

Dr. Marie-Christine Record

„Noplees“ and „Controlder“ Status

Controlder:

•focus on experimental work and microstructure control

•no national project submitted by now

•open for collaboration

Noplees: •bilateral German (Aachen,Stuttgart) -French (Montpellier) project submitted end Jan 2002 (CERC3, DFG-CNRS)

•focus on thermodynamics

•tentative duration : 3 years

•final decision on funding still pending

Possible Collaborative Groupings

Melt composition/Thermodynamics: WG 1+2, TU Chemnitz (D12), Univ Sofia (BG1), Univ. Metz (F4), Univ Krakow(PL2), Chalmers (S1) , ACCESS (D2)

Processing :

•general Siemens (D9),

•solid state processing : •solderpaste printing Univ Dresden (D11) • diffusion soldering Polish Academy (PL1),• transient LiquidPhase Sintering Univ Waterloo (CDN4)

•melt properties: •elctrical conductivity Univ. Metz (F4), •viscosity, surface tension, density Univ. Metz (F4), TU Chemnitz (D14), Univ Krakow (PL2, PL4)• dopants TU Chemnitz (D12), Univ Sofia (BG1), ACCESS (D3) , Chalmers (S1)

•nucleation: •seed additions Univ. Metz (F4), •thermal history TU Chemnitz (D14) Univ. Metz (F4),

•process atmosphere: Univ Sofia (BG1) Univ Dresden (D11) , ACCESS (D3)

Possible Collaborative Groupings

Microstructure analysis: TU Chemnitz (D12), Univ Toronto (CDN2), ACCESS (D3) , TU Dresden (D10) Univ Krakow(PL2) Slovak Academy (SK1) Open Univ (UK2) Univ Bordeaux (F5),

•solidification

•T-t schedules: TU Chemnitz (D12), whisker formation Shipley (CH3), ACCESS (D3) , Univ. Metz (F4), ICMCB (F6) Slovak Academy (SK1) Open Univ (UK5) Univ Waterloo (CDN5), Univ Dresden (D11)

•solidifcation boundary conditions:

PWB: Slovak Academy (SK1)Univ Toronto (CDN3), Univ Waterloo (CDN5), Univ Dresden (D11) Siemens (D8),

component Univ Dresden (D11)Siemens (D8),

geometry ACCESS (D3),

size Polish Academy (PL1) Univ Augsburg (D7), Univ Vienna(A3), ACCESS (D3),

composition Univ Toronto (CDN2) Shipley (CH3), ACCESS (D3),

wetting TU Chemnitz (D12), TU Chemnitz (D14), Univ. Metz (F4), Univ Krakow(PL2) Slovak Academy (SK1),

•solid state transformations:

•recrystallization/grain growth Univ Toronto (CDN2) Open Univ (UK5)

Possible Collaborative Groupings

Characterization / Reliability:

•general Siemens (D8),

•aging :

•long term heat treatments TU Chemnitz (D12) TU Dresden (D10) Univ Dresden (D11) Univ Waterloo (CDN5) Univ Bordeaux (F5),

• thermal cycling/fatigue Univ. Toronto (CDN1) Chalmers (S1), Siemens (D9) Univ Vienna(A3), Fraunhofer IZM (D4) Fraunhofer IZM (D5) Univ Berlin (D6) Open Univ (UK1)

• cyclic mechanical load: Univ Augsburg (D7) , Siemens (D9) Fraunhofer IZM (D5)

• creep TU Dresden (D10), ICMCB (F6), Open Univ (UK2) Fraunhofer IZM (D5) Univ Berlin (D6)

• mechanical properties EMPA (CH2) Siemens (D9), Univ Krakow(PL2) Chalmers (S1) Slovak Academy (SK1) Open Univ (UK2) Univ Vienna(A3),

• electrical properties Siemens (D9), Univ Krakow(PL2) Chalmers (S1)

• thermal properties Slovak Academy (SK1)

• stresses/cracking Univ Augsburg (D7) Open Univ (UK1)

• corrosion EMPA (CH2) Chalmers (S1)

Possible Collaborative Groupings

Modelling/Simulation

•analytic expressions Open Univ (UK2)

•melt properties: TU Chemnitz (D14)

•microstructure formation: ACCESS (D3), Bulgarian Academy (BG2), Fraunhofer IZM (D4)

•creep Siemens (D9),

•fatigue Chalmers (S1) , Bulgarian Academy (BG2)

•stresses - strains Univ Berlin (D6)

•thermomechanical Fraunhofer IZM (D5) Univ Berlin (D6) Univ Bordeaux (F5),

•mechanistic history Open Univ (UK2)

•thermoelectric history ACCESS (D3) :

Thermoelectric modelling

Current distributions in multiphase systems:effects on electric load on life-time

75% of 220 crystals well-oriented over the area 8-9 mm21 mm

Confined spaces/self-assembly

a b

Twin plane

E.A.Goodilin, E.S.Reddy, J.G.Noudem,M.Tarka ,G.J.SchmitzJournal of Crystal Growth 241(2002)512

H.O.Jacobs, A.R.Tao, A.Schwartz,

D.H.Gracias,G.M.Whitesides

Science 296(2002)323 (April 2002)