Inspection system, inspection device, inspection method, and program

Abstract

To provide technology that makes it possible to automatically inspect a circuit board at high speed which includes solder bumps and on which electronic components are mounted.SOLUTION: Provided is an inspection system for inspecting a component mounting board on which solder bumps are formed and on which electronic components are mounted. The inspection system comprises: three-dimensional data generation means for generating three-dimensional data of a region including at least a solder joint by the solder bumps by using a plurality of X-ray images in which the component mounting board is captured; longitudinal section image extraction means for extracting, from the three-dimensional data, a longitudinal section image indicating a longitudinal section passing through the center of the solder joint; inspection model generation means for generating an inspection model for inspection by using a plurality of longitudinal section images; and inspection means for performing inspection by the inspection model by using a plurality of longitudinal section images extracted from the three-dimensional data of each instance of the component mounting board which are the object of inspection and having different observation directions.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an inspection system, an inspection device, an inspection method, and a program, and more particularly to a technique for inspecting an object based on three-dimensional data acquired using an X-ray CT. [Background technology]

[0002] In recent years, various products have become smaller and more precise, and for example, the density of components mounted on component-mounted boards has increased, and the number of parts that cannot be accurately inspected by visual inspection has increased due to an increase in the number of parts that are shaded in the imaging field of the visual inspection device. In response to this, a technology has become publicly known that uses X-ray CT inspection to inspect parts that cannot be inspected by appearance (for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-17304 A [Patent Document 2] JP 2000-275191 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, some electronic components used in component mounting boards have bumps for solder bonding formed on the bottom of the package, such as BGA (Ball Grid Array).As for types of defects such as non-wetting of solder bumps and pillow defects, it is not possible to properly distinguish between good and bad by inspection using a single feature such as the solder area in a specific horizontal section and a threshold value to determine pass / fail, and therefore a complex inspection that combines judgments using multiple feature amounts is required.

[0005] For such complicated inspections, inspection using machine learning models (so-called AI) trained using techniques such as deep learning is suitable; however, there is a problem in that the computational costs of learning and inspecting (inference) three-dimensional data (3D voxels) are high, making high-speed automated inspection difficult.

[0006] The present invention has been made in view of the above circumstances, and has an object to enable high-speed automatic inspection of a board on which electronic components including solder bumps are mounted. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention adopts the following configuration. An inspection system for inspecting a component mounting board on which an electronic component having solder bumps is mounted, comprising: a three-dimensional data generating means for generating three-dimensional data of an area including at least the solder joints formed by the solder bumps using a plurality of X-ray images of the component mounting board; a longitudinal section image extraction means for extracting, from the three-dimensional data, a longitudinal section image showing a longitudinal section passing through a center of the solder joint; an inspection model generating means for generating an inspection model for the inspection using a plurality of the longitudinal cross-sectional images; an inspection means for performing an inspection using the inspection model by using a plurality of the longitudinal section images having different observation directions extracted from the three-dimensional data of each of the component mounting boards to be inspected; The inspection system includes:

[0008] In the above, the term "center" does not refer to the exact center point, but includes the area near the center point. For example, in the horizontal direction, the center can be a range from the center point to half the length of the shortest side of the pad of the solder joint. Also, an "inspection model" is a model (so-called AI) that has been machine-learned using learning data, and generating an inspection model includes having the model learn. Note that machine learning may be supervised learning or unsupervised learning.

[0009] In this way, by using longitudinal cross-sectional images (i.e., two-dimensional data) extracted from three-dimensional data of the solder joint to train an inspection model and to perform inspection using the trained inspection model, it becomes possible to perform high-speed, high-precision inspection even when inspecting component-mounted boards on which components such as BGAs, which have solder bumps formed on the bottom surface of the package, are mounted.

[0010] The longitudinal section images used for learning by the inspection model generating means may include a plurality of the longitudinal section images having different observation directions for each of the three-dimensional data. In this manner, by extracting a plurality of longitudinal section images having different observation directions for each of the three-dimensional data, i.e., for each of the inspection regions, it is possible to improve the efficiency and accuracy of learning.

[0011] The longitudinal section image extraction means may vertically plot the brightness variance value of the horizontal tomographic image acquired from the three-dimensional data, and determine the position of the tomographic slice at which the brightness variance value is maximum as the vertical position that identifies the central portion. The longitudinal section image extraction means may vertically plot the brightness variance value of the horizontal tomographic image acquired from the three-dimensional data, and determine the position of the tomographic slice at the center of a plurality of tomographic slices at which the brightness variance value exceeds a predetermined threshold as the vertical position that identifies the central portion.

[0012] The longitudinal section image extraction means further comprises: The horizontal position that identifies the central portion may be the center of the label of a binarized image of the horizontal tomographic image in which the brightness variance value is maximum, or the position of the center of gravity calculated by weighting the horizontal tomographic image in which the brightness variance value is maximum by brightness.

[0013] The longitudinal section image output means further comprises: The horizontal position that identifies the central portion may be the center of the label of a binarized image of a horizontal tomographic image at the center of multiple horizontal faults whose brightness variance value exceeds a predetermined threshold, or the position of the center of gravity calculated by weighting the horizontal tomographic image at the center of multiple horizontal faults whose brightness variance value exceeds a predetermined threshold by brightness.

[0014] The longitudinal section image extraction means The horizontal position that identifies the central portion may be the center of the label of an image obtained by binarizing the horizontal tomographic image in which the edge strength is maximum, or the center of gravity calculated by weighting the horizontal tomographic image in which the edge strength is maximum by brightness.

[0015] The longitudinal section image output means includes: The horizontal position that identifies the central portion may be the center of the label of a binarized image of a horizontal tomographic image at the center of multiple horizontal tomographic sections whose edge strength exceeds a predetermined threshold, or the position of the center of gravity calculated by weighting the horizontal tomographic image at the center of multiple horizontal tomographic sections whose edge strength exceeds a predetermined threshold by brightness.

[0016] The longitudinal section image extraction means extracts the position of the center of a label of an image obtained by performing maximum intensity projection in the vertical direction on each horizontal tomographic image of an area including a predetermined range in the horizontal direction of the solder joint in the three-dimensional data, or the position of a center of gravity calculated by weighting the image obtained by performing maximum intensity projection by brightness, as a horizontal position specifying the central portion. Here, the predetermined range in the horizontal direction is a range that is set so as to include an area near the center of the three-dimensional data.

[0017] The longitudinal section image extraction means may determine, as the horizontal position specifying the central portion, the center of a label of an image obtained by vertically averaging each horizontal tomographic image of an area including a predetermined horizontal range of the solder joint in the three-dimensional data, or the position of a center of gravity calculated by weighting the image obtained by the average projection by brightness. Here, the predetermined horizontal range is a range set to include an area near the center in the three-dimensional data.

[0018] With the above configuration, the vertical (hereinafter also referred to as Z direction) and horizontal (hereinafter also referred to as XY direction) positions of the center for extracting a longitudinal section image can be efficiently identified using a known image processing method with a low processing load.

[0019] The present invention also provides a method for producing a semiconductor device comprising the steps of: An inspection apparatus for inspecting a component mounting board on which an electronic component having solder bumps is mounted, comprising: an inspection model for the inspection that is generated using a longitudinal section image showing a longitudinal section passing through a center of the solder joint, the longitudinal section image being extracted from three-dimensional data of an area including at least the solder joint formed by the solder bump, the longitudinal section image being generated using a plurality of X-ray images of the component mounting board; A plurality of the longitudinal cross-sectional images extracted from the three-dimensional data of the component mounting board to be inspected and observed in different directions; The inspection is carried out by The present invention can also be regarded as an inspection device characterized by the above.

[0020] The present invention also provides a method for producing a semiconductor device comprising the steps of: 1. A method for inspecting a component mounting board on which an electronic component having solder bumps is mounted, comprising: a three-dimensional data generating step of generating three-dimensional data of an area including at least a solder joint formed by the solder bumps using a plurality of X-ray images of the component mounting board; a longitudinal section image extraction step of extracting, from the three-dimensional data, a longitudinal section image showing a longitudinal section passing through a center of the solder joint; an inspection model generation step of generating an inspection model for the inspection using the longitudinal section image; an inspection step of performing an inspection using the inspection model by using a plurality of the longitudinal section images having different observation directions extracted from the three-dimensional data of the component mounting board to be inspected; The present invention can also be regarded as an inspection method having the above-mentioned features.

[0021] Furthermore, the present invention can also be understood as a program for causing a computer to execute each step described in the above-mentioned inspection method, or a computer-readable recording medium on which such a program is non-transiently recorded.

[0022] The present invention can be achieved by combining the above-described configurations and processes as long as no technical contradiction occurs. Effect of the Invention

[0023] According to the present invention, it is possible to provide a technique that enables high-speed automatic inspection of a substrate on which electronic components including solder bumps are mounted. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a block diagram showing a schematic functional configuration of an X-ray inspection system according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing a solder joint of a component mounting board to be inspected in the embodiment, as viewed from a horizontal direction. [Diagram 3] FIG. 3 is a flowchart illustrating an example of a process performed in the inspection terminal according to the embodiment. [Figure 4] FIG. 4 is a schematic diagram showing the configuration and functional blocks relating to X-ray imaging of the X-ray imaging apparatus according to the embodiment. [Diagram 5]Fig. 5A is a first explanatory diagram showing the relationship between each horizontal tomographic image that can be extracted from the three-dimensional data of the solder joint according to the embodiment and the feature amount of each horizontal tomographic image. Fig. 5B is a second explanatory diagram showing the relationship between each horizontal tomographic image that can be extracted from the three-dimensional data of the solder joint according to the embodiment and the feature amount of each horizontal tomographic image. [Figure 6] Fig. 6A is an explanatory diagram showing an example of a horizontal tomographic image that can be extracted from three-dimensional data according to the embodiment and an image obtained by binarizing the horizontal tomographic image. Fig. 6B is an explanatory diagram showing an example of a horizontal tomographic image that can be extracted from three-dimensional data according to the embodiment and an example of an edge image thereof. [Figure 7] Fig. 7A is a first explanatory diagram for explaining a plurality of longitudinal sectional images for which pass / fail judgment is performed by the inspection unit according to the embodiment, and Fig. 7B is a second explanatory diagram for explaining a plurality of longitudinal sectional images for which pass / fail judgment is performed by the inspection unit according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] <Application Examples> (Configuration of application example) An example of an embodiment of the present invention will be described below. The present invention can be applied as an X-ray inspection system including an X-ray inspection device for taking an X-ray image of a component mounting board on which electronic components, such as BGA, having metal bumps for solder bonding formed on the bottom surface of the package, are mounted, and inspecting the component mounting board based on the taken image.

[0026] 1 is a schematic block diagram showing the functional configuration of an X-ray inspection system according to an application example. The X-ray inspection system 1 according to the application example is configured to include an X-ray imaging device 11, an inspection terminal 12, and a data server 13, and is an inspection system used to inspect component mounting boards in which solder bumps are formed on the bottom surface of packages such as BGA. The X-ray imaging device 11, the inspection terminal 12, and the data server 13 are connected to each other so as to be able to communicate with each other by communication means not shown.

[0027] Although not shown, the inspection terminal 12 can be a general-purpose computer equipped with a processor such as a CPU or DSP, a storage means, an input means such as a keyboard or a mouse, and an output means such as a liquid crystal display.

[0028] As shown in FIG. 1, the inspection terminal 12 has the following functional units: an image acquisition unit 121 , a three-dimensional data generation unit 122 , an image extraction unit 123 , a model generation unit 124 , an inspection unit 125 , and a storage unit 126 .

[0029] The image acquisition unit 121 acquires a plurality of X-ray image data obtained by capturing an area including a solder joint, which is an inspection target portion of a component mounting board, in the X-ray imaging device 11. The image data may be acquired directly from the X-ray imaging device 11, or may be acquired from the data server 13 after being temporarily transmitted from the X-ray imaging device 11 to the data server 13 and stored therein.

[0030] The three-dimensional data generating unit 122 generates data on the three-dimensional shape of the solder joint (hereinafter, simply referred to as three-dimensional data) based on the acquired X-ray image data. The data can be generated (reconstructed) by a method such as CT (Computed Tomography) or Since known techniques such as tomosynthesis can be applied, detailed explanation will be omitted.

[0031] The image extraction unit 123 extracts a vertical cross-sectional image to be used for determining whether the component mounting board is good or bad from the three-dimensional data generated by the three-dimensional data generation unit 122. Specifically, a vertical cross-sectional image showing a vertical cross section passing through the center of the solder joint is extracted. The "center" does not mean only the exact center point, but also means including the area near the center point. Here, the center will be explained with reference to FIG. 2. FIG. 2 is a schematic diagram of the solder joint of the component mounting board to be inspected viewed from the horizontal direction. As shown in FIG. 2, for example, in the horizontal direction, the half length of the shortest horizontal distance D of the pad having the smallest area among the pads P to be soldered in the solder joint to be inspected is set to D / 2, and the center can be within a range of D / 2 from the center point C. Note that the image extraction unit 123 in this application example corresponds to the vertical cross-sectional image extraction means according to the present invention.

[0032] The model generation unit 124 generates an inspection model for inspection by using multiple longitudinal section images extracted by the image extraction unit. Specifically, machine learning is performed by a method such as deep learning using a large amount of data of longitudinal section images extracted from three-dimensional data of solder joints of multiple inspection objects, and a trained model (so-called AI) is generated. The machine learning method may be supervised learning or unsupervised learning. The model generation unit 124 may be capable of re-training an already trained model. The model generation unit 124 in this application example corresponds to the inspection model generation means according to the present invention.

[0033] The inspection unit 125 performs pass / fail judgment on each of a plurality of longitudinal section images, which are extracted from the three-dimensional data of each component mounting board to be inspected, and which have different observation directions and include a common point on the three-dimensional data, using the inspection model generated by the model generation unit 124. For example, for one inspection target portion (solder joint), if there is even one longitudinal section image with a score below a predetermined value, it may be judged as defective.

[0034] The storage unit 126 is configured by the above-mentioned storage means, and includes, for example, a main storage unit such as a read-only memory (ROM) or a random access memory (RAM), and an auxiliary storage unit such as an EPROM, a hard disk drive (HDD), a removable medium, etc. The auxiliary storage unit stores an operating system (OS), various programs, etc., and the programs are loaded into the working area of ​​the main storage unit and executed, and the inspection terminal 12 is controlled through the execution of the programs, thereby realizing each functional unit.

[0035] Next, a flow of processing performed by the inspection terminal 12 in the X-ray inspection system 1 according to the application example will be described with reference to Fig. 3. Fig. 3 is a flowchart showing a flow of an example of processing performed by the inspection terminal 12. First, an X-ray tomographic image of a board is captured by the X-ray imaging device 11, and the image acquisition unit 121 acquires X-ray image data from the X-ray imaging device 11 or the data server 13 (S101). Then, the three-dimensional data generation unit 122 creates three-dimensional data of an area including a solder joint from multiple X-ray images (S102).

[0036] Next, the image extraction unit 123 extracts a vertical section image showing a vertical section passing through the center of the solder joint from the three-dimensional data (S103). Then, the model generation unit 124 performs machine learning using the extracted vertical section images as learning data to generate a machine learning model for inspection (S104). After that, the inspection unit 125 performs pass / fail judgment using the inspection model generated in step S104 for each of the multiple vertical section images with different observation directions extracted from the three-dimensional data of each component mounting board to be inspected (S105), and ends a series of routines. Note that the process of step S104 can be prevented from being executed once the inspection model has been generated, unless there is some trigger, such as the passage of a predetermined period of time.

[0037] According to the configuration of this application example as described above, even when inspecting a component mounting board on which components such as BGAs having solder bumps formed on the bottom surface of the package are mounted, there is no need to set complicated inspection standards, and it is possible to perform high-speed, high-precision inspection.

[0038] <Embodiment> In the following, the embodiments of the present invention will be described in detail by way of example with reference to the drawings (including the drawings already described in the above application examples). However, the specific configurations described in each embodiment are not intended to limit the scope of the present invention unless otherwise specified.

[0039] (System Configuration) 1 is a schematic block diagram showing the functional configuration of an X-ray inspection system 1 according to this embodiment. The X-ray inspection system 1 according to this embodiment is an inspection system including an X-ray imaging device 11, an inspection terminal 12, and a data server 13, and is used to inspect component mounting boards in which metal bumps for soldering are formed on the bottom surface of packages such as BGA. The X-ray imaging device 11, the inspection terminal 12, and the data server 13 are connected to each other so as to be able to communicate with each other by communication means (not shown).

[0040] (About X-ray equipment) Fig. 4 is a schematic diagram showing the configuration and functional blocks related to X-ray photography of the X-ray photography device 11. As shown in Fig. 4, the X-ray photography device 11 includes an X-ray source 10, an X-ray camera 20, a work stage 30 that holds a component mounting board (hereinafter, work) W to be inspected, and a terminal 100, and performs X-ray photography of the work W transported from an upstream process inside the device.

[0041] The workpiece W is transported from an upstream process by a carry-in conveyor (not shown) and placed on the workpiece stage 30. The workpiece stage 30 is configured to be movable in the horizontal and vertical directions by a stage having XYZ drive axes.

[0042] The X-ray camera 20 is a two-dimensional X-ray detector that detects X-rays irradiated from the X-ray source 10 and transmitted through the workpiece W. As the X-ray camera 20, an II (Image Intensifier) ​​tube or an FPD (Flat Panel Detector) can be used.

[0043] Both the X-ray source 10 and the X-ray camera 20 are configured to be movable by an XY stage, and the X-ray source 10 irradiates the workpiece W with X-rays, and an X-ray image of the transmitted light is taken by the X-ray camera 20. The X-ray source 10 and the X-ray camera 20 revolve on revolving orbits C1 and C2, respectively, and take X-ray images of the workpiece W at multiple positions on the orbits. The movement of each stage is achieved by a combination of a servo motor and a ball screw, but since this technology is well known, a description thereof will be omitted.

[0044] The X-ray imaging device 11 includes a terminal 100 for control and operation. The terminal 100 is realized, for example, by a general-purpose computer. Specifically, the computer may include a control unit 110 realized by a processor such as a CPU (not shown), a main memory unit 101 and an auxiliary memory unit 102 configured by a storage means (not shown), an input unit 103 configured by an input device such as a keyboard or a mouse (not shown), an output unit 104 configured by a liquid crystal display or the like (not shown), a communication unit 105 that communicates information with the examination terminal 12, the data server 13, etc. The terminal 100 may be configured separately from an imaging unit including an X-ray camera 20, etc.

[0045] Each part of the X-ray imaging device 11 is controlled by a control signal from the control unit 110 of the terminal 100. The control unit 110 of the X-ray imaging device 11 further includes the following functional units: an X-ray source control unit 111, an X-ray source XY stage control unit 112, a work stage control unit 113, a camera XY stage control unit 114, and an X-ray camera control unit 115.

[0046] The camera XY stage control unit 114 transmits a control signal for driving the camera XY stage (not shown) and for horizontally moving the X-ray camera 20. The X-ray camera control unit 115 transmits a control signal for causing the X-ray camera 20 to capture an X-ray image.

[0047] The X-ray source control unit 111 transmits signals for starting and ending irradiation of X-rays by the X-ray source 10 and for adjusting the X-ray intensity. The X-ray source XY stage control unit 112 transmits signals for driving the X-ray source XY stage (not shown) to move the X-ray source 10 in the horizontal direction.

[0048] The workpiece stage control unit 113 transmits a control signal to the workpiece stage 30 to control the horizontal and vertical positions of the workpiece W to be optimal for imaging.

[0049] (About the data server) The data server 13 stores imaging conditions in the X-ray imaging device 11, information related to the inspection target board (e.g., type, shape, dimensions, etc. of the component), information related to the inspection conditions, etc., and is provided with an area for storing data (three-dimensional data, longitudinal section image, inspection model, etc.) generated in the inspection terminal 12. Note that a program for controlling the inspection terminal 12 may be stored in the data server 13.

[0050] (About the inspection terminal) As described in the application example, the inspection terminal 12 can be configured by a general-purpose computer. The inspection terminal 12 may be configured by a single computer, or may be configured by multiple computers that cooperate with each other. The functional units of the inspection terminal 12 are as described above, but the image extraction unit 123 and the inspection unit 125 will be described in more detail.

[0051] The image extraction unit 123 extracts a vertical cross-sectional image showing a vertical cross-section passing through the center of the solder joint to be inspected from the three-dimensional data generated by the three-dimensional data generation unit 122. In this case, the image extraction unit 123 plots, for example, the brightness variance value of the horizontal cross-sectional image obtained from the three-dimensional data in the vertical direction, and sets the position of the cross-section where the brightness variance value is maximum as the vertical position that specifies the "center".

[0052] Fig. 5A is an explanatory diagram showing the relationship between the three-dimensional data of a solder joint and the brightness variance value of each horizontal tomographic image (XY image) extracted from the data, plotted in the vertical direction (Z direction). As shown in Fig. 5A, the brightness variance increases closer to the center of the solder joint (in terms of image characteristics, the contrast between the solder part and other parts increases), so the center can be found with high accuracy by setting the position of the horizontal tomographic image with the maximum brightness variance value as the vertical position that specifies the center of the solder joint.

[0053] Furthermore, the image extraction unit 123 binarizes the horizontal tomographic image in which the brightness variance value specified as above is maximized, and sets the position of the center of the label of the binarized image as the horizontal position that specifies the "center". Fig. 6A is an explanatory diagram showing an example of a horizontal tomographic image and an image obtained by binarizing the same. The image extraction unit 123 calculates the position of the center of the label (white part) of the binarized image as shown on the right side of Fig. 6A by a desired publicly known technique, and sets this as the horizontal position that specifies the center of the solder joint, thereby reducing the processing load and quickly (efficiently) finding the center.

[0054] The inspection unit 125 performs pass / fail judgment using an inspection model for each of a plurality of longitudinal section images extracted from the three-dimensional data of each component mounting board to be inspected, the longitudinal section images having different observation directions and including a common point on the three-dimensional data. The inspection model is stored in the storage unit 126 or the data server 13.

[0055] Here, the multiple longitudinal section images having different observation directions and including a common point on the three-dimensional data can be extracted, for example, as follows. Fig. 7A and Fig. 7B are explanatory diagrams for explaining multiple longitudinal section images for which the inspection unit 125 performs pass / fail judgment. Fig. 7A is a horizontal tomographic image including the solder joint (indicated by T in Fig. 7A) to be inspected. The image extraction unit 123 determines a central point in the three-dimensional shape data of the solder joint T by the above-mentioned method, and determines four longitudinal sections including the point, for example, shifted in phase by 45°, as shown in Fig. 7A. Then, longitudinal section images of the four sections as shown in Fig. 7B are extracted.

[0056] The inspection unit 125 performs a judgment based on the inspection model for each of the four vertical cross-sectional images thus obtained (specifically, calculates a score related to the quality and judges whether it falls below a predetermined score). If the score of any one of the four vertical cross-sectional images does not satisfy the standard, the corresponding solder joint is judged to be defective.

[0057] According to the X-ray inspection system 1 of the present embodiment described above, it is possible to perform pass / fail judgment by using AI (inspection model) using a longitudinal section image (i.e., two-dimensional data) including a central portion identified from three-dimensional data by a known image processing method, instead of three-dimensional data. That is, there is no need to set complicated inspection standards, and it is possible to perform pass / fail judgment with high accuracy and high speed by using AI that has performed machine learning using images similar to those used during inspection.

[0058] (Variation 1) In the above embodiment, an example of a method in which the image extraction unit 123 identifies the position that is the center of the solder joint that is the inspection target portion is shown, but the vertical and horizontal positions that are the "center" of the solder joint can be identified in various ways other than the above example.

[0059] Specifically, the image extraction unit 123 may plot the brightness variance value of the horizontal tomographic image acquired from the three-dimensional data in the vertical direction, and the position of the fault that is the center of the multiple faults where the brightness variance value exceeds a predetermined threshold value may be set as the vertical position that specifies the central portion. FIG. 5B is a graph in which the vertical position of the horizontal tomographic image that can be extracted from the three-dimensional data of the solder joint is plotted on the horizontal axis, and the feature amount (here, brightness variance) of each fault is plotted vertically. In FIG. 5B, the dashed line indicates the predetermined threshold value, and the point plotted with a black circle in the figure indicates the (vertical) position of the horizontal fault that is the center of the multiple faults where the brightness variance value exceeds the predetermined threshold value. That is, in this modification, the image extraction unit 123 determines the position of the horizontal tomographic image located at the point plotted with the black circle in FIG. 5B as the vertical position that specifies the central portion. The point plotted with a black square in FIG. 5B indicates the position of the horizontal tomographic image where the feature amount is maximum.

[0060] (Variation 2) The image extraction unit 123 may also plot the edge strength of the horizontal tomographic image acquired from the three-dimensional data in the vertical direction, and determine the position of the tomographic image at which the edge strength is maximum as the vertical position that identifies the center. Fig. 6B is a diagram showing a horizontal tomographic image extracted from the three-dimensional data and an edge image obtained by performing image processing on the horizontal tomographic image. The image extraction unit 123 according to this modification calculates the edge strength of each horizontal tomographic image extracted from the three-dimensional data from an edge image such as that shown on the right side of Fig. 6B, and determines the position of the horizontal tomographic image at which the strength is maximum as the vertical position that identifies the center.

[0061] (Variation 3) Furthermore, the image extraction unit 123 may plot the edge strength of the horizontal tomographic image acquired from the three-dimensional data in the vertical direction, and determine the position of the fault that is the center of the multiple faults where the edge strength exceeds a predetermined threshold as the vertical position that specifies the center. When the feature amount in the graph of Fig. 5B is the edge strength, the "brightness variance value" described in the first modification can be understood as "edge strength".

[0062] (Variation 4) Furthermore, when the image extraction unit 123 specifies the vertical position that specifies the center based on the brightness variance value of the horizontal tomographic image, the position of the center calculated by weighting the horizontal tomographic image with the maximum brightness variance value by brightness may be set as the horizontal position that specifies the center. Note that any known technology may be used as a method for calculating the position of the center of the horizontal tomographic image.

[0063] (Variation 5) In addition, when the image extraction unit 123 identifies the vertical position that identifies the center based on the brightness variance value of the horizontal tomographic image, the image extraction unit 123 may determine the center position of the label of the binarized image of the horizontal tomographic image that is the center of multiple horizontal tomographic slices whose brightness variance value exceeds a predetermined threshold value as the horizontal position that identifies the center.

[0064] (Variation 6) In addition, when the image extraction unit 123 identifies the vertical position that identifies the center based on the brightness variance value of the horizontal tomographic image, the image extraction unit 123 may determine the horizontal position that identifies the center as the center position, which is calculated by weighting the horizontal tomographic image that is the center of multiple horizontal tomographic slices whose brightness variance value exceeds a predetermined threshold value by brightness.

[0065] (Variation 7) In addition, when the image extraction unit 123 identifies the vertical position that identifies the center based on the edge strength of the horizontal tomographic image, the image extraction unit 123 may determine the center position of the label of the image obtained by binarizing the horizontal tomographic image in which the edge strength is maximum as the horizontal position that identifies the center.

[0066] (Variation 8) In addition, when the image extraction unit 123 identifies the vertical position that identifies the center based on the edge strength of the horizontal tomographic image, the image extraction unit 123 may determine the horizontal position that identifies the center as the center of gravity position calculated by weighting the horizontal tomographic image with the maximum edge strength by brightness.

[0067] (Variation 9) In addition, when the image extraction unit 123 identifies the vertical position that identifies the center based on the edge strength of the horizontal tomographic image, the image extraction unit 123 may determine the horizontal position that identifies the center to be the center position of the label of the binarized image of the horizontal tomographic image that is the center of multiple horizontal tomographic slices whose edge strength exceeds a predetermined threshold.

[0068] (Variation 10) In addition, when the image extraction unit 123 identifies the vertical position that identifies the center based on the edge strength of the horizontal tomographic image, the image extraction unit 123 may determine the horizontal position that identifies the center as the center position, which is calculated by weighting the horizontal tomographic image that is the center of multiple horizontal tomographic slices whose edge strength exceeds a predetermined threshold value by brightness.

[0069] (Variation 11) In addition, the image extraction unit 123 binarizes the images obtained by performing maximum intensity projection in the vertical direction on each horizontal tomographic image of the region including a predetermined range of the solder joint in the three-dimensional data. The position of the center of the label on the image may be taken as the horizontal position that identifies the center.

[0070] (Variation 12) In addition, the image extraction unit 123 may determine, as the horizontal position that identifies the center, the position of the center of gravity calculated by weighting, by brightness, the image obtained by maximum intensity projection in the vertical direction of each horizontal tomographic image of an area that includes a predetermined horizontal range of the solder joint in the three-dimensional data.

[0071] (Variation 13) In addition, the image extraction unit 123 may determine the position of the center of the label of an image obtained by vertically averaging each horizontal tomographic image of an area that includes a predetermined horizontal range of the solder joint as the horizontal position that identifies the center.

[0072] (Variation 14) In addition, the image extraction unit 123 may determine the position of the center of gravity, which is calculated by weighting the image obtained by vertically projecting the average value of each horizontal tomographic image of an area that includes a predetermined horizontal range of the solder joint, by brightness, as the horizontal position that identifies the center.

[0073] According to each of the above-mentioned modified examples, it is possible to extract longitudinal section images for generating an inspection model and for an inspection target while suppressing the processing load on the processor. In addition, since the inspection is performed using longitudinal section images (two-dimensional data) passing through the center of the solder joint, it is possible to perform a high-speed and high-precision inspection even in the case of an inspection of a component mounting board on which components such as BGAs having solder bumps formed on the bottom surface of the package are mounted.

[0074] <Other> The above examples merely exemplify the present invention, and the present invention is not limited to the above specific embodiments. Various modifications and combinations of the present invention are possible within the scope of the technical concept. For example, in the above X-ray inspection system 1, the data server 13 is not an essential component, and the data stored in the data server 13 may be saved in the inspection terminal 12 and / or the X-ray imaging device 11.

[0075] In the above embodiment, the X-ray inspection system 1 is described as including the X-ray imaging device 11 and the inspection terminal 12, but each function of the inspection terminal 12 may be incorporated in the X-ray imaging device 11. That is, the present invention can also be applied to an X-ray inspection device in which the terminal 100 of the X-ray imaging device 11 also functions as the inspection terminal 12.

[0076] Also, the pass / fail judgment of the inspection unit 125 can be set in various ways. For example, instead of judging that even one image among the multiple longitudinal section images does not satisfy the standard as a failure, images with scores not satisfying the standard exceeding a predetermined ratio may be judged as failure. Also, regarding the multiple longitudinal section images used by the inspection unit 125 for inspection, although an example in which the image extraction unit 123 extracts four longitudinal section images has been described in the above embodiment, this is not limited thereto. The image extraction unit 123 may extract two, three, or five or more longitudinal section images, and the inspection unit 125 may perform inspection based on them.

[0077] <Appendix 1> An inspection system (1) for inspecting a component mounting board on which an electronic component having solder bumps is mounted, comprising: a three-dimensional data generating means (122) for generating three-dimensional data of an area including at least the solder joints formed by the solder bumps using a plurality of X-ray images of the component mounting board; a longitudinal section image extraction means (123) for extracting, from the three-dimensional data, a longitudinal section image showing a longitudinal section passing through a center of the solder joint; an inspection model generating means (124) for generating an inspection model for the inspection using the plurality of longitudinal cross-sectional images; an inspection means (125) for performing an inspection using the inspection model by using a plurality of the longitudinal section images having different observation directions extracted from the three-dimensional data of each of the component mounting boards to be inspected; An inspection system comprising:

[0078] <Appendix 2> The longitudinal section images used for learning of the inspection model generating means include a plurality of the longitudinal section images having different observation directions for each of the three-dimensional data. 2. An inspection system as described in claim 1.

[0079] <Appendix 3> The longitudinal section image extraction means A brightness variance value of a horizontal tomographic image obtained from the three-dimensional data is plotted in a vertical direction, and the position of the tomographic layer at which the brightness variance value is maximum is determined as a vertical position that identifies the central portion. 2. An inspection system as described in claim 1.

[0080] <Appendix 4> The longitudinal section image extraction means A brightness variance value of a horizontal tomographic image obtained from the three-dimensional data is plotted in a vertical direction, and a position of a fault that is a center of a plurality of faults in which the brightness variance value exceeds a predetermined threshold value is determined as a vertical position that identifies the center portion. 2. An inspection system as described in claim 1.

[0081] <Appendix 5> The longitudinal section image extraction means An edge intensity of a horizontal tomographic image obtained from the three-dimensional data is plotted in a vertical direction, and a position of the tomographic image at which the edge intensity is maximum is determined as a vertical position that specifies the center portion. 2. An inspection system as described in claim 1.

[0082] <Appendix 6> The longitudinal section image extraction means Plotting edge intensities of horizontal tomographic images obtained from the three-dimensional data in a vertical direction, and determining a position of a fault that is a center of a plurality of faults where the edge intensity exceeds a predetermined threshold as a vertical position that identifies the center portion. 2. An inspection system as described in claim 1.

[0083] <Appendix 7> The longitudinal section image extraction means The center of the label of the binarized image of the horizontal tomographic image having the maximum brightness variance value, or the position of the center of gravity calculated by weighting the horizontal tomographic image having the maximum brightness variance value by brightness, is set as the horizontal position that specifies the central portion. 4. An inspection system as described in claim 3.

[0084] <Appendix 8> The longitudinal section image output means includes: The position of the center of the label of the image obtained by binarizing the horizontal tomographic image at the center of the horizontal tomographic layers having the brightness variance value exceeding a predetermined threshold value, or the position of the center of gravity calculated by weighting the horizontal tomographic image at the center of the horizontal tomographic layers having the brightness variance value exceeding a predetermined threshold value by brightness, is determined by the center the horizontal position of the part to be identified, 5. An inspection system as described in claim 4.

[0085] <Appendix 9> The longitudinal section image extraction means The position of the center of the label of the binarized image of the horizontal tomographic image with the maximum edge strength, or the position of the center of gravity calculated by weighting the horizontal tomographic image with the maximum edge strength by brightness, is set as the horizontal position that specifies the central portion. 6. An inspection system as described in claim 5.

[0086] <Appendix 10> The longitudinal section image output means includes: The horizontal position that specifies the central portion is determined as a center of a label of a binarized image of a horizontal tomographic image at the center of a plurality of horizontal tomographic sections where the edge strength exceeds a predetermined threshold, or a center of gravity calculated by weighting the horizontal tomographic image at the center of a plurality of horizontal tomographic sections where the edge strength exceeds a predetermined threshold by brightness. 7. An inspection system as described in claim 6.

[0087] <Appendix 11> The longitudinal section image extraction means In the three-dimensional data, the position of the center of the label of an image obtained by performing maximum intensity projection in the vertical direction on each horizontal tomographic image of an area including a predetermined range in the horizontal direction of the solder joint, or the position of the center of gravity calculated by weighting the image obtained by performing maximum intensity projection by brightness, is set as the horizontal position that specifies the center. 7. An inspection system according to any one of claims 1 to 6,

[0088] <Appendix 12> The longitudinal section image extraction means In the three-dimensional data, the position of the center of the label of an image obtained by vertically averaging each horizontal tomographic image of an area including a predetermined range of the solder joint in the horizontal direction, or the position of the center of gravity calculated by weighting the image obtained by the average projection by brightness, is set as the horizontal position that specifies the center. 7. An inspection system according to any one of claims 1 to 6,

[0089] <Appendix 13> An inspection apparatus for inspecting a component mounting board on which an electronic component having solder bumps is mounted, comprising: an inspection model for the inspection that is generated using a longitudinal section image showing a longitudinal section passing through a center of the solder joint, the longitudinal section image being extracted from three-dimensional data of an area including at least the solder joint formed by the solder bump, the longitudinal section image being generated using a plurality of X-ray images of the component mounting board; A plurality of the longitudinal cross-sectional images extracted from the three-dimensional data of the component mounting board to be inspected and observed in different directions; The inspection is carried out by An inspection device comprising:

[0090] <Appendix 14> 1. A method for inspecting a component mounting board on which an electronic component having solder bumps is mounted, comprising: A three-dimensional data generating step (S102) of generating three-dimensional data of an area including at least the solder joints formed by the solder bumps using a plurality of X-ray images of the component mounting board. )and, a longitudinal section image extraction step (S103) of extracting, from the three-dimensional data, a longitudinal section image showing a longitudinal section passing through a center of the solder joint; an inspection model generation step (S104) of generating an inspection model for the inspection using the plurality of longitudinal cross-sectional images; an inspection step (S105) of performing an inspection using the inspection model by using a plurality of the vertical cross-sectional images having different observation directions extracted from the three-dimensional data of the component mounting board to be inspected; The inspection method includes:

[0091] <Appendix 15> A program for causing a computer to execute each step of the inspection method described in Appendix 14. [Explanation of symbols]

[0092] 1. X-ray inspection system 10...X-ray source 11. X-ray equipment 12. Inspection terminal 13. Data Server 20. X-ray camera 30. Work Stage 100... Terminal 110... Control unit C1, C2...Turning trajectory O...center point P···Pad W... Work

Claims

1. An inspection system for inspecting a component mounting board on which an electronic component having solder bumps is mounted, comprising: a three-dimensional data generating means for generating three-dimensional data of an area including at least the solder joints formed by the solder bumps using a plurality of X-ray images of the component mounting board; a longitudinal section image extraction means for extracting, from the three-dimensional data, a longitudinal section image showing a longitudinal section passing through a center of the solder joint; an inspection model generating means for generating an inspection model for the inspection using a plurality of the longitudinal cross-sectional images; an inspection means for performing an inspection using the inspection model by using a plurality of the longitudinal section images having different observation directions extracted from the three-dimensional data of each of the component mounting boards to be inspected; An inspection system comprising:

2. The longitudinal section images used for learning of the inspection model generating means include a plurality of the longitudinal section images having different observation directions for each of the three-dimensional data.

2. The inspection system according to claim 1 .

3. The longitudinal section image extraction means A brightness variance value of a horizontal tomographic image obtained from the three-dimensional data is plotted in a vertical direction, and the position of the tomographic slice at which the brightness variance value is maximum is determined as a vertical position that identifies the central portion.

2. The inspection system according to claim 1 .

4. The longitudinal section image extraction means A brightness variance value of a horizontal tomographic image obtained from the three-dimensional data is plotted in a vertical direction, and a position of a fault that is a center of a plurality of faults in which the brightness variance value exceeds a predetermined threshold value is determined as a vertical position that identifies the center portion.

2. The inspection system according to claim 1 .

5. The longitudinal section image extraction means An edge intensity of a horizontal tomographic image obtained from the three-dimensional data is plotted in a vertical direction, and a position of the tomographic image at which the edge intensity is maximum is determined as a vertical position that specifies the center portion.

2. The inspection system according to claim 1 .

6. The longitudinal section image extraction means Plotting edge intensities of horizontal tomographic images obtained from the three-dimensional data in a vertical direction, and determining a position of a tomographic slice at the center of a plurality of tomographic slices where the edge intensity exceeds a predetermined threshold as a vertical position that identifies the center portion.

2. The inspection system according to claim 1 .

7. The longitudinal section image extraction means The center of the label of the binarized image of the horizontal tomographic image having the maximum brightness variance value, or the position of the center of gravity calculated by weighting the horizontal tomographic image having the maximum brightness variance value by brightness, is set as the horizontal position that specifies the central portion.

4. The inspection system according to claim 3 .

8. The longitudinal section image output means includes: The position of the center of the label of the image obtained by binarizing the horizontal tomographic image at the center of the horizontal tomographic layers having the brightness variance value exceeding a predetermined threshold value, or the position of the center of gravity calculated by weighting the horizontal tomographic image at the center of the horizontal tomographic layers having the brightness variance value exceeding a predetermined threshold value by brightness, is determined by the center the horizontal position of the part to be identified, 5. The inspection system according to claim 4.

9. The longitudinal section image extraction means The position of the center of the label of the binarized image of the horizontal tomographic image with the maximum edge strength, or the position of the center of gravity calculated by weighting the horizontal tomographic image with the maximum edge strength by brightness, is set as the horizontal position that specifies the central portion.

6. The inspection system according to claim 5 .

10. The longitudinal section image output means includes: The horizontal position that specifies the central portion is determined as a center of a label of a binarized image of a horizontal tomographic image at the center of a plurality of horizontal tomographic sections where the edge strength exceeds a predetermined threshold, or a center of gravity calculated by weighting the horizontal tomographic image at the center of a plurality of horizontal tomographic sections where the edge strength exceeds a predetermined threshold by brightness.

7. The inspection system according to claim 6,

11. The longitudinal section image extraction means In the three-dimensional data, the position of the center of the label of an image obtained by performing maximum intensity projection in the vertical direction on each horizontal tomographic image of an area including a predetermined range in the horizontal direction of the solder joint, or the position of the center of gravity calculated by weighting the image obtained by performing maximum intensity projection by brightness, is set as the horizontal position that specifies the center. An inspection system according to any one of claims 1 to 6, characterized in that

12. The longitudinal section image extraction means In the three-dimensional data, the position of the center of the label of an image obtained by vertically averaging each horizontal tomographic image of an area including a predetermined range of the solder joint in the horizontal direction, or the position of the center of gravity calculated by weighting the image obtained by the average projection by brightness, is set as the horizontal position that specifies the center. An inspection system according to any one of claims 1 to 6, characterized in that

13. An inspection apparatus for inspecting a component mounting board on which an electronic component having solder bumps is mounted, comprising: an inspection model for the inspection that is generated using a longitudinal section image showing a longitudinal section passing through a center of the solder joint, the longitudinal section image being extracted from three-dimensional data of an area including at least the solder joint formed by the solder bump, the longitudinal section image being generated using a plurality of X-ray images of the component mounting board; A plurality of the longitudinal cross-sectional images extracted from the three-dimensional data of the component mounting board to be inspected and observed in different directions; The inspection is carried out by An inspection device comprising:

14. 1. A method for inspecting a component mounting board on which an electronic component having solder bumps is mounted, comprising: a three-dimensional data generating step of generating three-dimensional data of an area including at least a solder joint formed by the solder bumps using a plurality of X-ray images of the component mounting board; a longitudinal section image extraction step of extracting, from the three-dimensional data, a longitudinal section image showing a longitudinal section passing through a center of the solder joint; an inspection model generating step of generating an inspection model for the inspection using the plurality of longitudinal cross-sectional images; an inspection step of performing an inspection using the inspection model by using a plurality of the longitudinal section images having different observation directions extracted from the three-dimensional data of the component mounting board to be inspected; The inspection method includes:

15. A program for causing a computer to execute each step of the inspection method according to claim 14.

Images