X-ray fluorescence analysis method, X-ray fluorescence analysis program, and X-ray fluorescence analysis device

Abstract

The actual measurement intensities (MC, MR) of Compton scattering rays and Rayleigh scattering rays are extracted from the spectrum of a target sample in which a resin-containing film is formed on a base material (S21, S22), and an actual measurement scattering intensity ratio (MC / R), which is the ratio of the actual measurement intensity of Rayleigh scattering rays to the actual measurement intensity of Compton scattering rays, is determined (S3). On the basis of the actually measured scattering intensity ratio of the target sample, the thickness of the thin film and the content of each element constituting the target sample are determined by a basic parametric method (S5-S11).

Description

Technical Field

[0001] The present disclosure relates to a fluorescent X-ray analysis method, an analysis program, and a fluorescent X-ray analysis apparatus. Background Art

[0002] Fluorescent X-ray analysis is an analysis method in which X-rays are irradiated onto a sample, and the constituent elements of the sample are analyzed by measuring the fluorescent X-rays emitted from the sample. As one of the analysis methods based on fluorescent X-ray analysis, a fundamental parameter method (hereinafter referred to as "FP method") is known.

[0003] The FP method is a method in which the content of an element contained in a sample is obtained by comparing the theoretical intensity calculated using various physical constants with the measured intensity obtained by measuring the sample. The calculation method of the theoretical intensity has been established and is disclosed in Patent Document 1, Non-Patent Document 1, and the like.

[0004] Patent Document 1 discloses a method in which, in view of the fact that the measured intensity of fluorescent X-rays is insufficient due to the shape of the sample or the like, correction is considered based on the shape of the sample, and a quantitative value of a target element is obtained by the FP method. In the method disclosed in Patent Document 1, the following situation is used to obtain the adhesion amount: even if the shape of the thin film sample or the fixed position of the sample changes, for a certain adhesion amount, the ratio of the fluorescent X-ray intensity to the scattered X-ray intensity is constant.

[0005] In Non-Patent Document 1, a method for quantifying CH 2 O, which is the main component of a resin film coated on an iron base material, by the FP method is disclosed. CH 2 O, which is the main component of the resin film, is a component that is difficult to measure by fluorescent X-rays. Therefore, in Non-Patent Document 1, RhKα Compton scattering is used to estimate the quantitative value of CH 2 O. In addition, Non-Patent Document 1 describes taking the ratio of the measured intensities of RhKα Compton scattering and FeKα for shape correction.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2003-107020

[0009] Non-Patent Documents

[0010] Non-Patent Document 1: "Advances in X-ray Analysis", Agne Technical Center, 40(2009), pp233 - p241 Summary of the Invention

[0011] Problems to be Solved by the Invention

[0012] As disclosed in Non-Patent Document 1, a method for quantitatively analyzing the main components of a resin film coated on a base material using scattered rays is known. Compared with the method of balancing the main components of the resin film, this method can reduce the influence of the specimen shape on the quantitative value.

[0013] However, the method disclosed in Non-Patent Document 1 is premised on using fluorescent X-rays from the main components of the base material for shape correction, and the fluorescent X-rays from the main components of the base material can penetrate the film. Therefore, it cannot be applied to specimens using a base material with a low transmittance of fluorescent X-rays such as aluminum.

[0014] In addition, in the method disclosed in Non-Patent Document 1, the quantitative value of the main components in the resin film is obtained by using the fact that the measured intensity of the scattered rays is proportional to the theoretical intensity. The fluorescent X-ray analyzer arranges the specimen so as to cover the opening formed on the specimen stage, and irradiates X-rays through the opening from the side of the specimen setting surface. The fluorescent X-ray analyzer detects the X-rays that have passed through the opening among the X-rays returned from the specimen. For the X-rays that have scattered in the deep part of the specimen, since they are irradiated onto the specimen stage and cannot pass through the opening, they cannot be detected.

[0015] When a resin specimen with sufficient thickness, that is, a massive resin, is used as a standard specimen, the X-rays that have scattered in the deep part of the specimen cannot be detected. If the massive resin is used as a standard specimen, some of the scattered X-rays cannot be detected, so the proportional relationship between the measured intensity and the theoretical intensity of the scattered rays does not hold. Therefore, in the method disclosed in Non-Patent Document 1, the massive resin cannot be used as a standard specimen.

[0016] The present disclosure has been completed to solve this problem, and one of its purposes is to provide a method for analyzing a target specimen in which a film containing a resin is formed on a base material by the FP method to expand the applicable range of this analysis.

[0017] Solution to the problem

[0018] The fluorescence X-ray analysis method of the present disclosure is a fluorescence X-ray analysis method for analyzing secondary X-rays obtained by irradiating a specimen with primary X-rays from an X-ray source having a rhodium target. The fluorescence X-ray analysis method includes the following steps: extracting the measured intensity of Compton scattered rays originating from rhodium from the spectrum of the object specimen made from secondary X-rays obtained by irradiating the object specimen with primary X-rays, where the object specimen is a specimen in which a resin-containing film is formed on a base material; extracting the measured intensity of Rayleigh scattered rays originating from rhodium from the spectrum of the object specimen; obtaining the ratio of the measured intensity of Rayleigh scattered rays to the measured intensity of Compton scattered rays, that is, the measured scattering intensity ratio, based on the respective measured intensities extracted from the spectrum of the object specimen; and obtaining the thickness of the film and the content of each element constituting the object specimen by the fundamental parameter method based on the measured scattering intensity ratio of the object specimen. The theoretical intensity of Compton scattered rays is obtained based on a first arithmetic expression in which the thickness of the film and the content of each element constituting the object specimen are variables. The theoretical intensity of Rayleigh scattered rays is obtained based on a second arithmetic expression in which the thickness of the film and the content of each element constituting the object specimen are variables. The steps of obtaining the thickness and content of the film include the following steps: substituting estimated values into the variables included in the first arithmetic expression and the second arithmetic expression to obtain an estimated scattering intensity ratio obtained based on the theoretical scattering intensity ratio, where the theoretical scattering intensity ratio is the ratio of the theoretical intensity of Rayleigh scattered rays to the theoretical intensity of Compton scattered rays; and updating the estimated values so that the estimated scattering intensity ratio converges to the measured scattering intensity ratio.

[0019] The analysis program included in the present disclosure is an analysis program for analyzing secondary X-rays obtained by irradiating a specimen with primary X-rays from an X-ray source having a rhodium target. The analysis program causes a computer to perform the following steps: extracting the measured intensity of Compton scattered rays derived from rhodium from the spectrum of the object specimen created based on the secondary X-rays obtained by irradiating the object specimen with primary X-rays, where the object specimen is a specimen in which a resin-containing film is formed on a base material; extracting the measured intensity of Rayleigh scattered rays derived from rhodium from the spectrum of the object specimen; calculating the ratio of the measured intensity of Rayleigh scattered rays to the measured intensity of Compton scattered rays, i.e., the measured scattering intensity ratio, based on the respective measured intensities extracted from the spectrum of the object specimen; and calculating the thickness of the film and the content of each element constituting the object specimen by the fundamental parameter method based on the measured scattering intensity ratio of the object specimen. The theoretical intensity of Compton scattered rays is calculated based on a first arithmetic expression having the thickness of the film and the content of each element constituting the object specimen as variables. The theoretical intensity of Rayleigh scattered rays is calculated based on a second arithmetic expression having the thickness of the film and the content of each element constituting the object specimen as variables. The steps of calculating the thickness and content of the film include the following steps: substituting estimated values into the variables included in the first arithmetic expression and the second arithmetic expression to calculate an estimated scattering intensity ratio calculated based on the theoretical scattering intensity ratio, where the theoretical scattering intensity ratio is the ratio of the theoretical intensity of Rayleigh scattered rays to the theoretical intensity of Compton scattered rays; and updating the estimated values so that the estimated scattering intensity ratio converges to the measured scattering intensity ratio.

[0020] The fluorescence X-ray analysis apparatus of the present disclosure includes: a sample stage for disposing a sample; an X-ray tube configured to irradiate primary X-rays from an X-ray source having a rhodium target toward the sample stage; a detector for detecting secondary X-rays from the sample disposed on the sample stage; and a control device for analyzing the secondary X-rays detected by the detector. The sample is an object sample in which a film containing a resin is formed on a base material. The theoretical intensity of Compton scattered rays derived from rhodium contained in the secondary X-rays from the object sample is obtained based on a first arithmetic expression having the thickness of the film and the content of each element constituting the object sample as variables. The theoretical intensity of Rayleigh scattered rays derived from rhodium contained in the secondary X-rays from the object sample is obtained based on a second arithmetic expression having the thickness of the film and the content of each element constituting the object sample as variables. The control device performs the following processes: creating an X-ray spectrum of the object sample based on the secondary X-rays; extracting the measured intensity of Compton scattered rays and the measured intensity of Rayleigh scattered rays from the created X-ray spectrum; obtaining the ratio of the measured intensity of Rayleigh scattered rays to the measured intensity of Compton scattered rays, that is, the measured scattering intensity ratio, based on the extracted measured intensities; and obtaining the thickness of the film and the content of each element constituting the object sample by the fundamental parameter method based on the measured scattering intensity ratio of the object sample. The thickness of the film and the content of each element constituting the object sample are obtained by the following processes: substituting estimated values into the variables included in the first arithmetic expression and the second arithmetic expression to obtain an estimated scattering intensity ratio obtained based on the theoretical scattering intensity ratio, where the theoretical scattering intensity ratio is the ratio of the theoretical intensity of Rayleigh scattered rays to the theoretical intensity of Compton scattered rays; and updating the estimated values so that the estimated scattering intensity ratio converges to the measured scattering intensity ratio.

[0021] Effect of the Invention

[0022] According to the present disclosure, it is possible to expand the applicable range when analyzing an object sample in which a film containing a resin is formed on a base material by the FP method. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a diagram schematically showing the overall structure of the fluorescence X-ray analysis apparatus.

[0024] Figure 2 is a functional block diagram of the detector and the control device.

[0025] Figure 3 is a diagram showing an example of the X-ray spectrum stored in the spectrum storage unit.

[0026] Figure 4 is a flowchart showing the analysis method.

[0027] Figure 5 is a flowchart showing the method for obtaining the sensitivity coefficient ratio. DETAILED DESCRIPTION

[0028] [Overall structure of the fluorescent X-ray analyzer]

[0029] Figure 1 This is a diagram schematically showing the overall structure of a fluorescent X-ray analyzer. Figure 1 The illustrated X-ray fluorescence analysis apparatus 10 includes a sample chamber 1 , a measurement chamber 5 , a control device 14 , an operation unit 15 , and an output unit 16 .

[0030] The X-ray fluorescence analyzer 10 is an energy dispersive X-ray fluorescence spectrometer (EDX) that measures the concentration of elements contained in the sample S. The space inside the sample chamber 1 and the measurement chamber 5 is surrounded by the housing 3 in an airtight manner, and the interior can be kept in a vacuum as needed.

[0031] The sample chamber 1 includes a sample stage 2 at the bottom. A circular opening 4 is formed in the sample stage 2. The sample S is placed on the sample stage 2 so that the measurement position of the surface of the sample S is exposed from the opening 4 at the bottom of the housing 3.

[0032] The measuring room 5 is provided with an X-ray tube 7 and a detector 8 on its wall surface 6. The X-ray tube 7 irradiates primary X-rays toward the sample S. The primary X-rays emitted by the X-ray tube 7 pass through the opening 4 and irradiate the measuring position of the sample S. The secondary X-rays obtained by irradiating the sample S with the primary X-rays are incident on the detector 8, and the energy and intensity of the secondary X-rays are measured.

[0033] The measuring chamber 5 is provided with a shutter 9, a primary X-ray filter 11, and a collimator 13. The shutter 9, the primary X-ray filter 11, and the collimator 13 are configured to be movable along the same axis as the measuring chamber 5 by a driving mechanism 12. Figure 1 Slide in the direction perpendicular to the paper surface.

[0034] The shade 9 is formed of an X-ray absorbing material such as lead, and can be inserted into the optical path of the primary X-rays to shield the primary X-rays when necessary.

[0035] The primary X-ray filter 11 is formed of a metal foil selected according to the purpose, and is used to attenuate the background component in the primary X-ray emitted from the X-ray tube 7 so as to improve the S / N ratio of the required characteristic X-ray. In the actual device, a plurality of primary X-ray filters 11 formed of different types of metals are used, and the primary X-ray filter 11 selected according to the purpose is inserted into the optical path of the primary X-ray by the driving mechanism 12.

[0036] The collimator 13 is an aperture having a circular opening in the center, and is used to determine the size of the primary X-ray beam irradiated to the sample S. The collimator 13 is formed of an X-ray absorbing material such as brass. In an actual device, a plurality of collimators 13 with different opening diameters are arranged along the same Figure 1 The collimators 13 selected according to the purpose are inserted into the primary X-ray line through the driving mechanism 12 .

[0037] In order to observe the measurement position of the sample S before or during measurement, an imaging unit 20 is provided at the bottom of the measurement chamber 5 . Specifically, the imaging unit 20 is arranged to face the surface of the sample S and is configured to capture the measurement position of the sample S through the opening 4 formed in the sample stage 2 .

[0038] Before measurement, the user performing fluorescent X-ray analysis displays the image acquired by the imaging unit 20 on the output unit 16, and adjusts the measurement position of the sample S while observing the image. When managing the fluorescent X-ray measurement results, the image data of the measurement position is stored and managed in association with the measurement results as an identifier.

[0039] The control device 14 is mainly composed of a CPU (Central Processing Unit) 141 as a calculation processing unit. For example, a personal computer or the like can be used as the control device 14. The control device 14 is connected to the X-ray tube 7, the detector 8, the operation unit 15, and the output unit 16.

[0040] The control device 14 controls the measurement of the fluorescent X-ray analyzer 10 based on the measurement conditions inputted by the operation unit 15 including a keyboard, a mouse, etc. Specifically, the control device 14 controls the tube voltage, the tube current, the irradiation time, etc. in the X-ray tube 7. In addition, the operation unit 15 may be a touch panel or the like integrally formed with the display screen of the display device.

[0041] The control device 14 acquires data of the secondary X-rays detected by the detector 8. The control device 14 analyzes the sample S based on the spectrum of the secondary X-rays detected by the detector 8.

[0042] The output unit 16 includes, for example, a display device composed of an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence). The display device displays an image based on the data sent from the control device 14. The display device can display various images generated by the control device 14. The display device can also display the analysis result obtained by the control device 14 together with the identification information (product name, product number, measurement position, etc.) for identifying the sample S.

[0043] The control device 14 includes a CPU 141 and a memory 142, wherein the memory 142 is used to store various programs and data including an analysis program 143. The memory 142 includes a ROM (Read Only Memory), a RAM (Random Access Memory), and an SSD (Solid State Drive). Instead of the SSD, an HDD (Hard Disk Drive) may be included.

[0044] The ROM stores various programs including the analysis program 143 and various parameters executed by the CPU 141. The RAM temporarily stores data used during the execution of various programs by the CPU 141, and functions as a temporary data storage used as a work area. The SSD is a non-volatile storage device for storing the measurement results obtained by the fluorescent X-ray analysis device 10.

[0045] The analysis program 143 is a program for analyzing the sample S based on the spectrum of the secondary X-rays detected by the detector 8. The CPU 141 reads out and executes the analysis program 143 to realize each process (step) related to the analysis method described later.

[0046] The analysis program 143 can also be recorded in a non-transitory computer-readable recording medium such as a floppy disk, a CD-ROM (Compact Disk Read Only Memory), a secondary storage device, a main storage device, and a memory card attached to the computer, and provided as a program product. Alternatively, the analysis program 143 can also be provided in a manner recorded in a recording medium such as a hard disk built into the computer. In addition, the analysis program 143 can also be provided by downloading via a network.

[0047] [Functional structure of control device]

[0048] Figure 2 The CPU 141 executes various programs to perform Figure 2 The operation of each functional block of the control device 14.

[0049] The detector 8 includes an X-ray detector 81, a preamplifier 82, and a proportional amplifier 83. The control device 14 includes an A / D converter (ADC) 106, a multi-channel analyzer (MCA) 107, a spectrum storage unit 111, a parameter storage unit 112, and a data processing unit 200. Although not shown in the figure, the control device 14 includes a control unit for controlling each device constituting the fluorescent X-ray analysis device 10.

[0050] The X-ray tube 7 includes a filament that emits thermal electrons and a target T that converts the thermal electrons into predetermined primary X-rays and then emits them. The target T is rhodium (Rh). Therefore, the X-ray tube 7 is configured to irradiate the sample stage 2 with primary X-rays from an X-ray source having a rhodium target.

[0051] When the primary X-rays emitted from the X-ray tube 7 are irradiated to the sample S, the secondary X-rays excited by the primary X-rays are emitted from the sample S, enter the X-ray detector 81 such as a silicon drift detector, and are detected as current signals.

[0052] The detected current is integrated inside the X-ray detector 81, and the integrated value is reset when it exceeds a certain time. As a result, the output signal of the X-ray detector 81 is a step-shaped current pulse signal. The current pulse signal is input to the preamplifier 82, and then input to the proportional amplifier 83 including a waveform shaping circuit, and the current pulse signal is formed into a pulse of an appropriate shape with a wave height corresponding to the height of each step and then output.

[0053] The A / D converter (ADC) 106 samples the analog signal of the pulse wave shape at a predetermined sampling period and digitizes it. The multi-channel analyzer (MCA) 107 distinguishes each pulse according to the wave height value of the digitized pulse signal and counts each pulse according to different energies, thereby creating a wave height distribution diagram, i.e., an X-ray spectrum, and stores it in the spectrum storage unit 111.

[0054] Figure 3 is a diagram showing an example of an X-ray spectrum stored in the spectrum storage unit 111. Figure 3 As shown, the secondary X-rays include fluorescent X-rays inherent to each element contained in the sample S (FeKα, ZnKα, etc. in the figure), as well as Rayleigh scattered rays (RhKαR in the figure) and Compton scattered rays (RhKαC in the figure) bounced back from the sample S.

[0055] The data processing unit 200 analyzes the X-ray spectrum stored in the spectrum storage unit 111 based on the analysis conditions input from the operation unit 15 and various parameters such as physical constants (fundamental parameters) stored in the parameter storage unit 112 , and outputs the analysis results to the output unit 16 .

[0056] In the present embodiment, the data processing unit 200 analyzes the X-ray spectrum obtained from the sample S by the FP method. Next, a specific analysis method will be described.

[0057] [Analysis method]

[0058] The following describes an analysis method for analyzing an X-ray spectrum by the data processing unit 200. As an example, the fluorescent X-ray analysis device 10 according to the present embodiment is configured as follows: Figure 2 As shown, a sample S in which a thin film F is formed on a base material B is an analysis object.

[0059] When it is desired to quantify elements in a thin film, the intensity of fluorescent X-rays obtained from the thin film is lower than that obtained from a block having sufficient thickness. Therefore, when quantifying elements in a thin film by fluorescent X-ray analysis, the film thickness needs to be considered.

[0060] The data processing unit 200 according to the present embodiment obtains the composition of the sample S and the film thickness t, which is the thickness of the thin film F, as analysis results by the FP method.

[0061] Figure 4 is a flow chart showing the analysis method. Figure 4 Each of the processes (steps) shown is a process executed by the control device 14 , and is realized by the CPU 141 executing various programs including the analysis program 143 .

[0062] In step S1 , the control device 14 irradiates primary X-rays from the X-ray tube 7 toward the sample S, and detects secondary X-rays from the sample S with the detector 8 , thereby acquiring an X-ray spectrum. The acquired X-ray spectrum is stored in the spectrum storage unit 111 .

[0063] In step S2, the control device 14 extracts the intensity of each spectral line appearing in the acquired X-ray spectrum. The control device 14 determines the spectral line to be extracted based on the analysis conditions input from the operation unit 15, for example. The substance constituting the base material B and the substance constituting the thin film F are input from the operation unit 15 as the analysis conditions. In addition, the "substance" includes at least one of a compound and an element.

[0064] In step S2, the processes of steps S21 to S23 are executed.

[0065] In step S21, the control device 14 extracts the intensity of the Compton scattered light, that is, the measured intensity M C .

[0066] In step S22, the control device 14 extracts the intensity of the Rayleigh scattered light, that is, the measured intensity M R .

[0067] In step S23, the control device 14 extracts the intensity of the fluorescent X-ray originating from element i, that is, the actual measured intensity M, for each inorganic element constituting the sample S. fi .

[0068] In step S3, the control device 14 obtains the measured scattering intensity ratio M based on the measured intensities extracted in step S2. C / R The measured scattering intensity is M C / R is the measured intensity M of the Rayleigh scattered light R Relative to the measured intensity M of the Compton scattered light C The ratio is calculated based on formula (1).

[0069] [Number 1]

[0070]

[0071] In step S4, the control device 14 obtains the measured fluorescence X-ray intensity ratio M of the fluorescence X-ray originating from element i for each inorganic element constituting the sample S based on the measured intensities extracted in step S2. fi / R The measured fluorescence X-ray intensity is M fi / R is the measured intensity M of the Rayleigh scattered light R Relative to the measured intensity M of the fluorescent X-ray from element i fi The ratio is calculated based on formula (2).

[0072] [Number 2]

[0073]

[0074] In step S5, the control device 14 calculates the theoretical intensity of each spectral line. In step S5, the processes of step S51 to step S53 are executed.

[0075] In step S51, the control device 14 calculates the theoretical intensity T of the Compton scattered light based on the following equation (3): C .

[0076] [Number 3]

[0077] T C =f C (t,W i1 , W i2 ,…)…(3)

[0078] W is the content of the element. Subscripts i1, i2, ... refer to the type of element, which are all the elements constituting the sample S. t is the film thickness of the thin film F. The elements constituting the sample S are determined based on the material constituting the base material B and the material constituting the thin film F input from the operation unit 15 as analysis conditions. In addition, since the content can be calculated by multiplying the content by the weight of the sample S, the content W is a variable equivalent to the "content".

[0079] As shown in formula (3), the content W of each element constituting the sample S isi1 , W i2 The theoretical intensity T of the Compton scattered light is expressed by a theoretical formula with the film thickness t of the thin film F as variables: C Formula (3) includes various parameters. The control device 14 calculates the theoretical intensity T by substituting various parameters stored in the parameter storage unit 112 and the initial values ​​of the variables input from the operation unit 15 as analysis conditions or the estimated values ​​corrected in steps S9 and S10 into formula (3). C The initial value may be directly input from the operation unit 15 or may be determined by the control device 14 based on the elements constituting the sample S. When the control device 14 determines based on the elements constituting the sample S, when the sample S is composed of five elements, as an example, the control device 14 sets the initial value of each element to 20%. The estimated value corrected in step S9 and step S10 will be described later and will be referred to as "corrected estimated value" hereinafter.

[0080] In step S52, the control device 14 calculates the theoretical intensity T of the Rayleigh scattered light based on the following equation (4): R .

[0081] [Number 4]

[0082] T R =f R (t,W i1 , W i2 ,…)…(4)

[0083] As shown in formula (4), the theoretical intensity T of Compton scattered light C Similarly, the theoretical intensity T of the Rayleigh scattered light is expressed by a theoretical formula using the content of each element constituting the sample S and the film thickness t of the thin film F as variables: R The control device 14 calculates the theoretical intensity T of the Rayleigh scattered radiation by substituting various parameters stored in the parameter storage unit 112 and the initial values ​​or corrected estimated values ​​of the variables input as analysis conditions from the operation unit 15 into equation (4). R .

[0084] In step S53, the control device 14 calculates the theoretical intensity T of the fluorescent X-ray originating from element i for each inorganic element constituting the sample S based on the following equation (5): fi .

[0085] [Number 5]

[0086] T fi =f fi (t,W i )…(5)

[0087] T fiThe theoretical intensity of the fluorescent X-ray from element i is expressed by a theoretical formula T with the film thickness t and the content of element i as variables as shown in formula (5). fi The control device 14 calculates the theoretical intensity T of the fluorescent X-ray from element i by substituting various parameters stored in the parameter storage unit 112 and the initial values ​​or corrected estimated values ​​of the variables input as analysis conditions from the operation unit 15 into equation (5). fi .

[0088] In addition, since the generation mechanism of Compton scattered rays, the generation mechanism of Rayleigh scattered rays, and the generation mechanism of fluorescent X-rays from each element are different from each other, equations (3) to (5) are different from each other. In addition, the theoretical formulas of equations (3) to (5) are determined based on the generation mechanism of spectral lines, respectively, and are well known. Therefore, the detailed description of equations (3) to (5) is omitted.

[0089] In step S6, the control device 14 calculates the estimated scattering intensity ratio E based on the following equation (6): C / R .

[0090] [Number 6]

[0091]

[0092] k C / R is the sensitivity coefficient ratio, is the sensitivity coefficient k of the Rayleigh scattered light R The sensitivity coefficient k relative to Compton scattered light C The sensitivity coefficient is k C / R It is obtained by measuring a standard sample with a known composition ratio and is stored in the parameter storage unit 112. C / R For the specific calculation method, refer to Figure 5 This will be described later.

[0093] In step S7, the control device 14 calculates the estimated fluorescent X-ray intensity ratio E associated with element i for each inorganic element constituting the sample S based on the following equation (7): fi / R .

[0094] [Number 7]

[0095]

[0096] k fi / R is the sensitivity coefficient ratio of the fluorescent X-ray from element i, is the sensitivity coefficient k of the Rayleigh scattered light R The sensitivity coefficient k to the fluorescent X-ray from element i fi The sensitivity coefficient is k fi / Ris obtained by measuring a standard sample containing element i and having a known content of each element, and is stored in the parameter storage unit 112. fi / R For the specific calculation method, refer to Figure 5 This will be described later.

[0097] In step S8, the control device 14 determines whether the estimated scattering intensity ratio E C / R Converges to the measured scattering intensity ratio M C / R , and estimate the fluorescence X-ray intensity ratio E fi / R Converges to the measured fluorescence X-ray intensity ratio M fi / R For example, in estimating the scattering intensity ratio E C / R Compared with the measured scattering intensity M C / R The difference is less than a predetermined first threshold value, and the estimated fluorescence X-ray intensity ratio E fi / R Compared with the measured fluorescence X-ray intensity M fi / R When the difference between the first threshold value and the second threshold value is smaller than a predetermined second threshold value, the control device 14 determines that convergence has been achieved. The first threshold value and the second threshold value may be predetermined, and may be determined based on, for example, required accuracy.

[0098] The method of determining convergence is not limited to the above method. For example, the control device 14 may determine that convergence has occurred when the difference between the estimated value before correction and the estimated value after correction is smaller than a third threshold value that is predetermined in advance.

[0099] When it is determined that there is no convergence (NO in step S8 ), the control device 14 executes the processes of step S9 and step S10 , and then executes the processes after step S5 again.

[0100] In step S9, the control device 14 calculates the content W of each element. i1 , W i2 ···Correction is made in the direction that the estimated intensity ratio converges to the measured intensity ratio.

[0101] In step S10, the film thickness t is adjusted to the corrected content W i1 , W i2 The total value of ··· is close to 100% direction correction.

[0102] In steps S5 to S7, the control device 14 calculates the content W of each element corrected in steps S9 and S10. i1 , W i2 ···and film thickness t are substituted into the above equations (3) to (5) to obtain the theoretical strength T C , T R , T fi , and thus the estimated scattering intensity ratio E C / Rand the estimated fluorescence X-ray intensity ratio E fi / R .

[0103] The control device 14 repeats the processing of step S9, step S10, and step S5 to step S7 until convergence.

[0104] When it is determined that the estimated scattering intensity ratio E when converged is reached ("Yes" in step S8), in step S11, the control device 14 outputs the analysis result to the output unit 16. More specifically, the estimated scattering intensity ratio E when converged is reached is output to the output unit 16. C / R and the estimated fluorescence X-ray intensity ratio E fi / R The content of each element W i1 , W i2 ···and film thickness t are output as the content rate of each element constituting the sample S and the film thickness t of the thin film F.

[0105] Furthermore, in the above-described embodiment, the elements constituting the sample S are identified by input from the operation unit 15 , but the elements constituting the sample S may be identified by qualitatively analyzing the obtained spectrum.

[0106] [Method for calculating the sensitivity coefficient ratio]

[0107] Figure 5 2 is a flowchart showing a method for obtaining the sensitivity coefficient ratio. C / R It is obtained from the X-ray spectrum of a standard sample with a known element content. fi / R It is obtained from the X-ray spectrum of a standard sample containing the inorganic elements contained in the sample to be analyzed and having a known content of each element. Figure 5 Each of the processes (steps) shown is a process executed by the control device 14, and is realized by the CPU 141 executing various programs including the analysis program 143. Next, as an example, the sensitivity coefficient ratio k is obtained. C / R , the sensitivity coefficient of lead is k fPb / R And the sensitivity coefficient of iron is k fFe / R .

[0108] Each sensitivity coefficient ratio can be obtained from the X-ray spectrum of a standard sample. The standard sample is a material whose constituent elements and the content of each constituent element are known. In the following example, the sensitivity coefficient ratio k C / R It is obtained based on the X-ray spectrum of the first standard sample. The sensitivity coefficient of lead is k fPb / R The sensitivity coefficient of iron is k fFe / RIt is obtained based on the X-ray spectrum of the second standard sample. The first standard sample is a resin block, i.e., a block resin, whose element content is known. The second standard sample is a block metal containing lead and iron and whose content of each element is known. In addition, the block resin and the block metal each have a thickness that does not require consideration of the film thickness in the FP method.

[0109] First, the control device 14 executes steps S110 to S150 to obtain the sensitivity coefficient ratio k based on the X-ray spectrum of the first standard sample. C / R In step S110 , the control device 14 acquires the X-ray spectrum of the first standard sample.

[0110] In step S120, the control device 14 extracts the measured intensity of each spectral line. In step S120, the processes of step S121 and step S122 are performed.

[0111] In step S121, the control device 14 extracts the intensity of the Compton scattered light, that is, the measured intensity M C More specifically, the control device 14 extracts the measured intensity M of the Compton scattered rays from the X-ray spectrum of the first standard sample. C .

[0112] In step S122, the control device 14 extracts the intensity of the Rayleigh scattered light, that is, the measured intensity M R More specifically, the control device 14 extracts the measured intensity M of the Rayleigh scattered rays from the X-ray spectrum of the first standard sample. R .

[0113] In step S130, the control device 14 generates a signal based on the measured strength M extracted in steps S121 and S122. C and the measured strength M R Based on the above formula (1), the measured scattering intensity ratio M is obtained. C / R .

[0114] In step S140, the control device 14 calculates the theoretical intensity of each spectral line. In step S140, the processes of step S141 and step S142 are performed.

[0115] In step S141, the control device 14 calculates the theoretical intensity T of the Compton scattered light for the first standard sample based on the above-mentioned formula (3). C In addition, the film thickness t is set to be infinite or a sufficiently large value to calculate the theoretical strength T C When the standard sample is a thin film, the control device 14 substitutes the film thickness of the thin film into the formula (3).

[0116] In step S142, the control device 14 calculates the theoretical intensity T of the Rayleigh scattered light for the first standard sample based on the above-mentioned equation (4). R As in step S141, the film thickness t is set to be infinite or to an appropriate sufficiently large value. When the standard sample is a thin film, the control device 14 substitutes the film thickness of the thin film into the formula (4).

[0117] In step S150, the control device 14 calculates the actual scattering intensity ratio M calculated in steps S130 and S140 by C / R , the theoretical intensity of Compton scattered rays T C and the theoretical intensity of Rayleigh scattered radiation T R Substitute into the following formula (8) to calculate the sensitivity coefficient ratio k C / R .

[0118] [Number 8]

[0119]

[0120] Next, the control device 14 executes steps S160 to S200 to obtain the sensitivity coefficient ratio k of lead based on the X-ray spectrum of the second standard sample. fPb / R The sensitivity coefficient of iron is k fFe / R In step S160 , the control device 14 acquires the X-ray spectrum of the second standard sample.

[0121] In step S170, the control device 14 extracts the measured intensity of each spectral line. In step S170, the processes of step S171 and step S172 are performed.

[0122] In step S171, the control device 14 extracts the intensity of the fluorescent X-rays originating from each inorganic element, that is, the measured intensity M fi More specifically, the control device 14 extracts the measured intensity M of the fluorescent X-ray originating from lead from the X-ray spectrum of the second standard sample. fPb and the measured intensity M of the fluorescent X-rays originating from iron fFe .

[0123] In step S172, the control device 14 extracts the intensity of the Rayleigh scattered light, that is, the measured intensity M R More specifically, the control device 14 extracts the measured intensity M of the Rayleigh scattered light from the X-ray spectrum of the second standard sample. R .

[0124] In step S180, the control device 14 generates a signal based on the measured intensity M of the fluorescent X-rays from element i extracted in steps S171 and S172. fi and the measured intensity M of the Rayleigh scattered light RBased on the above formula (2), the measured fluorescence X-ray intensity ratio M is calculated. fi / R More specifically, the control device 14 calculates the measured fluorescence X-ray intensity ratio M of lead. fPb / R The measured fluorescence X-ray intensity ratio of iron is M fFe / R .

[0125] In step S190, the control device 14 calculates the theoretical intensity of each spectral line. In step S190, the processes of step S191 and step S192 are performed.

[0126] In step S191, the control device 14 calculates the theoretical intensity T of the fluorescent X-rays from each inorganic element based on the above formula (5). fi More specifically, in this embodiment, the control device 14 calculates the theoretical intensity T of the fluorescent X-rays from lead for the second standard sample. fPb and the theoretical intensity T of the fluorescent X-ray originating from iron fFe As in step S141, the film thickness t is set to be infinite or to an appropriate sufficiently large value. When the standard sample is a thin film, the control device 14 substitutes the film thickness of the thin film into the formula (5).

[0127] In step S192, based on the above equation (4), the theoretical intensity T of the Rayleigh scattered light is calculated for the second standard sample. R As in step S141, the film thickness t is set to be infinite or to an appropriate sufficiently large value. When the standard sample is a thin film, the control device 14 substitutes the film thickness of the thin film into the formula (4).

[0128] In step S200, the control device 14 calculates the actual measured fluorescent X-ray intensity ratio M calculated in steps S180 and S190. fi / R , the theoretical intensity of fluorescent X-rays T fi and the theoretical intensity of Rayleigh scattered radiation T R Substitute the following formula (9) to calculate the sensitivity coefficient ratio k of fluorescent X-rays: fi / R More specifically, the sensitivity coefficient of lead is k fPb / R The measured fluorescence X-ray intensity of lead is calculated by fPb / R , Theoretical strength of lead T fPb and the theoretical intensity of Rayleigh scattered radiation T R Substituting into equation (9) we can obtain the sensitivity coefficient of iron: fFe / R The measured fluorescence X-ray intensity of iron is calculated by fFe / R , Theoretical strength of iron T fFe and the theoretical intensity of Rayleigh scattered radiation T R Substitute into formula (9) and find .

[0129] [Number 9]

[0130]

[0131] In step S210 , the control device 14 stores the sensitivity coefficient ratio calculated in each of steps S150 and S200 in the parameter storage unit 112 , and ends the process.

[0132] exist Figure 5 In the process, the block resin is used as the first standard sample, and the control device 14 obtains the sensitivity coefficient ratio k based on the X-ray spectrum of the first standard sample. C / R In addition, the control device 14 can also obtain the sensitivity coefficient ratio k based on the X-ray spectrum of the second standard sample as the bulk metal. C / R In addition, it is preferable to use a standard sample composed of a component close to that of the target sample to be measured to obtain the sensitivity coefficient ratio, but it is also possible to use a standard sample composed of a component different from that of the target sample to obtain the sensitivity coefficient ratio.

[0133] [Examples and Comparative Examples]

[0134] The accuracy of the analysis value obtained by the analysis method according to the present embodiment was studied. The sample S is a resin-coated paper clip (gem clip). The base material is iron (Fe), and the resin is polyethylene (C 2 H 4 ). Table 1 shows the analysis results of quantitative analysis of lead (Pb) in the resin film of the sample S performed by the analysis method according to the present embodiment and the calibration curve method, and the respective analysis conditions.

[0135] [Table 1]

[0136]

[0137] In the examples, the quantitative analysis of lead in the resin film of the sample S was performed according to the analysis method of the present embodiment. Figure 4 The analysis method shown analyzes the X-ray spectrum obtained by placing the sample S non-destructively on the sample stand 2. In addition, block-shaped polyethylene, iron, and lead are used as standard samples. Figure 5 The method shown is used to obtain each sensitivity coefficient ratio.

[0138] In Comparative Example 1, the X-ray spectrum obtained by placing the sample S intact on the sample stage 2 was analyzed according to the calibration curve method. In Comparative Example 2, the sample S was destroyed, the resin coating was removed from the base material, and only the resin coating was placed on the sample stage 2, and the X-ray spectrum obtained was analyzed according to the calibration curve method.

[0139] Here, the calibration curve method in Comparative Examples 1 and 2 is a quantitative analysis method that uses the correlation between the intensity of the fluorescent X-rays derived from lead in the X-ray spectrum obtained by measuring a standard sample with a known lead content and the lead content to draw a calibration curve. In addition, in the calibration curve method of Comparative Examples 1 and 2, the following known method is used: a calibration curve is prepared based on the ratio of the measured intensity of the fluorescent X-rays of lead to the intensity of the continuous scattered X-rays near the fluorescent X-rays of lead, thereby correcting the influence of the sample shape.

[0140] In Comparative Example 1, the analysis was performed without separating the base material from the thin film, so the analysis value of lead was lower than that of the case where the analysis was performed by other methods. This is because: in Comparative Example 1, although shape correction was performed, the film thickness of the thin film could not be measured in the calibration curve method, so it was affected by the film thickness.

[0141] In Comparative Example 2, the base material and the thin film were separated and only the thin film was measured, so the film thickness was also corrected as a part of the shape. Therefore, compared with Comparative Example 1, the analysis value in Comparative Example 2 became higher.

[0142] As described above, in the case of the calibration curve method, by separating the base material and the thin film and performing measurement in a state of only the thin film, a highly accurate analysis result can be obtained.

[0143] The analysis results in the examples are close to the analysis results in the comparative example 2. That is, by using the analysis method according to the present embodiment, the target component in the resin film can be measured at a high level without destroying the sample S.

[0144] [Effects obtained by using the scattering intensity ratio]

[0145] As shown in Table 1, by using the analysis method according to the present embodiment, the target component in the resin film can be measured without destroying the sample S. Therefore, the analysis method according to the present embodiment can also be applied to indestructible samples such as those shipped as products or assembled into products after measurement.

[0146] In the analysis method according to the present embodiment, the ratio of the intensity of Rayleigh scattered rays to the intensity of Compton scattered rays is used. By normalizing by dividing the intensity of Compton scattered rays by the intensity of Rayleigh scattered rays, the influence of the shape of the sample S on the quantitative value can be corrected.

[0147] In addition, as a comparative example, when the fluorescence X-rays from the base material are used for standardization, if the transmittance of the fluorescence X-rays is low for the thin film, the fluorescence X-rays cannot be detected and therefore cannot be used. In particular, when the main component of the base material B of the sample S is a light element with an atomic number of less than 21 (scandium), the energy of the fluorescence X-rays of the element is low and it is difficult to penetrate the thin film, so it is difficult to detect using the fluorescence X-ray analysis device 10. In contrast, Rayleigh scattered rays can be detected regardless of the type of base material. Therefore, according to the method involved in the present embodiment, standardization is performed using the intensity of the Rayleigh scattered rays, so that the sample S formed with a resin thin film can be analyzed regardless of the base material of the sample S, and the scope of application of the analysis using the FP method can be expanded. That is, according to the method involved in the present embodiment, a sample containing a base material with a light element with an atomic number of less than 21 as the main component can be analyzed.

[0148] In addition, in the present embodiment, by using the ratio of the intensity of Rayleigh scattered rays to the intensity of Compton scattered rays, a block-shaped resin as a resin block can be used as a standard sample. The reason for this will be described below.

[0149] It is known that the measured intensity of the scattered rays is proportional to the theoretical intensity. The depth of primary X-rays penetrating into resin materials is deeper than that of primary X-rays penetrating into metal materials. Figure 1 As shown, scattered rays I1 of primary X-rays incident near the surface of sample S pass through opening 4 from sample S and enter detector 8. On the other hand, scattered rays I2 of primary X-rays incident deep inside sample S strike sample stage 2 and do not reach detector 8.

[0150] Therefore, when a block of resin is used as a standard sample, the intensity of the scattered light I2 of the primary X-ray incident deep into the sample S cannot be detected, so the proportional relationship between the measured intensity and the theoretical intensity of the scattered light is destroyed and the sensitivity coefficient cannot be calculated.

[0151] Here, since both Compton scattered rays and Rayleigh scattered rays are scattered rays, some scattered rays cannot be detected in either type of scattered rays. By using the scattering intensity ratio, the influence of the scattered rays that cannot be detected can be eliminated, so even when the block resin is used as a standard sample, the sensitivity coefficient ratio can be obtained. As a result, the block resin can be used as a standard sample.

[0152] As described above, by using the analysis method according to the present embodiment, it is possible to expand the application range of analysis based on the FP method.

[0153] In the above embodiment, analysis was performed using Compton scattered rays and Rayleigh scattered rays derived from RhKα. However, if sufficient intensity can be obtained, analysis by the FP method can be performed similarly even if Compton scattered rays and Rayleigh scattered rays derived from RhKβ are used.

[0154] In the above embodiment, the control device 14 calculates the theoretical intensity T of the Compton scattered rays. C and the theoretical intensity of Rayleigh scattered radiation T R Afterwards, the estimated scattering intensity ratio E is calculated C / R In addition, the control device 14 may not calculate the theoretical intensity T of the Compton scattered rays separately. C and the theoretical intensity of Rayleigh scattered radiation T R , and directly calculate the estimated scattering intensity ratio E C / R .

[0155] [Way]

[0156] It will be understood by those skilled in the art that the above-described embodiments are specific examples of the following aspects.

[0157] (Item 1) A fluorescent X-ray analysis method according to one embodiment is a fluorescent X-ray analysis method for analyzing secondary X-rays obtained by irradiating a sample with primary X-rays from an X-ray source having a rhodium target. The fluorescent X-ray analysis method includes the following steps: extracting the measured intensity of Compton scattered rays originating from rhodium from a spectrum of a target sample produced based on secondary X-rays obtained by irradiating the target sample with primary X-rays, wherein the target sample is a sample in which a thin film containing a resin is formed on a base material; extracting the measured intensity of Rayleigh scattered rays originating from rhodium from the spectrum of the target sample; obtaining a ratio of the measured intensity of Rayleigh scattered rays to the measured intensity of Compton scattered rays, i.e., a measured scattering intensity ratio, based on each measured intensity extracted from the spectrum of the target sample; and obtaining the thickness of the thin film and the content of each element constituting the target sample by a fundamental parameter method based on the measured scattering intensity ratio of the target sample. The theoretical intensity of the Compton scattered rays is obtained based on a first calculation formula with the thickness of the thin film and the content of each element constituting the target sample as variables. The theoretical intensity of Rayleigh scattered rays is obtained based on a second calculation formula using the thickness of the thin film and the content of each element constituting the target sample as variables. The step of obtaining the thickness and content of the thin film includes the following steps: substituting estimated values ​​into the variables included in the first calculation formula and the second calculation formula to obtain an estimated scattering intensity ratio obtained based on a theoretical scattering intensity ratio, wherein the theoretical scattering intensity ratio is a ratio of the theoretical intensity of Rayleigh scattered rays to the theoretical intensity of Compton scattered rays; and updating the estimated value so that the estimated scattering intensity ratio converges to the measured scattering intensity ratio.

[0158] According to the fluorescent X-ray analysis method described in the first item, the applicable scope of the analysis based on the FP method can be expanded by using the scattering intensity ratio. More specifically, even for a sample in which a resin film is formed on a base material whose main component is an element that is difficult to measure by fluorescent X-rays, analysis based on the FP method can be performed without destroying the sample. In addition, for the resin component, the primary X-ray penetrates deep into the deep part, so there is a situation where the scattered rays that penetrate into the deep part and bounce back cannot be detected. Even in this case, the influence of the undetectable scattered rays can be eliminated by using the scattering intensity ratio, so the block resin can be used as a standard sample. Therefore, even in the case of a standard sample in which it is difficult to prepare a thin film, analysis based on the FP method can be performed.

[0159] (Second item) In the fluorescent X-ray analysis method described in the first item, the film contains at least one inorganic component. The theoretical intensity of the fluorescent X-rays originating from the inorganic component is obtained based on a third calculation formula with the thickness of the film and the content of the inorganic component as variables. The fluorescent X-ray analysis method further includes the following steps: detecting spectral lines generated by the fluorescent X-rays originating from the inorganic component based on the spectrum of the target sample, and extracting the measured intensity of the fluorescent X-rays originating from the inorganic component, namely the measured fluorescent X-ray intensity; and obtaining the ratio of the measured intensity of the Rayleigh scattered rays to the measured intensity of the fluorescent X-rays originating from the inorganic component, namely the measured fluorescent X-ray intensity ratio, based on each measured intensity extracted from the spectrum of the target sample. The step of obtaining the thickness and content of the film further includes the following steps: substituting estimated values ​​into the variables included in the second calculation formula and the third calculation formula, and obtaining an estimated fluorescent X-ray intensity ratio based on the theoretical fluorescent X-ray intensity ratio, wherein the theoretical fluorescent X-ray intensity ratio is the ratio of the theoretical intensity of the Rayleigh scattered rays to the theoretical intensity of the fluorescent X-rays originating from the inorganic component. In the step of updating the estimated values, the estimated values ​​are updated so that the estimated scatter intensity ratio converges to the actually measured scatter intensity ratio and the estimated fluorescent X-ray intensity ratio converges to the actually measured fluorescent X-ray intensity ratio.

[0160] According to the fluorescent X-ray analysis method described in the second item, the content of the inorganic component in the thin film resin can be determined.

[0161] (Item 3) In the fluorescent X-ray analysis method described in Item 1 or Item 2, the Rayleigh scattered light is Rayleigh scattered light derived from RhKα. The Compton scattered light is Rayleigh scattered light derived from RhKα.

[0162] According to the fluorescent X-ray analysis method described in the third aspect, by performing analysis using scattered rays derived from RhKα having an intensity higher than that of RhKβ, it is possible to improve the analysis accuracy.

[0163] (Item 4) In the fluorescent X-ray analysis method described in any one of Items 1 to 3, the base material contains a light element having an atomic number of 21 or less as a main component.

[0164] According to the fluorescent X-ray analysis method described in the fourth aspect, the FP method can be applied also to a sample in which a resin thin film is formed on a base material mainly composed of an element that is difficult to measure by fluorescent X-rays.

[0165] (Item 5) In the fluorescent X-ray analysis method described in any one of Items 1 to 4, the estimated scattering intensity ratio is obtained by multiplying the theoretical scattering intensity ratio by the sensitivity coefficient ratio. The fluorescent X-ray analysis method further includes the following steps: using a block resin with known contents of each element as a standard sample, extracting the measured intensity of Compton scattered rays from the spectrum of the standard sample obtained by irradiating the standard sample with primary X-rays; extracting the measured intensity of Rayleigh scattered rays from the spectrum of the standard sample; obtaining the measured scattering intensity ratio of the standard sample based on each measured intensity extracted from the spectrum of the standard sample; and obtaining the sensitivity coefficient ratio based on the theoretical scattering intensity ratio of the standard sample obtained by substituting the contents of each element constituting the standard sample and the thickness of the standard sample and the measured scattering intensity ratio of the standard sample based on the first calculation formula and the second calculation formula.

[0166] According to the fluorescent X-ray analysis method described in the fifth item, even when it is difficult to prepare a standard sample of a thin film, analysis based on the FP method can be performed.

[0167] (Item 6) The analysis program involved in one method is an analysis program for analyzing secondary X-rays obtained by irradiating a specimen with primary X-rays from an X-ray source having a rhodium target. The analysis program causes a computer to perform the following steps: extracting the measured intensity of Compton scattered rays originating from rhodium from the spectrum of the object specimen created based on the secondary X-rays obtained by irradiating the object specimen with primary X-rays, where the object specimen is a specimen in which a resin-containing film is formed on a base material; extracting the measured intensity of Rayleigh scattered rays originating from rhodium from the spectrum of the object specimen; calculating the ratio of the measured intensity of Rayleigh scattered rays to the measured intensity of Compton scattered rays, i.e., the measured scattering intensity ratio, based on the respective measured intensities extracted from the spectrum of the object specimen; and calculating the thickness of the film and the content of each element constituting the object specimen by the fundamental parameter method based on the measured scattering intensity ratio of the object specimen. The theoretical intensity of Compton scattered rays is calculated based on a first arithmetic expression with the thickness of the film and the content of each element constituting the object specimen as variables. The theoretical intensity of Rayleigh scattered rays is calculated based on a second arithmetic expression with the thickness of the film and the content of each element constituting the object specimen as variables. The steps of calculating the thickness and content of the film include the following steps: substituting estimated values into the variables included in the first arithmetic expression and the second arithmetic expression to calculate an estimated scattering intensity ratio calculated based on the theoretical scattering intensity ratio, where the theoretical scattering intensity ratio is the ratio of the theoretical intensity of Rayleigh scattered rays to the theoretical intensity of Compton scattered rays; and updating the estimated values so that the estimated scattering intensity ratio converges to the measured scattering intensity ratio.

[0168] (Item 7) The fluorescent X-ray analysis apparatus according to one aspect includes: a specimen stage for disposing a specimen; an X-ray tube configured to irradiate the specimen stage with primary X-rays from an X-ray source having a rhodium target; a detector for detecting secondary X-rays from the specimen disposed on the specimen stage; and a control device for analyzing the secondary X-rays detected by the detector. The specimen is an object specimen in which a film containing a resin is formed on a base material. The theoretical intensity of Compton scattered rays derived from rhodium contained in the secondary X-rays from the object specimen is obtained based on a first arithmetic expression having the thickness of the film and the contents of the respective elements constituting the object specimen as variables. The theoretical intensity of Rayleigh scattered rays derived from rhodium contained in the secondary X-rays from the object specimen is obtained based on a second arithmetic expression having the thickness of the film and the contents of the respective elements constituting the object specimen as variables. The control device performs the following processes: producing an X-ray spectrum of the object specimen based on the secondary X-rays; extracting the measured intensity of Compton scattered rays and the measured intensity of Rayleigh scattered rays from the produced X-ray spectrum; obtaining the ratio of the measured intensity of Rayleigh scattered rays to the measured intensity of Compton scattered rays, i.e., the measured scattering intensity ratio, based on the respective extracted measured intensities; and obtaining the thickness of the film and the contents of the respective elements constituting the object specimen by the fundamental parameter method based on the measured scattering intensity ratio of the object specimen. The thickness of the film and the contents of the respective elements constituting the object specimen are obtained by the following processes: substituting estimated values into the variables included in the first arithmetic expression and the second arithmetic expression to obtain an estimated scattering intensity ratio obtained based on the theoretical scattering intensity ratio, where the theoretical scattering intensity ratio is the ratio of the theoretical intensity of Rayleigh scattered rays to the theoretical intensity of Compton scattered rays; and updating the estimated values so that the estimated scattering intensity ratio converges to the measured scattering intensity ratio.

[0169] According to the analysis program described in Item 6 and the fluorescent X-ray analysis apparatus described in Item 7, it is possible to expand the applicable range of the analysis based on the FP method by using the scattering intensity ratio. More specifically, even for a specimen in which a resin film is formed on a base material mainly composed of an element for which it is difficult to perform fluorescent X-ray measurement, it is possible to perform the analysis based on the FP method without destroying the specimen. In addition, for the resin component, since the primary X-rays enter deep, there is a case where scattered rays that enter deep and bounce back cannot be detected. Even in this case, it is possible to eliminate the influence of the undetected scattered rays by using the scattering intensity ratio, and thus a massive resin can be used as a standard specimen. Therefore, even in a case where it is difficult to prepare a standard specimen of a film, it is possible to perform the analysis based on the FP method.

[0170] The embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The scope of the present invention is represented not by the description of the above embodiments but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0171] Description of Reference Numerals

[0172] 1: Specimen chamber; 2: Specimen stage; 3: Housing; 4: Opening; 5: Measurement chamber; 6: Wall surface; 7: X-ray tube; 8: Detector; 9: Shutter; 10: Fluorescent X-ray analyzer; 11: X-ray filter; 12: Driving mechanism; 13: Collimator; 14: Control device; 15: Operation unit; 16: Output unit; 20: Imaging unit; 81: X-ray detector; 82: Preamplifier; 83: Scaling amplifier; 106: A / D converter; 107: Multichannel analyzer; 111: Spectrum storage unit; 112: Parameter storage unit; 142: Memory; 143: Analysis program; 200: Data processing unit.

Claims

1. A fluorescence X-ray analysis method for analyzing secondary X-rays obtained by irradiating a specimen with primary X-rays from an X-ray source having a rhodium target, the fluorescence X-ray analysis method comprises the following steps: extracting the measured intensity of Compton scattered rays originating from rhodium from the spectrum of the object specimen produced based on the secondary X-rays obtained by irradiating the object specimen with the primary X-rays, wherein the object specimen is a specimen in which a resin-containing film is formed on a base material; extracting the measured intensity of Rayleigh scattered rays originating from rhodium from the spectrum of the object specimen; based on the respective measured intensities extracted from the spectrum of the object specimen, obtaining a ratio of the measured intensity of the Rayleigh scattered rays to the measured intensity of the Compton scattered rays, i.e., a measured scattering intensity ratio; and based on the measured scattering intensity ratio of the object specimen, obtaining the thickness of the film and the content of each element constituting the object specimen by the fundamental parameter method, wherein the theoretical intensity of the Compton scattered rays is obtained based on a first arithmetic expression in which the thickness of the film and the content of each element constituting the object specimen are variables, the theoretical intensity of the Rayleigh scattered rays is obtained based on a second arithmetic expression in which the thickness of the film and the content of each element constituting the object specimen are variables, the steps of obtaining the thickness of the film and the content include the following steps: substituting an estimated value into the variables included in the first arithmetic expression and the second arithmetic expression to obtain an estimated scattering intensity ratio obtained from the theoretical scattering intensity ratio, wherein the theoretical scattering intensity ratio is the ratio of the theoretical intensity of the Rayleigh scattered rays to the theoretical intensity of the Compton scattered rays; and updating the estimated value so that the estimated scattering intensity ratio converges to the measured scattering intensity ratio.

2. The fluorescence X-ray analysis method according to claim 1, wherein, the film contains at least one inorganic component, the theoretical intensity of the fluorescence X-rays originating from the inorganic component is obtained based on a third arithmetic expression in which the thickness of the film and the content of the inorganic component are variables, the fluorescence X-ray analysis method further comprises the following steps: detecting a spectral line generated by the fluorescence X-rays originating from the inorganic component from the spectrum of the object specimen, and extracting the measured intensity of the fluorescence X-rays originating from the inorganic component, i.e., the measured fluorescence X-ray intensity; and based on the respective measured intensities extracted from the spectrum of the object specimen, obtaining a ratio of the measured intensity of the Rayleigh scattered rays to the measured intensity of the fluorescence X-rays originating from the inorganic component, i.e., a measured fluorescence X-ray intensity ratio, the steps of obtaining the thickness of the film and the content further include the following steps: substituting the estimated value into the variables included in the second arithmetic expression and the third arithmetic expression, and obtaining an estimated fluorescence X-ray intensity ratio from the theoretical fluorescence X-ray intensity ratio, wherein the theoretical fluorescence X-ray intensity ratio is the ratio of the theoretical intensity of the Rayleigh scattered rays to the theoretical intensity of the fluorescence X-rays originating from the inorganic component, In the step of updating the estimated values, update the estimated values such that the estimated scattered intensity ratio converges to the measured scattered intensity ratio and the estimated fluorescent X-ray intensity ratio converges to the measured fluorescent X-ray intensity ratio.

3. The fluorescent X-ray analysis method according to claim 1 or 2, wherein, the Rayleigh scattered ray is a Rayleigh scattered ray derived from RhKα, the Compton scattered ray is a Rayleigh scattered ray derived from RhKα.

4. The fluorescent X-ray analysis method according to claim 1 or 2, wherein, the base material mainly comprises an element with an atomic number of 21 or less.

5. The fluorescent X-ray analysis method according to claim 1 or 2, wherein, the estimated scattered intensity ratio is obtained by multiplying the theoretical scattered intensity ratio by the sensitivity coefficient ratio, the fluorescent X-ray analysis method further includes the following steps: using a bulk resin with a known content of each element as a standard sample, extracting the measured intensity of the Compton scattered ray from the spectrum of the standard sample obtained by irradiating the primary X-ray to the standard sample; extracting the measured intensity of the Rayleigh scattered ray from the spectrum of the standard sample; calculating the measured scattered intensity ratio of the standard sample based on the respective measured intensities extracted from the spectrum of the standard sample; and calculating the sensitivity coefficient ratio based on the first arithmetic expression and the second arithmetic expression, according to the theoretical scattered intensity ratio of the standard sample obtained by substituting the content of each element constituting the standard sample and the thickness of the standard sample, and the measured scattered intensity ratio of the standard sample.

6. An analysis program for analyzing secondary X-rays obtained by irradiating a sample with primary X-rays from an X-ray source having a rhodium target, the analysis program causing a computer to execute the following steps: extracting the measured intensity of the Compton scattered ray derived from rhodium from the spectrum of the object sample made based on the secondary X-rays obtained by irradiating the object sample with the primary X-rays, wherein, the object sample is a sample in which a resin-containing film is formed on a base material; extracting the measured intensity of the Rayleigh scattered ray derived from rhodium from the spectrum of the object sample; calculating the ratio of the measured intensity of the Rayleigh scattered ray to the measured intensity of the Compton scattered ray, i.e., the measured scattered intensity ratio, based on the respective measured intensities extracted from the spectrum of the object sample; and calculating the thickness of the film and the content of each element constituting the object sample by the fundamental parameter method based on the measured scattered intensity ratio of the object sample, wherein the theoretical intensity of the Compton scattered ray is calculated based on a first arithmetic expression with the thickness of the film and the content of each element constituting the object sample as variables, the theoretical intensity of the Rayleigh scattered ray is calculated based on a second arithmetic expression with the thickness of the film and the content of each element constituting the object sample as variables, the steps of calculating the thickness of the film and the content include the following steps: Substitute the estimated values into the variables included in the first arithmetic expression and the second arithmetic expression to obtain an estimated scattering intensity ratio obtained based on the theoretical scattering intensity ratio, where the theoretical scattering intensity ratio is the ratio of the theoretical intensity of the Rayleigh scattered ray to the theoretical intensity of the Compton scattered ray; and Update the estimated values so that the estimated scattering intensity ratio converges to the measured scattering intensity ratio.

7. A fluorescent X-ray analysis apparatus, comprising: A specimen stage for disposing a specimen; An X-ray tube configured to irradiate the specimen stage with primary X-rays from an X-ray source having a rhodium target; A detector that detects secondary X-rays from the specimen disposed on the specimen stage ； and A control device that analyzes the secondary X-rays detected by the detector, wherein The specimen is a target specimen in which a film containing resin is formed on a base material, The theoretical intensity of the Compton scattered ray originating from rhodium included in the secondary X-rays from the target specimen is obtained based on a first arithmetic expression using the thickness of the film and the content of each element constituting the target specimen as variables, The theoretical intensity of the Rayleigh scattered ray originating from rhodium included in the secondary X-rays from the target specimen is obtained based on a second arithmetic expression using the thickness of the film and the content of each element constituting the target specimen as variables, The control device performs the following processes: Produce an X-ray spectrum of the target specimen based on the secondary X-rays; Extract the measured intensity of the Compton scattered ray and the measured intensity of the Rayleigh scattered ray from the produced X-ray spectrum; Based on the respective measured intensities extracted, obtain the ratio of the measured intensity of the Rayleigh scattered ray to the measured intensity of the Compton scattered ray, i.e., the measured scattering intensity ratio; and Based on the measured scattering intensity ratio of the target specimen, obtain the thickness of the film and the content of each element constituting the target specimen by the fundamental parameter method, The thickness of the film and the content of each element constituting the target specimen are obtained by the following processes: Substitute the estimated values into the variables included in the first arithmetic expression and the second arithmetic expression to obtain an estimated scattering intensity ratio obtained based on the theoretical scattering intensity ratio, where the theoretical scattering intensity ratio is the ratio of the theoretical intensity of the Rayleigh scattered ray to the theoretical intensity of the Compton scattered ray; and Update the estimated values so that the estimated scattering intensity ratio converges to the measured scattering intensity ratio.

Images