Ultrasonic Processing

Laser vibrometers will help you to develop efficient tools for ultrasonic processing applications. Already used in various industries for applications such as wire bonding, welding and food cutting, Polytec vibrometers are essential for FE model validation and verification.

Polytec Scanning Vibrometers are perfectly suited for the verfication of numeric simulaitons of ultrasonic welding tools. It's inherent properties like

  • full-field measurements (1D and 3D)
  • linear frequency response
  • high frequnecy bandwidth
  • geometry import from CAE

allow for a quick evaluation of the uniformity of deflection at the active surface. 

Case Study: 3D Sonotrode measurement

Measured with PSV-400-3D Scanning Virbometer

  • 7641 DOF/ 2547 measurement points
  • Bandwidth: 100kHz
  • Nominal operating frequency: 20kHz

The deflection shapes were measured in 5 sections, using mirrors to get optical access to the active surface.



Sonotrode

For the measurement the sonotrode was setup in a support with a mirror placed below to allow a view for the scanning laser vibrometer to the active surface. The sonotrode was excited with a periodic chirp singal from the PSV signal generator in order make a broadband excitation.

The object geometry with the nodes and elements was loaded into the PSV and aligned to the sonotrode with a simple referencing procedure (3D-alignment) in order to match the numeric geometry to the object in the video image of the PSV.

Sonotrode
Sonotrode grid

Deflection Shape 20kHz

The measured deflection shape at 20 kHz shows a well designed sonotrode: The active surface moves up and down very uniformely. There are hardly now parasitic modes visible.

Deflection Shape at 7kHz

If the frequency is shifted away from the driving frequency, other modes become dominant. In the example at 7 kHz  the deflection shape will introduce in-plane motion to the active surface, which is not desired in this case

Applications

Surface Vibration Measurements Application Note VIB-G-14
Laser Vibrometry for Quality Assurance in Heavy Wire Bonds (by M. Schneider-Ramelow, Polytec LM INFO Special 1/2004)
Bookmark this PDF Ultrasonic Welding Tools Application Note VIB-P-03
Testing Power and Microelectronic Interconnects (by W. Wroczewski, G. Khatibi et al., InFocus 1/2010)
Innovative Bonding Techniques (by F. Balle, G. Wagner et al., InFocus 1/2009)