Inspection device and inspection method

Abstract

This inspection device for inspecting an object to be inspected comprises: an X-ray generation tube that has a target having an X-ray generation unit for generating an X-ray upon being irradiated with an electron beam and that radiates an X-ray towards the object to be inspected; and a plurality of X-ray detectors. Each of the plurality of X-ray detectors detects an X-ray that has been: radiated from foreign matter present on an inspected surface of the object to be to inspected irradiated with the X-ray from the X-ray generation unit; and totally reflected by the inspected surface.

Description

[Technical field]

[0001] The present invention relates to an inspection device and an inspection method. [Background technology]

[0002] Patent Document 1 describes a high-resolution X-ray microscope with a fluorescent X-ray analysis function, which includes a detector that detects fluorescent X-rays generated from a sample by focusing an electron beam on a target for X-ray generation by an objective lens and irradiating the sample with X-rays generated from the target, and an analysis unit that analyzes the fluorescent X-rays from the detection results of the detector. Patent Document 1 also describes incorporating all or a part of the detector into the magnetic circuit of the objective lens. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-236622 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a problem of foreign matter with dimensions of several tens of micrometers or less being introduced into products, causing defects. For example, in lithium-ion batteries, for components made from carbon, copper, and aluminum, foreign matter that is micronized stainless steel or parts of the components can be introduced into the battery during manufacturing.

[0005] If a foreign object is introduced into a lithium-ion battery during its manufacture, the separator that maintains insulation inside the battery may be broken by vibrations caused by the foreign object after the battery is shipped. In such a case, the battery may short-circuit, potentially catching fire or exploding.

[0006] If foreign objects could be detected non-destructively, it would be possible to prevent the distribution of products that may ignite or explode. Methods for detecting foreign objects on the surface of a sample using X-rays and identifying their elements include X-ray fluorescence (also known as XRF) and grazing incidence X-ray fluorescence (also known as TXRF). In X-ray fluorescence, elements in the sample substrate are also excited, and in grazing incidence X-ray fluorescence, the incident X-rays are scattered by the foreign objects. Therefore, these measurement methods have the problem that the intensity ratio of the fluorescent X-rays generated by the foreign objects is weak.

[0007] An object of the present invention is to provide an advantageous technique for detecting foreign matter present on an inspection target surface with high sensitivity. [Means for solving the problem]

[0008] One aspect of the present invention relates to an inspection device for inspecting an object to be inspected, the inspection device comprising: an X-ray generating tube having a target including an X-ray generating unit that generates X-rays when irradiated with an electron beam, emitting X-rays toward the object to be inspected; and a plurality of X-ray detectors, each of which detects X-rays emitted from a foreign object present on the object to be inspected that has been irradiated with X-rays from the X-ray generating unit and totally reflected by the object to be inspected.

[0009] Another aspect of the present invention relates to an inspection method for inspecting an object to be inspected, the inspection method including an X-ray detection step of emitting X-rays toward the object to be inspected and detecting, by a plurality of X-ray detectors, the X-rays emitted from a foreign object present on the inspection surface of the object to be inspected and totally reflected by the inspection surface, and a processing step of processing outputs from the plurality of X-ray detectors. Effect of the Invention

[0010] According to the present invention, an advantageous technique is provided for detecting foreign matter present on an inspection target surface with high sensitivity. [Brief description of the drawings]

[0011] [Figure 1]FIG. 1 is a diagram illustrating a configuration of an inspection apparatus according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing a specific example of the configuration of an inspection apparatus according to an embodiment. [Diagram 3] FIG. 2 is a diagram showing a schematic configuration example of an X-ray generating tube. [Figure 4] FIG. 3 is an enlarged schematic diagram of a portion of the inspection device shown in FIG. 2. [Diagram 5] FIG. 3 is an enlarged schematic diagram of a portion of the inspection device shown in FIG. 2. [Figure 6] 13 is a diagram illustrating an example of the relationship between the distance Dxs (horizontal axis) and the count number (vertical axis) of foreign matter detected by an X-ray detector. [Figure 7] FIG. 2 is a diagram showing a specific example of the configuration of an inspection apparatus according to an embodiment. [Figure 8] FIG. 11 is a diagram illustrating the configuration of an inspection device according to a second embodiment. [Figure 9] FIG. 13 is a diagram illustrating the configuration of an inspection device according to a third embodiment. [Figure 10] FIG. 13 is a diagram illustrating a configuration of an inspection device according to a fourth embodiment. [Figure 11] FIG. 13 is a diagram illustrating a configuration of an inspection device according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0013] FIG. 1 shows a schematic configuration of an inspection apparatus IA according to a first embodiment of the present disclosure. The inspection apparatus IA may be configured as an inspection apparatus that inspects an inspection target surface TS arranged on an inspection surface IP, for example. Here, the inspection surface IP is a surface on which the inspection target surface TS is to be arranged, and the inspection target surface TS is one surface of an inspection target IT. The inspection apparatus IA may include an X-ray generating tube 101. The X-ray generating tube 101 has a target (not shown) including an X-ray generating unit XG that generates X-rays by being irradiated with an electron beam, and radiates X-rays XR toward the inspection surface IP. A foreign material FS irradiated with X-rays XR from the X-ray generating unit XG generates X-rays according to the material that constitutes the foreign material FS, and such X-rays are also called fluorescent X-rays or characteristic X-rays. A part of the X-rays generated by the foreign material FS irradiated with X-rays XR are totally reflected by the inspection target surface TS. The X-rays emitted from the foreign material FS and totally reflected by the inspection target surface TS are shown as X-rays XF. The inspection apparatus IA may include an X-ray detector 120. The X-ray detector 120 may be configured to detect X-rays XF emitted from a foreign matter FS present on an inspection target surface TS irradiated with X-rays XR from the X-ray generator XG and totally reflected by the inspection target surface TS. The inspection apparatus IA may further include a processor that performs processing to detect the foreign matter FS based on the output from the X-ray detector 120. The processor may further perform processing to identify a substance that constitutes the foreign matter FS based on the output from the X-ray detector 120. The processor may be realized, for example, by a control unit that controls the operation of the inspection apparatus IA.

[0014] FIG. 2 shows a more specific configuration example of the inspection apparatus IA shown in FIG. 1. The inspection apparatus IA may include an X-ray generator 100, an X-ray detector 120, and a control unit 140. The X-ray generator 100 may include an X-ray generating tube 101 and a driving circuit 103 that drives the X-ray generating tube 101. The X-ray generator 100 may further include a boost circuit 102 that supplies a boosted voltage to the driving circuit 103. The X-ray generator 100 may further include a container (not shown) that stores the X-ray generating tube 101, the driving circuit 103, and the boost circuit 102, and the container may be filled with an insulating fluid such as insulating oil. The control unit 140 may be configured to control the X-ray generator 100 and the X-ray detector 120. The control unit 140 may also include the functions of the processor described above. More specifically, the control unit 140 may perform a process of detecting a foreign object FS based on an output from the X-ray detector 120. Moreover, the control unit 140 may further perform a process of identifying a substance constituting the foreign matter FS based on the output from the X-ray detector 120. The control unit 140 may be configured, for example, by a PLD (abbreviation for Programmable Logic Device) such as an FPGA (abbreviation for Field Programmable Gate Array), an ASIC (abbreviation for Application Specific Integrated Circuit), a general-purpose or dedicated computer with an embedded program, or a combination of all or part of these.

[0015] The inspection apparatus IA may further include an X-ray detection panel 130 that detects X-rays emitted from the X-ray generation unit XG and transmitted through an inspection target IT having an inspection target surface TS. The control unit 140 may be configured to generate an image of the X-rays transmitted through the inspection target IT (a transmitted image of the inspection target IT) based on the output from the X-ray detection panel 130, and detect a foreign object FS present on the inspection target surface TS based on the image. By using the X-ray detection panel 130, it is also possible to detect a foreign object present inside the inspection target IT and a foreign object present on the surface opposite to the inspection target surface TS. The control unit 140 may be configured to detect the presence of the foreign object FS, as well as the position and / or size of the foreign object FS. By providing the X-ray detection panel 130 in addition to the X-ray detector 120, the X-ray detection panel 130 can detect a foreign object FS that cannot be detected by the X-ray detector 120, thereby improving the accuracy of detecting the foreign object FS. In addition, the inspection device IA, which acquires transmission images and detects foreign bodies using X-rays emitted from a single X-ray generating tube, is advantageous in terms of compactness and cost reduction compared to a system having two devices that separately acquire transmission images and detect foreign bodies.

[0016] The inspection apparatus IA may further include a display unit 150, and the control unit 140 may be configured to cause the display unit 150 to display information indicating the constituent material of the foreign matter FS identified based on the output of the X-ray detector 120. The control unit 140 may also be configured to cause the display unit 150 to display a transmission image of the inspection target IT generated based on the output from the X-ray detection panel 130. The control unit 140 may also be configured to cause the display unit 150 to display information indicating the position and / or size of the foreign matter detected based on the output from the X-ray detection panel 130. The control unit 140 may be configured as a single unit or may be configured by being divided into multiple units.

[0017] 3 shows a schematic configuration example of an X-ray generating tube 101. The X-ray generating tube 101 may include an electron gun EG, an anode 93 having a target 933 including an X-ray generating unit XG that generates X-rays by collision with electrons from the electron gun EG, and an insulating tube 92. In the X-ray generating tube 101, the anode 93 may be arranged so as to close one of two open ends of the insulating tube 92, and a blocking member 91 including the electron gun EG may be arranged so as to close the other of the two open ends of the insulating tube 92. A deflector 94 that deflects the flow of electrons (electron beam) from the electron gun EG may be arranged on the outside of the insulating tube 92. The X-ray generating tube 101 shown in FIG. 3 is an example of a sealed transmission type X-ray generating tube in which the internal space of the insulating tube 92 is maintained in a vacuum state and X-rays pass through the target 933 and a target holding plate 932 described later. However, a non-sealed open type or a non-transmitting reflection type X-ray generating tube may also be used as the X-ray generating tube 101.

[0018] The deflector 94 may be disposed outside the X-ray generating tube 101. In a direction parallel to the axis AX of the X-ray generating tube 101, the deflector 94 may be provided between the anode 93 and the cathode (not shown). In one example, in a direction parallel to the axis AX of the X-ray generating tube 101, the deflector 94 is provided between the electron gun EG and the target 933. Specifically, an imaginary plane 97 that crosses the deflector 94 may be located in a space between an imaginary plane 95 that contacts the tip of the electron gun EG and an imaginary plane 96 that contacts a part of the target 933. The imaginary planes 95, 96, and 97 are planes that are perpendicular to the axis AX of the X-ray generating tube 101.

[0019] The anode 93 may include a target 933, a target holding plate 932 that holds the target 933, and an electrode 931 that holds the target holding plate 932. The electrode 931 is electrically connected to the target 933 and may apply an electric potential to the target 933. The target 933 generates X-rays when electrons (electron beams) emitted from the electron gun EG collide with the target 933. The X-ray generating unit XG is a portion on the surface of the target 933 that is collided with by the electrons (electron beams). The X-rays generated by the X-ray generating unit XG are transmitted through the target holding plate 932 and radiated to the outside of the X-ray generating tube 101. The anode 93 may be maintained at, for example, a ground potential, but may also be maintained at another potential.

[0020] The target 933 is made of a metal material. The target 933 is desirably made of a material with a high melting point, such as tungsten, tantalum, or molybdenum, which contributes to improving the generation efficiency of X-rays. The target holding plate 932 can be made of a material that easily transmits X-rays, such as beryllium or diamond. The target holding plate 932 is desirably made of diamond, which allows the thickness of the target holding plate 932 to be thinned while maintaining its strength, and the distance between the inspection surface IP (inspection target surface TS) and the target 933 (X-ray generating unit XG) can be reduced. The thickness of the target holding plate 932 is desirably thin. Specifically, the thickness of the target holding plate 932 is desirably 4 mm or less, and more desirably 2 mm or less, 1 mm or less, or 0.3 mm or less. The thickness of these target holding plates 932 can be set with reference to the distance from the X-ray generating unit XG to the inspection surface IP, which is necessary to identify elements contained in foreign matter, which will be described later. In order to identify elements contained in foreign matter, it is desirable for the target holding plate 932 to be as thin as possible, but from the viewpoints of processing costs and individual differences of the target holding plate 932, and strength required to maintain the internal space of the insulating tube 92 in a vacuum state, it is desirable for the target holding plate 932 to be thick. Therefore, it is desirable to use an optimal thickness for the target holding plate 932. Note that FIG. 3 is not intended to show the relationship between the thickness of the target 933 and the thickness of the target holding plate 932. For example, the thickness of the target 933 may be several μm, and the thickness of the target holding plate 932 may be several hundred μm.

[0021] 4 is a schematic diagram showing an enlarged portion of the inspection apparatus IA in FIG. 2. A foreign object FS may be present on the inspection target surface TS. X-rays (characteristic X-rays) XF emitted from the foreign object FS so as to be totally reflected on the inspection target surface TS are incident on the X-ray capture section 121 of the X-ray detector 120. On the other hand, fluorescent X-rays that may be generated from the inspection target IT itself due to irradiation of X-rays XR from the X-ray generation section XG are hardly incident on the X-ray capture section 121 of the X-ray detector 120 arranged to detect the X-rays (characteristic X-rays) XF. Therefore, the ratio of fluorescent X-rays emitted from the inspection target IT itself and detected by the X-ray detector 120 to the X-rays (characteristic X-rays) XF emitted from the foreign object FS and detected by the X-ray detector 120 can be made extremely small.

[0022] The X-ray detector 120 may be a silicon drift detector (SDD), a CdTe detector, or a CdZnTe detector. The X-ray detector 120 may be an energy dispersive detector. When the X-ray detector 120 is an energy dispersive detector, the control unit (or processor) 140 can determine the material or element constituting the foreign matter FS from the element profile of energy dispersion (count value for each energy). The control unit (or processor) 140 may incorporate commercially available software to determine the material or element constituting the foreign matter FS. Examples of such software include "XRS-FP Quantitative XRF Analysis Software" by AMETEK Corporation, or software by Uniquant.

[0023] The specifications of the X-ray detector 120 can be determined according to the energy resolution required for foreign object detection. Examples of detectors with low energy resolution include detectors using scintillators, Si pin photodiodes, or CCDs. Examples of detectors with higher energy resolution include detectors using proportional counters. Examples of detectors with even higher energy resolution include detectors using an energy dispersive detection method such as a CdTe direct transition crystal or a Si drift detector. Examples of detectors with even higher energy resolution include detectors using a wavelength dispersive detection method that uses a spectroscopic crystal to determine energy from the angle.

[0024] In order for the fluorescent X-rays from the foreign object FS to be totally reflected by the inspection target surface TS, the angle at which the fluorescent X-rays from the foreign object FS are incident on the inspection target surface TS must be the total reflection critical angle θ c It must be the following:

[0025]

number

[0026] Where: θ c :Total internal reflection critical angle r e : Classical radius of electron (2.818×10 -15 m) N0: Avogadro's number λ: wavelength of X-rays ρ: Density (g / cm 3 ) Zi, Mi, xi: Atomic number, atomic weight, and atomic ratio (molar ratio) of the i-th atom f' i : Atomic scattering factor (anomalous dispersion term) of the i-th atom

[0027] Theoretically, the critical angle of total reflection when the inspection target surface TS is metallic is approximately 1° or less, but in reality, the critical angle of reflection often differs from the theoretical value when the metal surface is oxidized or carbonized, or covered with a graphite layer. It has been confirmed through experiments that when X-rays XR are irradiated onto the inspection target surface TS, if the total reflection conditions are met, the angle (critical angle of total reflection) between the inspection target surface TS and the characteristic X-rays XF emitted from the foreign matter FS and totally reflected by the inspection target surface TS is 5° or less. Here, the foreign matter FS is defined as the distance D between the X-ray generator XG and the inspection surface IP (inspection target surface TS). XS , so the position where the X-rays XR emitted from the foreign material FS and totally reflected by the inspection target surface TS can be regarded as the position where the X-rays XR from the X-ray generator XG are incident on the inspection surface IP. Also, if the foreign material FS is located at a position where the X-rays XR from the X-ray generator XG are incident perpendicularly on the inspection surface IP as in Figure 4, the position where the X-rays XR emitted from the foreign material FS and totally reflected by the inspection target surface TS can be regarded as the position where the X-rays XR from the X-ray generator XG are incident perpendicularly on the inspection surface IP.

[0028] Since the total reflection critical angle is 5° or less, the angle θ formed by an imaginary line connecting the position where the X-rays XR from the X-ray generating unit XG are incident on the inspection surface IP and the X-ray intake unit 121 of the X-ray detector 120, and the inspection surface IP (the angle formed by an imaginary line connecting the intersection of the axis of the X-ray generating tube 101 and the inspection surface IP and the center of the X-ray intake unit of the X-ray detector 120, and the inspection surface IP) can be 5° or less, desirably 2° or less, and more desirably 1° or less. The smaller the angle θ, the smaller the ratio of fluorescent X-rays emitted from the inspection object IT itself and detected by the X-ray detector 120 to X-rays (characteristic X-rays) XF emitted from the foreign material FS and detected by the X-ray detector 120 can be.

[0029] The X-ray detector 120 may be disposed at a position where an extension plane of the inspection surface IP crosses the X-ray detector 120. The X-ray take-in unit 121 may include a window portion 122 that transmits X-rays XF, as shown in FIG. 5. The window portion 122 may have, for example, a diameter of several mm and a thickness of several hundred μm. The window portion 122 may be made of, for example, beryllium. As shown in FIG. 5, the inspection device IA may include a slit member 125 having a slit (opening) on ​​a virtual line connecting a position where the X-rays XR from the X-ray generation unit XG are incident on the inspection surface IP and the X-ray take-in unit 121 of the X-ray detector 120. The size of the slit provided in the slit member 125 and the position of the X-ray detector 120 may be determined according to the range on the inspection target surface TS where the X-rays XR hit, the material that may constitute the inspection target surface TS and the foreign matter FS, and the like. As shown in FIG. 7, consider the case where foreign bodies FS1 and FS3 are present at both ends of a width Y on the inspection target surface TS where the X-ray XR hits, and the distance Z from the center of the width Y to the X-ray capture unit 121 is the same length as the width Y. In this case, the width W of the slit s By setting the lower limit of Y×tan θ and the distance X2 between the center of the X-ray capture unit 121 and the inspection surface IP to Y×tan θ, it is possible to detect all foreign objects on the inspection surface TS within the range where the X-rays XR hit.

[0030] In order to increase the intensity of the X-rays XF detected by the X-ray detector 120, the distance D from the X-ray generator XG to the inspection surface IP is xs It is desirable to reduce the distance D xs 1 shows the results of an experiment that shows the relationship between the fluorescent X-ray count (horizontal axis) and the count number (vertical axis) of foreign matter FS detected by the X-ray detector 120. The count number is the total count number (peak count) per certain time of the energy corresponding to the position of the fluorescent X-ray (for example, Ni Kα ray) emitted from a specific element contained in the foreign matter. Considering the count number TH required to identify an element, the distance D from the X-ray generating part XG to the inspection surface IP xsIt is preferable that the thickness is 5 mm or less, more preferable that the thickness is 4 mm or less, and even more preferable that the thickness is 3 mm or less. As the X-ray generating tube 101, for example, a transmission sealed type microfocus X-ray source manufactured by Canon Anelva Corporation, specifically the G series, and more specifically the G-511 series or G-311 series, is useful.

[0031] In order to detect foreign particles of a few μm to a few tens of μm in size with high sensitivity in a transmission image, the distance D from the inspection surface IP to the X-ray detection panel 130 is sf D xs For example, if 10 pixels are required to detect a foreign object with a diameter of 5 μm, and an X-ray detection panel (FPD) with a pixel pitch of 100 μm is used, the magnification required for detection is 100x10 / 5=200 times, and for a foreign object with a diameter of 50 μm, the magnification required for detection is 20 times. Therefore, D sf / D xs It is preferable to set the value to 20 or more, and more preferable to set the value to 200 or more. This enables foreign matter to be detected with high sensitivity using a transmission image.

[0032] The inspection system IA is useful for detecting relics attached to materials in the production process of lithium-ion batteries, for example, but this is only one example and it is also useful for other applications. The inspection system IA may be used, for example, to measure and analyze airborne particles such as PM2.5 that affect the environment and health. In this case, compared to conventional techniques that measure the number and size of particles periodically (for example, every hour or every day), the inspection system IA can measure the number and size of particles and simultaneously identify the substances or elements that make up the particles, enabling more advanced environmental and health measures. Alternatively, the use of the inspection system IA in the field of semiconductors, which have become increasingly miniaturized in recent years, for example, mask manufacturing equipment for EUV, inspection equipment, and inspection equipment for semiconductor manufacturing processes, can improve yields and quickly resolve abnormality causes using elemental information on foreign matter.

[0033] Hereinafter, an inspection method for inspecting an inspection target surface TS arranged on an inspection target surface IP using an inspection device IA will be described. The inspection method may include an X-ray detection step of emitting X-rays toward the inspection target surface IP (inspection target surface TS) and detecting X-rays XF emitted from a foreign object FS present on the inspection target surface TS and totally reflected by the inspection target surface TS with an X-ray detector 120, and a processing step of processing the output of the X-ray detector 120. The processing step may include a step of detecting a foreign object FS and / or a step of identifying a material constituting the foreign object FS. The inspection method may further include a step of detecting X-rays transmitted through an inspection target object IT having an inspection target surface TS with an X-ray detection panel 130, and in the processing step, the output of the X-ray detector 120 and the output of the X-ray detection panel 130 may be processed. The processing step may include a step of detecting the presence of a foreign object FS and the position of the foreign object FS based on the output of the X-ray detection panel 130. Alternatively, the processing step may include detecting the presence of a foreign object FS, the location of the foreign object FS, and the size of the foreign object FS based on the output of the X-ray detection panel 130.

[0034] FIG. 8 shows a schematic configuration of the inspection apparatus IA of the second embodiment. Matters not described as the second embodiment may follow the first embodiment. The inspection apparatus IA of the second embodiment is configured to inspect an inspection object IT. The inspection apparatus IA includes an X-ray generating tube 101, which has a target including an X-ray generating unit XG that generates X-rays by being irradiated with an electron beam, and radiates X-rays XR toward the inspection object IT. The inspection apparatus IA may also include a plurality of X-ray detectors. Each of the plurality of X-ray detectors detects X-rays radiated from a foreign material FS1 present on the inspection object surface TS of the inspection object IT irradiated with X-rays from the X-ray generating unit and totally reflected by the inspection object surface TS.

[0035] The inspection apparatus IA may include, for example, a first X-ray detector 1201 and a second X-ray detector 1202 as the multiple X-ray detectors. The first X-ray detector 1201 and the second X-ray detector 1202 may be arranged to face each other across the axis AX of the X-ray generating tube 101. From another perspective, the first X-ray detector 1201 and the second X-ray detector 1202 may be arranged to face each other. The inspection apparatus IA of the second embodiment may include slit members 1251 and 1252 similar to the slit member 125 in the inspection apparatus IA of the first embodiment. The slit members 1251 and 1252 may be provided for the first X-ray detector 1201 and the second X-ray detector 1202, respectively. X-rays are emitted radially (for example, in all directions of 360 degrees) from the X-ray generating unit XG, and some of the X-rays may be totally reflected by the inspection target surface TS. The X-rays totally reflected by the inspection target surface TS may include, for example, an X-ray XF11 incident on the first X-ray detector 1201 and an X-ray XF12 incident on the second X-ray detector 1202. The illustrated X-rays XF11 and XF12 may also be understood as trajectory vectors of X-ray photons. In addition to the foreign matter FS1, there may be foreign matter on the inspection target surface TS. Therefore, there is a possibility that the X-rays emitted from the foreign matter FS1 and totally reflected by the inspection target surface TS are blocked by other foreign matter and do not enter at least one of the multiple X-ray detectors. However, by arranging multiple X-ray detectors, the possibility that the X-rays emitted from the foreign matter FS1 and totally reflected by the inspection target surface TS can be detected by any of the multiple X-ray detectors is increased.

[0036] Fig. 9 shows a schematic configuration of the inspection apparatus IA of the third embodiment. Fig. 9 is a view of the inspection apparatus IA seen from an oblique direction. Matters not described as the third embodiment may follow the second embodiment described with reference to Fig. 8. Although the illustration of a slit member is omitted in Fig. 9, a slit member may be provided as in the second embodiment. The inspection apparatus IA may include a transport mechanism CV that transports the inspection object IT along a transport direction DIR.

[0037] The first X-ray detector 1201 and the second X-ray detector 1202 can be disposed at positions spaced apart from each other in a direction parallel to the transport direction DIR or a direction parallel to the longitudinal direction of the inspection object IT. 9 shows X-rays XF11 (trajectory vector of X-ray photons) and XF12 (trajectory vector of X-ray photons) emitted from a foreign object FS1 irradiated with X-rays XR from the X-ray generator XG and totally reflected at the inspection object surface TS. X-rays XF11 are incident on the first X-ray detector 1201, and X-rays XF12 are incident on the second X-ray detector 1202.

[0038] A foreign object FS2 different from the foreign object FS1 may exist on the inspection target surface TS. In the example of FIG. 9, the foreign object FS2 exists between the foreign object FS1 and the first X-ray detector 1201. When the X-ray XF11 is blocked by the foreign object FS2, the first X-ray detector 1201 cannot detect the X-ray XF11. However, the second X-ray detector 1202 can detect the X-ray XF12 from the foreign object FS1. This reduces the possibility of overlooking a foreign object on the inspection target surface TS of the inspection target IT, and prevents a decrease in the manufacturing yield. In addition, the position of the foreign object can be estimated from the positional relationship between the second detector 1202 that detected the foreign object and the first detector 1201 that did not detect the foreign object. For example, in the example of FIG. 9, it can be estimated that the foreign object FS2 exists between the foreign object FS1 and the second X-ray detector 1202.

[0039] The inspection apparatus IA may comprise an additional X-ray detector arranged to detect X-rays totally reflected from foreign objects present on the opposite surface to the inspection target surface TS.

[0040] FIG. 10 shows a schematic configuration of the inspection device IA of the fourth embodiment. Matters not described as the fourth embodiment may follow the second or third embodiment. The inspection device IA may have a plurality of X-ray detectors. The first X-ray detector 1201 and the second X-ray detector 1202 as the plurality of X-ray detectors have X-ray intake units 1211 and 1212, respectively. The angle between the inspection surface IP and a virtual line connecting the intersection of the axis AX of the X-ray generating tube 101 and the inspection surface IP and the center of the X-ray intake unit 1211 is θ1. The angle between the inspection surface IP and a virtual line connecting the intersection of the axis AX of the X-ray generating tube 101 and the inspection surface IP and the center of the X-ray intake unit 1212 is θ2. θ1 and θ2 are preferably 5° or less, and more preferably 2° or less.

[0041] θ1 and θ2 may be the same or different. In a configuration in which θ1 and θ2 are different from each other, even if the first detector 1201 cannot detect the X-ray XF11 emitted from the foreign object FS1 and totally reflected by the inspection target surface TS, the second detector 1202 may be able to detect the X-ray XF12 emitted from the foreign object FS1 and totally reflected by the inspection target surface TS. A configuration in which θ1 and θ2 are different from each other can also be understood as a configuration in which the distance between the inspection surface IP and the first X-ray capture unit 1211 and the distance between the inspection surface IP and the second X-ray capture unit 1212 are different from each other. Such a configuration is advantageous for detecting various foreign objects with different characteristics, and is also advantageous for dealing with the inspection target surface TS having various characteristics.

[0042] The second to fourth embodiments are advantageous in cases where there are multiple foreign objects on the same inspection target surface, or where a foreign object different from the expected foreign object is present on the inspection target surface, and are also advantageous in improving the detection accuracy of foreign objects. For example, when the inspection speed is increased or when foreign objects on the inspection target surface are inspected while the inspection target is being transported, the amount of fluorescent X-rays detected is limited, and there is a possibility that sufficient foreign object detection accuracy or foreign object identification accuracy cannot be obtained. However, such problems can be solved or reduced by providing multiple detectors as in the second to fourth embodiments. For example, the control unit 140 processes the count values ​​(outputs) for each energy of the fluorescent X-rays from the foreign object obtained by the multiple detectors, thereby improving the foreign object detection and identification accuracy. For example, a judgment step performed by an average value obtained by averaging the count values ​​for each energy, or a judgment step by processing the variation of the count values ​​for each energy, are possible. These can be said to improve the foreign object detection and identification accuracy by the control unit 140 comparing the outputs from each of the multiple detectors. Furthermore, when the position of the surface of the inspection object varies due to vibration or a difference in the thickness of the inspection object, the use of the inspection device of the fourth embodiment has the effect of improving the accuracy of detecting and identifying foreign objects.

[0043] FIG. 11 shows a schematic configuration of the inspection apparatus IA of the fifth embodiment. Matters not described as the fifth embodiment may follow the first to fourth embodiments. The inspection apparatus IA of the fifth embodiment is configured to inspect an inspection object IT. The inspection apparatus IA includes an X-ray generating tube 101, which has a target including an X-ray generating unit XG that generates X-rays by being irradiated with an electron beam, and radiates X-rays XR toward the inspection object IT. The inspection apparatus IA may also include a plurality of X-ray detectors. Each of the plurality of X-ray detectors detects X-rays radiated from a foreign object present on the inspection object surface of the inspection object IT irradiated with X-rays from the X-ray generating unit XG and totally reflected by the inspection object surface. The plurality of X-ray detectors may include a first X-ray detector 1201 for inspecting a first inspection object surface TS1 of the inspection object IT and a second X-ray detector 1202 for inspecting a second inspection object surface TS2 of the inspection object IT. The first X-ray detector 1201 may have a first X-ray capture unit 1211, and the second X-ray detector 1202 may have a second X-ray capture unit 1212. The first inspection target surface TS1 and the inspection target surface TS2 may be surfaces on opposite sides of the inspection target IT. The first inspection target surface TS1 and the second inspection target surface TS2 may be arranged symmetrically with respect to the virtual plane VP. The first X-ray capture unit 1211 and the second X-ray capture unit 1222 may be arranged to face each other via the virtual plane VP. The inspection target IT may be transported by a transport mechanism (not shown) in a direction perpendicular to the paper surface in FIG. 11. The virtual plane VP may be set parallel to the transport direction. According to the fifth embodiment, two surfaces of the inspection target IT can be inspected. The inspection device IA may include multiple X-ray generating tubes, but by including only a single X-ray generating tube 101, the inspection device IA can be made smaller and less expensive.

[0044] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention.

Claims

1. An inspection device for inspecting an inspection object, comprising: an X-ray generating tube having a target including an X-ray generating unit that generates X-rays by being irradiated with an electron beam, and emitting X-rays toward the inspection object; A plurality of X-ray detectors; an X-ray detection panel that detects X-rays emitted from the X-ray generation unit and transmitted through the inspection object, each of the plurality of X-ray detectors detects X-rays emitted from a foreign object present on an inspection target surface of the inspection target irradiated with X-rays from the X-ray generating unit and totally reflected by the inspection target surface; An inspection device characterized by:

2. a processor for performing processing to detect the foreign object based on outputs from the plurality of X-ray detectors, 2. The inspection apparatus according to claim 1 .

3. The processor further performs a process of identifying a substance that constitutes the foreign object.

3. The inspection apparatus according to claim 2.

4. The distance between the inspection surface on which the inspection target surface of the inspection object is placed and the X-ray generating unit is 5 mm or less.

2. The inspection apparatus according to claim 1 .

5. The distance between the inspection surface on which the inspection object surface of the inspection target is placed and the X-ray generating unit is 3 mm or less.

2. The inspection apparatus according to claim 1 .

6. an angle formed by a virtual line connecting an intersection point between an axis of the X-ray generating tube and an inspection surface on which the inspection target surface of the inspection object is disposed and a center of an X-ray capture portion of one of the plurality of X-ray detectors, and the inspection surface is 5° or less; 2. The inspection apparatus according to claim 1 .

7. an angle formed by a virtual line connecting an intersection point between an axis of the X-ray generating tube and an inspection surface on which the inspection target surface of the inspection object is placed and a center of an X-ray capture unit of one of the plurality of X-ray detectors, and the inspection surface is 2° or less; 2. The inspection apparatus according to claim 1 .

8. Further comprising a slit member having a slit on the virtual line, 7. The inspection apparatus according to claim 6.

9. The X-ray generating tube is a sealed transmission type.

2. The inspection apparatus according to claim 1 .

10. The X-ray generating tube includes a target holding plate that holds the target, and the thickness of the target holding plate is 4 mm or less.

2. The inspection apparatus according to claim 1 .

11. The target holding plate comprises diamond.

11. The inspection apparatus according to claim 10.

12. An inspection device for inspecting an inspection object, comprising: an X-ray generating tube having a target including an X-ray generating unit that generates X-rays by being irradiated with an electron beam and a target holding plate that holds the target, and radiating X-rays toward the inspection object; a plurality of X-ray detectors; the target holding plate includes diamond; The distance between an inspection surface on which the inspection target surface of the inspection object is placed and the X-ray generating unit is 5 mm or less, The X-ray generating tube is of a sealed transmission type, each of the plurality of X-ray detectors detects X-rays emitted from a foreign object present on the inspection target surface irradiated with X-rays from the X-ray generating unit and totally reflected by the inspection target surface; An inspection device characterized by:

13. the plurality of X-ray detectors include a first X-ray detector and a second X-ray detector, the first X-ray detector and the second X-ray detector are disposed to face each other across an axis of the X-ray generating tube; 13. The inspection device according to claim 1, wherein the inspection device is a semiconductor laser.

14. the plurality of X-ray detectors include a first X-ray detector having a first X-ray capture portion and a second X-ray detector having a second X-ray capture portion; an angle formed by a virtual line connecting an intersection point between an axis of the X-ray generating tube and an inspection surface on which the inspection target surface of the inspection object is placed and a center of the first X-ray intake unit, and the inspection surface is different from an angle formed by a virtual line connecting the intersection point and a center of the second X-ray intake unit, and the inspection surface; 13. The inspection device according to claim 1, wherein the inspection device is a semiconductor laser.

15. the plurality of X-ray detectors include a first X-ray detector and a second X-ray detector; a position of the first X-ray detector and a position of the second X-ray detector are different from each other in a direction parallel to an inspection surface on which the inspection target surface of the inspection object is placed; 13. The inspection device according to claim 1, wherein the inspection device is a semiconductor laser.

16. the plurality of X-ray detectors include a first X-ray detector for inspecting a first inspection surface of an inspection object and a second X-ray detector for inspecting a second inspection surface of the inspection object; the first X-ray detector has a first X-ray capture unit, and the second X-ray detector has a second X-ray capture unit; the first inspection surface and the second inspection surface are disposed symmetrically with respect to a virtual plane, the first X-ray capture unit and the second X-ray capture unit are disposed to face each other across the imaginary plane.

13. The inspection device according to claim 1, wherein the inspection device is a semiconductor laser.

17. the X-ray generating tube is disposed so that the X-rays emitted from the X-ray generating tube include X-rays that are perpendicularly incident on an inspection surface on which the inspection target surface is disposed.

13. The inspection device according to claim 1, wherein the inspection device is a semiconductor laser.

18. An inspection method for inspecting an inspection object, comprising: an X-ray detection step of emitting X-rays toward the inspection object, and detecting, by a plurality of X-ray detectors, X-rays emitted from foreign matter present on an inspection object surface of the inspection object and totally reflected by the inspection object surface; detecting the X-rays transmitted through the inspection object with an X-ray detection panel; and processing the output of the plurality of X-ray detectors and the output of the X-ray detection panel.

13. An inspection method comprising:

19. The processing step includes a step of detecting the foreign object.

20. The inspection method according to claim 18.

20. The processing step includes a step of identifying a substance constituting the foreign matter.

20. The inspection method according to claim 18.

21. the processing step includes a step of detecting the presence and position of the foreign object based on an output of the X-ray detection panel.

20. The inspection method according to claim 18.

22. the processing step includes a step of detecting the presence, position, and size of the foreign object based on an output of the X-ray detection panel.

20. The inspection method according to claim 18.

23. the processing step includes a step of comparing outputs of the plurality of X-ray detectors.

23. The inspection method according to any one of claims 18 to 22.

24. In the X-ray detection step, X-rays are emitted from an X-ray generating tube so as to include X-rays that are perpendicularly incident on an inspection surface on which an inspection target surface of the inspection object is placed.

23. The inspection method according to any one of claims 18 to 22.

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