Mechanical and Thermal Characterisation of Materials
Precise materials data form the basis for reliable products. Understanding the properties of materials and knowledge of the relationship between production processes, stresses and failure mechanisms makes it possible to improve processes and products. Materials can be characterised individually or in their application. The measurements can also be carried out at various level of humidity and temperature, in order to determine the material behaviour for the process or application conditions. For the reliability assessment with FEM, the parameters are used to produce material models.
Key material characteristics are:
- Young’s-modulus and transverse contraction
Measurement of the Young’s-modulus for material samples (also on thin layers). Determining Poisson’s ratio for material samples with optical deformation analysis.
- Viscoelastic properties
Determining temperature- and time-dependent modulus of adhesives, polymers, moulding compounds for the relaxation behaviour of the materials.
- Creep properties
Time- and temperature-dependent plastic behaviour of metals and metal alloys (e.g. solder) under stress for the description of damage accumulation.
- Moisture absorption and swelling
Determining moisture absorption of materials (polymers, adhesives) and induced swelling. Determining moisture diffusion in materials by measurements and of transport mechanisms by molecular modelling.
- Determining thermo-mechanical expansion
Determining des thermal expansion coefficients over the range -100°C to 450°C for all materials and composites (moulding compounds, circuit boards, etc.).
- Determining fracture-mechanical properties
Assessing toughness for the micro/nano range (cohesive crack) Clarification of crack initiating and crack dissemination behaviour, experimental fracture mechanics at the interface.
- Determining thermal conductivity and heat capacity
Measurements of material samples to determine the thermal conductivity and heat capacity. Determining the thermal conductivity of thermal interface materials (TIM) dependent on contact forces.