Precise Localisation and Detailed Mapping of Hotspots and Temperature Differences
The principle of non-contact thermographic temperature measurement allows the error-free determination of the temperature of small objects with small heat capacity. This is often impossible, however, even when using the smallest contacting temperature sensors, as their heat dissipation frequently falsifies the measurement results. In many cases, the use of thermocouples is impossible due to the design or function of the circuit itself. In addition, the structures of electronic measurement objects are sometimes so small that temperature sensors cannot be attached to them.
However, thermographic systems with a high spatial resolution are able to make such small structures clearly visible and, in addition, to determine their exact temperature distribution along with their chronological sequence. By means of specific close-ups and powerful infrared microscopic lenses, users can thermographically measure hotspots of just a few micrometres in size on the surface of components such as semiconductor components. If SIL lenses (Solid Immersion Lenses) are additionally used, even smaller structure sizes can be detected. In combination with appropriate active thermography methods (lock-in thermography), temperature differences of less than 1 mK are clearly visible for failure localisation.
InfraTec offers matching lenses and cameras with cooled and uncooled detectors with native resolutions up to (1,920 × 1,536) IR pixels. With MicroScan – available for cameras with both cooled and uncooled detectors - the spatial resolution can be further improved. The thermograms obtained in this way ensure that components and assemblies are depicted down to the smallest detail and that failures can be precisely detected and localised. Thermal images with an enormous spatial resolution of a few megapixels pay off especially for complex assemblies, where many structures can be captured simultaneously on the respective measurement and test object. If the pixel number of the detector of the used camera is too small, the number of images required for the complete acquisition of the measurement object increases.
Lock-in Thermography in Electronics and Electrical Engineering
By means of lock-in analysis procedure of InfraTec's IRBIS® 3 active, errors that only cause mK or μK deviations can be reliably detected and assigned to their location: