CeramTec launches Rubalit® ZTA

Very high flexural strength, good thermal conductivity, excellent electrical insulation and top values for dielectric strength: all this is offered by the new high-performance substrate Rubalit® ZTA, which we are presenting at PCIM in Nuremberg. ZTA stands for Zirconia Toughened Alumina - and for a material that is also predestined for high-performance applications such as electromobility and power generation due to the properties mentioned.

With Rubalit® ZTA and another high-tech substrate announced for this year, we are expanding our substrate portfolio  to include solutions specifically tailored for use in highly electrified industries and e-mobility. The power electronic modules in this environment must meet increasingly stringent requirements in terms of their temperature resistance and miniaturization. With these key specifications in mind, we have developed a substrate with impressive properties.

Compared to the widely used aluminum oxide as a substrate material, the flexural strength has been improved by 40 percent to more than 625 MPa. In practice, this means a significantly higher fatigue strength of power modules built on Rubalit® ZTA. Thermal conductivity is more than 26 W/mK, and in dielectric strength the new substrate reaches 25 kV/mm. This makes Rubalit® ZTA clearly superior to common PCB materials, for example. Its thermal conductivity, temperature resistance and insulating properties also make the substrate an ideal material for use in passive components or chip resistors.
 

Why manufacturers of power electronics use the need the new Rubalit® ZTA ceramic substrate? Three questions for David Hassler, Product Manager E-Mobility at CeramTec:

David, how do you answer manufacturers of power electronics when asked why they need the new Rubalit® ZTA ceramic substrate?

Reinforced alumina offers strong thermal and mechanical performance at a good price/performance ratio. Current levels in power electronics are getting higher and higher. Ideally, the conversion of ever higher currents must be pre-vented from causing excessive heat loss and thermal stress for the simultane-ously ever smaller modules. Rubalit® ZTA meets these requirements out-standingly well.

Almost 40 percent increase in flexural strength is quite something. How was this achieved?

Rubalit® ZTA is the result of intensive development work. A high flexural strength ensures that the conductive metallisation does not detach from the ceramic substrate even during extreme temperature cycles, making the power converters very durable. To ensure this, we have carried out many elaborate life tests on Rubalit® ZTA - and improved the product until we reached this value.

When will Rubalit® ZTA be available on the market?

We will launch the product as a substrate in the masterplate format of 138 x 190.5 x 0.32 mm at the start of the PCIM in Nuremberg - i.e. in mid-May. In addition, D-samples for qualification are available immediately. In the near future, however, we will of course also offer other thicknesses.