Thickness measurement device, thickness measurement method, and thickness measurement program

Abstract

To provide a thickness measurement device, thickness measurement method, and thickness measurement program that can measure a thickness of a member.SOLUTION: A thickness measurement device comprises: an X-ray source control unit that constitutes a laminate, and controls to irradiate the laminate with X-rays of a plurality of amounts of energy in accordance with the number of a plurality of material members different in material; an acquisition unit that acquires a plurality of pieces of transmission X-ray image information arising from respective different amounts of energy to be generated in responce to the detection of the X-rays transmitted through the laminate; a first calculation unit that calculates a prescribed luminance value on the basis of a luminance value based on each of the plurality of pieces of transmission X-ray image information, and a weighting coefficient to be multiplied with the luminance value; and a second calculation unit that calculates a thickness of one material member of the plurality of material members on the basis of the prescribed luminance value calculated by the first calculation unit and an X-ray absorption coefficient corresponding to each of the plurality of the material members.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a thickness measurement device, a thickness measurement method, and a thickness measurement program. [Background technology]

[0002] Conventionally, there exists an apparatus that irradiates a subject with radiation and obtains an image from the radiation that has passed through the subject, and that performs energy subtraction to obtain a difference image. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-162358 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, the thickness of a component has been measured using radiation. The invention described in Patent Document 1 only acquires a differential image, but is unable to acquire the thickness of the component.

[0005] The present disclosure provides a thickness measurement device, a thickness measurement method, and a thickness measurement program capable of measuring the thickness of a member. [Means for solving the problem]

[0006] A thickness measurement device of one embodiment includes an X-ray source control unit that controls the irradiation of the stack with X-rays of multiple energy amounts corresponding to the number of multiple material components that constitute the stack and are each made of different materials; an acquisition unit that acquires multiple pieces of transmission X-ray image information resulting from each of the different energy amounts generated in response to detecting X-rays that have passed through the stack; a first calculation unit that calculates a predetermined luminance value based on a luminance value based on each of the multiple pieces of transmission X-ray image information and a weighting coefficient by which the luminance value is multiplied; and a second calculation unit that calculates a thickness of one of the multiple material components based on the predetermined luminance value calculated by the first calculation unit and an X-ray absorption coefficient corresponding to each of the multiple material components. Effect of the Invention

[0007] The thickness measurement device, thickness measurement method, and thickness measurement program disclosed herein are capable of measuring the thickness of a member. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram for explaining a thickness measurement device according to an embodiment. [Diagram 2] FIG. 2 is a block diagram for explaining a thickness measurement device (processing unit) according to an embodiment. [Diagram 3] FIG. 13 is a diagram for explaining a laminate formed by laminating three material members as an example. [Figure 4] 1 is a flowchart for explaining a thickness measurement method according to an embodiment. [Diagram 5] An example of the experimental results will be described below. (A) is a cross-sectional view for explaining an example of a laminate, and (B) is a diagram for explaining an example of calculation of the thickness of the adhesive constituting the laminate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment will be described below.

[0010] [Overview of thickness measurement device 1] First, an overview of a thickness measurement device 1 according to an embodiment will be described. FIG. 1 is a diagram for explaining a thickness measurement device 1 according to an embodiment.

[0011] The thickness measurement device 1 is a device that irradiates electromagnetic waves such as radiation onto a laminate 20 (object) in which multiple members (material members) made of different materials are stacked, and measures the thickness of one member (material member) constituting the laminate 20 (object). That is, the thickness measurement device 1 is a device that applies energy subtraction to obtain multiple pieces of image information for one laminate 20 (object), and measures the thickness of one member constituting the laminate 20 (object) by using the brightness values ​​recorded in each piece of image information.

[0012] The thickness measurement device 1 includes, for example, an X-ray source 2, an X-ray detection unit (detection unit) 3, and a processing unit .

[0013] The X-ray source 2 is an X-ray generating device that generates X-rays to be irradiated onto the laminate 20. The X-ray source 2 includes, for example, a fixed anode X-ray tube. For example, a metal such as tungsten or molybdenum is used as a target for the anode of the X-ray tube. The X-ray source 2 sets the amount of X-rays (amount of energy) to be generated, for example, based on the control of the processing unit 10 described later. The X-ray source 2 can change at least one of the tube voltage, tube current, and irradiation time when irradiating X-rays, and by changing at least one of the tube voltage, tube current, and irradiation time, the intensity or irradiation time (amount of energy) of the irradiated X-rays is changed. For the X-ray source 2, for example, a known X-ray irradiation device may be used. The target may be, for example, a member made of various materials including a metal member.

[0014] The detection unit 3 detects, for example, X-rays that have been irradiated from the X-ray source 2 and then transmitted through the object. The detection unit 3 detects, for example, the intensity of the transmitted X-rays that have been transmitted through the object. The detection unit 3 may be, for example, a known detection device for X-rays. The detection unit 3 may be, for example, an imaging device capable of imaging using X-rays. In this case, the detection unit 3 (imaging device) may generate image information (X-ray image information) when imaging. When an object is present between the X-ray source 2 and the detection unit 3, the detection unit 3 (imaging device) may generate an image of X-rays that have passed through the object (transmitted X-ray image information).

[0015] The processing unit 10 may, for example, transmit and receive information between the X-ray source 2 and the X-ray detection unit 3. The processing unit 10 may, for example, be a computer (information processing device) such as a server, a desktop computer, or a laptop computer.

[0016] The processing unit 10 controls the X-ray source 2 to irradiate the stack 20 with X-rays. In this case, the processing unit 10 controls the X-ray source 2 to irradiate the target with X-rays of multiple energy amounts according to the number of multiple material members constituting the stack 20. As an example, in the case of a stack 20 in which two material members are stacked, the processing unit 10 controls the X-ray source 2 to irradiate the stack 20 with X-rays of two energy amounts (high energy and low energy) in sequence. Similarly, as an example, in the case of a stack 20 in which three material members are stacked, the processing unit 10 controls the X-ray source 2 to irradiate the stack 20 with X-rays of three energy amounts (high energy, medium energy, and low energy) in sequence. In the case of a stack 20 in which four or more material members are stacked, the processing unit 10 controls the X-ray source 2 to irradiate the stack 20 with X-rays of four or more energy amounts in sequence in the same manner as described above.

[0017] When the detection unit 3 detects X-rays that have transmitted through the stack 20, the processing unit 10 acquires transmitted X-ray image information generated by the detection unit 3. The processing unit 10 acquires a plurality of pieces of transmitted X-ray image information generated by the detection unit 3 in accordance with each of a plurality of energy amounts of X-rays irradiated to the stack 20. Information on the luminance of the X-rays that have transmitted through the stack 20 is recorded in the transmitted X-ray image information. The processing unit 10 calculates a predetermined luminance value D by using Equation (1) described later based on the luminance information (luminance value) recorded in each of the multiple pieces of transmitted X-ray image information and a weighting coefficient by which the luminance value (the luminance value corresponding to each piece of transmitted X-ray image information) is multiplied. sub The formula (1) is used to calculate the predetermined luminance value D when the number of material members constituting the laminate 20 is three. sub This is the calculation formula. The processing unit 10 determines the predetermined luminance value D sub and the X-ray absorption coefficient of each of the plurality of material members constituting the stack 20, the processing unit 10 calculates the thickness of one of the plurality of material members. As an example, similar to the case of formula (1), when the number of material members constituting the stack 20 is three (the first material member 21, the second material member 22, and the third material member 23), the processing unit 10 can calculate the thickness t2 of the second material member 22 by formula (12) described later.

[0018] [Details of thickness measurement device 1] Next, the thickness measurement device 1 according to an embodiment will be described in detail. In particular, the processing unit 10 will be described in detail. FIG. 2 is a block diagram for explaining the thickness measurement device 1 (processing unit 10) according to one embodiment. FIG. 3 is a diagram for explaining a laminate 20 in which three material members are laminated as an example.

[0019] As shown in FIG. 2, the thickness measurement device 1 (processing unit 10) includes, for example, a communication unit 121, a storage unit 122, a display unit 123, and a control unit 110. The communication unit 121, the storage unit 122, and the display unit 123 may be an embodiment of the output unit. The control unit 110 includes, for example, an X-ray source control unit 111, an acquisition unit 112, a first calculation unit 113, a second calculation unit 114, and an output control unit 115. The control unit 110 may be configured, for example, by an arithmetic processing device of the thickness measurement device 1. The control unit 110 (for example, an arithmetic processing device) may realize the functions of each unit (for example, the X-ray source control unit 111, the acquisition unit 112, the first calculation unit 113, the second calculation unit 114, and the output control unit 115) by, for example, appropriately reading and executing various programs stored in the storage unit 122.

[0020] The communication unit 121 is, for example, a communication interface capable of transmitting and receiving various information to and from a device (external device) outside the processing unit 10 (information processing device). The communication unit 121 may communicate with, for example, the X-ray source 2 and the detection unit 3. The communication unit 121 may also communicate with, for example, a server and a user terminal (not shown). The user terminal may be, for example, a terminal used by a user of the luminance acquisition device, and may be a desktop, a laptop, a tablet, a smartphone, or the like.

[0021] The storage unit 122 may store, for example, various information and programs. Examples of the storage unit 122 may be a memory, a solid state drive, a hard disk drive, etc. Note that the storage unit 122 may be, for example, a storage area and a server on a cloud.

[0022] The display unit 123 is, for example, a display capable of displaying various characters, symbols, images, and the like.

[0023] The X-ray source control unit 111 controls the X-ray source 2 via, for example, a communication unit 121 . The X-ray source control unit 111 may control the X-ray source 2 to change at least one of the tube voltage, tube current, and irradiation time when irradiating X-rays (change the amount of energy of X-rays) based on information inputted via, for example, an input unit (not shown) of the thickness measurement device 1. The input unit may be, for example, a keyboard and a mouse. The X-ray source control unit 111 controls the X-ray source 2 to change, for example, the irradiation energy (amount of energy) of X-rays and irradiate the target laminate 20 with X-rays multiple times.

[0024] As an example, the X-ray source control unit 111 performs control so that the stack 20 is irradiated with X-rays having a plurality of energy amounts corresponding to the number of material members that constitute the stack 20 and are made of different materials. As a specific example, when the stack 20 is formed by stacking three material members, the X-ray source control unit 111 controls the X-ray source 2 to irradiate the stack 20 with X-rays having three different amounts of energy. That is, the X-ray source control unit 111 performs control to irradiate the stack 20 with X-rays having three different amounts of energy according to the number of three material members constituting the stack 20. In other words, the X-ray source control unit 111 controls the X-ray source 2 to irradiate the stack 20 with n number of X-rays having different amounts of energy according to the number n of material members constituting the stack 20 (n>2). As a specific example in this case, the X-ray source control unit 111 controls the X-ray source 2 so as to irradiate the stack 20 with X-ray irradiation energy of a first energy amount (high energy) (see FIG. 3). Similarly, the X-ray source control unit 111 controls the X-ray source 2 to irradiate the same stack 20 as the stack 20 irradiated with X-rays of the first energy amount described above with X-rays of the second energy amount (medium energy) (first energy amount > second energy amount) (see Figure 3). Similarly, the X-ray source control unit 111 controls the X-ray source 2 to irradiate the same stack 20 as the stack 20 irradiated with the X-rays of the first and second energy amounts described above with an X-ray irradiation energy of a third energy amount (low energy) (first energy amount > second energy amount > third energy amount) (see Figure 3).

[0025] When the number of material members constituting the stack 20 is two, the X-ray source 2 is controlled to irradiate the stack 20 with X-rays having two different amounts of energy. When the number of material members constituting the stack 20 is four, the X-ray source 2 is controlled to irradiate the stack 20 with X-rays having four different amounts of energy. Similarly, when the number of material members constituting the stack 20 is five or more, the X-ray source 2 is controlled to irradiate the stack 20 with X-rays having five or more different amounts of energy according to the number of material members. In this case, it is preferable that the positions of the X-ray source 2, the detection unit 3, and the laminate 20 are kept constant.

[0026] The detector 3 detects, for example, X-rays that have passed through the stack 20 (transmitted X-rays) (see FIG. 3) and generates image information (transmitted X-ray image information). As an example, when the number of material members constituting the laminate 20 is three, the detection unit 3 generates first image information when the target is irradiated with X-rays having a first energy amount. Similarly, the detection unit 3 generates second image information when the target is irradiated with X-rays having a second energy amount. Similarly, the detection unit 3 generates third image information when the target is irradiated with X-rays having a third energy amount.

[0027] The acquisition unit 112 acquires multiple pieces of transmitted X-ray image information (n pieces of image information (n>2) (first image information, ...nth image information)) resulting from different amounts of energy generated in response to detecting X-rays that have passed through the stack 20. As an example, when the number of material components constituting the laminate 20 is three, the acquisition unit 112 acquires first image information generated corresponding to a first amount of energy, second image information generated corresponding to a second amount of energy, and third image information generated corresponding to a third amount of energy. Similarly, as an example, when the number of material components constituting the laminate 20 is two, the acquisition unit 112 acquires first image information generated corresponding to a first amount of energy, and second image information generated corresponding to a second amount of energy. Similarly, as an example, when the number of multiple material components constituting the laminate 20 is four or more, the acquisition unit 112 acquires four or more pieces of image information, such as first image information generated in response to a first amount of energy, second image information generated in response to a second amount of energy, third image information generated in response to a third amount of energy, and fourth image information generated in response to a fourth amount of energy, etc.

[0028] The acquiring unit 112 may acquire multiple pieces of transmitted X-ray image information from an external device, for example, via the communication unit 121. The external device may be, for example, the detection unit 3 and a server (not shown), etc. Alternatively, when an external memory storing multiple pieces of transmitted X-ray image information is connected to an interface of the processing unit 10, the acquiring unit 112 may acquire multiple pieces of transmitted X-ray image information from the external memory.

[0029] The first calculation unit 113 calculates a predetermined luminance value based on the luminance value based on each of a plurality of pieces of transmitted X-ray image information (n pieces of image information (n>2)) and a weighting coefficient by which the luminance value is multiplied. As an example, when the number of the material members constituting the laminate 20 is three, the first calculation unit 113 calculates the luminance values ​​D H ,D M ,D L and weighting factor K H ,K M ,K L Based on this, a predetermined luminance value D sub Calculate. (1) A first brightness value D of the transmitted X-ray based on first image information (first transmitted X-ray image information) generated in response to irradiation of the X-ray with the first energy amount. H , and its first luminance value D H The first weighting factor K to be multiplied H . (2) A second brightness value D of the transmitted X-ray based on second image information (second transmitted X-ray image information) generated in response to irradiation of the X-ray with the second energy amount. M , and its second luminance value D M The second weighting factor K to be multiplied M . (3) A third brightness value D of the transmitted X-ray based on the third image information (third transmitted X-ray image information) generated in response to irradiation of the X-ray of the third energy amount. L , and its third luminance value D L The third weighting factor K to be multiplied by L .

[0030] As a specific example, the first calculation unit 113 calculates the predetermined luminance value as D sub , the first luminance value is D H , the first weighting factor is K H , the second luminance value is D M , the second weighting factor is K M , the third luminance value is D L , the third weighting factor is K L Then, the given luminance value D sub may be calculated based on the following formula (1):

[0031]

number

[0032] The first luminance value, the second luminance value, and the third luminance value may be, for example, luminance values ​​recorded in the image information (the first image information, the second image information, and the third image information). Alternatively, the first luminance value, the second luminance value, and the third luminance value may be obtained by, for example, substituting the intensity value of the X-rays (transmitted X-ray intensity) for the luminance value when the detection unit 3 acquires the intensity of the X-rays. That is, as an example, when the detection unit 3 acquires the transmitted X-ray intensity based on the first energy amount, the control unit 110 may convert the value of the X-ray intensity into a luminance value to obtain the first luminance value (first image information). Similarly, as an example, when the detection unit 3 acquires the transmitted X-ray intensity based on the second energy amount, the control unit 110 may convert the value of the X-ray intensity into a luminance value to obtain the second luminance value (second image information). Similarly, as an example, when the detection unit 3 acquires the transmitted X-ray intensity based on the third energy amount, the control unit 110 may convert the value of the X-ray intensity into a luminance value to obtain the third luminance value (third image information).

[0033] A first luminance value D of each pixel constituting the first image information H is expressed by the following equation (2). Here, the X-ray absorption coefficient of the first material member 21 when X-rays are irradiated to the stacked body 20 with a first energy amount is μ1(H), the X-ray absorption coefficient of the first material member 21 when X-rays are irradiated to the stacked body 20 with a second energy amount is μ1(M), and the X-ray absorption coefficient of the first material member 21 when X-rays are irradiated to the stacked body 20 with a third energy amount is μ1(L). Similarly, the X-ray absorption coefficient of the second material member 22 when X-rays are irradiated to the stacked body 20 with the first energy amount is μ2(H), the X-ray absorption coefficient of the second material member 22 when X-rays are irradiated to the stacked body 20 with the second energy amount is μ2(M), and the X-ray absorption coefficient of the second material member 22 when X-rays are irradiated to the stacked body 20 with the third energy amount is μ2(L). Similarly, the X-ray absorption coefficient of the third material member 23 when X-rays are irradiated to the stacked body 20 with the first energy amount is μ3(H), the X-ray absorption coefficient of the third material member 23 when X-rays are irradiated to the stacked body 20 with the second energy amount is μ3(M), and the X-ray absorption coefficient of the third material member 23 when X-rays are irradiated to the stacked body 20 with the third energy amount is μ3(L). The thickness of the first material member 21 is denoted as t1, the thickness of the second material member 22 is denoted as t2, and the thickness of the third material member 23 is denoted as t3.

[0034]

number

[0035] Similarly, the second luminance value D of each pixel constituting the second image information M is expressed by the following equation (3).

[0036]

number

[0037] Similarly, the third luminance value D of each pixel constituting the third image information L is expressed by the following equation (4).

[0038]

number

[0039] The weighting coefficient may be a value that depends on the X-ray absorption coefficient of one or more other material members among the multiple material members that make up the stack 20, excluding the material member that is the subject of thickness calculation. As an example, in the case of a laminate 20 in which three material members (a first material member 21, a second material member 22, and a third material member 23) are laminated, when calculating the thickness t2 of the second material member 22, the first weighting coefficient, the second weighting coefficient, and the third weighting coefficient may be values ​​that depend on the X-ray absorption coefficients of the first material member 21 and the third material member 23, respectively. That is, the first weighting coefficient, the second weighting coefficient, and the third weighting coefficient are each determined based on a predetermined luminance value D sub When calculating the first luminance value D H , the second luminance value D M and the third brightness value D L This is a coefficient that is used to adjust the

[0040] Here, the weighting factor K H ,K M ,K L and the X-ray absorption coefficients μ1(H), μ1(M), and μ1(L) are related by the following equation (5).

[0041]

number

[0042] In addition, the weighting factor K H ,K M ,K L and the X-ray absorption coefficients μ3(H), μ3(M), and μ3(L) are related by the following equation (6).

[0043]

number

[0044] The second calculator 114 calculates the thickness of one of the multiple material components based on the predetermined luminance value calculated by the first calculator 113 and the X-ray absorption coefficients corresponding to each of the multiple material components. As an example, the second calculation unit 114 may calculate the thickness of one material member (second material member 22) based on a predetermined luminance value and the X-ray absorption coefficients of each of the three material members (first material member 21, second material member 22, and third material member 23). The second calculator 114 may use, as the X-ray absorption coefficient, an absorption coefficient that is not dependent on the thickness of the material member (no thickness dependency), or a radiance absorption coefficient that is dependent on the thickness of the material member (has thickness dependency). For example, the second calculator 114 may use a radiance absorption coefficient that is dependent on the thickness when it is desired to obtain the thickness of the second material member 22 more accurately, and may use an absorption coefficient that is not dependent on the thickness when it is desired to obtain the thickness of the second material member 22 relatively simply.

[0045] As an example, the thickness-dependent radiance absorption coefficient utilizes the X-ray absorption coefficient that changes depending on the thickness of the second material member 22, so that it is possible to more accurately calculate the thickness of the second material member 22. Here, the radiance absorption coefficient μ A The inventor's experiments have revealed that the correlation between the thickness t of the material and the luminance absorption coefficient μ is as shown in the following formula (7). Note that a is a coefficient and b is a constant. Formula (7) expresses the relationship between the thickness t of the material and the luminance absorption coefficient μ A In other words, it shows the thickness dependency of the luminance absorption coefficient of the member.

[0046]

number

[0047] On the other hand, in order to obtain the radiance absorption coefficient, it is necessary to carry out experiments and calculations in advance, but the thickness-independent absorption coefficient may be publicly known. Therefore, as an example, by using the thickness-independent absorption coefficient, it is possible to calculate the thickness of the second material member 22 relatively simply and more quickly than when carrying out experiments and calculations to obtain the radiance absorption coefficient. As another example, the amount of calculation required to obtain the thickness of the second material member 22 using the absorption coefficient is considered to be less than the amount of calculation required to obtain the thickness of the second material member 22 using the radiance absorption coefficient, and the processing load on the control unit 110 can be reduced.

[0048] By substituting the formulas (2) to (4) into the above formula (1), the following formula (8) is obtained.

[0049]

number

[0050] In addition, equation (6) is L Solving for and substituting into equation (5) gives K H / K M By solving this, we obtain the following equation (9).

[0051]

number

[0052] Similarly, equation (6) can be expressed as K H Solving for and substituting into equation (5) gives K L / K M By solving, we obtain equation (10).

[0053]

number

[0054] By substituting equations (9) and (10) into equation (8), we obtain the following equation (11).

[0055]

number

[0056] By solving equation (11) for t2, we obtain the following equation (12).

[0057]

number

[0058] Therefore, when determining the thickness t2 of the second material member 22 in the laminate 20 in which three material members (the first material member 21, the second material member 22, and the third material member 23) are stacked, the second calculation unit 114 may calculate the thickness t2 of the second material member 22 using the above formula (12) obtained based on the above formula (1). In addition, in formula (12), the X-ray absorption coefficient may be an absorption coefficient that is not dependent on the thickness of the material component (no thickness dependency), or may be a radiance absorption coefficient that is dependent on the thickness of the material component (has thickness dependency).

[0059] When a luminance absorption coefficient having thickness dependency is used, the luminance absorption coefficient of the second material member 22 is expressed by equation (13) for the first energy amount, equation (14) for the second energy amount, and equation (15) for the third energy amount using equation (7).

[0060]

number

[0061]

number

[0062]

number

[0063] By substituting equations (13) to (15) into equation (12) and solving for t2, we obtain equation (16).

[0064]

number

[0065] Here, in equation (16), c is expressed by equation (17), and d is expressed by equation (18).

[0066]

number

[0067]

number

[0068] Therefore, when using a radiance absorption coefficient that is thickness-dependent, the second calculation section 114 can obtain the thickness t2 of the second material member 22 by equation (16) obtained from equations (12) to (15). On the other hand, when the second calculation section 114 uses an absorption coefficient that is not thickness-dependent, it is possible to obtain the thickness t2 of the second material member 22 by equation (12).

[0069] The above-mentioned second calculation section 114 is capable of calculating the thickness t2 of the second material member 22 for each pixel based on the luminance values ​​(first luminance value, second luminance value, and third luminance value) of the pixel values ​​constituting the first image information, the second image information, and the third image information, respectively. The thickness measurement device 1 is capable of calculating the thickness t2 of the second material member 22 in the planar direction of the laminate 20 (the direction along the detection surface of the detection section 3). In other words, the thickness measurement device 1 is capable of calculating the thickness t2 of the planar second material member 22.

[0070] Even when the number of material members constituting the stack 20 is two, and even when the number of material members constituting the stack 20 is four or more, the control unit 110 is able to determine the thickness of one of the material members (e.g., the second material member 22, etc.) among the multiple material members constituting the stack 20 in the same manner as in the case where the number of material members constituting the stack 20 described above is three.

[0071] As an example, when the number of material members constituting the laminate 20 is two, similarly to the formula (1), the first calculation unit 113 calculates the predetermined luminance value as D sub , the first luminance value is D H , the first weighting factor is K H , the second luminance value is D L , the second weighting factor is K L Then, the given luminance value D sub may be calculated based on the following formula (19):

[0072]

number

[0073] In this case, the second calculation unit 114 can calculate the thickness t2 of the second material member 22, the thickness of which is to be calculated, using the following formula (20) based on formula (19) (absorption coefficient independent of thickness). Here, the absorption coefficient of the first material member 21 corresponding to the first energy is μ1(H), the absorption coefficient of the first material member 21 corresponding to the second energy is μ1(L), the absorption coefficient of the second material member 22 corresponding to the first energy is μ2(H), and the absorption coefficient of the second material member 22 corresponding to the second energy is μ2(L).

[0074]

number

[0075] Furthermore, in the case of a radiance absorption coefficient that is thickness-dependent, the second calculation unit 114 can calculate the thickness t2 of the second material member 22 by the following formula (21). As in the above-mentioned case, μ2(H) is expressed by formula (13), and μ2(L) is expressed by formula (15).

[0076]

number

[0077] Furthermore, even if the number of material members constituting the stack 20 is four or more, the amount of energy irradiated to the stack 20 may be changed in response to the number of material members constituting the stack 20 (for example, in one-to-one correspondence), and the terms represented by the luminance value and weighting coefficient in equation (1) may be increased according to the number of material members, i.e., the number of energy amounts. The processing unit 10 can, for example, obtain the thickness of one material member (the second material member 22, for example) from an equation obtained by increasing the number of terms based on equation (1), similarly to equations (12), (16), (20), and (21).

[0078] The output control unit 115 may control the output unit to output the thickness t2 of the second material member 22 calculated by the second calculation unit 114. The output unit may be, for example, a communication unit 121, a storage unit 122, a display unit 123, etc. That is, the output control unit 115 may control the communication unit 121 to transmit information on the thickness t2 of the second material member 22 calculated by the second calculation unit 114 to an external device. Here, the external device may be a server, a user terminal (not shown), or the like. The output control unit 115 may control the storage unit 122 to store information on the thickness t2 of the second material member 22 calculated by the second calculation unit 114, for example. The output control unit 115 may control the display unit 123 to display the thickness t2 of the second material member 22 calculated by the second calculation unit 114, for example.

[0079] [Thickness measurement method] Next, a thickness measurement method according to an embodiment will be described. FIG. 4 is a flowchart illustrating a thickness measurement method according to an embodiment.

[0080] In step ST101, the X-ray source control unit 111 controls the X-ray source 2 to irradiate the stack 20 with X-rays having a plurality of energy amounts corresponding to the number of material members that constitute the stack 20 and are made of different materials. As one example, when the stack 20 is made up of three material members, the X-ray source control unit 111 controls the X-ray source 2 to irradiate the stack 20 with X-rays of three different energy amounts according to the number of the three material members. Similarly, as one example, when the stack 20 is made up of two material members, the X-ray source control unit 111 controls the X-ray source 2 to irradiate the stack 20 with X-rays of two different energy amounts. Similarly, as one example, when the stack 20 is made up of four or more material members, the X-ray source control unit 111 controls the X-ray source 2 to irradiate the stack 20 with X-rays of four or more different energy amounts.

[0081] In step ST102, when the detection unit 3 detects X-rays that have passed through the stack 20 in response to the X-ray irradiation in step ST101, the acquisition unit 112 acquires multiple pieces of transmitted X-ray image information resulting from each of the different amounts of energy generated in response to the detection. As an example, when there are three material components, the acquisition unit 112 acquires transmitted X-ray image information corresponding to each of three different energy amounts. Similarly, as an example, when there are two material components, the acquisition unit 112 acquires transmitted X-ray image information corresponding to each of two different energy amounts. Similarly, as an example, when there are four or more material components, the acquisition unit 112 acquires transmitted X-ray image information corresponding to each of four or more different energy amounts.

[0082] In step ST103, the first calculation unit 113 calculates a predetermined luminance value based on the luminance value based on each of the plurality of pieces of transmitted X-ray image information acquired in step ST102 and a weighting coefficient by which the luminance value is multiplied. As an example, when the number of material components is three, the first calculation unit 113 calculates the predetermined luminance value based on formula (1). Similarly, as an example, when the number of material components is two, the first calculation unit 113 calculates the predetermined luminance value based on formula (19). Similarly, as an example, when the number of material components is four or more, the first calculation unit 113 calculates the predetermined luminance value by increasing the terms of the luminance value and the weighting coefficient based on formula (1) according to the number of different amounts of energy irradiated to the stack 20.

[0083] In step ST104, the second calculation unit 114 calculates the thickness of one of the multiple material members based on the predetermined luminance value calculated in step ST103 and the X-ray absorption coefficients corresponding to each of the multiple material members. In this case, the second calculation unit 114 may use, as the X-ray absorption coefficient, an absorption coefficient that is not dependent on the thickness of the material member (not thickness-dependent), or a luminance absorption coefficient that is dependent on the thickness of the material member (has thickness dependence). As an example, when the number of material members is three, the second calculator 114 may calculate the thickness of one material member (second material member 22) based on a predetermined luminance value and the X-ray absorption coefficients of each of the three material members (first material member 21, second material member 22, and third material member 23) (see formula (12) and formulas (16) to (18)). Similarly, as an example, when the number of material members is two, the second calculator 114 may calculate the thickness of one material member (second material member 22) by formulas (20) and (21). Even when the number of material members is four or more, the second calculator 114 may calculate the thickness of one material member in the same manner as described above.

[0084] [Experimental Results] Next, experimental results of the above-described embodiment will be described. An example of the experimental results will be described with reference to Fig. 5. Fig. 5(A) is a cross-sectional view for explaining an example of a laminate 20, and Fig. 5(B) is a diagram for explaining an example of calculation of the thickness of the adhesive constituting the laminate 20. The horizontal axis of Fig. 5(B) indicates the width in the planar direction of the laminate 20, and the vertical axis indicates the thickness. The solid line in Fig. 5(B) indicates the thickness calculated using the thickness measuring device 1 of this embodiment, and the dots indicate the actual thickness obtained by CT cross-section measurement.

[0085] As shown in FIG. 5(A), the laminate 20 is configured by laminating an aluminum member as a first material member 21, an adhesive as a second material member 22, and a resin as a third material member 23. In this example, the thickness of the adhesive of the second material member 22 was measured. The thicknesses indicated by the solid line and the dots in Fig. 5(B) are roughly consistent with each other, and it is understood that the thickness measured using the thickness measuring device 1 of this embodiment is accurate.

[0086] [Functions and circuits] Next, the functions and circuits of the above-mentioned thickness measurement device 1 will be described. Each unit of the thickness measurement device 1 may be realized as a function of a computer arithmetic processing device or the like. That is, the X-ray source control unit 111, the acquisition unit 112, the first calculation unit 113, the second calculation unit 114, and the output control unit 115 (control unit 110) of the thickness measurement device 1 may be realized as an X-ray source control function, an acquisition function, a first calculation function, a second calculation function, and an output control function (control function) by a computer arithmetic processing device or the like, respectively. The thickness measurement program can cause a computer to realize each of the above-mentioned functions. The thickness measurement program may be recorded in a non-transitory computer-readable storage medium, such as a memory, a solid-state drive, a hard disk drive, or an optical disk. The storage medium may be rephrased as a non-transitory computer-readable medium that stores the thickness measurement program. As described above, each part of the thickness measurement device 1 may be realized by a processing device of a computer or the like. The processing device or the like is constituted by, for example, an integrated circuit or the like. Therefore, each part of the thickness measurement device 1 may be realized as a circuit constituting the processing device or the like. That is, the X-ray source control unit 111, the acquisition unit 112, the first calculation unit 113, the second calculation unit 114, and the output control unit 115 (control unit 110) of the thickness measurement device 1 may be realized as an X-ray source control circuit, an acquisition circuit, a first calculation circuit, a second calculation circuit, and an output control circuit (control circuit) constituting the processing device of a computer or the like. The communication unit 121, the storage unit 122, and the display unit 123 (output unit) of the thickness measurement device 1 may be realized as a communication function, a storage function, and a display function (output function) including the functions of an arithmetic processing device, etc. The communication unit 121, the storage unit 122, and the display unit 123 (output unit) of the thickness measurement device 1 may be realized as a communication circuit, a storage circuit, and a display circuit (output circuit) by being configured, for example, by an integrated circuit, etc. The communication unit 121, the storage unit 122, and the display unit 123 (output unit) of the thickness measurement device 1 may be configured as a communication device, a storage device, and a display device (output device) by being configured, for example, by being configured by a plurality of devices.

[0087] The thickness measurement device 1 can be configured by combining one or any two or more of the above-mentioned multiple units. In this disclosure, the term "information" is used, but the term "information" can be replaced with "data" and the term "data" can be replaced with "information."

[0088] [Variations] In the above-described embodiment, the device using X-rays has been described. However, the thickness measuring device 1 and the like of the present disclosure may use not only X-rays but also light and radiation (electromagnetic waves) of various wavelengths (wavelength ranges). In this case, the thickness measuring device 1 and the like may obtain a transmission image using light and radiation (electromagnetic waves) such as infrared light, visible light, and ultraviolet light, and calculate the thickness of some of the members constituting the laminate 20. Examples of members for obtaining a transmission image using electromagnetic waves of various wavelengths (wavelength ranges) and calculating the thickness, etc. may be members made of various materials including metals, semiconductors, materials for semiconductor manufacturing substrates, glass, and resins. That is, the thickness measurement device 1 may include an electromagnetic wave source control unit that controls an electromagnetic wave source so as to irradiate the laminate 20 with electromagnetic waves of multiple energy amounts corresponding to the number of multiple material components that constitute the laminate 20 and are each made of different materials; an acquisition unit 112 that acquires multiple pieces of transmission image information resulting from each of the different energy amounts generated in response to detection by the detection unit 3 of the electromagnetic waves that have transmitted through the laminate 20; a first calculation unit 113 that calculates a predetermined luminance value based on a luminance value based on each of the multiple pieces of transmission image information and a weighting coefficient by which the luminance value is multiplied; and a second calculation unit 114 that calculates a thickness of one of the multiple material components based on the predetermined luminance value calculated by the first calculation unit 113 and an electromagnetic wave absorption coefficient (absorption coefficient) corresponding to each of the multiple material components.

[0089] [Aspects and Effects of the Present Embodiment] Next, one aspect of this embodiment and the effects of each aspect will be described. Note that each aspect described below is an example at the time of filing, and this embodiment is not limited to the aspects described below. In other words, this embodiment is not limited to each aspect described below, and may be realized by appropriately combining each of the above-mentioned parts. In addition, a lower aspect may be able to cite any of the higher aspects. The effects described below are merely examples, and the effects of each aspect are not limited to those described below. Each aspect may, for example, have at least one of the effects described below.

[0090] (Aspect 1) A thickness measurement device of one embodiment includes an X-ray source control unit that controls the irradiation of the stack with X-rays of multiple energy amounts corresponding to the number of multiple material components that constitute the stack and are each made of different materials; an acquisition unit that acquires multiple pieces of transmission X-ray image information resulting from each of the different energy amounts generated in response to detecting X-rays that have passed through the stack; a first calculation unit that calculates a predetermined luminance value based on a luminance value based on each of the multiple pieces of transmission X-ray image information and a weighting coefficient by which the luminance value is multiplied; and a second calculation unit that calculates a thickness of one of the multiple material components based on the predetermined luminance value calculated by the first calculation unit and an X-ray absorption coefficient corresponding to each of the multiple material components. This allows the thickness measurement device to apply energy subtraction to calculate the thickness of one of the material members that make up the laminate. The thickness measuring device can calculate the thickness of the second material member regardless of the variation in thickness and shape of the material member that is not the target of thickness calculation by using the captured images with each of the multiple energy amounts corresponding to the number of multiple laminated members. That is, the thickness measuring device can apply energy subtraction to measure the thickness of the material member that is the target of measurement without needing the thickness (size) of the material member that is not the target of measurement among two or more types (multiple types) of material members that are overlapped in the shooting direction. In other words, the thickness measuring device can apply energy subtraction to obtain information on the weight value (K) and brightness value (D) from the high and low energy images, and calculate the thickness of the material member that is the target of measurement without needing the thickness information of the material member that is not the target of measurement. The thickness measuring device can calculate the thickness t2 of the second material member for each pixel based on the luminance value of the pixel value constituting the image information (transmitted X-ray image information) corresponding to each of the multiple energy amounts. Therefore, the thickness measuring device can calculate the thickness t2 of the second material member in the planar direction of the laminate (the direction along the detection surface of the detection unit). In other words, the thickness measuring device can calculate the thickness t2 of the planar second material member. Furthermore, even if there is unevenness in brightness across the entire detection surface of the detection unit, the thickness measurement device can measure the thickness of the second material member using the brightness of each pixel that constitutes the detection unit, so that the thickness measurement device can measure the thickness at that position using the brightness at a local position based on the pixel, so that even if there is unevenness in brightness across the entire detection unit (entire image), it is possible to obtain a more accurate thickness than when it is affected by uneven brightness.

[0091] (Aspect 2) In one embodiment of the thickness measuring device, the X-ray source control unit controls the irradiation of the stacked body with X-rays of three different energy amounts according to the number of three material components constituting the stacked body, the first calculation unit calculates a predetermined luminance value based on a first luminance value of the transmitted X-rays based on first transmitted X-ray image information generated in response to the irradiation of X-rays with the first energy amount and a first weighting coefficient by which the first luminance value is multiplied, a second luminance value of the transmitted X-rays based on second transmitted X-ray image information generated in response to the irradiation of X-rays with the second energy amount and a second weighting coefficient by which the second luminance value is multiplied, and a third luminance value of the transmitted X-rays based on third transmitted X-ray image information generated in response to the irradiation of X-rays with the third energy amount and a third weighting coefficient by which the third luminance value is multiplied, and the second calculation unit may calculate a thickness of one material component based on the predetermined luminance value and the X-ray absorption coefficients of each of the three material components. As a result, the thickness measuring device can use energy subtraction to measure the thickness of the second material member in a stack of three material members (a first material member, a second material member, and a third material member), regardless of the thicknesses of the first material member and the third material member.

[0092] (Aspect 3) In one aspect of the thickness measurement device, the second calculation unit may use, as the X-ray absorption coefficient, an absorption coefficient that is independent of the thickness of the material member, or a radiance absorption coefficient that is dependent on the thickness of the material member. This allows the thickness measurement device to calculate the thickness t2 of the second material member by using either an X-ray absorption coefficient (absorption coefficient) that is not thickness-dependent or an X-ray absorption coefficient (radiance absorption coefficient) that is thickness-dependent. As an example, when the thickness measurement device uses an absorption coefficient that is not thickness-dependent, it is possible to calculate the thickness of the second material member in a relatively simple manner based on formula (12). As an example, the amount of calculation required to calculate the thickness of the second material member using the absorption coefficient is considered to be less than the amount of calculation required to calculate the thickness of the second material member using the radiance absorption coefficient, and the thickness measurement device can reduce the processing load on the control unit. As another example, when the thickness measurement device uses a radiance absorption coefficient that is thickness-dependent, it uses an X-ray absorption coefficient that changes depending on the thickness of the second material member, and therefore can more accurately calculate the thickness of the second material member based on equations (16) to (18) that use equation (12).

[0093] (Aspect 4) In one aspect of the thickness measurement device, the first calculation unit calculates the predetermined luminance value D sub , the first luminance value is D H , the first weighting factor is K H , the second luminance value is D M , the second weighting factor is K M , the third luminance value is D L , the third weighting factor is K L Then, the given luminance value D sub may be calculated based on the above formula (1). As a result, when the thickness measurement device uses energy subtraction, the predetermined luminance value D sub can be obtained.

[0094] (Aspect 5) In one aspect of the thickness measuring device, the second calculation unit may calculate the thickness t2 of the second material member by the above formula (12) obtained based on the above formula (1), where μ1(H), μ1(M), μ1(L) are X-ray absorption coefficients corresponding to the first to third energy amounts of a first material member among the three material members, μ2(H), μ2(M), μ2(L) are X-ray absorption coefficients corresponding to the first to third energy amounts of a second material member among the three material members, μ3(H), μ3(M), μ3(L) are X-ray absorption coefficients corresponding to the first to third energy amounts of a third material member among the three material members, and t2 is the thickness of the second material member to be calculated. As a result, the thickness measuring device can use energy subtraction to measure the thickness of the second material member in a stack of three material members (a first material member, a second material member, and a third material member), regardless of the thicknesses of the first material member and the third material member.

[0095] (Aspect 6) In one embodiment of the thickness measurement method, a computer executes the following steps: an X-ray source control step of controlling the stack to irradiate the stack with X-rays of multiple energy amounts corresponding to the number of multiple material components that make up the stack and are each made of different materials; an acquisition step of acquiring multiple pieces of transmission X-ray image information resulting from each of the different energy amounts generated in response to detecting X-rays that have passed through the stack; a first calculation step of calculating a predetermined luminance value based on a luminance value based on each of the multiple pieces of transmission X-ray image information and a weighting coefficient by which the luminance value is multiplied; and a second calculation step of calculating a thickness of one of the multiple material components based on the predetermined luminance value calculated in the first calculation step and an X-ray absorption coefficient corresponding to each of the multiple material components. As a result, the thickness measurement method can achieve the same effects as the thickness measurement device of the above-mentioned aspect.

[0096] (Aspect 7) A thickness measurement program of one embodiment causes a computer to realize an X-ray source control function that controls the stack to be irradiated with X-rays of multiple energy amounts corresponding to the number of multiple material components that constitute the stack and are each made of different materials; an acquisition function that acquires multiple pieces of transmission X-ray image information resulting from each of the different energy amounts generated in response to detecting X-rays that have passed through the stack; a first calculation function that calculates a predetermined luminance value based on a luminance value based on each of the multiple pieces of transmission X-ray image information and a weighting coefficient by which the luminance value is multiplied; and a second calculation function that calculates a thickness of one of the multiple material components based on the predetermined luminance value calculated by the first calculation function and an X-ray absorption coefficient corresponding to each of the multiple material components. As a result, the thickness measurement program can achieve the same effect as the thickness measurement device of the above-described aspect. [Explanation of symbols]

[0097] 1 Thickness measurement device 2 X-ray source 3 X-ray detection unit (detection unit) 10 Processing section 20 Laminate 21 First material member 22 Second material member 23 Third material member 110 Control section 111 X-ray source control unit 112 Acquisition Department 113 First Calculation Section 114 Second Calculation Section 115 Output control section 121 Communications Department 122 Storage section 123 Display section

Claims

1. an X-ray source control unit that controls the X-ray source control unit to irradiate the stack with X-rays having a plurality of energy levels corresponding to the number of material members each having a different material; an acquisition unit that acquires a plurality of pieces of transmitted X-ray image information resulting from different amounts of energy generated in response to detection of X-rays transmitted through the laminate; a first calculation unit that calculates a predetermined luminance value based on a luminance value based on each of the plurality of pieces of transmitted X-ray image information and a weighting coefficient by which the luminance value is multiplied; a second calculator that calculates a thickness of one of the plurality of material members based on a predetermined luminance value calculated by the first calculator and an X-ray absorption coefficient corresponding to each of the plurality of material members; A thickness measurement device comprising:

2. the X-ray source control unit controls irradiation of the stack with X-rays having three different energy levels in accordance with the number of three material members constituting the stack; The first calculation unit is a first luminance value of the transmitted X-ray based on first transmitted X-ray image information generated in response to irradiation with X-rays of a first energy amount, and a first weighting coefficient by which the first luminance value is multiplied; a second luminance value of the transmitted X-ray based on second transmitted X-ray image information generated in response to irradiation with X-rays of a second energy amount, and a second weighting coefficient by which the second luminance value is multiplied; a third luminance value of the transmitted X-rays based on third transmitted X-ray image information generated in response to irradiation with X-rays of a third energy amount, and a third weighting coefficient by which the third luminance value is multiplied; Calculate a predetermined luminance value based on the The second calculation unit calculates a thickness of one material member based on the predetermined luminance value and the X-ray absorption coefficients of each of the three material members. The thickness measurement device according to claim 1 .

3. The second calculator uses, as the X-ray absorption coefficient, an absorption coefficient that is independent of the thickness of a material member, or a radiance absorption coefficient that is dependent on the thickness of a material member. The thickness measurement device according to claim 2 .

4. The first calculation unit calculates the predetermined luminance value D ｓｕｂ , the first luminance value is D Ｈ , the first weighting factor is K Ｈ , the second luminance value is D Ｍ , the second weighting factor is K Ｍ , the third luminance value is D Ｌ , the third weighting factor is K Ｌ Then, the predetermined luminance value D ｓｕｂ is calculated based on the following formula (1) [0010] The thickness measurement device according to claim 2 .

5. The second calculation unit is The X-ray absorption coefficients of the first material member among the three material members corresponding to the first to third energy amounts are μ １ (H), μ １ (M), μ １ (L), The X-ray absorption coefficients of the second material member among the three material members corresponding to the first to third energy amounts are μ ２ (H), μ ２ (M), μ ２ (L), The X-ray absorption coefficients of the third material member among the three material members corresponding to the first to third energy amounts are μ ３ (H), μ ３ (M), μ ３ (L), The thickness of the second material member to be calculated is t ２ Then, The second material member t is calculated by the following formula (2) obtained based on the above formula (1): ２ Calculate the thickness of [0025] The thickness measurement device according to claim 4.

6. The computer an X-ray source control step of controlling the X-ray source so that the stack is irradiated with X-rays having a plurality of energy amounts corresponding to the number of material members each made of different materials; an acquiring step of acquiring a plurality of pieces of transmitted X-ray image information resulting from different amounts of energy generated in response to detecting X-rays transmitted through the laminate; a first calculation step of calculating a predetermined luminance value based on a luminance value based on each of the plurality of pieces of transmitted X-ray image information and a weighting coefficient by which the luminance value is multiplied; a second calculation step of calculating a thickness of one of the plurality of material members based on the predetermined luminance value calculated in the first calculation step and an X-ray absorption coefficient corresponding to each of the plurality of material members; A thickness measurement method to perform.

7. On the computer, an X-ray source control function that controls the X-ray source to irradiate the laminate with X-rays having a plurality of energy levels corresponding to the number of material members each made of different materials; an acquisition function for acquiring a plurality of pieces of transmitted X-ray image information resulting from different amounts of energy generated in response to detection of X-rays transmitted through the laminate; a first calculation function that calculates a predetermined luminance value based on a luminance value based on each of the plurality of pieces of transmitted X-ray image information and a weighting coefficient by which the luminance value is multiplied; a second calculation function that calculates a thickness of one of the plurality of material members based on a predetermined luminance value calculated by the first calculation function and an X-ray absorption coefficient corresponding to each of the plurality of material members; A thickness measurement program that makes this possible.

Images