Piezoelectric Rings

Advanced Electro Ceramics

CeramTec is a world leader in the design and manufacture of complex electronic ceramic components and assemblies used in a wide range of applications and cutting edge technologies.

CeramTec’s Global Electroceramics Divisions specialise in the development and production of various rings sizes, bearing variety of electrode and metallisation configurations. This variety of Rings is fabricated from 33 published and additional custom in-house piezoelectric material formulations to address needs such as high power, sensitivity, stability in cryogenic temperatures as also in high temperatures and extreme pressure imposing applications.

 

Applications include
  • Sensors
  • Actuators
  • Welding
  • Ultrasonic cleaning
  • Medical:
    · Ultrasonic scalpel, debriding
    · Cauterisation
    · Phacoemulsification
    · Ultrasonic aspirators
    · Therapeutic ultrasound
  • Accelerometers
Features
  • Choice of silver finish available on request
  • Evaporated and chemically deposited metallisation's available
  • Surface roughness's as low as 0.15μm available for specific demanding application
  • Thickness/Radial frequency tuning available on request
  • Wide choice of PZT formulations
Typical Electrode Configurations

Standard

Flat Lapped Silver

Metallisation free border

Other custom electrode configurations are available on request. Rings are supplied on request with a ‘break edge’ on outside and inside diameters.

Dimensional Range
  • Outside Diameter from 1mm (0.04”) to 150mm (5.9”)
  • Inside Diameter from 0.5mm (0.02”) to 140mm (5.5”)
  • Thickness from 0.15mm (0.006”) to 25mm (1”)

Parts can be produced to the size ranges shown, but not in every combination of dimensions expressed above.


Standard Mechanical Tolerances
  • Outside Diameter ± 0.150mm
  • Inside Diameter ± 0.150mm
  • Thickness ± 0.05mm
  • Flatness 0.002**/0.012mm MAX (** lapped silver or sputtered)
  • Parallelism 0.007**/0.012mm MAX (** lapped silver or sputtered)
  • Concentricity 0.2mm TIR

Tighter mechanical tolerances are achievable but are dependent on the ring inside and outside diameters and thickness.


Metallisation Type
  • Silver fired thick film standard - Silver fired thick film flat lapped
  • Electroless nickel - Gold flash
  • Tin - Evaporated Gold, Nickel and others available on request
Typical Impedance Responce Trace (Radial Resonance)

The above is a typical impedance trace measured on a dedicated analyser and depicting the resonance and anti-resonance points associated with the ring shaped component. This data allows the calculation of piezoelectric activity and other important characteristics required for the application.

Useful Equations

Capacitance

Static displacement

Planar coupling factor

Radial frequency

Voltage (static)

Mechanical quality factor

Thickness frequency

Effective coupling factor

Ceramic Testing

Appropriate statistical methods ranging from AQL’s to 100% testing are used on electrical parameters in accordance with EN-50324-1. A brief summary is provided in hard copy and typically includes low field measurements of capacitance, tan delta and the main parameters used to determine piezoelectric activity. Procedures other than this can be negotiated, and additional data requirements (electronic format, sample quantity, etc) are available on request.