X-ray inspection system, X-ray inspection method, and storage medium

Abstract

An X-ray inspection system comprises: an X-ray generating unit that irradiates an inspection object with X-rays; an X-ray photographing unit that photographs the X-rays that have passed through the inspection object; a storage unit that stores at least information related to the inspection object; a three-dimensional data producing unit that uses information from a plurality of X-ray images photographed by the X-ray photographing unit to produce three-dimensional data of the inspection object; a user confirmation image producing unit that uses the three-dimensional data of the inspection object to produce a user confirmation image that represents the shape of an inspection object portion in the inspection object as a two-dimensional shape of an observation object surface desired by a user; and a display unit that displays the image produced by the user confirmation image producing unit.

Description

Technical Field

[0001] The present invention relates to an X-ray inspection system, an inspection method using X-rays, and a program. Background Art

[0002] In the past, there has been known a technology for measuring the three-dimensional shape of an object using an image captured by illuminating the object with light (for example, Patent Document 1), and checking the presence and type of defects in the object by comparing the measured shape with a pre-set judgment standard.

[0003] When performing inspections based on the three-dimensional shape of an object, it is desirable for the user to be able to confirm the specific state of the inspected portion and whether the good / bad judgment results are appropriate. Furthermore, it is desirable to be able to confirm the actual state of the inspected portion and the portion to be measured when setting the judgment criteria prior to the inspection (hereinafter referred to as "teaching").

[0004] In contrast, Patent Document 2 proposes a technique for displaying the shape of an inspection target area in a visual inspection device using multiple images, allowing the user to easily identify the inspection target area. Specifically, the technique discloses displaying an image showing the display target range of a component-mounted substrate being inspected, viewed from above the substrate surface; an image with the YZ plane as the front; and an image with the XZ plane as the front, all aligned in scale and position, on the same screen.

[0005] In this specification, the vertical direction is referred to as the Z axis, the direction indicating depth in the horizontal direction is referred to as the Y axis, and the direction intersecting the Y axis at right angles in the horizontal direction is referred to as the X axis.

[0006] On the other hand, in recent years, the miniaturization and precision of various products have been continuously advancing. For example, the density of component mounting has increased, even on component mounting substrates. This has led to an increase in the number of areas that are shadowed by the field of view of the imaging device, resulting in an increase in the number of components that cannot be accurately inspected during visual inspection. Furthermore, a technology for inspecting parts that cannot be inspected visually using X-ray CT is known (e.g., Patent Document 3).

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-71782

[0010] Patent Document 2: Japanese Patent Application Laid-Open No. 2012-149905

[0011] Patent Document 3: Japanese Patent Application Laid-Open No. 2017-223468 Summary of the Invention

[0012] Problems to be solved by the invention

[0013] However, as described in the aforementioned patent document 3, it is desirable that the user be able to confirm the state of the inspection target part even when performing an inspection by obtaining a three-dimensional shape through X-ray CT. However, the technology described in patent document 2 is applied to visual inspection using visible light and has the problem that it is impossible to confirm the state of the inspection target part or the part to be measured during inspection using X-ray CT images.

[0014] The present invention has been made in view of the above-mentioned actual situation, and an object thereof is to provide a technology that allows a user to easily confirm the state of an inspection object portion when performing an inspection by measuring the three-dimensional shape of the inspection object using a plurality of X-ray images.

[0015] Means for solving problems

[0016] In order to achieve the above-mentioned object, the present invention adopts the following structure.

[0017] The X-ray inspection system of the present invention comprises: an X-ray generating unit that irradiates an inspection object with X-rays; an X-ray photographing unit that photographs the X-rays that have passed through the inspection object; a storage unit that stores at least information related to the inspection object; a three-dimensional data production unit that uses information from a plurality of X-ray images photographed by the X-ray photographing unit to produce three-dimensional data of the inspection object; a user confirmation image production unit that uses the three-dimensional data of the inspection object to produce a user confirmation image that represents the shape of the inspection object portion in the inspection object as the two-dimensional shape of the observation object surface desired by the user; and a display unit that displays the image produced by the user confirmation image production unit.

[0018] In addition, the above-mentioned X-ray inspection system can also be configured as an X-ray inspection device in which each unit is integrated. In addition, the "user's desired observation object surface" is not limited to the surface that can be visually confirmed from the appearance, but also includes a cross-section at any position (and direction) in the shape defined by the three-dimensional data. According to such a structure, the three-dimensional shape of the inspection object can be measured based on multiple image data obtained by X-raying the inspection object, and the part of the inspection object that the user wants to confirm is displayed as a two-dimensional shape represented from the direction that the user wants to confirm. Therefore, the user can also easily confirm the state of the part that cannot be confirmed based on the appearance information of the inspection object.

[0019] In addition, the user confirmation image production unit may also include: a reference plane determination unit, which uses the three-dimensional data of the inspection object to determine the specified horizontal tomographic position of the inspection object part; a horizontal projection image acquisition unit, which obtains a horizontal projection image obtained by projection processing of a specified distance in the vertical direction from the horizontal tomographic position; a brightness curve acquisition unit, which obtains the brightness curve (profile) of the observation object surface desired by the user based on the horizontal projection image; and a relative shape curve production unit, which converts the brightness curve into a relative shape curve that expresses physical quantities related to the shape of the inspection object part as relative values.

[0020] Here, physical quantities related to shape include, for example, dimensions such as height and width, as well as inclinations and angles. With this configuration, it is possible to present the user with an image that relatively displays physical quantities related to the two-dimensional shape, showing the desired location from the desired direction, using a brightness curve derived from a horizontally projected image that can be acquired based on three-dimensional data of the inspection object. For example, rather than displaying an image that displays dimensions in absolute values, an image can be displayed using relative contour lines relative to a predetermined point, allowing the user to be presented with an image of the two-dimensional shape without performing processing such as converting the brightness curve into dimensions.

[0021] Alternatively, the brightness curve acquisition unit may project the horizontal projection image in the depth direction of the observation target surface desired by the user at least within a projection range calculated using information related to the inspection target object stored in the storage unit, thereby acquiring the brightness curve.

[0022] This structure allows the use of data related to the shape and size of the inspection target area to determine the range of projection processing, thereby accurately extracting the area that the user wants to confirm within the inspection target area for projection processing. As a result, the brightness curve of the area that the user wants to confirm can be accurately extracted.

[0023] In addition, the user confirmation image production unit may further include a scale matching unit that uses the relative shape curve and the information related to the inspection object stored in the storage unit to match the scales of the vertical axis and the horizontal axis in the user confirmation image.

[0024] This configuration enables the user to be presented with a two-dimensional image that dimensionally represents the shape of the inspection target part using dimensional data of the inspection target part. Since the two-dimensional shape derived from the relative shape curve represents only the relative outline of the inspection target part, by displaying the inspection target part with the same scale on the vertical and horizontal axes, an easily viewable image can be presented that minimizes the user's discomfort.

[0025] Alternatively, the object to be inspected may be a component mounting substrate, the portion to be inspected may be a soldering portion of a component electrode, the surface to be observed desired by the user may be a surface showing the long side or short side direction of the component electrode, the prescribed horizontal section position of the portion to be inspected may be a joining surface between the solder and the substrate, and the physical quantity related to the shape of the portion to be inspected may be a dimension representing height.

[0026] With this structure, the shape of the wetting bump (hereinafter referred to as the fillet) of the solder portion can be easily confirmed at a location that cannot be confirmed visually on a substrate with a high component mounting density.

[0027] Alternatively, the user confirmation image generating unit may further include a fillet start position determining unit configured to determine a solder fillet start position based on the gradient of the relative shape curve and the information stored in the storage unit. Furthermore, based on the thus determined solder fillet start position, an image representing a two-dimensional shape of the component electrode soldered portion may be displayed with the scales of the vertical and horizontal axes thereof aligned.

[0028] Alternatively, the user confirmation image generating unit may further include an electrode shape estimating unit that estimates the shape of the component electrode based on the relative shape curve and the information stored in the storage unit, and reflects the estimated shape in the user confirmation image. With this configuration, the positional relationship between the shape of the solder fillet and the component electrode can be simultaneously confirmed even in locations where the user cannot visually view the solder fillet.

[0029] In addition, it is also possible that the storage unit also stores measurement information of the appearance inspection of the component mounting substrate, and the user confirmation image production unit also has an electrode shape synthesis unit, which obtains the shape of the component electrode from the measurement information, and reflects the shape of the component electrode in the user confirmation image after performing a scale conversion to match the relative shape curve.

[0030] The shape of the component electrode can be determined based on the image data used for appearance inspection, so by synthesizing the shape of the component electrode obtained thereby, the user can confirm the shape of the component electrode and the solder fillet of the welding part based on the image reflecting the actual shape of the component electrode.

[0031] In addition, the user confirmation image production unit may also include: a reference plane determination unit, which determines the horizontal slice position of a specified part of the measurement object based on the three-dimensional data of the inspection object; a horizontal projection image acquisition unit, which obtains a horizontal projection image obtained by projecting the three-dimensional data of the inspection object in the vertical direction for a specified distance from the horizontal slice position of the specified part; a brightness curve acquisition unit, which obtains the brightness curve of the observation object surface desired by the user based on the horizontal projection image; a vertical projection image acquisition unit, which obtains a vertical projection image obtained by projecting the three-dimensional data of the inspection object in the depth direction of the observation object surface desired by the user; and an absolute shape curve production unit, which uses the vertical projection image to convert the brightness curve into an absolute shape curve that expresses a physical quantity related to the shape of the inspection object part as an absolute value.

[0032] With this configuration, an image showing the dimensions of the two-dimensional shape of the part the user wishes to check can be displayed to the user, showing the part the user wishes to check from the direction the user wishes to check. Therefore, the user can confirm the shape of the part to be checked with a less uncomfortable feeling by using an image showing a two-dimensional shape that matches the actual shape of the part to be checked.

[0033] Furthermore, the vertical projection image acquisition unit may determine a projection range for performing a projection process in a depth direction of the observation target plane desired by the user, using the horizontal projection image and the information on the inspection target object stored in the storage unit.

[0034] Through such a structure, the range of projection processing of the image for obtaining the brightness curve can be made consistent with the range of projection processing used to obtain the vertical projection image, and the position of the inspection object part that serves as the basis of the original data for obtaining the absolute shape curve can be matched to obtain an absolute shape curve with good accuracy.

[0035] Alternatively, the user confirmation image generating unit may further include an electrode shape estimating unit that estimates the shape of the component electrode based on the absolute shape curve and the information stored in the storage unit, and reflects the estimated shape in the user confirmation image. With this configuration, the positional relationship between the shape of the solder fillet and the component electrode can be simultaneously confirmed even in locations where the user cannot visually view the solder fillet.

[0036] In addition, it is also possible that the storage unit also stores measurement information of the appearance inspection of the component mounting substrate, and the user confirmation image production unit also has an electrode shape synthesis unit. The electrode shape synthesis unit obtains the shape of the component electrode based on the measurement information, and reflects the shape of the component electrode in the user confirmation image after performing a scale conversion to match the absolute shape curve.

[0037] According to such a structure, during the inspection of a component mounting substrate, by representing an image of a two-dimensional shape that conforms to the actual shape of the solder fillet obtained from an X-ray image and the actual shape of the component electrode obtained from an image during appearance inspection, the user can easily and accurately confirm the shape of the desired inspection object portion.

[0038] In addition, the X-ray inspection method of the present invention has the following steps: obtaining multiple X-ray images obtained by photographing the inspection object using X-rays; using information from the multiple X-ray images obtained by photographing the inspection object, creating three-dimensional data of the inspection object; using the three-dimensional data of the inspection object, creating a user confirmation screen that represents the shape of the inspection object part in the inspection object as the two-dimensional shape of the observation object surface desired by the user; and displaying the user confirmation screen.

[0039] Furthermore, the present invention can also be understood as a program for causing a computer to execute the above-mentioned method, or a computer-readable recording medium on which such a program is non-transitorily recorded.

[0040] Furthermore, the above-mentioned structures and processes can be combined with each other to constitute the present invention as long as no technical contradiction occurs.

[0041] Effects of the Invention

[0042] According to the present invention, it is possible to provide a technique that allows a user to easily check the state of an inspection object when performing an inspection by measuring the three-dimensional shape of the inspection object using a plurality of X-ray images. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] [ Figure 1 ] Figure 1 This is a schematic diagram showing a schematic configuration of an X-ray inspection apparatus according to an application example of the present invention.

[0044] [ Figure 2 ] Figure 2 This is a flowchart showing the flow of confirmation image display processing in an X-ray inspection apparatus according to an application example of the present invention.

[0045] [ Figure 3 ] Figure 3This is a block diagram showing a schematic configuration of an X-ray inspection system according to the first embodiment.

[0046] [ Figure 4 ] Figure 4 This is an explanatory diagram showing the relationship between the inspection target site, its three-dimensional data, the horizontal projection image, and the brightness value curve in the first embodiment.

[0047] [ Figure 5 ] Figure 5 This is a diagram showing an example of image processing in the X-ray inspection system according to the first embodiment.

[0048] [ Figure 6 ] Figure 6 This is a flowchart showing the flow of confirmation image display processing in the X-ray inspection system according to the first embodiment.

[0049] [ Figure 7 ] Figure 7 This is a block diagram showing a schematic configuration of an X-ray inspection system according to a second embodiment.

[0050] [ Figure 8 ] Figure 8 This is an explanatory diagram showing the relationship between the inspection target part, its three-dimensional data, the vertical projection image, and the brightness value curve in the second embodiment.

[0051] [ Figure 9 ] Figure 9 This is a diagram showing an example of image processing in the X-ray inspection system according to the second embodiment.

[0052] [ Figure 10 ] Figure 10 This is a flowchart showing the flow of confirmation image display processing in the X-ray inspection system according to the second embodiment.

[0053] [ Figure 11 ] Figure 11 This is a block diagram showing a schematic configuration of an X-ray inspection system according to a third embodiment. DETAILED DESCRIPTION

[0054] <Application Examples>

[0055] (Structure of Application Example)

[0056] The present invention can be applied, for example, as an X-ray inspection apparatus for performing X-ray imaging of an inspection object (eg, a component-mounted substrate) and inspecting the inspection object based on the imaged image. Figure 1 1 is a schematic diagram showing a schematic configuration of an X-ray inspection apparatus 9 according to this application example. The X-ray inspection apparatus 9 is generally configured to include a control terminal 91 and an imaging unit 94 including an X-ray source 92 and an X-ray camera 93 .

[0057] The control terminal 91 can be constituted by, for example, a general-purpose computer, and includes functional units such as a drive control unit 911 , a storage unit 912 , a three-dimensional data creation unit 913 , an inspection unit 914 , an image creation unit 915 , and a display unit 916 .

[0058] An X-ray source 92 irradiates an inspection object O conveyed by conveying rollers (not shown) with X-rays, and an X-ray camera 93 captures X-rays transmitted through the inspection object O. The X-ray source 92 is movable via an X-stage 921 and a Y-stage 922, and the X-ray camera 93 is movable via an X-stage 931 and a Y-stage 932. The X-ray source 92 and the X-ray camera 93 are movable on circular orbits C1 and C2, respectively, via these stages, and capture images at various positions along the orbits.

[0059] Drive control unit 911 controls the driving of each unit constituting X-ray inspection apparatus 9. Thus, X-ray inspection apparatus 9 changes the relative positions of inspection object O, X-ray source 92, and X-ray camera 93, and images inspection object O from a plurality of imaging positions.

[0060] The storage unit 912 stores at least information related to the inspection object O (for example, in the case of a component-mounted substrate, the type, shape, and size of the component) and information related to inspection criteria, such as threshold values. Furthermore, the storage unit 912 may store programs for controlling the inspection apparatus and data for creating user confirmation images, which will be described later.

[0061] The three-dimensional data generator 913 generates three-dimensional data of the inspection object O (or a portion thereof) based on the multiple X-ray images captured as described above. Since the method for generating (constructing) this data can be applied to well-known technologies such as CT (Computed Tomography) and tomosynthesis, a detailed description is omitted. Furthermore, the inspection unit 914 performs an inspection to determine the quality of the inspection object O by comparing the three-dimensional data generated by the generator 913 with the inspection reference stored in the storage unit 912.

[0062] The image generator 915 uses the three-dimensional data generated by the three-dimensional data generator 913 to generate a user confirmation image that represents the shape of the inspection target portion of the inspection target object O as a two-dimensional shape when viewed from a predetermined direction (for example, an image with the XZ plane of the inspection target object as the front). Furthermore, the display unit 916 is configured to include a display device such as a liquid crystal display, and displays the user confirmation image generated by the image generator 91.

[0063] (Processing Flow)

[0064] Figure 2The following steps illustrate the processing performed by the X-ray inspection apparatus 9 in this application example. First, the X-ray inspection apparatus 9 performs X-ray imaging of the inspection object O from multiple different positions, acquiring multiple sets of X-ray image data (S901). Next, the X-ray inspection apparatus 9 creates three-dimensional data of the inspection object O based on the multiple sets of X-ray image data acquired in step S901 (S902).

[0065] The X-ray inspection apparatus 9 then inspects the inspection object O based on the three-dimensional data generated in step S902 (S903). Specifically, for example, the three-dimensional data is compared with an inspection reference (threshold value) related to the shape of the inspection object O, which is stored in advance in the storage unit 912, to determine the quality of the inspection object O. The determination result may also be displayed on the display unit 916.

[0066] The X-ray inspection apparatus 9 also uses the three-dimensional data generated in step S902 to perform pre-processing (S904) for generating a user confirmation image, described later. Specifically, for example, a brightness curve is obtained from the three-dimensional data in a user-desired direction (e.g., with the XZ plane of the inspection object O as the front) for the inspection target portion.

[0067] Then, based on the processing of step S904, the X-ray inspection apparatus 9 creates a user confirmation image (S905) that shows the two-dimensional shape of the inspection target portion of the inspection object O when viewed from a direction desired by the user. Specifically, for example, an image is created that shows a relative shape curve that relatively shows the dimensions related to the shape of the inspection target portion.

[0068] The X-ray inspection apparatus 9 then displays the image generated in step S904 on the display unit 916 (step S906), concluding the series of processing steps. The display unit 916 may automatically display an image of a predetermined inspection target area, or may wait for user input and then display an image in response to an instruction. Furthermore, an image for user confirmation may be displayed along with the inspection results of step S903.

[0069] With the X-ray inspection apparatus 9 of this application example, even when the shape of the inspection target area cannot be visually confirmed, the user can easily confirm the shape of the area. This makes it easy to determine the validity of inspection results, set inspection benchmarks, and perform other tasks.

[0070] <Implementation Method 1>

[0071] Then, based on Figures 3 to 6, a more detailed example of the mode for implementing the present invention is described. However, the size, material, shape, relative arrangement, etc. of the components described in the embodiment do not mean that the scope of the present invention is limited to them unless otherwise specified.

[0072] (System Structure)

[0073] Figure 3 This is a schematic block diagram showing the functional configuration of the X-ray inspection system 1 of this embodiment. Although not shown, the X-ray inspection system 1 of this embodiment includes a CT apparatus and an information processing terminal, and is used, for example, for inspecting component-mounted substrates.

[0074] The CT apparatus includes an X-ray source 11, an X-ray camera 12, and a table 13 for holding an object to be inspected. By relatively moving these components, tomographic images of the object at different positions (and orientations) can be acquired. The CT apparatus can employ any desired known technology, and therefore, a detailed description of the X-ray source 11, X-ray camera 12, and table 13 will be omitted.

[0075] The information processing terminal can be a general-purpose computer having a processor such as a CPU or DSP, a main storage unit such as a read-only memory (ROM) and a random access memory (RAM), a storage unit 24 including auxiliary storage units such as an EPROM, a hard disk drive (HDD), and removable media, an input unit 25 such as a keyboard and a mouse, and an output unit 26 such as a liquid crystal display. Furthermore, the information processing terminal may be composed of a single computer or a plurality of computers operating in conjunction with each other.

[0076] The auxiliary storage unit stores an operating system (OS), various programs, various information about the inspection object, various inspection standards, etc. These programs are loaded into the working area of ​​the main storage unit and executed. The execution of these programs controls the various components, thereby realizing the functional units that achieve the specified purpose, as described below. Furthermore, some or all of these functional units may be implemented using hardware circuits such as ASICs and FPGAs.

[0077] Next, the functional units of the information processing terminal will be described. The information processing terminal includes a control unit 21, a three-dimensional data creation unit 22, and a confirmation image creation unit 23. The control unit 21 is responsible for controlling various components of the CT apparatus and the information processing terminal. For example, it controls the drive of the X-ray source 11, X-ray camera 12, and table 13, controls the input devices of the input unit 25, and controls output to the output unit 26.

[0078] The three-dimensional data generator 22 generates three-dimensional shape data of the inspection target region (hereinafter referred to as "three-dimensional data") based on multiple X-ray tomographic images of the inspection target obtained from the CT apparatus. Although not described in detail, the generated three-dimensional data is compared with a predetermined inspection standard to perform an inspection to determine the quality of the inspection target.

[0079] (Regarding the verification image production department)

[0080] The confirmation image generator 23 uses the three-dimensional data generated by the three-dimensional data generator 22 to create a user confirmation image that represents the shape of a desired inspection area within the inspection object as a two-dimensional shape when viewed from a predetermined direction. Furthermore, to create this image, the confirmation image generator 23 includes various functional units: a reference plane determination unit 231, a horizontal projection image acquisition unit 232, a brightness curve acquisition unit 233, a relative shape curve creation unit 234, a fillet position determination unit 235, a scale matching unit 236, and an electrode shape estimation unit 237.

[0081] The reference plane identification unit 231 identifies the horizontal slice position serving as the reference plane (e.g., the solder joint surface) based on the image feature values ​​of the horizontal slice images (images in the XY plane) having different Z-axis coordinates in the three-dimensional data. For example, the degree of brightness variation (hereinafter referred to as brightness variance) in the image can be used as the image feature value.

[0082] As a specific processing method, for example, the three-dimensional data is searched in the Z-axis direction to identify the horizontal slice with the highest brightness variance. The reference plane is then determined as the position offset from the Z-axis coordinate of this horizontal slice by a predetermined value in the -Z direction. Alternatively, the predetermined offset value can be pre-set by the user for each component type and stored in the storage unit 24.

[0083] The horizontal projection image acquisition unit 232 projects a predetermined range of three-dimensional data based on the reference plane determined by the reference plane determination unit 231, creating a horizontal projection image that emphasizes the solder shape of the welded portion being inspected. Specifically, for example, the horizontal slice image average value is projected in the Z direction from the Z-axis coordinate of the reference plane by a predetermined amount (the average value of the brightness value of each pixel is calculated and reflected in the entire image). The projection range can also be pre-set by the user based on previously acquired information on the maximum height of solder wetting bumps on the component and stored in the storage unit 24.

[0084] The brightness curve acquisition unit 233 projects the horizontal projection image produced by the horizontal projection image acquisition unit 232, and obtains a curve of brightness values ​​in the direction that the user wants to confirm (since it is a horizontal image, it is the short side direction or long side direction of the welding part) (hereinafter, the brightness value curve in the short side direction is recorded as the short side direction brightness curve, and the brightness curve in the long side direction is recorded as the long side direction brightness curve). The projection range can be determined based on the brightness curve of the horizontal projection image in the direction that is paired with the direction that the user wants to confirm, as well as the component design information (such as pad width, electrode width, etc.) and brightness gradient stored in the storage unit 24. In addition, here, the brightness curve refers to the contour shape obtained by plotting the brightness value on the two-dimensional coordinates.

[0085] Figure 4 This is an explanatory diagram showing the relationship between the inspection object, its three-dimensional data, the horizontal projection image, the short side direction brightness value curve, and the long side direction brightness value curve. In the following, in this manual, the user's desired direction is described as the long side direction. When you want to confirm the curve of the brightness value in the long side direction, the range of the projection processing is determined based on the brightness curve in the short side direction, etc. Figure 4 Based on the brightness curve in the short side direction, the width of the electrode in the weld is determined, and the amount corresponding to the width is projected in the long side direction. In addition, the projection processing here is preferably based on maximum value projection (reflecting the pixel with the highest brightness value).

[0086] The relative shape curve generator 234 converts the brightness curve obtained by the brightness curve acquirer 233 into a curve representing the shape relative to the Z-axis direction (i.e., height) (hereinafter referred to as a relative height curve). Specifically, the brightness curve is converted by setting the reference plane (i.e., the solder joint surface) to 0% and the height of the highest solder wetting protrusion to 100%. For example, the relative height can be calculated by subtracting the brightness value of the reference plane from the brightness curve value, dividing it by the brightness value of the highest solder wetting protrusion minus the brightness value of the reference plane, and then multiplying this value by 100.

[0087] As an example, the brightness of the reference surface can be set to the average brightness of the area outside the solder in the horizontal projection image. This area outside the solder can also be determined by binarization of the horizontal projection image. Furthermore, the brightness of the location where the solder wetting protrusion is highest can be preset by the user or set to 255 as a default value.

[0088] The fillet position determination unit 235 determines the position of the solder fillet within the relative height curve based on the gradient of the relative height curve and the component design information (pad length) stored in the storage unit 24. This process is performed for both the fillet located on the front side of the electrode when viewed from the outside (so-called front fillet) and the fillet located on the back side of the electrode whose shape cannot be visually confirmed (so-called back fillet).

[0089] The scale matching unit 236 matches the scales of the vertical axis (Z direction, height) and the horizontal axis (longitudinal length of the fillet) of the relative height curve. The relative height curve is created based on the brightness curve, and the coordinates in the vertical axis are completely different from the coordinates in the longitudinal direction, whose dimensions are clearly defined as part of component design information, such as the pad length. Therefore, by matching the scales in the vertical axis with the scales in the longitudinal direction, a two-dimensional image that is visually comfortable to the user can be provided. The result of the scale matching process for the relative height curve will be referred to as the processed relative height curve.

[0090] The electrode shape estimation unit 237 estimates the approximate electrode shape of the component and performs processing to superimpose the estimated electrode shape on the processed relative height curve. Specifically, for example, the minimum value of the processed relative height curve, which forms a trough between the weld leg positions, is assumed to be the electrode tip position. The relative height curve data for the backside weld leg position is then approximated based on this electrode tip position, and the approximate electrode shape is estimated based on the component design information (electrode thickness) stored in the storage unit 24. Figure 5 A display example of a processed relative height curve in the case where the estimated electrode shape is superimposed and displayed is shown.

[0091] (Flow of User Confirmation Image Display Processing)

[0092] Next, refer to Figure 6 The following describes the process flow from capturing an X-ray image of the substrate being inspected to displaying a user confirmation image in this embodiment. First, under the control of the control unit 21, the CT apparatus captures an X-ray tomographic image of the substrate (S101). The three-dimensional data generator 22 then creates three-dimensional data of the substrate based on the multiple X-ray tomographic images (S102).

[0093] Next, the user uses the input unit 25 to select the pads (hereinafter referred to as pads) on the component of the substrate for which the user confirmation image is desired to be displayed (S103). The number of pads to be set is not limited to one; multiple pads may be set. The confirmation image generator 23 then executes the processing of loop L1, described below, for all the set pads.

[0094] In loop L1, the reference plane determination unit 231 first determines the reference plane serving as the solder joint surface based on the three-dimensional data generated in step S102 (S104). The horizontal projection image acquisition unit 232 then projects the three-dimensional data from the reference plane determined in step S104 to obtain a horizontal projection image (S105). The brightness curve acquisition unit 233 then further projects the horizontal projection image obtained in step S105 to obtain a brightness curve for the direction the user wishes to confirm (S106). Furthermore, the relative shape curve creation unit 234 converts the brightness curve obtained in step S106 into a relative height curve (S107), and the fillet position determination unit 235 determines the fillet position within the relative height curve (S108). The scale matching unit 236 then matches the scales of the vertical and horizontal axes of the relative height curve (S109), thereby generating a processed relative height curve. The electrode shape estimation unit 237 then estimates the approximate electrode shape of the target pad and performs processing for superimposing the estimated electrode shape on the processed relative height curve (S110), thereby completing a series of loop L1 processing. Furthermore, the information of the generated user confirmation image can be stored in the storage unit 24 by the confirmation image generation unit 23. The details of each process from steps S104 to S110 are omitted because they have been explained in the description of each functional unit.

[0095] After the above-described loop L1 processing is completed for all pads, the control unit 21 waits for the user to designate a pad. When the user selects an arbitrary pad from the pads set in step S103 via the input unit 25 (S111), the control unit 21 causes the output unit 26 to display the user confirmation image created in loop L1 for the pad (S112), temporarily terminating this routine.

[0096] With the X-ray inspection system 1 described above, users can visually confirm the approximate contour of a component mounting substrate weld, which is invisible from the outside, as two-dimensional information when viewed from a desired position and direction. This makes it easy to determine the validity of X-ray inspection results for component mounting substrates. Furthermore, it also facilitates the teaching of inspection standards based on this information.

[0097] <Implementation Method 2>

[0098] Then, based on Figures 7 to 10 An X-ray inspection system 2 according to another embodiment of the present invention will be described. The X-ray inspection system 2 of this embodiment shares many configurations with the aforementioned X-ray inspection system 1, and therefore, the same configurations and functions are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0099] Figure 7 This is a schematic block diagram showing the functional structure of the X-ray inspection system 2 of this embodiment. Figure 7 As shown, the X-ray inspection system 2 of this embodiment has the same configuration as the X-ray inspection system 1 except for a part of the functional units of the confirmation image generating unit 30 .

[0100] The confirmation image generator 30 in the X-ray inspection system 2 includes functional units such as a reference plane determination unit 231, a horizontal projection image acquisition unit 232, a brightness curve acquisition unit 233, a vertical projection image acquisition unit 301, a leg height determination unit 302, an absolute shape curve generation unit 303, and an electrode shape estimation unit 304. The reference plane determination unit 231, the horizontal projection image acquisition unit 232, and the brightness curve acquisition unit 233 are identical to those of the X-ray inspection system 1, and therefore their description is omitted.

[0101] The vertical projection image acquisition unit 301 projects the three-dimensional data generated by the three-dimensional data generation unit 22 in the direction the user wishes to confirm (here, the longitudinal direction) to obtain a vertical projection image of the weld to be inspected. The projection range (the distance in the direction opposite to the longitudinal direction) and projection method are preferably the same as those used in the projection process performed by the brightness curve acquisition unit 233 (i.e., maximum projection). This allows the range underlying the brightness curve to match the range underlying the vertical projection image.

[0102] The fillet height determination unit 302 determines the wetting protrusion height of the fillet (hereinafter also referred to as fillet height) based on the brightness curve acquired by the brightness curve acquisition unit 233 and the vertical projection image acquired by the vertical projection image acquisition unit 301 .

[0103] Figure 8 This is an explanatory diagram showing the relationship between the inspection target part, its three-dimensional data, the vertical projection image, and the long-side brightness value curve of the horizontal projection image. Figure 8 First, the vertical projection image is aligned with the horizontal axis of the brightness curve, using the peak value P of the brightness curve as a reference. Next, the horizontal axis coordinate of the vertical projection image corresponding to the peak value P of the brightness curve is determined. A scan is performed along the vertical axis from the reference plane on the vertical axis of the horizontal axis coordinate. The weld foot height F is determined based on the gradient of the brightness value curve obtained from this scan. Specifically, the brightness curve along the vertical axis of the scanned vertical projection image can be differentiated once, and the location with the smallest differential value (i.e., the location with the largest inclination of the brightness curve) is used as the weld foot height F. The vertical projection image is obtained by projecting three-dimensional data, so once the vertical axis coordinate on the vertical projection image is determined, the actual height can be determined.

[0104] The absolute shape curve generator 303 uses the fillet wetting height and the longitudinal brightness curve determined by the fillet height determination unit 302 to convert the brightness values ​​into absolute heights. Specifically, the brightness values ​​are converted to absolute heights by aligning the determined fillet height with the peak of the longitudinal brightness curve and aligning the reference plane height (which is always 0) with the brightness curve value corresponding to the fillet start position (i.e., the boundary with the reference plane). For example, a single conversion method using ax + by + c = 0 (x = brightness, y = height) can be used. Figure 9 This is a diagram showing the long-side brightness curve and the absolute height curve after conversion.

[0105] The electrode shape estimation unit 304 estimates the approximate electrode shape of the component and performs processing to superimpose and display the estimated electrode shape on the absolute height curve. The specific method of this processing is the same as that of the electrode shape estimation unit 237 in the first embodiment, differing only in that the curve used for estimation is an absolute curve, so a detailed description is omitted.

[0106] Next, refer to Figure 10 , the processing from capturing an X-ray image of the substrate to be inspected to displaying an image for user confirmation in this embodiment is described, but the description of the steps for performing the same processing as in the first embodiment is omitted.

[0107] Specifically, steps S101 to S103 are the same as those in the first embodiment. X-ray images are acquired and three-dimensional data is generated. The user then specifies any pad for which a confirmation image is desired. The confirmation image generator 30 then executes Loop L2 for each designated pad to generate a user confirmation image. Furthermore, steps S104 to S106 within this Loop L2 are the same as those in the first embodiment.

[0108] After acquiring the brightness curve in step S106, the vertical projection image acquisition unit 301 acquires a vertical projection image based on the three-dimensional data generated in step S102 (S201). Next, the fillet height determination unit 302 determines the fillet height based on the brightness curve and the vertical projection image (step S202).

[0109] Next, the absolute shape curve generator 303 uses the fillet height and brightness curve determined in step S202 to convert the brightness curve into an absolute height curve (S203). The electrode shape estimator 304 then estimates the component's electrode shape and performs processing to superimpose the estimated electrode shape on the absolute height curve (S204), completing a series of loop L2 processes.

[0110] The subsequent processing, steps S111 and S112, are identical to those in Embodiment 1, and their description is omitted. With this structured X-ray inspection system 2, the user can confirm in an image that the contour shape matches the actual solder shape, thereby enhancing the user's sense of confidence. This allows for more efficient verification of the validity of inspection results and teaching of inspection standards.

[0111] <Implementation Method 3>

[0112] Then, based on Figure 11 The X-ray inspection system 3 of this embodiment shares many configurations with the aforementioned X-ray inspection system 1 , and therefore, the same configurations and functions are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0113] Figure 11 This is a schematic block diagram showing the functional structure of the X-ray inspection system 3 of this embodiment. Figure 11 As shown, the X-ray inspection system 3 of this embodiment is configured to cooperate with a visual inspection device 50 that performs visual inspection of an inspection object. Furthermore, the confirmation image generator 40 differs from the X-ray inspection system 1 in that it includes an electrode shape acquisition unit 401 and an electrode shape synthesis unit 402 as functional units.

[0114] The appearance inspection device 50 performs visual inspection of component-mounted substrates using the so-called color highlight method. The color highlight method involves irradiating the substrate with light of multiple colors (wavelengths) at varying angles of incidence. The solder surface is photographed while exhibiting color characteristics corresponding to its normal direction (the color of the light source in the direction of regular reflection when viewed from a camera). This method captures the three-dimensional shape of the solder surface as two-dimensional hue information. This inspection method enables highly accurate detection of the visually identifiable electrode shape and fillet tilt on the solder pad portion of the substrate.

[0115] In the X-ray inspection system 3 of this embodiment, information communication with the visual inspection device 50 is configured to obtain information related to the visual inspection of the same substrate (e.g., color highlight image information, etc.) performed using the visual inspection device 50. The communication method can adopt any desired known technology and can be a wired connection method or a wireless connection method. In addition, at least a portion of the information obtained from the visual inspection device 50 can be stored in the storage unit 24. With this configuration, even if communication with the visual inspection device 50 is interrupted, at least the information stored in the storage unit 24 can be used in the X-ray inspection system 3.

[0116] The electrode shape acquisition unit 401 acquires the electrode shape measured based on the color highlight image of the inspection target substrate that has been visually inspected by the visual inspection device 50. The visual inspection device 50 may measure the electrode shape based on the color highlight image, and the storage unit 24 may store the electrode shape of each pad. However, the storage unit 24 may store only the color highlight image, and the electrode shape acquisition unit 401 may perform the electrode shape measurement.

[0117] The electrode shape synthesis unit 402 performs processing to superimpose and display the electrode shape obtained by the electrode shape acquisition unit 401 (hereinafter referred to as the actual electrode shape) on the processed relative height curve adjusted by the scale adjustment unit 236. Specifically, the actual electrode shape is scaled (resolution and coordinate system matching) to match the processed relative height curve and then superimposed on the processed relative height curve. This allows the user confirmation image output to the output unit 26 to display the weld contour reflecting the actual electrode shape.

[0118] In this embodiment, the processing for displaying the user confirmation image differs from that of the X-ray inspection system 1 of the first embodiment only in the portion related to acquisition and superimposition processing of the electrode shape, and therefore description thereof is omitted.

[0119] According to the X-ray inspection system 3 of the present embodiment as described above, the user can confirm the shapes of the component electrodes and fillets of the welded portion through an image reflecting the actual electrode shapes, thereby improving the user's sense of confidence.

[0120] <Other>

[0121] The above-described embodiments are merely illustrative of the present invention and are not limited to the specific embodiments described above. Various modifications and combinations of the present invention are possible within the scope of its technical concept. For example, the X-ray inspection apparatus 2 of the above-described embodiment 2 and the X-ray inspection apparatus of embodiment 2 can be combined to display a user confirmation image in which the actual electrode shape is superimposed on the absolute height curve.

[0122] Furthermore, at least a portion of the storage unit in each of the above examples may be provided as a storage device separate from the information processing terminal, or may be connected to the cloud. Furthermore, in each of the above examples, the X-ray inspection system may be provided as an integrated device, i.e., a CT device and a console may be integrated into one device. Furthermore, in each of the above examples, the substrate inspection may be performed at any time between steps S102 and S112, and the inspection results may be displayed on the user confirmation screen displayed in step S112.

[0123] Furthermore, in the first embodiment, the estimated electrode shape may be calculated before the scale matching process in step S109, and the scale matching of the relative height curve may be performed along with the electrode shape. In other words, the processes of step S109 and step S110 may be swapped. Furthermore, in the second embodiment, the process of step S201 may be performed before step S104 or step S105.

[0124] <Note>

[0125] One embodiment of the present invention is an X-ray inspection system (1) comprising:

[0126] An X-ray generating unit (11) irradiates an inspection object with X-rays;

[0127] an X-ray photographing unit (12) for photographing X-rays that have passed through the inspection object;

[0128] a storage unit (24) storing at least information related to the inspection object;

[0129] a three-dimensional data creating unit (22) that creates three-dimensional data of the inspection object using information of a plurality of X-ray images captured by the X-ray capturing unit;

[0130] a user confirmation image producing unit (23) which uses the three-dimensional data of the inspection object to produce a user confirmation image showing the shape of the inspection object portion in the inspection object as the two-dimensional shape of the observation target surface desired by the user; and

[0131] A display unit (26) displays the image produced by the image producing unit after the user confirms the image.

[0132] Another embodiment of the present invention is an X-ray inspection method comprising the following steps:

[0133] Step (S101), obtaining a plurality of X-ray images obtained by photographing an inspection object using X-rays;

[0134] Step (S102), creating three-dimensional data of the inspection object using information of a plurality of X-ray images obtained by photographing the inspection object;

[0135] Step (L1) of creating a user confirmation screen that shows the shape of the inspection target portion in the inspection target object as a two-dimensional shape of an observation target surface desired by the user using the three-dimensional data of the inspection target object; and

[0136] Step (S112): displaying the user confirmation screen.

[0137] Description of labels

[0138] 1, 2, 3: X-ray inspection system; 9: X-ray inspection device; 11, 92: X-ray source; 12, 93: X-ray camera; 921, 931: X-table; 922, 932: Y-table; C1, C2: circular orbit; O: inspection object; P: peak value; F: weld foot wetting height.

Claims

1. An X-ray inspection system comprising: An X-ray generating unit that irradiates an inspection object with X-rays; an X-ray imaging unit that captures X-rays that have passed through the inspection object; a storage unit storing at least information related to the inspection object; a three-dimensional data creating unit that creates three-dimensional data of the inspection object using information from a plurality of X-ray images captured by the X-ray capturing unit; a user confirmation image creating unit that uses the three-dimensional data of the inspection object to create a user confirmation image that represents the shape of the inspection target portion in the inspection object as a two-dimensional shape of an observation target surface desired by the user; and a display unit that displays the image produced by the image producing unit for confirmation by the user, The user confirmation image generating unit comprises: a reference plane determining unit for determining a predetermined horizontal slice position of the inspection target portion using the three-dimensional data of the inspection target object; a horizontal projection image acquisition unit configured to acquire a horizontal projection image obtained by performing a projection process for a predetermined distance in a vertical direction from the horizontal slice position; a brightness curve acquiring unit for acquiring a brightness curve of the observation target surface desired by the user based on the horizontal projection image; and A relative shape curve creating unit converts the brightness curve into a relative shape curve expressing a physical quantity related to the shape of the inspection target portion as a relative value.

2. The X-ray inspection system according to claim 1, wherein: The brightness curve acquisition unit acquires the brightness curve by performing projection processing on the horizontal projection image in the depth direction of the observation target plane desired by the user at least within a projection range calculated using the information on the inspection target object stored in the storage unit.

3. The X-ray inspection system according to claim 1 or 2, characterized in that The user confirmation image creating unit further includes a scale matching unit that matches the scales of the vertical axis and the horizontal axis in the user confirmation image using the relative shape curve and the information on the inspection object stored in the storage unit.

4. The X-ray inspection system according to claim 1 or 2, characterized in that The inspection object is a component mounting substrate, The inspection target portion is a welding portion of a component electrode. The user's desired observation target surface is a surface showing the long side or short side direction of the component electrode. The predetermined horizontal cross-sectional position of the inspection target portion is the joint surface between the solder and the substrate. The physical quantity related to the shape of the inspection target site is a dimension indicating height.

5. The X-ray inspection system according to claim 4, wherein: The user confirmation image generating unit further includes a fillet start position determining unit configured to determine a start position of a solder fillet based on a gradient of the relative shape curve and information stored in the storage unit.

6. The X-ray inspection system according to claim 4, wherein: The user confirmation image creation unit further includes an electrode shape estimation unit that estimates a shape of the component electrode based on the relative shape curve and the information stored in the storage unit and reflects the estimated shape on the user confirmation image.

7. The X-ray inspection system according to claim 4, wherein: The storage unit further stores measurement information of the appearance inspection performed on the component mounting substrate. The user confirmation image creation unit further includes an electrode shape synthesis unit that obtains the shape of the component electrode from the measurement information, performs scale conversion to match the relative shape curve, and then reflects the shape of the component electrode on the user confirmation image.

8. An X-ray inspection system comprising: An X-ray generating unit that irradiates an inspection object with X-rays; an X-ray imaging unit that captures X-rays that have passed through the inspection object; a storage unit storing at least information related to the inspection object; a three-dimensional data creating unit that creates three-dimensional data of the inspection object using information from a plurality of X-ray images captured by the X-ray capturing unit; a user confirmation image creating unit that uses the three-dimensional data of the inspection object to create a user confirmation image that represents the shape of the inspection target portion in the inspection object as a two-dimensional shape of an observation target surface desired by the user; and a display unit that displays the image produced by the image producing unit for confirmation by the user, The user confirmation image generating unit comprises: a reference plane determining unit for determining a horizontal slice position of a predetermined portion of the inspection object based on the three-dimensional data of the inspection object; a horizontal projection image acquisition unit for acquiring a horizontal projection image obtained by projecting the three-dimensional data of the inspection object by a predetermined distance in the vertical direction from a horizontal slice position of the predetermined portion; a brightness curve obtaining unit for obtaining a brightness curve of the observation target surface desired by the user based on the horizontal projection image; a vertical projection image acquisition unit that acquires a vertical projection image obtained by projecting the three-dimensional data of the inspection object in the depth direction of the observation target surface desired by the user; and An absolute shape curve creating unit converts the brightness curve into an absolute shape curve expressing a physical quantity related to the shape of the inspection target site as an absolute value, using the vertical projection image.

9. The X-ray inspection system according to claim 8, wherein: The vertical projection image acquisition unit determines a projection range for performing a projection process in a depth direction of an observation target plane desired by the user, using the horizontal projection image and the information on the inspection target object stored in the storage unit.

10. The X-ray inspection system according to claim 8 or 9, characterized in that The inspection object is a component mounting substrate, The inspection target portion is a welding portion of a component electrode. The user's desired observation target surface is a surface showing the long side or short side direction of the component electrode. The predetermined horizontal cross-sectional position of the inspection target portion is the joint surface between the solder and the substrate. The physical quantity related to the shape of the inspection target site is a dimension indicating height.

11. The X-ray inspection system according to claim 10, wherein: The user confirmation image creation unit further includes an electrode shape estimation unit that estimates a shape of the component electrode based on the absolute shape curve and the information stored in the storage unit and reflects the estimated shape on the user confirmation image.

12. The X-ray inspection system according to claim 10, wherein: The storage unit further stores measurement information of the appearance inspection performed on the component mounting substrate. The user confirmation image creation unit further includes an electrode shape synthesis unit that obtains the shape of the component electrode based on the measurement information, performs scale conversion to match the absolute shape curve, and then reflects the shape of the component electrode in the user confirmation image.

13. An X-ray inspection method comprising the following steps: Acquiring a plurality of X-ray images obtained by photographing the inspection object using X-rays; creating three-dimensional data of the inspection object using information from a plurality of X-ray images obtained by imaging the inspection object; creating a user confirmation image that shows the shape of the inspection target portion in the inspection target object as a two-dimensional shape of an observation target surface desired by the user, using the three-dimensional data of the inspection target object; and displaying the user confirmation image, In the step of creating the user confirmation image, the following processing is performed: determining a predetermined horizontal slice position of the inspection target portion using the three-dimensional data of the inspection target object; Acquire a horizontal projection image obtained by performing a projection process for a predetermined distance in the vertical direction from the horizontal slice position; Obtaining a brightness curve of the observation target surface desired by the user based on the horizontal projection image; and The brightness curve is converted into a relative shape curve expressing a physical quantity related to the shape of the inspection target region as a relative value.

14. An X-ray inspection method comprising the following steps: Acquiring a plurality of X-ray images obtained by photographing the inspection object using X-rays; creating three-dimensional data of the inspection object using information from a plurality of X-ray images obtained by imaging the inspection object; creating a user confirmation image that shows the shape of the inspection target portion in the inspection target object as a two-dimensional shape of an observation target surface desired by the user, using the three-dimensional data of the inspection target object; and displaying the user confirmation image, In the step of creating the user confirmation image, the following processing is performed: determining a horizontal slice position of a predetermined portion of the inspection object based on the three-dimensional data of the inspection object; Acquiring a horizontal projection image obtained by projecting the three-dimensional data of the inspection object by a predetermined distance in the vertical direction from a horizontal slice position of the predetermined portion; obtaining a brightness curve of the observation object surface desired by the user based on the horizontal projection image; Obtaining a vertical projection image obtained by projecting the three-dimensional data of the inspection object in the depth direction of the observation target surface desired by the user; and The brightness curve is converted into an absolute shape curve expressing a physical quantity related to the shape of the inspection object region as an absolute value using the vertically projected image.

15. A program product for causing a computer to execute the steps of the X-ray inspection method according to claim 13 or 14.

Images