Test body for checking image quality during x-ray inspection of test object, use of such test body, and method for determining defect detection sensitivity and / or for determining depth of field

Abstract

To provide a test body for checking image quality during X-ray inspection of a test object.SOLUTION: A test object 2 comprises a first layer of a test object 10 to be checked, the test object 10 being arranged on an intermediate layer 15. A test body 1 includes a first test layer 3 and a solid spacer plate 9 arranged on the first test layer 3, the thickness of the first test layer 3 corresponding to the thickness of the test object 10, the thickness of the spacer plate 9 corresponding to the thickness of the intermediate layer 15, a plurality of first holes 5 being formed in the first test layer 3, the depth and the diameter of the plurality of first holes 5 being equal, the size of the plurality of first holes 5 corresponding to a part of the size of the test object 10 to be detected as a defect, the material constituting the first test layer 3 having an absorption coefficient corresponding to the absorption coefficient of the test object 10, and the material constituting the spacer plate 9 having an absorption coefficient corresponding to an absorption coefficient of the intermediate layer 15.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a test object for checking image quality during X-ray inspection of a test object, the test object having a plurality of layers of the test object to be checked, the test object being the same size in each individual layer and having intermediate layers between each of these layers, and to the use of such a test object for determining the defect detection sensitivity and / or for determining the depth of field of an X-ray system. The present invention also relates to a method for determining the defect detection sensitivity and / or for determining the depth of field of an X-ray system. [Background technology]

[0002] The field of use of the invention is X-ray based material testing. The use of X-rays for imaging allows the investigation of hidden structures without destroying the test object. The inspection is carried out in an X-ray system with an X-ray tube (hereafter referred to as the "tube") and an X-ray detector (hereafter referred to as the "detector") as imaging system. The test object to be inspected is placed on and between the manipulators. Any or all of these three components can move in translation and / or rotation depending on the X-ray system. The whole device is placed in a radiation shielded room. In many systems the inspection of the test object is done manually. The operator has to periodically check the image quality individually to ensure that the imaging chain (X-ray tube, manipulator, X-ray detector) is able to image the required defect size. For better reproducibility and to increase the level of automation, an automatic inspection of the imaging system by the system is required. A test object is needed that can be periodically moved into the image, in which the system can evaluate whether the system is able to reproduce the required defect size or whether adjustments of the system parameters are required to bring it back to the desired state. Up until now, such checks have been performed, for example, by inserting a resolution sample and adjusting the focus of the X-ray tube based on that image.

[0003] The focal spot size is a parameter that influences the quality of a laminographic scan, but there are also other parameters such as the precision of the manipulation, the movement or alignment of the object.

[0004] US Patent No. 6,694,047 and EP Patent No. 0874536 describe test bodies intended to cover many different application cases with a single test body. The test body accommodates a perforated penetrameter with different filter thicknesses, wire pairs and step wedges. Depending on the application, the area of ​​the test body to be used has to be selected and at a specific position in the test volume, the quality of the image, for example the signal-to-noise ratio (SNR) or contrast-to-noise ratio (CNR), can be evaluated. If evaluation is carried out for several areas in the test volume, the measurements have to be carried out sequentially and the test body has to be placed in different positions.

[0005] The ASTM E 2737 standard also describes the image quality at several points in the test space. Here too, a perforated penetrameter and a step wedge are used to mimic real-world applications, for example to evaluate SNR and CNR. As an example, the procedure is as follows: if the test object is made of aluminum and has a maximum penetration length of 100 mm, 100 mm of aluminum is used as a filter. If one wishes to see a 1 mm void in this aluminum, a perforated penetrameter with a corresponding hole size is placed on the filter. If one can detect this void in the X-ray image, one can assume that one can detect a void of this size.

[0006] The main drawback of the conventional solution is that the image quality is checked only at one point in the image. It is possible to check the quality at several points by moving the test piece to different points, but this is very time-consuming. The longer such an image quality check takes, the less useful it becomes, since the image quality may change, for example due to thermal drift. Now suppose that three points are checked in the test volume, and the first two meet the specifications without any problems, but the third does not. In this case, the question arises: are the first two still within the specifications, or has the system changed and now the first two checked points have also deteriorated? Several rechecks would be required to be able to ascertain reliable information regarding these points. The advantage of checking three points simultaneously is that different system states can be excluded as failure factors. Summary of the Invention [Problem to be solved by the invention]

[0007] The object of the invention is to provide a test object from which information regarding the image quality of an X-ray procedure in all image areas of one or more planes can be ascertained. [Means for solving the problem]

[0008] The above problem is solved according to the invention by a test body having the features of claim 1, by the use of the test body having the features of claim 9 and by a method having the features of claim 10. Advantageous embodiments are set out in the dependent claims.

[0009] The problem is therefore solved by a test body similar in structure to the test object inspected by the X-ray system. The test body according to the invention is used for a test object to be inspected, which has layers of test objects to be checked, which are respectively of the same size and arranged on a solid spacer plate. The test body has a test layer, the thickness of which corresponds to the thickness of the test objects in the test object. In order to achieve the best possible imitation of the test object, the test body also has a solid (i.e. entirely made of material, without holes etc.) spacer plate arranged on the first test layer, which has the same thickness as the intermediate layer and is made of a material with an absorption coefficient corresponding to the absorption coefficient of the material of the intermediate layer. In order to evaluate whether the desired image quality is ensured over the entire surface of the test object, a plurality of first holes are formed in the first test layer, the depth and the diameter of the plurality of first holes being equal and the size of the plurality of first holes corresponds to a portion of the size of the associated test object to be detected as a defect. The material that makes up the first test layer has an absorption coefficient that corresponds to that of the material under test, ensuring that its absorption of the X-ray radiation is as close as possible to the test object. Multiple first holes allow different points / areas across the X-ray beam to be inspected simultaneously, one advantage of which is that different system conditions can be ruled out as defects.

[0010] According to an advantageous development of the invention, it is provided that in case the test object has a second layer, the following further features are present: the test object has a second test layer arranged on a side of the spacer plate opposite to the first test layer, the thickness of the second test layer corresponds to the thickness of the test objects in the second layer, the second test layer is made of a material having an absorption coefficient corresponding to the absorption coefficient of the material of the test objects in the second layer, a plurality of first holes are formed in the second test layer, the depth and the diameter of the plurality of first holes are equal, and the size of the plurality of first holes corresponds to a portion of the size of the associated test objects to be detected as defects. The quality of the depth of field (i.e., whether it is at different depths corresponding to the levels of the two test layers) can be easily assessed because the combination of the first test layer, the spacer plate and the second test layer of the test object corresponds in thickness to the first, intermediate and second layers, respectively, of the test object, each being made of materials having corresponding absorption coefficients, thereby resulting in similar absorption of X-rays within the test object, and the second test layer of the test object is positioned at the same position in the beam path as the layer having the test object to be inspected in the test object.

[0011] According to yet another advantageous development of the invention, it is provided that the test specimen has at least one of the combinations of an additional spacer plate and an additional test layer, the additional spacer plate and the additional test layer corresponding to the spacer plate and the second test layer according to the previous paragraph, respectively. This also makes it possible to simulate test objects using a test specimen with multiple test layers, possibly even test layers with test objects of the same size in the same layer but different sizes in different layers.

[0012] According to a further advantageous development of the invention, it is provided that in each test layer a second hole is formed, the second hole having a diameter at least twice the diameter of the first hole and the same depth as the first hole, which facilitates the measurement of the CNR.

[0013] According to yet another advantageous development of the invention, it is provided that in each test layer a third hole is formed, the third hole having a diameter at least four times the diameter of the first hole and the same depth as the first hole, which also facilitates the measurement of the CNR.

[0014] According to yet another advantageous development of the invention, it is provided that the first and / or second and / or third holes are arranged in at least one of the respective test layers in a matrix covering a large part of the surface of the test layer, in particular that all holes are arranged in a common matrix. Due to the large area distribution of the holes, it is not necessary to position the test object in a large number of positions to determine the image quality over the entire surface of the test object, but rather this can be achieved by a single position that corresponds to the position of the test object during the inspection. This saves time and prevents possible inaccuracies when positioning the test object at different points in the beam path multiple times.

[0015] According to a further advantageous development of the invention, the test object is a circuit board and the test objects are solder balls, which is the most common application case within the scope of the invention.

[0016] In such a case, the test layer is preferably made of a material with a relatively high atomic number (in the context of this application, this is understood to mean an atomic number greater than 22), such as nickel, tin or copper, or an alloy containing at least one of these substances, and / or the spacer plate is made of a material with a relatively low atomic number (in the context of this application, this is understood to mean an atomic number less than 14), preferably silicon. These are the materials to be examined and tested that are used in the most common applications within the scope of the present invention.

[0017] The above problem is also solved by the use of a test object for determining the defect detection sensitivity and / or the depth of field of an X-ray system comprising a tube, a detector, and a holder arranged between the tube and the detector for receiving a test object.

[0018] Finally, the above problem is also solved by a method for determining the defect detection sensitivity and / or depth of field of an X-ray system comprising a tube, a detector and a holder arranged between the tube and the detector for receiving a test object, which method comprises taking a single X-ray image of a test object according to the present invention, which is located in the beam path instead of the test object at the location where the test object is located during inspection, and then evaluating the X-ray image. [Brief description of the drawings]

[0019] Further details and advantages of the invention will now be explained with reference to the exemplary embodiments shown in the drawings. [Figure 1] FIG. 1 is a schematic diagram of a cross-section of a test layer with a hole viewed from above. [Diagram 2] FIG. 2 is a schematic longitudinal section of a portion of a test layer with a hole. [Diagram 3] FIG. 3 is an isometric view of three test layers according to FIG. 1 arranged one on top of the other. [Figure 4] FIG. 4 is a schematic longitudinal section of a portion of a test specimen having two test layers with a spacer plate between them. [Diagram 5] FIG. 5 is a comparison of a test object depicted diagrammatically in longitudinal section with an associated test specimen in schematic view in longitudinal section. [Figure 5a] FIG. 5a is an enlarged view of the test specimen according to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] 1 to 4 show a part of the test body 1 associated with the test object 2 and the whole of the test body 1, and the structure of the test object 2 is as follows: the test object 2 is a circuit board having two layers, and the test object 10 to be inspected is present on the circuit board. In the first layer, a ball grid array (BGA) having balls (solder balls) with a diameter of 200 μm is present. The second layer is arranged 300 μm apart and is composed of a BGA having solder balls with a diameter of 20 μm. Between the two layers, there is a silicon substrate (corresponding to the intermediate layer 15 shown in FIG. 5). It is desirable to be able to detect voids (air mixed in the balls) of 10% of the ball size in each layer.

[0021] Fig. 1 is a schematic top-down view of a cross section of a first test layer 3 of a test body 1 according to the invention (see Fig. 4, Fig. 5 and Fig. 5a for another embodiment). The first test layer 3 is made of the same material as a test object 10 of the first level of a test object 2 (shown in Fig. 5 for another exemplary embodiment) associated with the test body 1. This association means that the test body 1 is used to check the image quality during a series of inspections of the same test object 2, and is structurally replicated. In this case, the test object 10 of the lower level of the test object 2 is a solder ball made of tin, and therefore the first test layer 3 is made of tin.

[0022] The surface of the first test layer 3 is formed with holes 5, 6, 7, which in the illustrated exemplary embodiment are arranged in a square matrix 8. There are three different types of holes: first holes 5 (also called T1 holes), second holes 6 (also called T2 holes) and third holes 7 (also called T4 holes). Their respective diameters and depths depend on the size of their corresponding test objects 10 and the size of the defects to be detected in those test objects 10. The diameter of the first holes 5 is also as large as the size of the defects to be detected. In this case, as mentioned above, this diameter is 10% of 200 μm, i.e. 20 μm. The depth of the first holes 5 is the same as the diameter, i.e. also 20 μm. It is assumed here that if the T1 holes (first holes 5) are detectable in the image, then 10% voids in the solder balls 10 (test objects 10) will also be detectable.

[0023] The second hole 6 (T2 hole) has a diameter twice that of the first hole 5, i.e. 40 μm, and the third hole 7 has a diameter four times that of the first hole 5, i.e. 80 μm. The depth of these holes 6, 7 is the same as that of the first hole 5, i.e. 20 μm. These holes 6, 7 are used to determine the CNR.

[0024] The set of three adjacent holes 5, 6, 7 in a row (for the first row, this is shown by way of example in FIG. 1) represents a perforated penetrometer 16 known from the prior art. In the prior art (see also the above-mentioned US Pat. No. 6,694,047 and EP Patent No. 0 874 536), the test specimen 1 only has one perforated penetrometer 16 or a small number (for example three) of perforated penetrometers 16. Since in the test specimen 1 according to the invention a large number of perforated penetrometers 16 are present in a large number of rows of the matrix 8, i.e. distributed over the entire surface of the first test layer 3, it is sufficient to take a single X-ray image of the test specimen 1 at only one point (corresponding to the position of the test object 2 under examination) to determine the image quality, SNR and CNR. This significantly reduces the time required for the evaluation of the test space. The following description of the second test layer 4 and the spacer plate 9 located between the two test layers 3, 4 is anticipated, but this also applies with regard to their position in the beam path along the X-ray beam.

[0025] Since in the second level of the test object 2 there are solder balls with a size (diameter) of 40 μm to be inspected, the thickness of the second test layer 4 is also 40 μm. Since 10% defects are to be detected, the diameter of the first hole 5 is 4 μm, and accordingly the diameter of the second hole 6 is 8 μm and the diameter of the third hole 7 is 16 μm. The depth of all holes 5, 6, 7 is 4 μm. This second test layer 4 is separated from the first test layer 3 by a spacer plate 9 with a thickness of 50 μm. In order to be as close as possible to the real application case, the spacer plate 9 is made of a silicon disk with a thickness of 50 μm. In principle any material close to the application case can be used for the spacer plate 9, and if possible, it is desirable that the spacer plate 9 has the same absorption coefficient as the corresponding material of the test object 2 or is of such a thickness that the absorption on the beam path through the spacer plate 9 corresponds approximately to the absorption on the beam path between the two planes of the test object 2. The overall structure can be seen in schematic partial longitudinal section in FIG.

[0026] By stacking the layers and components of the test object 2 (here, BGA) and adjusting their actual distance to the focus of the X-ray tube, it is possible to detect the depth of field of the system, which is not constant for the test volume. Therefore, it is important to know the structure of the circuit board to check whether the size of the defect can be detected at the actual distance.

[0027] It is difficult to give a general description of the test specimen 1, since the size of the holes 5, 6, 7 and the arrangement of the test layers 3, 4, 14 must be flexibly adapted to the application, i.e. the test object 2 to be inspected. The above description is therefore based on an exemplary application. In the following, the configuration of the test specimen 1 according to the invention is described on the basis of another exemplary embodiment according to Fig. 5 and Fig. 5a. In Fig. 5, the test object 2 to be inspected is shown on the left and its copy, the test specimen 1, on the right. In Fig. 5a, the test specimen 1 of Fig. 5 is enlarged in order to facilitate the recognition, in particular, of the holes 5, 6, 7.

[0028] The exemplary test object 2 is a circuit board with different levels on which different components reside, the structure of which will be described below from bottom to top, with only those components essential to the invention being described.

[0029] At the lowest level, the test objects 10 are a number of solder balls 10 in the form of package balls 11 with a diameter of 200 μm, which are usually made of tin or an alloy with a high tin content. Above that, an intermediate layer 15 is arranged. Following this, there is a further level with test objects 10 in the form of a number of solder balls 10 (here C4 bumps 12 with a diameter of 40 μm, which are usually made of tin or an alloy with a high tin content). Above that, another intermediate layer 15 is provided. Above this intermediate layer 15, there is a level of test objects 10 in the form of a number of solder balls 10 (here microbumps 13 with a diameter of 10 μm, which are usually made of tin or an alloy with a high tin content). The next level is again an intermediate layer 15. Above that, there is another structure made up of the two levels mentioned above, namely the microbumps 13 and the intermediate layer 15 on top of them.

[0030] As part of the non-destructive X-ray analysis of such circuit boards, the quality of the solder connections between the functional and carrier components of the circuit board, i.e. the quality of the test object 10, is checked (among others). This is usually done by means of a laminography process known in the prior art. For X-ray images taken using the laminography process, it is necessary to check periodically whether the imaging chain achieves a sufficiently high image quality. In particular, this is crucial as to whether defects whose size exceeds a predeterminable level can be detected in the test object 10 and, as a consequence, whether this circuit board has to be removed from the manufacturing process. In order to provide such an evaluation of the image quality within the scope of the inspection sequence of the circuit board designed in this way, a test body 1 according to the invention is used. As already mentioned above with respect to the alternative embodiment shown in FIGS. 1 to 4, the test body 1 according to the invention reproduces the test object 2 as accurately as possible in terms of X-ray characteristics. A test specimen 1 according to the invention shown on the right side of Figure 5 and in Figure 5a, which corresponds to the test object 2 shown on the left side of Figure 5 (described in more detail above), is held in the beam of the X-ray system at the point where the test object 2 is located during the examination and a single image of the test specimen 1 is taken, using which the information already mentioned above for the other exemplary embodiments regarding the image quality can be ascertained over the entire test area, i.e. both in the plane perpendicular to the X-ray beam and over the direction of the X-ray beam (i.e. in the depth direction).

[0031] In the following, the structure of a test specimen 1 associated with a test object 2 in FIG. 5 will be described so that the aforementioned image quality check can be carried out with as little effort as possible.

[0032] The bottom layer, the first test layer 3 (corresponding to the layer of package balls 11 of the test object 2), is made of copper with a thickness of 200 μm. On its surface, three types of holes 5, 6, 7 are formed (as already explained for the other exemplary embodiments in FIGS. 1 to 4): first holes 5 (T1 holes) with a diameter of 20 μm, second holes 6 (T2 holes) with a double diameter and third holes 7 (T4 holes) with a quadruple diameter. All holes 5, 6, 7 have the same depth of 20 μm (corresponding to the diameter of the first holes 5).

[0033] A spacer plate 9 made of silicon with a thickness of 50 μm is placed on top of the first test layer 3. This corresponds to the intermediate layer 15 of the test object 2.

[0034] Thereon is arranged a second test layer 4 made of copper with a thickness of 40 μm, which corresponds to the level of the C4 bumps 12 of the test object 2. On its surface too (as already explained for the other exemplary embodiments in FIGS. 1-4 and for the first test layer 3 of this exemplary embodiment) three types of holes 5, 6, 7 are formed: a first hole 5 with a diameter of 4 μm, a second hole 6 with a double diameter and a third hole 7 with a quadruple diameter. All holes 5, 6, 7 have the same depth of 4 μm (corresponding to the diameter of the first hole 5). The holes 5, 6, 7 are arranged in a matrix 8 (only in plan view, as can be seen in FIGS. 1 and 3) and form a number of perforated penetrometers 16 (see also FIGS. 1 and 4). Each perforated penetrometer 16 is formed by three different holes 5, 6, 7 next to each other.

[0035] On top of the second test layer 4 another spacer plate 9 made of silicon with a thickness of 20 μm is arranged. This corresponds to the intermediate layer 15 of the test object 2.

[0036] Thereon is arranged a third test layer 14 made of copper with a thickness of 10 μm, which corresponds to the level of the microbumps 13 of the test object 2. On its surface too (as already explained for the first test layer 3 and the second test layer 4 of this embodiment) three types of holes 5, 6, 7 are formed: a first hole 5 with a diameter of 1 μm, a second hole 6 with twice the diameter and a third hole 7 with four times the diameter. All holes 5, 6, 7 have the same depth of 1 μm (corresponding to the diameter of the first hole 5). These holes 5, 6, 7 are also arranged in a matrix 8 in which a plurality of perforated penetrometers 16 are formed.

[0037] A further spacer plate 9 made of silicon with a thickness of 20 μm is arranged on top of the third test layer 14. This corresponds to the middle layer 15 of the test object 2.

[0038] Thereon is arranged a fourth test layer 14 made of copper with a thickness of 10 μm, which corresponds to the level of the microbumps 13 of the test object 2. On its surface too (as already explained for the first test layer 3 and the second test layer 4 of this embodiment) three types of holes 5, 6, 7 are formed: a first hole 5 with a diameter of 1 μm, a second hole 6 with twice the diameter and a third hole 7 with four times the diameter. All holes 5, 6, 7 have the same depth of 1 μm (corresponding to the diameter of the first hole 5). These holes 5, 6, 7 are also arranged in a matrix 8 in which a plurality of perforated penetrometers 16 are formed.

[0039] Another spacer plate 9 made of silicon with a thickness of 20 μm is arranged on top of the fourth test layer 14. This corresponds to the middle layer 15 of the test object 2.

[0040] The test specimen 1 of the present invention is therefore a device which corresponds exactly to the test object 2, and by means of this test specimen 1 it is possible to carry out simple and rapid inspection of the image quality during a series of inspections of such a test object 2. [Explanation of symbols]

[0041] 1. Test specimen 2. Test Objectives 3. First test layer 4. Second test layer 5 First hole 6 Second hole 7 Third Hole 8. Matrix 9 Spacer Plate 10 Test subject, especially solder balls 11 Package Balls 12 C4 Bump 13 Microbump 14 Additional Test Tiers 15 Middle Class 16 Hole permeameter

Claims

1. A test object (1) for checking image quality during an X-ray examination of a test object (2), said test object (2) having a first layer of a test object (10) to be checked and an intermediate layer (15) on which said test object (10) is arranged, The test specimen (1) has a first test layer (3) and a solid spacer plate (9) arranged on the first test layer (3), the thickness of the first test layer (3) corresponds to the thickness of the test object (10) in the test subject (2), and the thickness of the spacer plate (9) corresponds to the thickness of the intermediate layer (15); The first test layer (3) has a plurality of first holes (5) formed therein, the depth and diameter of the plurality of first holes (5) being equal, and the size of the plurality of first holes (5) corresponding to a portion of the size of the associated test object (10) that is detected as a defect; the material constituting said first test layer (3) has an absorption coefficient corresponding to the absorption coefficient of said associated test object (10); the material of which the spacer plate (9) is made has an absorption coefficient corresponding to the absorption coefficient of the intermediate layer (15); Test specimen (1).

2. the test specimen (1) is associated with the test object (2), the test object (2) having a second layer of the test subject (10) to be inspected arranged on a side of the intermediate layer (15) opposite to the first layer, the test specimen (1) has a second test layer (4) arranged on the side of the spacer plate (9) opposite to the first test layer (3); the thickness of the second test layer (4) corresponds to the thickness of the test object (10) in the second layer, and the second test layer (4) is made of a material having an absorption coefficient corresponding to the absorption coefficient of the material of the test object (10) in the second layer, The second test layer (4) has a plurality of first holes (5) formed therein, the depth and diameter of the plurality of first holes (5) being equal, and the size of the plurality of first holes (5) corresponding to a portion of the size of the associated test object (11) that will be detected as a defect. A test specimen (1) according to claim 1.

3. 3. The test specimen (1) according to claim 2, comprising at least one combination of an additional spacer plate (9) and an additional test layer (14), wherein the additional spacer plate (9) and the additional test layer (14) correspond to the spacer plate (9) and the second test layer (4) according to claim 2, respectively.

4. 4. The test specimen (1) of claim 3, wherein each test layer (3, 4, 14) has a plurality of second holes (6) formed therein, each having a diameter at least twice the diameter of the first holes (5), and the plurality of second holes (6) have the same depth as the first holes (5).

5. 5. The test specimen (1) of claim 4, wherein each test layer (3, 4, 14) has a plurality of third holes (7) formed therein, each having a diameter at least four times the diameter of the first holes (5), and the third holes (7) have the same depth as the first holes (5).

6. 6. The test body (1) according to claim 5, wherein the first holes (5) and / or the second holes (6) and / or the third holes (7) are each arranged in a matrix (8) covering most of the surface of the test layer in at least one of the test layers (3, 4, 14).

7. A test specimen (1) as described in claim 6, wherein all holes (5, 6, 7) are arranged within a common matrix (8).

8. 2. The test specimen (1) of claim 1, wherein the test object (2) is a circuit board and the test target (10) is a solder ball.

9. 4. The test specimen (1) according to claim 3, wherein the test layer (3, 4, 14) is made of a material having an atomic number greater than 22 and / or the spacer plate (9) is made of a material having an atomic number less than 14.

10. A test specimen (1) as described in claim 9, wherein the test layer (3, 4, 14) is made of nickel, tin or copper, or an alloy containing at least one of these substances, and / or the spacer plate (9) is made of silicon.

11. Use of a test object (1) according to any one of claims 1 to 10 for determining the defect detection sensitivity and / or the depth of field of an X-ray system comprising a tube, a detector and a holder arranged between the tube and the detector for receiving the test object (2).

12. 1. A method for determining defect detection sensitivity and / or depth of field of an X-ray system comprising a tube, a detector, and a holder arranged between the tube and the detector for receiving the test object (2), comprising: A method for taking a single X-ray image of a test object (1) according to any one of claims 1 to 10, which is positioned in the beam path instead of the test object (2) at the location where the test object (2) is located during the inspection, and then evaluating the X-ray image.

Images