Material Characterization

Why material charaterization?

  • Get thermal and mechanical properties for finite element simulations (FEM)
  • Reveal best material combination for specific application
  • Find adequate parameters for processing of solder- and sintering-layers, casting compounds, base plates, housings, terminals, interconnections, windings, dielectrics
  • Improve lifetime and reliability of packaging concepts
  • Reduce development time and costs
© Fraunhofer IISB

Sample preparation for simultaneous thermal analysis at the NETZSCH STA 449 F3 Jupiter

Research and applications

  • Temperature dependent characterization of mechanical properties including creep-, fatigue-, fracture- and failure-investigations
  • Material property mapping by spatially resolved nanoindentation. Application examples: Properties of intermetallic phases,  die-attaches, bond wires and phase boundaries
  • Thermal analysis of materials: Specific heat of semiconductors, die-attaches, solder pastes (evaporation of fluxes, melting temperature, solidification behavior), sintering pastes (drying / sintering time, temperature and atmosphere), substrates, TIMs

Assembly of test specimens

  • Soldering: All kind of solders (lead-free, lead, gold, etc.)
  • Silver-sintering: Representative specimens for tensile tests and nanoindentation (same thickness and porosity as die-attaches or base-plate attaches)
  • Wire ultrasonic bonding and resistance welding

Tensile and compression testing

Global mechanical material parameters:

  • Temperature dependent
  • Young’s modulus, tensile-, compressive-, yield-, creep- and fatigue strength
  • Different strain rates for time-dependent material behavior
  • Stress-strain curves for nonlinear FEM
  • Special data for different material models, e.g. Ramberg-Osgood

Nanoindentation

Local and global mechanical material parameters:

  • Temperature dependent
  • Young’s modulus, hardness, creep parameters
  • 3D-Mapping of material properties
  • Quantitative scratch and wear testing
  • According to test standard ISO 14577
Nano indents
© Fraunhofer IISB

Nano indents

Berkovich nanoindent on a silver-sintered bond line obtained by nanomechanical microscopy
© Fraunhofer IISB

Berkovich nanoindent on a silver-sintered bond line obtained by nanomechanical microscopy

Simultaneous thermal analysis STA

Thermal material parameters:

  • Characteristic temperatures (Sintering, melting, formation of intermetallics, decomposition, oxidation, glass transition)
  • Temperature dependent specific heat capacity measurements
  • Analyse of peak areas in dependence of mass change
  • Kinetics of reactions (e.g. oxidation, sintering)
  • Evaluation of mass change steps (leakage of organics, debinding)

 

  Tensile Testing Nanoindentation STA
Specimen Rectangular cross
section from sheets
to bulk materials
Sample size up to
50 x 50 mm²
Liquid or solid objects
Temperature RT to 300°C RT to 500°C RT to 1500 °C
Atmosphere N2, Air N2,Air, Ar N2, Air, Ar, O2

 

 

Micro scale thick silver-sintered dog bone immediately before hot tensile test
© Fraunhofer IISB

Micro scale thick silver-sintered dog bone immediately before hot tensile test

Mechanical behavior of silver-sintered dog bone in tensile test at different test temperatures and sintering pressures
© Fraunhofer IISB

Mechanical behavior of silver-sintered dog bone in tensile test at different test temperatures and sintering pressures

 

Material Characterization

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