| Ceramic / named example | Thermal conductivity | Bare-ceramic CTE | Selection focus |
|---|---|---|---|
| Aluminacuramik Power | 24 W/m·K | 6.8 ppm/K | Cost-conscious thermal isolation |
| Aluminum nitridecuramik Thermal | 170 W/m·K | 4.8 ppm/K | Low substrate thermal resistance |
| Silicon nitridecuramik Performance | 90 W/m·K | 2.5 ppm/K | Mechanical and cycling robustness |
| Zirconia-toughened aluminacuramik Power Plus (HPS) | 26 W/m·K | 7.4 ppm/K | Toughened alumina power substrates |
| LTCC glass ceramicKyocera GL570 | 2.8 W/m·K | 3.4 ppm/K | Embedded RF routing and packaging |
Representative product values, not universal limits or a manufacturing offer. Rogers conductivity: 20°C; CTE: 20–300°C. Kyocera GL570 CTE: room temperature–400°C; conductivity as published. Copper-clad stack CTE differs from bare ceramic. Sources: Rogers data sheet; Kyocera LTCC data. Review data definitions and limitations.
What these numbers represent
The Rogers examples refer to bare ceramic properties in the cited product sheet. Conductivity is stated at 20°C and CTE over 20–300°C. The LTCC example is Kyocera GL570, whose CTE is specified from room temperature to 400°C. These measurements do not describe identical temperature intervals.
Why stack properties differ
Adding copper changes expansion, heat spreading and mechanical behavior. The effective CTE of a complete substrate is not automatically the bare ceramic number. Contact resistance, attachment layers and temperature dependence must also be considered when predicting assembly performance.
How to use the table responsibly
Use the numbers to develop a shortlist or a sensitivity calculation. Obtain the current grade data and test methods from the selected supplier before release. Do not derive a working-voltage rating from a generic dielectric-strength number or a lifetime from a strength value.
Engineering example
A CTE quoted over room temperature–400°C is an average over that interval. Applying it to a very different temperature range may be unsuitable when precision or stress prediction is important.
Before you release the design
- Record grade and data-sheet revision.
- Use relevant temperatures and measurement methods.
- Distinguish material, substrate and assembly properties.
Sources and further technical reading
Manufacturer references support the material and process context. Worked examples and checklists are engineering guidance; they are not test results or supplier guarantees.