Method, system and probe for measuring and visualizing values of electromagnetic parameters of a PCB

Abstract

The invention relates to a method, a system and a probe for measuring and visualizing values of electromagnetic parameters of a PCB, wherein a probe head of the probe non-contact measures values of at least one electromagnetic parameter at at least two different locations of the PCB; a camera fixed in place relative to the probe head records an image of an area of the PCB around the probe head for each of the different locations; for each of the different locations, the measured values of the electromagnetic parameter are associated with the recorded image of the area of the PCB around the probe head; a position of each recorded image of the area on a map representation of the PCB is determined; the map representation of the PCB is overlaid with the measured values of the electromagnetic parameter, and the map representation of the PCB is visualized together with the overlaid measured values of the electromagnetic parameter.

Description

Technical Field

[0001] The present invention relates to a method, system, and probe for visualizing the measurement values ​​of electromagnetic parameters of a printed circuit board (PCB), wherein the probe tip non-contactly measures the value of at least one electromagnetic parameter at at least two different locations of the PCB, and an image of the area of ​​the PCB around the probe tip is recorded for each of the different locations relative to a camera fixed in place relative to the probe tip. Background Technology

[0002] A probe, particularly an oscilloscope probe, is a device used to connect a signal source (such as a measurement point in an electronic circuit used to measure signals in that circuit) to an oscilloscope. Specifically, the probe has a physical connection to the oscilloscope, thus establishing an electrical connection. Depending on the signal source and the measurement to be performed, a probe can be as simple as a wire (e.g., a passive probe) or as complex as an active differential probe, which includes an amplifier to keep the probe input capacitance at a very low level, thereby minimizing the probe's influence on the signal to be measured.

[0003] Different oscilloscope probes exist for various applications, such as debugging complex electronic circuits, measuring the signal integrity of high-speed serial bus signals, and characterizing power electronic devices with high voltage levels.

[0004] Furthermore, it should be noted that due to the miniaturization of electronic circuits, it has become increasingly difficult to precisely place the probe head or probe tip of a probe at the desired measurement point for measuring the signal. In view of this problem, European patent application EP 3 686 610 A1 describes a probe, a measurement system and method for applying the probe, wherein an image capturing device, such as a camera, is securely arranged at the probe. The image capturing device captures image data around the area of ​​the probe tip and then provides the captured image data to the user while positioning the probe tip at the desired measurement point. Therefore, the user can have a detailed view of the area around the probe tip, and the positioning of the probe tip is simplified.

[0005] The aforementioned electronic circuits are mainly located on the PCB.

[0006] It should also be noted that the probe can be connected not only to an oscilloscope, but also to a spectrum analyzer, signal analyzer, or electromagnetic interference (EMI) test receiver.

[0007] Unlike probes that come into direct contact with electronic circuits, there are also so-called near-field probes, which do not come into direct contact with electronic circuits and measure parameters based on non-touch or non-contact measurement methods.

[0008] Near field probes are used to analyze electromagnetic compatibility (EMC) problems in electronic circuits and to determine the cause (e.g. EMI) thereof. There are multiple near field probe sets, including E- and H-field probes for oscilloscopes, signal and spectrum analyzers and EMI test receivers.

[0009] For example, if a developer has to find out the cause for exceeding the emission limit of an EMC standard, a near field measurement is usually performed. Based on the field strength measurement, the developer already knows multiple critical frequencies of the device or module under test. A practical approach to reduce EMI is to analyze the near field, locate the source and propose targeted countermeasures. Furthermore, passive near field probes can also be used for immunity measurements.

[0010] With these near field probes, a specific parameter, e.g. an EMI or EMC parameter, can be measured at a desired measurement point or location and the value of the parameter at this specific location can be shown or displayed on e.g. an oscilloscope.

[0011] However, for example, in order to clearly determine which areas of a PCB are high in EMI and where the EMI source exactly resides, it is necessary to obtain the values of the EMC or EMI parameter at different locations or areas of the PCB. Therefore, probe measurements have to be performed at multiple locations of the PCB and each value has to be saved or noted in order to obtain the respective parameter value for each location. At the end of the measurement, the user then has to manually compare these values to each other and check at which locations the highest values exist. This procedure is quite complex for the user. SUMMARY

[0012] It is therefore an object of the present invention to simplify the location of EMI sources on a PCB.

[0013] This object is achieved by the embodiments of the present invention. The embodiments of the present invention further improve the central idea of the present invention.

[0014] The present invention relates to a method for visualizing measurement values of electromagnetic parameters of a PCB, wherein a probe head of a probe non-contact measures values of at least one electromagnetic parameter at at least two different locations of the PCB and a camera fixed in position relative to the probe head records an image of an area of the PCB around the probe head for each of the different locations. Then, for each of the different locations, the measurement values of the electromagnetic parameter are associated with the recorded image of the area of the PCB around the probe head and a position of each recorded image of the area on a map representation of the PCB is determined. Furthermore, the map representation of the PCB is overlaid with the measurement values of the electromagnetic parameter and the map representation of the PCB is visualized together with the overlaid measurement values of the electromagnetic parameter.

[0015] Advantageously, the electromagnetic parameter can be an electromagnetic compatibility (EMC) parameter or an electromagnetic interference (EMI) parameter.

[0016] In a preferred embodiment, a map representation of the PCB is available at the beginning of the method, wherein each recorded image of the area is compared to the map representation of the PCB and the position of each recorded image of the area on the map representation of the PCB is determined based on the comparison. The map representation of the PCB can be a graphical map representation of the PCB, in particular a photo or an image of the PCB, and the graphical map representation of the PCB is recorded or pre-recorded at the beginning of the method. It is also possible that the map representation of the PCB is a pre-available layout of the PCB and the image of the PCB is generated by using the recorded images of the area.

[0017] In another preferred embodiment, a map representation of the PCB is not available at the beginning of the method, wherein the map representation of the PCB is generated by using the recorded images of the area after the correlation and before the determination. In this case, the position of each recorded image of the area on the map representation of the PCB can be determined based on the previous generation.

[0018] Advantageously, the superimposed measured values of the electromagnetic parameter can be visualized on the map representation of the PCB by using 2-dimensional, 2.5-dimensional or 3-dimensional techniques, wherein the superimposed measured values of the electromagnetic parameter can be overlaid with pseudo-colors on the map representation of the PCB, the map representation of the PCB can be pseudo-color coded based on the superimposed measured values of the electromagnetic parameter to visualize it, or the superimposed measured values of the electromagnetic parameter can be visualized on the map representation of the PCB using a bar chart.

[0019] The present application also relates to a system for visualizing measurement values of electromagnetic parameters of a PCB, wherein the system comprises a probe having a probe head for non-contact measurement of values of at least one electromagnetic parameter at at least two different locations of the PCB and a camera fixed in position relative to the probe head and for recording an image of an area of the PCB around the probe head for each of the different locations. Furthermore, the system comprises a processing device for associating the measurement values of the electromagnetic parameter with the recorded image of the area of the PCB around the probe head for each of the different locations, determining a position of each recorded image of the area on a map representation of the PCB and superimposing the map representation of the PCB with the measurement values of the electromagnetic parameter. Furthermore, the system comprises a visualization device for visualizing the map representation of the PCB together with the superimposed measurement values of the electromagnetic parameter.

[0020] Advantageously, the camera can be arranged in the probe, in particular in the probe head, or close to the probe, and the probe can comprise a button or a micro button for triggering the camera to record the image of the area.

[0021] Furthermore, the system can also comprise an oscilloscope, a spectrum analyzer, a signal analyzer or an EMI test receiver, wherein the processing device and the visualization device can be arranged in the oscilloscope, the spectrum analyzer, the signal analyzer or the EMI test receiver and the probe and the camera are connected with the oscilloscope, the spectrum analyzer, the signal analyzer or the EMI test receiver.

[0022] The present application also relates to a probe for measuring values of electromagnetic parameters of a PCB, wherein the probe comprises a probe head for non-contact measurement of values of at least one electromagnetic parameter at at least two different locations of the PCB and a camera for recording an image of an area of the PCB around the probe head for each of the different locations. Furthermore, the probe comprises a processing unit for associating the measurement values of the electromagnetic parameter with the recorded image of the area of the PCB around the probe head for each of the different locations, determining a position of each recorded image of the area on a map representation of the PCB and superimposing the map representation of the PCB with the measurement values of the electromagnetic parameter. Furthermore, the probe comprises a transmission unit for transmitting the map representation of the PCB together with the superimposed measurement values of the electromagnetic parameter to a visualization device.

[0023] Advantageously, the transmission unit can be configured to transmit a map representation of the PCB along with superimposed measurements of the electromagnetic parameters to an oscilloscope, spectrum analyzer, signal analyzer, or EMI test receiver.

[0024] By measuring values ​​at different locations, recording images of those locations, and correlating the measurements with the corresponding images, the location of the corresponding image on the PCB can be found, and that location can be associated with the corresponding measurement value. Through this correlation, a corresponding map representation of the entire PCB and all measurement values ​​can be displayed together, thus providing users with detailed information on where EMI sources exist and areas with particularly high EMI levels. Attached Figure Description

[0025] These and other aspects and advantages of the invention will become more apparent when studied in conjunction with the accompanying drawings in the following detailed description, wherein:

[0026] Figure 1 A flowchart of a method according to an embodiment of the present invention is shown;

[0027] Figure 2 A flowchart of a method according to an embodiment of the present invention is shown;

[0028] Figure 3 A flowchart of a method according to an embodiment of the present invention is shown;

[0029] Figure 4 A system for visualizing the measured values ​​of electromagnetic parameters of a PCB is schematically illustrated according to one embodiment of the present invention.

[0030] Figure 5 A system for visualizing the measured values ​​of electromagnetic parameters of a PCB is schematically illustrated according to one embodiment of the present invention.

[0031] Figure 6 A probe for measuring the values ​​of electromagnetic parameters of a PCB is schematically shown according to one embodiment of the present invention. Detailed Implementation

[0032] As described above, near-field probes are used to analyze EMC problems in electronic circuits and identify their sources. Therefore, electromagnetic parameters of electronic circuits on a PCB are measured to find the causes of emissions exceeding EMC standards. To reduce EMI, near-field analysis is performed to locate the sources of EMI and propose targeted countermeasures.

[0033] So far, the user had to save or note the measured values of the electromagnetic parameters at each location of the PCB and then had to manually compare and check where the highest values and thus the highest EMI were measured, which is very complex and requires a lot of time and effort.

[0034] In contrast, in the present application, a method, a system and a probe for visualizing measured values of electromagnetic parameters of a PCB are provided, wherein the values of the electromagnetic parameters at different locations of the PCB are measured non-contact and at each location an image of the area around the probe head is recorded by a camera. The measured values and the image of each location are correlated and the position of the image on the PCB is determined. Based on this position, a map representation of the PCB is overlaid with the measured values of the electromagnetic parameters and then said map representation is visualized with the overlaid measured values of the EMC parameters.

[0035] Figure 1 A block diagram of a method for visualizing measured values of electromagnetic parameters of a PCB is shown. In step S11, a probe head of a probe non-contact measures values of at least one electromagnetic parameter at at least two different locations of the PCB. Thus, at least two values, preferably a plurality of values, of electromagnetic parameters, such as EMC or EMI parameters, are obtained by non-contact measurement using a probe with a probe head.

[0036] Furthermore, the method also comprises a step S12, in which, in this step, a camera fixed in position relative to the probe head records an image of the area of the PCB around the probe head for each of the different locations. The camera being fixed in position relative to the probe head means that when the probe with the probe head is moved to another location or area on the PCB, the camera is also moved in a similar manner so that the camera can then record the area of the PCB around the probe head at the new location. This is possible, for example, in the case of the camera being arranged in the probe, in particular the probe head, at the probe, or the camera being arranged in close proximity to the probe by a fixed connection to the probe, so that when the probe is moved, the camera moves in a similar manner together with the probe.

[0037] In step S12, for each different location, an image of the area of the PCB around the probe head is recorded. Alternatively, the camera can record or output a video stream (comprising a plurality of images) of each location and then, for the other steps of the method, the video stream of the area is used instead of the image of the area. By recording only one image per location, the amount of data transmission will be significantly reduced.

[0038] By measuring the values of the electromagnetic parameters at each different location of the PCB and the image, there are a plurality of values and images and one value and one image for each location.

[0039] Hence, in step S13, the method further comprises, for each of the different positions, associating the measured value of the electromagnetic parameter with the recorded image of the area of the PCB around the probe head.

[0040] After this association, then in step S14, the position of each recorded image of the area on the map representation of the PCB can be determined, and in step S15, the map representation of the PCB is overlaid with the measured values of the electromagnetic parameter. This means that, by using the recorded image of each area, so for each position for which a measurement has been made, the corresponding position on the PCB can be determined, and then, by knowing the exact position, the map representation can be overlaid with the measured values.

[0041] The step of overlaying the map representation of the PCB with the measured values of the electromagnetic parameter in step S15 means that, for example based on the knowledge of the measured positions on the map representation of the PCB, each measured value of the electromagnetic parameter can be assigned or allocated or attached to a position on the map representation of the PCB.

[0042] Then in step S16, the map representation of the PCB is visualized together with the overlaid measured values of the electromagnetic parameter.

[0043] The visualization in step S16 means that the map representation of the PCB is displayed together with the measured values of the electromagnetic parameter, based on 2-dimensional, 2.5-dimensional or 3-dimensional techniques, for example, the measured values of the electromagnetic parameter are overlaid on the map representation of the PCB with pseudo-colors, the map representation of the PCB is pseudo-color coded based on the overlaid measured values of the electromagnetic parameter to visualize it, or the overlaid measured values of the electromagnetic parameter are visualized on the map representation of the PCB using a bar chart. These overlay techniques between a map or map representation and values already exist, so are not described in more detail here.

[0044] It refers to a map of a country, for example, overlaid with different values of a temperature parameter, for example, values known from multiple weather applications, just as an example. Another option is a 3-dimensional view of the PCB, for example, to paint different parts (hardware components) of the PCB in different colors according to the measured values of the electromagnetic parameter.

[0045] Furthermore, different values can be displayed, which are distributed over the PCB by using a bar chart with different heights on the 3-dimensional map representation of the PCB to display the measured values. Furthermore, the map representation of the PCB can be overlaid with pseudo-colors to display different measured values.

[0046] As already described before, the probe with the probe head is connected to an oscilloscope, spectrum analyzer, signal analyzer or EMI test receiver. Thus, the map representation of the PCB and the superimposed measured values of the electromagnetic parameters can be visualized together on the display of the oscilloscope, spectrum analyzer, signal analyzer or EMI test receiver. This can be achieved in addition to any display of the measured values or by replacing the measured values so displayed.

[0047] Alternatively, also a separate additional display can be used which is attached.

[0048] Displaying the generated map representation of the covered PCB will provide the user with the most helpful overview about where the critical parts in the electronic circuit are located, and in addition, simple documentation can be done, e.g. by a screen shot.

[0049] Figure 2 Another block diagram of a method for visualizing measured values of electromagnetic parameters of a PCB is shown, wherein, Figure 1 The determination step S14 is described in more detail in steps S14a and S14b of Figure 2 Steps S11, S12, S13, S15 and S16 are similar to steps S11, S12, S13, S15 and S16 of Figure 1 Steps S11, S12, S13, S15 and S16 of

[0050] Further, in the method shown in Figure 2 the map representation of the PCB is available at the beginning of the method, wherein the map representation of the PCB is a graphical map representation of the PCB, in particular a photo or image of the PCB, and the graphical map representation of the PCB is recorded or pre-recorded, e.g. at the beginning of the method, wherein the recording at the beginning of the method can be done by any camera. This means that the map representation of the PCB, e.g. the photo or image, is already available before step S11 is performed.

[0051] This already pre-available map representation of the PCB is then used in steps S14a and S14b, wherein in step S14a each recorded image of the area is compared to the map representation of the PCB and in step S14b the position of each recorded image of the area on the map representation of the PCB is determined based on the comparison of step S14a.

[0052] For steps S14a and S14b, a smart bitmap processing algorithm is used to compare for each of the different positions the respective image of the area of the PCB around the probe head to the map representation of the PCB and to determine the position of each recorded image of the area on the map representation of the PCB. As such algorithms already exist, they are not described in more detail here.

[0053] Instead of a photo or image as a map representation or graphical map representation of the PCB, in the method of Figure 2 the map representation can also be a pre-available layout of the PCB and the pre-available layout of the PCB is superimposed with the measured values. In case the pre-available layout of the PCB is used at the beginning as a map representation of the PCB and it is desired to obtain a photo or image to visualize the superimposed measured values of the electromagnetic parameters, a photo or image of the PCB can be generated or created based on the recorded images of the areas in step S12. Thus, even if only the layout of the PCB is pre-available at the beginning of the method, a photo or image of the PCB can be visualized in step S16 together with the superimposed measured values of the electromagnetic parameters.

[0054] Figure 3 It is further described a method for visualizing measured values of electromagnetic parameters of a PCB, wherein, Figure 3 the method of Figure 2 is particularly used in case no map representation of the PCB is available at the beginning of the method. Likewise, steps S11, S12, S13, S15 and S16 correspond to Figure 1 steps S11, S12, S13, S15 and S16 of the method of

[0055] In the method of Figure 2 the map representation of the PCB is already available at the beginning of the method, unlike Figure 2 is that in Figure 3 after the associating step S13, there is another step S17 in which the map representation is generated or created or constructed by using the recorded images of the areas. In order to generate such a map representation of the PCB, it is preferred that the recorded images of the areas of the PCB together cover the whole PCB so that by joining or assembling or connecting the individual recorded images of each area of the PCB, a complete image of the PCB can be generated as a map representation of the PCB. Techniques for generating a map representation by using different single images are already known, just as an example, it is called the technique of making a panoramic picture by using multiple single pictures (photo stitcher technique).

[0056] Furthermore, it should be noted that, preferably, in the steps S11 and S12 of measuring these values and recording the images of the areas, the different positions are selected in a specific order, which is saved, so that it is clear in the step S17 which images must be connected to each other. As an example, when the PCB has a square shape, the first position is in the upper left corner, then from this corner, the next position is selected along the left line of the square to the lower left corner, then the next position is selected by moving to the right. After that, the next position is selected from the lower line to the upper line and the positions are moved to the right on the upper line. This process is done according to the size of the area of the whole square, so that each area of the PCB is covered in the corresponding order.

[0057] The different positions of the steps S11 and S12 can be selected in the method shown in Figure 1 , Figure 2 and Figure 3 in the specific order as described above, wherein in the method of Figure 1 and the method of Figure 2 it is also possible to select the positions randomly without a specific order. In case of a random positioning of the probes and probe head in the steps S11 and S12, it should preferably be ensured that each area of the PCB is covered by a probe.

[0058] In the method of Figure 3 the determination step S14 of the method of Figure 1 is further specified, wherein in the step S14c the position of each recorded image of an area on the map representation of the PCB is determined based on the generating step S17. Since in the step S17 each recorded image of an area is joined together to become the map representation of the PCB, it is known where each recorded image is placed on the map representation of the PCB. This information is stored and then used in the step S14c to determine the position. In this case, it is no longer necessary to use an intelligent bitmap processing algorithm to compare the recorded images of the areas with the map representation of the PCB to find each position of each recorded image.

[0059] Figure 4 A system for visualizing measured values of electromagnetic parameters of a PCB is schematically shown, wherein the system comprises a probe 21 having a probe head 22 to non-contact measure values of at least one electromagnetic parameter at at least two different positions of a PCB 24. The system further comprises a camera 23 fixed in position relative to the probe head 22 to record, for each of the different positions, an image of an area 25 of the PCB 24 around the probe head 22. It can be seen from Figure 4 that the camera 23 is fixed at the probe 21 or the probe head 22. The camera 23 can also be integrated in the probe 21 or the probe head 22.

[0060] Only relevant is that the camera 23 can record images of the area 25 of the PCB around the probe head 22. By placing the camera 23 at or in the probe 21 or the probe head 22, it can be further ensured that in case the probe head 22 or the probe 21 is moved from one position to another, the camera 23 is moved in a similar way, so that always a respective area 25 of the PCB 24 around the probe head 22 is recorded.

[0061] Furthermore, the system comprises a processing device 26 and a visualization device 27, wherein the processing device 26, for each of the different positions, correlates the measured values of the electromagnetic parameters with the recorded images of the area 25 of the PCB 24 around the probe head 22, determines the position of each recorded image of the area 25 on the map representation of the PCB 24, and superimposes the map representation of the PCB 24 with the measured values of the electromagnetic parameters. The visualization device 27 visualizes the map representation of the PCB 24 together with the superimposed measured values of the electromagnetic parameters.

[0062] The processing device 26 and the visualization device 27 can for example be placed in an oscilloscope 28, a spectrum analyzer, a signal analyzer or an EMI test receiver, and the probe 21 and the camera 23 are electrically connected with the oscilloscope 28, the spectrum analyzer, the signal analyzer or the EMI test receiver. In particular, in the system of Figure 4 In the system of

[0063] Furthermore, the probe can comprise a button or a micro button for triggering the camera to record an image of the area. By such a button or micro button, the user can trigger the recording of the image when repositioning the probe. Furthermore, by this button not only the recording of the image can be triggered, but also the measurement of the values on the respective position. Thus, by pressing the button or micro button only once, the recording of the image and the measurement of the values are triggered.

[0064] In Figure 5 In the system of Figure 5 In the system of

[0065] However, in the system of Figure 4The camera 33 is not positioned directly at the probe 31 or the probe head 32, nor inside the probe 31 or the probe head 32, but somewhere around or close to the probe 31 and the probe head 32 (but not directly at the probe 31 or the probe head 32), such that the camera 33 can record the area 35 around the probe head 32 of the PCB 34. To ensure that the position of the camera 33 is fixed with respect to the probe head 32, the camera 33 is fixed to the probe 31 or the probe head 32 by a rigid connection 39. By this rigid connection 39, it is again ensured that the camera 33 moves in a similar way as the probe 31 or the probe head 32 and thus can always record the area 35 around the probe head 32 of the PCB 34.

[0066] Figure 5 The processing device 36 and the visualization device 37 in the oscilloscope 38 have similar functions as the processing device 26 and the visualization device 27 in Figure 4

[0067] With regard to the visualization devices 27 and 37, it should be noted that, in Figure 4 and Figure 5 In the oscilloscopes 28 and 38, the visualization devices 27, 37 are shown to be placed. However, it is also possible to use separate visualization devices to visualize the map representation of the PCB together with the superimposed measured values of the electromagnetic parameter.

[0068] Figure 6 A probe 41 for measuring values of an electromagnetic parameter of a PCB 44 is shown, which comprises a probe head 42 for non-contact measurement of values of at least one electromagnetic parameter at at least two different locations of the PCB 44, a camera 43 for recording, for each of the different locations, an image of an area 45 around the probe head 42 of the PCB 44, a processing unit 46 for associating, for each of the different locations, the measured values of the electromagnetic parameter with the recorded image of the area 45 around the probe head 42 of the PCB 44, determining a position of each recorded image of the area 45 on a map representation of the PCB 44, and superimposing the map representation of the PCB 44 with the measured values of the electromagnetic parameter. Furthermore, the probe 41 also comprises a transmission unit (not explicitly shown in Figure 6 for transmitting the map representation of the PCB 44 together with the superimposed measured values of the electromagnetic parameter to a visualization device 47.

[0069] Figure 6 The visualization device in can also be similar to Figure 4 and Figure 5 ​placed in an oscilloscope, or a spectrum analyzer, a signal analyzer or an EMI test receiver and the transmission unit transmits the map representation of the PCB together with the superimposed measured values of the electromagnetic parameters to the oscilloscope, the spectrum analyzer, the signal analyzer or the EMI test receiver.

[0070] With regard to the positioning and arrangement of the camera 43 in or at the probe 41 or the probe head 42, reference can also be made to Figure 4 the system shown, wherein the video camera 23 is also located in or at the probe 21 or the probe head 22.

[0071] Similarly to Figure 4 and Figure 5 , also in Figure 6 the visualization device can be an additional device separate from the oscilloscope and the visualization device is connected to the probe for transmitting the map representation of the PCB to the visualization device.

[0072] Furthermore, Figure 1 , Figure 2 and Figure 3 the method can be performed by Figure 4 each system of Figure 5 and Figure 6 the probe.

[0073] With the present invention, it is possible to display or visualize a map representation of a PCB, wherein measured values of electromagnetic parameters can be overlaid on the map representation, so that a user has an overview about where critical parts of EMC and EMI in electronic circuits on the PCB are located.

Claims

1. A method for visualizing measurement values of electromagnetic parameters of a printed circuit board, PCB, comprising: - non-contact measurement (SI 1) of values of at least one electromagnetic parameter at at least two different locations of the PCB by a probe head of a probe; - recording (SI 2), for each of the different locations, of an image of an area of the PCB around the probe head by a camera fixed in place with respect to the probe head; - associating (SI 3), for each of the different locations, the measurement values of the electromagnetic parameter with the recorded image of the area of the PCB around the probe head; - determining (SI 4) a position of each recorded image of the area on a map representation of the PCB; - superimposing (SI 5) the map representation of the PCB with the measurement values of the electromagnetic parameter; - visualizing (SI 6) the map representation of the PCB together with the superimposed measurement values of the electromagnetic parameter, wherein the map representation of the PCB is not available at the beginning of the method, and wherein the method further comprises, after the associating step (SI 3) and before the determining step (SI 4): - generating (SI 7) the map representation of the PCB by using the recorded images of the area; and wherein the determining step (SI 4) further comprises: - determining (SI 4c), based on the generating step, the position of each recorded image of the area on the map representation of the PCB.

2. The method according to claim 1, wherein the electromagnetic parameter is an electromagnetic compatibility, EMC, parameter or an electromagnetic interference, EMI, parameter.

3. The method according to any one of claims 1-2, wherein in the visualizing step (SI 6), the superimposed measurement values of the electromagnetic parameter are visualized on the map representation of the PCB by using 2-dimensional, 2.5-dimensional or 3-dimensional techniques.

4. The method according to claim 3, wherein in the visualizing step (SI 6), the superimposed measurement values of the electromagnetic parameter are overlaid on the map representation of the PCB in pseudo-color, the map representation of the PCB is pseudo-color coded based on the superimposed measurement values of the electromagnetic parameter to visualize it, or the superimposed measurement values of the electromagnetic parameter are visualized on the map representation of the PCB using a bar chart.

5. A system for visualizing measurement values of electromagnetic parameters of a printed circuit board, PCB (24, 34), comprising: - a probe (21, 31) having a probe head (22, 32) configured to non-contact measurement of values of at least one electromagnetic parameter at at least two different locations of the PCB (24, 34); - a camera (23, 33) fixed in place with respect to the probe head (22, 32) and configured to record, for each of the different locations, an image of an area (25, 35) of the PCB (24, 34) around the probe head (22, 32); - a processing device (26, 36) configured to: - non-contact measurement of values of at least one electromagnetic parameter at at least two different locations of the PCB by a probe head of a probe; - recording, for each of the different locations, of an image of an area of the PCB around the probe head by a camera fixed in place with respect to the probe head; - associating, for each of the different locations, the measurement values of the electromagnetic parameter with the recorded image of the area of the PCB around the probe head; - determining a position of each recorded image of the area on a map representation of the PCB; - superimposing the map representation of the PCB with the measurement values of the electromagnetic parameter; - visualizing the map representation of the PCB together with the superimposed measurement values of the electromagnetic parameter, wherein the map representation of the PCB is not available at the beginning of the method, and wherein the method further comprises, after the associating step and before the determining step: - generating the map representation of the PCB by using the recorded images of the area; and wherein the determining step further comprises: - determining, based on the generating step, the position of each recorded image of the area on the map representation of the PCB. • for each of said different positions, associating a measured value of said electromagnetic parameter with a recorded image of a zone (25, 35) of said PCB (24, 34) around said probe head (22, 32), • determining a position of each recorded image of said zone (25, 35) on a map representation of said PCB (24, 34), and • superimposing the map representation of said PCB (24, 34) with the measured values of said electromagnetic parameter; and - a visualization device (27, 37) configured to visualize the map representation of said PCB (24, 34) with the superimposed measured values of said electromagnetic parameter; wherein the map representation of the PCB is not available at the beginning for the processing device (26, 36), and the processing device (26, 36) is further configured to, after associating the measured values and before determining the position of each recorded image, - generate the map representation of the PCB by using the recorded images of the zone; and - determine the position of each recorded image of the zone on the map representation of the PCB based on the generation of the map representation.

6. The system of claim 5, wherein, the camera (23, 33) is arranged in the probe (21, 31) or close to the probe (21, 31).

7. The system of any one of claims 5-6, wherein, the system further comprises an oscilloscope (28, 38), a spectrum analyzer, a signal analyzer or an electromagnetic interference test receiver, wherein the processing device (26, 36) and the visualization device (27, 37) are arranged in the oscilloscope (28, 38), the spectrum analyzer, the signal analyzer or the electromagnetic interference test receiver and the probe (21, 31) and the camera (23, 33) are connected with the oscilloscope (28, 38), the spectrum analyzer, the signal analyzer or the electromagnetic interference test receiver.

8. The system of any one of claims 5-6, wherein the probe (21, 31) comprises a button or a micro button for triggering the camera (23, 33) to record the image of the zone (25, 35).

9. The system of claim 6, wherein, the camera (23, 33) is arranged in the probe head (22, 32).

10. A probe (41) for measuring values of electromagnetic parameters of a printed circuit board, PCB (44), comprising: - a probe head (42) configured to non-contact measure values of at least one electromagnetic parameter at at least two different positions of the PCB (44); - a camera (43) configured to, for each of said different positions, record an image of a zone (45) of the PCB (44) around the probe head (42); - a processing unit (46) configured to: • for each of said different positions, associating a measured value of said electromagnetic parameter with a recorded image of said area (45) of the PCB (44) around the probe head (42), • determining the position of each recorded image of said area (45) on a map representation of said PCB (44), and • superimposing the map representation of said PCB (44) with the measured values of said electromagnetic parameter; and - a transmission unit configured to transmit the map representation of said PCB (44) with the superimposed measured values of said electromagnetic parameter to a visualisation device (47), wherein the map representation of the PCB is not available to the processing unit (46) at the outset, and the processing unit (46) is further configured to, after associating the measured values and before determining the position of each recorded image, - generate the map representation of the PCB by using the recorded images of the area; and - determine the position of each recorded image of the area on the map representation of the PCB based on the generation of the map representation.

11. Probe according to claim 10, wherein, the transmission unit being configured to transmit the map representation of said PCB (44) with the superimposed measured values of said electromagnetic parameter to an oscilloscope, a spectrum analyser, a signal analyser or an electromagnetic interference test receiver.

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