„CONTROLDER“ (Control of microstructure in solders) G.J.Schmitz presented at the COST 531 WG6 meeting Berlin, January 14 th 2003 ACCESS Materials&Processes Intzestr 5 D Aachen, Germany

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 systemthermodynamicsinterfaces diffusion =+ +

Results of H.J.Diepers Directional Growth of a 3-D Dendrite in Al-Si7 200  m r = 3  m  T = 20 K/mm v = 5 mm/s anisotropy 30% in kinetics

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 T e =775,71 K System Al-Ag-Cu

fcc + hcp +  CuAg 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

NOPLEES Coordination: Suzana G. Fries Partners: Finacial and Scientific Support 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 mm 2 1 mm Confined spaces/self-assembly ab Twin plane E.A.Goodilin, E.S.Reddy, J.G.Noudem,M.Tarka,G.J.Schmitz Journal 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)