Method and apparatus for detecting aging-dictated damage or delamination on components, in particular power modules of power electronic devices, and power electronic device, in particular converter
To facilitate a reliable detection of age-related damage or delamination on components the following is proposed: [i] within the scope of radiofrequency reflectometry, scanning a component by radiofrequency signal irradiation in the micrometer or millimeter wavelength range and by measuring at least one reflection signal, which was reflected at the component, in punctiform, one-dimensional or two-dimensional fashion for the purposes of generating at least one first radiofrequency image representation; [ii] scanning the component in direct time offset fashion with respect to the radiofrequency signal irradiation by a combination of ultrasonic signal irradiation and the radiofrequency signal irradiation in the micrometer or millimeter wavelength range and by measuring at least one further reflection signal, which was reflected at the component; and [iii] comparing the radiofrequency image representations generated based on the reflection signals, wherein determined changes in the radiofrequency image representations indicate damage or delamination on the component.
1. A method for detecting aging-dictated damage or delamination on components, in which, in a course of radiofrequency reflectometry, a component is scanned by radiofrequency signal irradiation in a microwave or millimeter-wave range and by measurement of at least one reflection signal, which was reflected at the component as a consequence of the radiofrequency signal irradiation, in punctiform, one-dimensional or two-dimensional fashion for generating at least one first radiofrequency image representation based on mathematical methods for image reconstruction, wherein:
a) the component is scanned directly with a time offset with respect to the radiofrequency signal irradiation by a combination of ultrasonic signal irradiation and the radiofrequency signal irradiation in the microwave or millimeter-wave range and by measurement of at least one further reflection signal, which was reflected at the component as a consequence of the ultrasonic signal irradiation and radiofrequency signal irradiation, in punctiform, one-dimensional or two-dimensional fashion for generating at least one second radiofrequency image representation, and
b) the radiofrequency image representations generated based on the reflection signals are compared, wherein ascertained changes in the radiofrequency image representations indicate damage or delamination on the component.
2. The method as claimed in claim 1 , wherein location and extent of damage or delamination on the component are specified during two-dimensional scanning with a difference image representation representing the changes in the radiofrequency image representations.
3. The method as claimed in claim 2 , wherein the damage or delamination on the component is indicated by maximum amplitudes in the difference image representation.
4. The method as claimed in claim 1 , wherein at least one sonotrode is used for the ultrasonic signal irradiation.
5. The method as claimed in claim 4 , wherein if the component is the power module, the ultrasonic signal irradiation is radiated in directly in the bottom region of the power module.
6. An apparatus for detecting aging-dictated damage or delamination on components comprising:
a radiofrequency antenna arrangement configured for transmitting and receiving, which arrangement, in a course of radiofrequency reflectometry, scans a component by radiofrequency signal irradiation in a microwave or millimeter-wave range and by measurement of at least one reflection signal, which was reflected at the component as a consequence of the radiofrequency signal irradiation, in punctiform, one-dimensional or two-dimensional fashion; and
a generating device for generating radiofrequency image representations which based on mathematical methods for image reconstruction, based on scan information supplied by the radiofrequency antenna arrangement, generates at least one first radiofrequency image representation, wherein:
a) an ultrasonic signal device, which together with the radiofrequency antenna arrangement and the generating device forms a functional unit and wherein the functional unit is configured in such a way that the component is scanned directly with a time offset with respect to the radiofrequency signal irradiation by a combination of ultrasonic signal irradiation, radiated in by the ultrasonic signal device, and the radiofrequency signal irradiation in the microwave or millimeter-wave range and by measurement of at least one further reflection signal, which was reflected at the component as a consequence of the ultrasonic signal irradiation and radiofrequency signal irradiation, in punctiform, one-dimensional or two-dimensional fashion, and at least one second radiofrequency image representation is generated based on further scan information supplied by the radiofrequency antenna arrangement; and
b) a comparison device, which functionally interacts with the functional unit in such a way that the radiofrequency image representations generated based on the reflection signals are compared, wherein ascertained changes in the radiofrequency image representations indicate damage or delamination on the component.
7. The apparatus as claimed in claim 6 , wherein the radiofrequency antenna arrangement is configured in such a way that during two-dimensional scanning the component is scanned in rows and columns, wherein each antenna serves or functions alternately as transmitter and receiver, wherein the duration for functioning/serving as receiver is a multiple of the duration for functioning/serving as transmitter, the multiple being dependent on the number of antennas in the radiofrequency antenna arrangement.
8. The apparatus as claimed in claim 7 , wherein the radiofrequency antenna arrangement is configured as an antenna array or as a T-shaped arrangement.
9. The apparatus as claimed in claim 6 , wherein the functional unit formed from the ultrasonic signal device and the radiofrequency antenna arrangement, and the comparison device are configured in such a way that location and extent of damage or delamination on the component are specified during two-dimensional scanning with a difference image representation representing the changes in the radiofrequency image representations.
10. The apparatus as claimed in claim 9 , wherein the functional unit formed from the ultrasonic signal device and the radiofrequency antenna arrangement, and the comparison device are configured in such a way that the damage or delamination on the component is indicated by maximum amplitudes in the difference image representation.
11. The apparatus as claimed in claim 6 , wherein the ultrasonic signal device contains at least one sonotrode.
12. The apparatus as claimed in claim 11 , wherein the sonotrode is configured in such a way that if the component is the power module, the ultrasonic signal irradiation is radiated in directly in the bottom region of the power module.
13. A power electronic device, in particular a converter, characterized by an apparatus as claimed in claim 6 which carries out the method as.