Abstract: Method for a non-destructive and image forming examination of a sample (1) by means of a heat flow thermography method where the examination consists of evaluating the presence of any gradients in heat flow velocity at respective depth distances from a surface of the sample (1), comprising exciting the sample (1) by means of periodic heat pulses P1 from at least one excitation source, and capturing thermal image sequences of a thermal flow originating from the heat pulses by at least one infrared camera (5), implementing relative time delays ?t between a starting point of imaging of the respective image sequences and a starting point of the periodic excitation, combining all captured image sequences to a resulting image sequence in which all images are arranged in a correct time sequence, and extracting from the resulting image sequence an indication of the existence and depth distance of a heat flow velocity transition from a surface of the sample.

Abstract: The invention provides a method for a non-destructive, non-contacting and image forming examination of a sample by means of heat flow thermography.

Abstract: A method for localizing a hot spot (27) in a sample (12), in particular an encapsulated device under test (DUT), by using lock-in thermography (LIT), where at least one heat source (23) of an electrical circuit is buried within the sample (12) and generated the hot spot (27) upon flow of current therein, comprises applying a non-harmonic excitation wave test signal at a lock-in frequency to the electrical circuit of the sample (12) to activate the heat source (23) for generating the hot spot (27); imaging the sample (12) using an infrared sensor (16) to obtain IR images of the sample (12) while the non-harmonic test signal is applied to the electrical circuit; and detecting a thermal response signal obtained from the imaging, the thermal response signal being in correlation to the thermal heat propagation within the sample (12).

Abstract: Method for a non-destructive and image forming examination of a sample (1) by means of a heat flow thermography method where the examination consists of evaluating the presence of any gradients in heat flow velocity at respective depth distances from a surface of the sample (1), comprising exciting the sample (1) by means of periodic heat pulses P1 from at least one excitation source, and capturing thermal image sequences of a thermal flow originating from the heat pulses by at least one infrared camera (5), implementing relative time delays ?t between a starting point of imaging of the respective image sequences and a starting point of the periodic excitation, combining all captured image sequences to a resulting image sequence in which all images are arranged in a correct time sequence, and extracting from the resulting image sequence an indication of the existence and depth distance of a heat flow velocity transition from a surface of the sample.

Abstract: The invention provides a method for a non-destructive, non-contacting and image forming examination of a sample by means of heat flow thermography.