TDK s high efficiency stacking HAS technology family

Combining more than 20 years of experience in supplying high-quality components to the automotive industry, TDK has developed a highly efficient stacking (HAS) technology based on copper inner electrodes of multilayer piezoelectric actuators – a patented technology of TDK.

Compared to conventional silver-palladium (AGPD) stacking, piezoelectric actuators with HAS technology offer better performance, better humidity stability, longer service life, and long-term reliable operation, even under harsh operating conditions.

actuator stacksWhat's so special about TDK's actuator stacking?

Minimized non-active areas for better performance and longer service life

Non-productive areas within the actuator can cause mechanical stress during operation. The larger the non-effective area, the greater the mechanical stress on the actuator, which can lead to larger cracks in the ceramic. With a non-inactive area width of only 100 m (400 microns for conventional stacking) in the TDK stack, the mechanical stress is significantly reduced, resulting in a longer actuator life, higher operating voltages (up to 180V), and greater stroke or extension (approx. +20%). That's why we call it Efficient Stacking Technology (HAS).

Copper inner electrode with better moisture resistance and better cost performance

Conventional multilayer actuators use silver-palladium alloy as the inner electrode, but silver can become very malleable and migraft under wet and electric field conditions, which can easily cause short circuits or failures between the inner electrode layers of the actuator. TDK's HAS series components use copper as the inner electrode, which effectively prevents metal migration between the electrode layers. In addition, copper is more stable and lower than the palladium market, enabling a high-performance and cost-effective solution. It's a win-win!

Lead-free high melting point metal welding, suitable for high temperature operation

Metal welds to external electrodes are also subjected to high mechanical stresses during operation, especially at high temperatures. TDK has developed a new type of lead-free, high-melting metal soldering that operates at high temperatures without embrittlement or contact loss. This innovative solder has better air permeability and elasticity, making it more reliable than lead-based solders. TDK's HAS elements have successfully passed the test of 2000 hours of trouble-free operation at 200 °C with no signs of embrittlement; In contrast, conventional actuators fail after only 1500 hours of testing at 180 °C.