ULTCC ceramics (Ultra Low Temperature Co-fired Ceramics)

ULTCC ceramics are novel multilayer ceramics that offer a variety of advantages. On the one hand, ULTCCs can be sintered at very low temperatures of 400 °C to 700 °C, making their manufacturing process very energy-efficient. On the other hand, these low sintering temperatures allow a wider range of conductor materials to be used for functionalization, making technology hybridization (semiconductor processes, polymer-based microcircuit fabrication) possible.

It is also possible to embed and sinter electrical circuits and packages into the ceramics. This reduces manufacturing costs and thus significantly extends the range of applications for ULTCC components. ULTCC components are excellently suited as rewiring carriers for electronic components, for housing and encapsulation technology or as substrate for high-frequency technology applications such as antennas, filters and circulators.

Fraunhofer IKTS develops customized RoHS- and REACH-compliant ULTCC materials and tapes based on glass-ceramic composites (GCC) consisting of low-melting glasses with suitable ceramic fillers. The type of glass in combination with the selected filling material determines the material properties, such as thermal expansion, thermal conductivity, insulation as well as electrical parameters (insulation resistance, permittivity, dielectric loss). The associated metallization pastes are based on silver and aluminum. The particular challenge is to adjust the binder and paste system as well as the manufacturing processes in such a way that the materials are co-sinterable in the temperature range mentioned above.

© Fraunhofer IKTS
© Fraunhofer IKTS
Gefügebild eines ULTCC-Substrats.
© Fraunhofer IKTS
Gesinterte Silberleiterbahn auf ULTCC-Substrat.

Technical characteristics


  • Sintering temperatures in the range of 400 °C to 700 °C (density = 4.2 g/cm3 at a sintering temperature 600–650 °C)
  • XYZ shrinkage: 15–17 %
  • Porosity < 1 vol. % and water absorption < 1 vol. %.
  • High-frequency characteristics: εr (4–50) and tanδ (0.005–0.0001) at < 30 GHz
  • Thermal properties: thermal expansion coefficient 3–10 ppm/K; thermal conductivity 1–20 W/mK
  • Integration of conductors (Ag/Al) and semiconductor elements (Si/SiC)
  • High degree of freedom in adapting material properties
  • RoHS- and REACH-compliant materials and processes


Services offered


  • Development of lead-free ULTCC materials
  • Production of hybrid substrates by integrating conductive, dielectric, magnetic or piezoelectric materialsDevelopment of ULTCC-based semi-finished products (pastes, inks, tapes) and components (e.g. for high-frequency applications)
  • Dielectric characterization of ULTCC materials (εr, tanδ)
  • Characterization of mechanical and thermal properties
  • Investigation of the shrinkage behavior