X-ray inspection device and X-ray inspection method

Abstract

To provide a technique that can reduce the inspection time for an object to be inspected in an X-ray inspection device.SOLUTION: An X-ray inspection device (1, 11) comprises: an X-ray source (10); an X-ray camera (20); and a holding unit (40) that holds an object to be inspected. The X-ray inspection device acquires and inspects a three-dimensional image of the object to be inspected with any one of the X-ray source, the X-ray camera, and the holding unit making a revolving motion as a revolving unit. The revolving unit sequentially makes the revolving motion at a plurality of places, and from a revolution end point of one revolving motion to a revolution start point of the next revolving motion, moves along a specific movement locus being a locus smoothly connecting revolving circles at the revolution end point and the revolution start point. The revolution start point of the next revolving motion is calculated, from among a plurality of candidate points set to be arranged on the revolving circle of the next revolving motion, as a point in which the revolving unit can move along the specific movement locus from the revolving circle of one revolving motion to the revolving circle of the next revolving motion in the shortest moving time.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an X-ray inspection apparatus that obtains a plurality of X-ray images of an object to be inspected and creates three-dimensional data. [Background technology]

[0002] Conventionally, there has been a technology that takes X-ray images of an object to be inspected, such as the surface of a circuit board, from multiple directions, creates 3D data from the multiple X-ray images, and inspects the internal structure of the inspection point. Examples of this technology include tomosynthesis and CT. In this technology, X-rays are irradiated from an X-ray source to the inspection point of the object to be inspected, and the transmitted X-rays are photographed by an X-ray camera. Then, multiple X-ray images are taken while changing the relative positions of the X-ray source, the object to be inspected, and the X-ray camera.

[0003] At that time, at least one of the X-ray source, the object to be inspected, and the X-ray camera is rotated to change the relative positions of each other, and when one rotation is completed and the image of the inspection point is completed, a movement is made to an image taking position for the next inspection point, and a rotation is made again. Therefore, in order to shorten the inspection time of the object to be inspected, it is necessary to efficiently perform the above-mentioned rotation and movement. Here, the rotation refers to a movement of turning in a circle at a constant speed, and does not include an acceleration run-up movement before the circular turn, or a deceleration braking movement after the circular turn. On the other hand, the movement refers to a movement from a turning circle to the next turning circle. For example, the movement distance related to the movement is the movement distance between the turning circles.

[0004] In response to this problem, a technique is known that finds an imaging path that shortens the time required to capture a plurality of radiographic images based on imaging conditions for capturing radiographic images by solving a combination / optimization problem of individual processing times (e.g., the time required for the radiation irradiated by the radiation generator to stabilize, the time required to move the radiation generator, the time required to translate the substrate holding part on the plane defined by the substrate rotation orbit, the time required by the detector driving part to move the detector and the substrate holding part in conjunction with the detector, etc.) (see, for example, Patent Document 1).

[0005] However, in conventional techniques, the optimization of the movement trajectories and movement times when moving the X-ray source, the object to be inspected, and the X-ray camera has not been fully considered. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2011-209054 A [Patent Document 2] JP 2013-247228 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of the above problems, and has an object to provide a technique capable of shortening the inspection time of an object to be inspected in an X-ray inspection apparatus. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides an X-ray source for generating X-rays to be irradiated onto an object to be inspected, an X-ray camera that captures an X-ray image of the inspection object using X-rays irradiated from the X-ray source; A holding unit that holds the test object, An X-ray inspection device in which any one of the X-ray source, the X-ray camera, and the holding unit rotates as a rotating unit to capture the X-ray images while changing the shooting direction, thereby obtaining and inspecting a 3D image of the inspection object, the rotating unit performs a sequential rotating motion at a plurality of locations and a moving motion for moving from a rotating end point of one rotating motion to a rotating start point of a next rotating motion; When the rotating unit moves from a rotation end point of one rotation motion to a rotation start point of a next rotation motion, any one of the rotating unit, the X-ray source, the X-ray camera, and the holding unit, moves along a specific movement trajectory that is a trajectory connecting a rotation circle of the one rotation motion and a rotation circle of the next rotation motion at the rotation end point and the rotation start point; a trajectory calculation unit that calculates the turning start point and the specific movement trajectory in the turning motion, This X-ray inspection device is characterized in that the starting point of the next rotational movement is calculated by the trajectory calculation unit as a point to which any of the rotation parts, that is, the X-ray source, the X-ray camera, and the holding part, can move from the rotation circle of the one rotational movement to the rotation circle of the next rotational movement in the shortest movement time along the specific movement trajectory.

[0009] According to this, when the rotating part moves from the end point of one rotational motion to the start point of the next rotational motion, the start point of the rotation to which the rotating part can move in the shortest moving time can be selected from among a plurality of candidate points arranged on the rotation circle of the next rotational motion. As a result, the rotating part can more reliably move from the end point of one rotational motion to the start point of the next rotational motion. As a result, the inspection time of the object to be inspected in the X-ray inspection device can be more reliably shortened. Here, the rotating part (the radiation source, the camera, and the holding part that perform the rotating motion) is controlled to arrive at the start point of the next rotational motion simultaneously during the moving motion. The shortest moving time in the above case is, for example, the time candidate of the moving time at which the radiation source and the camera, which are the rotating part, arrive at the start point of the next rotational motion simultaneously is calculated for each candidate point, and the shortest moving time among the calculated time candidates is selected.

[0010] In the present invention, the plurality of candidate points may be set for both cases where any of the X-ray source, the X-ray camera, and the holding unit, which are the rotating unit, rotates the rotation circle of the next rotation motion clockwise and counterclockwise. This makes it possible to select candidates for the rotation start point of the next rotation motion from a wider range, and increases the possibility of selecting a rotation start point that allows the rotation unit to move from the rotation end point of one rotation motion to the rotation start point of the next rotation motion in a shorter time.

[0011] In the present invention, the trajectory calculation unit may include a plurality of arithmetic units, and the movement times for the plurality of candidate points may be calculated in parallel using the plurality of arithmetic units. In this way, the movement times of the turning unit for the plurality of candidate points can be calculated in parallel using the plurality of arithmetic units, and it becomes possible to determine the turning start point of the next turning motion more quickly. Note that the term "multiple arithmetic units" as used herein includes not only a case where there are a plurality of independent arithmetic units, but also a case where multiple arithmetic functions are used within a single arithmetic unit.

[0012] Furthermore, in the present invention, the rotating unit may be configured so that there is no stopping section during the rotating motion and the moving motion. Here, in the conventional technology, when transitioning from a rotating motion to a moving motion or from a moving motion to a rotating motion, the rotating unit had to stop once. In addition, a run-up distance and a braking distance were required for accelerating and decelerating motion during the rotating motion. In contrast, in the present invention, the rotating unit is configured so that there is no stopping section during the rotating motion and the moving motion, so that the rotating unit does not need to perform accelerating or decelerating motion for stopping between the rotating motion and the moving motion. As a result, there is no need to perform additional rotating motion for accelerating and decelerating before and after the rotating motion for taking an X-ray image. Therefore, the total movement time of the multiple rotational movements and the moving movements can be reduced, and the inspection time can be shortened.

[0013] Also, in the present invention, the specific movement trajectory may be a trajectory in which the linear velocity of the turning part is continuous at the turning end point and / or the turning start point. Also, in the present invention, the specific movement trajectory may be a trajectory in which the linear velocity and acceleration of the turning part are continuous at the turning end point and / or the turning start point, or the linear velocity, acceleration and jerk of the turning part are continuous at the turning end point and / or the turning start point. In this case, the acceleration of the turning part may be 0 at the turning end point and / or the turning start point.

[0014] That is, in the specific movement trajectory of the present invention, it is required that the linear velocity of the turning part is continuous at the turning end point and / or turning start point. And it is desirable that the linear velocity and acceleration are continuous. Also, it is ideal that the linear velocity, acceleration and jerk are continuous. And, when the acceleration is continuous, it is ideal that the acceleration is 0.

[0015] This makes it possible to reduce the acceleration and impact acting on the rotating part when transitioning from a rotating motion to a moving motion, or from a moving motion to a rotating motion. As a result, it becomes possible to further shorten the inspection time. As mentioned above, the rotating motion refers to a motion that turns in a circle at a constant speed, and does not include an accelerating run-up motion before a circular turn, or a decelerating braking motion after a circular turn. On the other hand, a moving motion refers to a motion that moves from a turning circle to the next turning circle.

[0016] In addition, in the present invention, the specific movement trajectory may be defined by a polynomial. Alternatively, the specific movement trajectory may be calculated by using a parameter for a trigonometric function. In this way, the specific movement trajectory can be obtained by a general mathematical solution. Note that the specific movement trajectory may be defined by other mathematical expressions and is not particularly limited.

[0017] Furthermore, in the present invention, the rotation unit may be any two of the X-ray source, the X-ray camera, and the holding unit, and the specific movement trajectory may be a trajectory that connects the rotation circle of one rotation motion and the rotation circle of the next rotation motion of any two of the X-ray source, the X-ray camera, and the holding unit that performs a rotation motion with a larger radius, at the rotation end point and the rotation start point.

[0018] Here, when the rotating part is any two of the X-ray source, the X-ray camera, and the holding part, the rotation circle of the rotation movement of one of the rotating parts is often different from the rotation circle of the other rotating part in order to obtain a three-dimensional image of the inspection area. In the present invention, the specific movement trajectory of the rotating part that performs a larger radius rotation of any two of the X-ray source, the X-ray camera, and the holding part is defined as a trajectory that smoothly connects the rotation circle of one rotation movement and the rotation circle of the next rotation movement at the rotation end point and the rotation start point. According to the inventors' intensive research, it was found that by doing so, the total time of multiple rotation movements and movement movements can be reduced. Therefore, this makes it possible to more reliably shorten the inspection time.

[0019] Furthermore, in the present invention, of any two of the X-ray source, the X-ray camera, and the holding unit, one that performs a rotational motion with a smaller radius may reach the starting point of the next rotational motion at the same time as any two of the X-ray source, the X-ray camera, and the holding unit, one that performs a rotational motion with a larger radius.

[0020] In this case, the X-ray source, the X-ray camera, and the holding unit may be rotated with a smaller radius among any two of the X-ray source, the X-ray camera, and the holding unit. In this case, the turning unit can be caused to reach the turning start point of the next turning motion at the same time as the turning unit that performs the turning motion with the larger radius. As a result, the turning unit can start the next turning motion earlier.

[0021] In addition, in the present invention, the specific movement trajectory may be determined within a range in which the linear velocity, axial velocity, or acceleration of any of the rotating parts, that is, the X-ray source, the X-ray camera, and the holding part, does not exceed a predetermined allowable value (allowable velocity or allowable acceleration). In this way, when the rotating part moves along the specific movement trajectory, it is possible to prevent the speed and acceleration of the X-ray source, the X-ray camera, the holding part, etc. from becoming excessive, thereby preventing device failure and improving reliability.

[0022] In addition, in the present invention, the specific movement trajectory may be determined so that the movement range of any of the X-ray source, the X-ray camera, and the holding unit, which are the rotating unit, does not exceed a predetermined allowable movement range. Alternatively, the movement time of the rotating unit on the specific movement trajectory may be determined so that the movement range of any of the X-ray source, the X-ray camera, and the holding unit, which are the rotating unit, does not exceed a predetermined allowable movement range. This makes it possible to prevent inconveniences such as the X-ray source, the X-ray camera, the holding unit, etc. colliding with structures in the device when the rotating unit moves along the specific movement trajectory, or errors occurring due to exceeding a limit range determined by software, thereby improving reliability.

[0023] In the present invention, the rotating part may be the X-ray source and the X-ray camera, and the holding part may be held at a predetermined position in the X-ray inspection device. In this case, the inspection object can be fixed and the X-ray camera and the X-ray source can be rotated and moved above and below the inspection object to perform the inspection, which makes it possible to simplify the moving mechanism, the carrying-in mechanism, etc. of the object to be inspected in the X-ray inspection device.

[0024] The present invention also provides an X-ray source for generating X-rays to be irradiated onto an object to be inspected; an X-ray camera that captures an X-ray image of the inspection object using X-rays irradiated from the X-ray source; A holding unit that holds the test object, An X-ray inspection method using an X-ray inspection device, in which any one of the X-ray source, the X-ray camera, and the holding unit rotates as a rotating unit to capture the X-ray images while changing the shooting direction, thereby obtaining and inspecting a 3D image of the inspection object, The rotating part is rotated in a succession of positions, and a moving motion is performed to move from a rotation end point of one rotation motion to a rotation start point of a next rotation motion; When the rotating unit moves from a rotation end point of one rotation motion to a rotation start point of a next rotation motion, any one of the rotating unit, the X-ray source, the X-ray camera, and the holding unit, moves along a specific movement trajectory that is a trajectory that connects a rotation circle of the one rotation motion and a rotation circle of the next rotation motion at the rotation end point and the rotation start point; The X-ray inspection method may be characterized in that the starting point of the next rotational movement is determined as a point to which any one of the rotation parts, that is the X-ray source, the X-ray camera, and the holding part, can move from the rotational circle of the one rotational movement to the rotational circle of the next rotational movement in the shortest moving time along the specific movement trajectory, among a plurality of candidate points set to be positioned on the rotational circle of the next rotational movement.

[0025] The present invention may also be an X-ray inspection method as described above, further characterized in that any one of the rotating parts, that is, the X-ray source, the X-ray camera, and the holding part, is moved from the rotating motion to the moving motion without being stopped.

[0026] In addition, at that time, the rotating part moves from the end point of one rotational motion to the end point of the next rotational motion. When moving to a start point, any one of the rotating parts, that is, the X-ray source, the X-ray camera, and the holding part, is moved along a specific movement trajectory that is a trajectory connecting a rotation circle of the first rotation motion and a rotation circle of the next rotation motion at the rotation end point and the rotation start point; The specific movement trajectory may be a trajectory in which the linear velocity of the turning part is continuous at the turning end point and / or the turning start point.

[0027] In addition, in this case, the specific movement trajectory may be a trajectory in which the linear velocity and acceleration of the turning part are continuous at the turning end point and / or the turning start point, or the linear velocity, acceleration and jerk of the turning part are continuous at the turning end point and / or the turning start point. In addition, when the acceleration is continuous at the turning end point and / or the turning start point, the acceleration may be set to 0.

[0028] In this case, the specific movement trajectory may be defined by a polynomial.

[0029] The present invention may also be a program that causes a computer to calculate the specific movement trajectory and output a drive signal for moving any one of the rotating parts, the X-ray source, the X-ray camera, and the holding part, along the specific movement trajectory to the determined rotation start point.

[0030] As described above, the present invention can be understood as an X-ray inspection apparatus including at least some of the above-mentioned means. The present invention can also be understood as an X-ray inspection method including at least some of the processing performed by the above-mentioned means. The present invention can also be understood as a computer program for causing a computer to execute each step of these methods, or a computer-readable storage medium that non-temporarily stores the program. The above configurations and processing can be combined with each other to constitute the present invention as long as no technical contradiction occurs. Effect of the Invention

[0031] According to the present invention, it is possible to reduce the inspection time of an object not to be inspected in an X-ray inspection apparatus. [Brief description of the drawings]

[0032] [Figure 1] 1 is a diagram showing an overview of an X-ray inspection apparatus in an embodiment of the present invention. [Diagram 2]4A to 4C are diagrams illustrating the relationship between the rotational motion and translational motion of an X-ray source or an X-ray camera in an embodiment of the present invention. [Diagram 3] 4A to 4C are diagrams illustrating examples of trajectories of rotation and movement of an X-ray source or an X-ray camera in an embodiment of the present invention. [Figure 4] 11A to 11C are diagrams for explaining a method for determining a turning start point of the next turning motion in an embodiment of the present invention. [Diagram 5] 1A to 1C are diagrams illustrating examples of trajectories of rotation and translation of an X-ray source or an X-ray camera in the prior art. [Figure 6] 4A to 4C are diagrams illustrating examples of trajectories of rotation and movement of an X-ray source or an X-ray camera in an embodiment of the present invention. [Figure 7] 4 is a first half of a flowchart showing a movement control routine for an X-ray source and an X-ray camera in an embodiment of the present invention. [Figure 8] 11 is a second half of a flowchart showing a movement control routine for an X-ray source and an X-ray camera in the embodiment of the present invention. [Figure 9] 11A and 11B are diagrams for explaining a method for determining a turning start point of the next turning motion in the comparative example. [Figure 10] 11A to 11C are diagrams illustrating examples of trajectories of rotation and movement of an X-ray source or an X-ray camera in a comparative example. [Figure 11] FIG. 13 is a diagram showing a modified example of the X-ray inspection apparatus according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] [Application example] An outline of an application example of the present invention will be described below with reference to some of the drawings. The present invention is applied to an X-ray inspection device 1 as shown in FIG. 1. In the X-ray inspection device 1, an X-ray source 10 irradiates an inspection object S with X-rays, and an X-ray image based on the amount of transmission is taken by an X-ray camera 20. The X-ray source 10 and the X-ray camera 20 each perform a revolving motion on a revolving circle 121, 122, and take X-ray images of the inspection object S at multiple positions on the trajectory. Thereafter, in order to inspect another inspection point, both the X-ray source 10 and the X-ray camera 20 perform a moving motion to the next revolving circle, and take X-ray images while further revolving on the revolving circle.

[0034] Here, when the X-ray source 10 and the X-ray camera 20 transition from a rotational motion to a moving motion, a stop section where they temporarily stop is provided as shown in Fig. 2(a). Accordingly, an acceleration motion and a deceleration motion on a rotational circle are added before and after the rotational motion. In this application example, as shown in Fig. 2(b), the stop section when the X-ray source 10 and the X-ray camera 20 transition from a rotational motion to a moving motion is eliminated. This eliminates unnecessary stop states and unnecessary rotational motions, and enables the X-ray source 10 and the X-ray camera 20 to move more quickly from one rotational circle to the next.

[0035] In this application example, as shown in FIG. 3, the locus of movement when moving from the n-th turning circle 122n to the n+1-th turning circle 122n+1 is a locus that smoothly connects the n-th turning circle 122n and the n+1-th turning circle 122n+1 at the turning end point and turning start point, and allows movement in the shortest time. This allows the X-ray source 10 and the X-ray camera 20 to move more quickly without excessive acceleration or impact. Note that the above-mentioned locus that smoothly connects the turning end point and turning start point, and allows movement in the shortest time, must be within a range in which the linear velocity, axial velocity, acceleration, and moving range of the X-ray source 10 and / or the X-ray camera do not exceed the allowable values ​​(do not become over-limit), as described later. Furthermore, in this case, the turning start point in the n+1-th turning circle 122n+1 is determined by a method as shown in FIG. 4. More specifically, for example, m candidate points (m is a predetermined integer) are set on the n+1th turning circle 122n+1. At this time, it is assumed that the X-ray camera 20 turns clockwise and counterclockwise on the n+1th turning circle 122n+1. Then, for a total of 2m (twice m) candidate points for the clockwise and counterclockwise cases, the turning end point on the nth turning circle 122n and the n+1th turning circle 122n are set. A curve that smoothly connects the turning start point on the turning circle 122n+1 and can be traveled in the shortest time is obtained, and the travel time is calculated. The candidate point with the shortest travel time is then set as the turning start point on the n+1th turning circle 122n+1. This makes it possible to minimize the travel time between the turning end point on the nth turning circle 122n and the turning start point on the n+1th turning circle 122n+1, thereby shortening the inspection time.

[0036] The present invention is applicable to an X-ray inspection apparatus 1 in which an inspection object S is fixed and an X-ray source 10 and an X-ray camera 20 are rotated above and below the inspection object S, as shown in Fig. 1. Also, the present invention can be applied to an X-ray inspection apparatus 11 in which an X-ray source 10 is fixed and an X-ray camera 20 and an inspection object S are rotated, as shown in Fig. 11.

[0037] The following describes in detail the embodiments of the present invention with reference to the drawings (including the drawings already described in the above application examples). However, the specific configurations described in the embodiments are not intended to limit the scope of the present invention unless otherwise specified. Example 1

[0038] The X-ray inspection device according to the first embodiment of the present invention is a device for determining, for example, the quality of the soldered state of electronic components soldered to a printed circuit board, bumps of a ball grid array (BGA), etc. More specifically, the X-ray source and the object to be inspected are moved relatively to each other to perform X-ray photography multiple times, obtain the internal state of the inspection target location, generate a cross-sectional image at an appropriate position, and inspect the quality based on the cross-sectional image.

[0039] <Device configuration> FIG. 1 shows an arrangement of an X-ray source 10, a holder 40 for holding an object S to be inspected, and an X-ray camera 20 in an X-ray inspection apparatus 1 according to a first embodiment of the present invention. In the X-ray inspection apparatus 1, X-ray images are taken at multiple shooting positions for each inspection point on the object S to be inspected, which is transported by transport rollers (not shown) and held by the holder 40, to obtain three-dimensional data. Specifically, the X-ray source 10 irradiates the object S to be inspected with X-rays, and an X-ray image of the transmitted light is taken by the X-ray camera 20. Both the X-ray source 10 and the X-ray camera 20 are movable by a stage (not shown). The X-ray source 10 and the X-ray camera 20 are moved on rotation circles 121 and 122 by these stages, respectively, and photography is performed at multiple positions on the rotation circles.

[0040] Each part in the X-ray inspection apparatus 1 is controlled based on a control signal from a control unit 100. The X-ray inspection apparatus 1 includes a camera XY stage control unit 101, a camera control unit 102, and an XY stage control unit 107 for X-ray source as the control unit 100. In addition, the X-ray inspection apparatus 1 includes a height measurement unit 103, an inspection object position control unit 104, an X-ray source control unit 105, and an imaging height control unit 106. Furthermore, the X-ray inspection apparatus 1 includes a calculation unit 111, a main memory unit 112, an auxiliary memory unit 113, an input unit 114, and an output unit 115.

[0041] The camera XY stage control unit 101 drives the camera XY stage (not shown) and transmits a control signal for moving the X-ray camera 20 in the horizontal direction. The camera control unit 102 transmits a control signal for taking an X-ray image by the X-ray camera 20. The height measurement unit 103 receives a signal from the displacement meter 30 and measures the height of the inspection location of the inspection object S. The inspection target position control unit 104 transmits a control signal to the conveying rollers and the holder 40 for the inspection object S, and controls the horizontal and vertical positions of the inspection object S to optimal positions for imaging.

[0042] The X-ray source control unit 105 transmits signals for starting and ending irradiation of X-rays by the X-ray source 10 as well as for adjusting the X-ray intensity. The imaging height control unit 106 transmits signals for controlling the height of the X-ray source 10 and the X-ray camera 20. The X-ray source XY stage control unit 107 transmits signals for driving the X-ray source XY stage (not shown) and moving the X-ray source 10 in the horizontal direction. Signals output from the camera XY stage control unit 101, the camera control unit 102, the inspection object position control unit 104, the X-ray source control unit 105, the imaging height control unit 106, and the X-ray source XY stage control unit 107 are determined based on the calculation results of the calculation unit 111 and information stored in the main memory unit 112 and the auxiliary memory unit 113.

[0043] In particular, the imaging command unit 111a of the calculation unit 111 transmits information required for acquiring an X-ray image to each unit including the camera control unit 102. In addition, the trajectory calculation unit 111b calculates the trajectory that the X-ray source 10 and the X-ray camera 20 should follow, and selects the rotation start point of the rotational motion, by a method described later. In addition, the exchange of information such as setting information and examination results with the user is performed via the input unit 114 and the output unit 115.

[0044] 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 object to be inspected S. The X-ray camera 20 may be an II (Image Intensifier) ​​tube or In this case, a flat panel detector (FPD) can be used. Although camera 20 is employed, multiple x-ray cameras may be used.

[0045] The displacement meter 30 measures the distance to the object S to be inspected at a plurality of positions on the object S to be inspected. Therefore, the displacement meter 30 can measure the warpage and tilt of the object S to be inspected. In the manufacturing process of the object S to be inspected, warpage and tilt may occur, and the amount of warpage and tilt varies from object to object. Therefore, the warpage and tilt of each object S to be inspected are measured, and the height position of the holding part 40 is adjusted so that appropriate X-ray photography can be performed.

[0046] With the above configuration, the X-ray inspection device 1 can control the positions of the X-ray source 10 and the X-ray camera 20 so that the substrate can be imaged from various directions. In this embodiment, based on the results of imaging from various directions, three-dimensional data called CT (Computed Tomography) is generated. A three-dimensional data generation method is used to generate three-dimensional data of a test portion of the test object S.

[0047] The calculation unit 111 may be a general-purpose calculation device called a CPU (Central Processing Unit). The main storage unit 112 may be a memory such as a RAM. The auxiliary storage unit 113 may be a ROM or a HDD. The input unit 114 may be any device such as a keyboard, a button, a switch, or a mouse that allows a user to input instructions to the calculation unit 111. The output unit 115 may be any device such as a display or a speaker that allows the output from the calculation unit 111 to be presented to the user by video, audio, or the like. That is, these functions may be realized using a general computer system. The calculation unit 111 reads and executes a program stored in the auxiliary storage unit 113, thereby performing the movement control of the X-ray source 10 and the X-ray camera 20 as described below. The calculation unit 111 in this embodiment may perform parallel calculations and may include multiple CPUs, or may include multiple parallel calculation functions in one CPU.

[0048] Here, as shown in FIG. 1, the X-ray source 10 and the X-ray camera 20 move on the turning circles 121 and 122, respectively, based on control signals from the X-ray source XY stage control unit 107 and the camera XY stage control unit 101, and X-ray images are taken at multiple positions on the trajectory. Then, by turning on the turning circles 121 and 122 for each inspection point on the inspection object S, it is possible to create a 3D image of the inspection point. Then, when inspecting the inspection object S, since there are multiple inspection points, the X-ray source 10 and the X-ray camera 20 perform one 360-degree turning motion (also called the n-th turning motion) to obtain an X-ray image of the inspection point, and then move to a position where the next inspection point can be photographed. Then, from that position, the next 360-degree turning motion (also called the n+1-th turning motion) is started.

[0049] 2 shows the trajectory of the X-ray source 10 or the X-ray camera 20 when the X-ray source 10 or the X-ray camera 20 performs an n-th rotation, a moving motion, and an n+1-th rotation. In this case, according to the conventional technology, as shown in FIG. 2(a), an accelerated motion is performed before the n-th rotation, the n-th rotation is performed at a constant speed, and after the n-th rotation (360 degrees) is completed, a decelerated motion is performed and the camera stops. Then, a moving motion is performed along a predetermined trajectory. This is because, during the rotation of the X-ray source 10 or the X-ray camera 20, a uniform circular motion at high speed is required to capture high-quality X-ray images at high speed.

[0050] Similarly, after the X-ray source 10 or the X-ray camera 20 has stopped moving, the X-ray source 10 or the X-ray camera 20 accelerates again to a predetermined speed before reaching the starting point of the rotation, and then the (n+1)th rotation (360 degrees) is started. In other words, the X-ray source 10 or the X-ray camera 20 starts the nth rotation when the imaging in the nth rotation is completed. After that, the vehicle stops temporarily with a deceleration distance, and moves with acceleration and deceleration in preparation for the n+1th turn. The drone moves and stops after moving. After that, it moves along a circular orbit so that it can take n+1 shots. As described above, in the conventional control, the X-ray source 10 or the X-ray camera 20 needs to be stopped and rotated for acceleration and deceleration before and after the stop, which results in a long examination time.

[0051] In contrast, in this embodiment, as shown in FIG. 2(b), there is no stopping section during the movement from the nth rotation to the n+1th rotation, and other than the rotation for taking X-ray images, no rotation for acceleration or deceleration before and after stopping is performed.

[0052] In this embodiment, the locus of the moving motion is set to be the locus that can move in the shortest time among the loci that smoothly connect the turning circle of the nth turning motion and the turning circle of the n+1th turning motion at the turning end point and the turning start point. Here, the locus that smoothly connects the turning circle of the nth turning motion and the turning circle of the n+1th turning motion may be a locus that makes the linear velocity of the X-ray source 10 or the X-ray camera 20 continuous at the turning end point and / or the turning start point. Alternatively, it is preferable that the linear velocity and acceleration of the X-ray source 10 or the X-ray camera 20 are continuous at the turning end point and / or the turning start point. Alternatively, it is ideal that the linear velocity, acceleration and jerk of the X-ray source 10 or the X-ray camera 20 are continuous at the turning end point and / or the turning start point. Also, when the acceleration is continuous, it is ideal that the acceleration is 0.

[0053] FIG. 3 shows an example of the trajectory of the movement movement in this case. The arrows and the numbers in circles 1 to 3 in the figure correspond to the n-th rotation movement, the movement movement, and the n+1-th rotation movement, respectively. FIG. 3(a) shows an example of the trajectory of the movement movement of the X-ray camera 20. As shown in FIG. 3(a), the trajectory 123a of the movement movement of the X-ray camera 20 is the curve that can be moved in the shortest time among the curves that smoothly connect the rotation circle 122a of the n-th rotation movement and the rotation circle 122b of the n+1-th rotation movement at the highest point of both (hereinafter, this point is also referred to as the 0 degree position or the 360 ​​degree position).

[0054] Similarly, FIG. 3(b) shows an example of the trajectory of the movement of the X-ray source 10. As shown in FIG. 3(b), the trajectory 123b of the movement of the X-ray source 10 smoothly connects the turning circle 121a of the n-th turning motion and the turning circle 121b of the n+1-th turning motion at the lowest point of both (hereinafter, this point is also referred to as the 180-degree position), and is a curve that can be moved in the shortest time. Here, the places where the trajectory of the movement motion and the turning circles of each turning motion are connected are different by 180 degrees in FIG. 3(a) and FIG. 3(b) because the X-ray source 10 and the X-ray camera 20 need to be placed in positions that are point-symmetric with respect to the inspection point of the inspection object S. In this case, when the X-ray camera 20 is placed at the 0-degree position or the 360-degree position, the X-ray source 10 needs to be placed at the 180-degree position.

[0055] 3, a curve that smoothly connects the turning circle of the n-th turning motion and the turning circle of the n+1-th turning motion at a predetermined point and can be moved in the shortest time can be derived as a polynomial by a known mathematical method, so the method of deriving the curve will not be described here in particular. In addition, as a method of deriving a curve that can be moved in the shortest time among the curves that smoothly connect the turning end point of the n-th turning motion and the turning start point of the n+1-th turning motion, the mathematical parameters such as the coefficients of each term of the polynomial curve obtained by a known method may be assigned, and the one with the shortest moving time may be selected by repeated calculation.

[0056] In Fig. 3, the movement time of the X-ray camera 20 when moving along the trajectory 123a shown in Fig. 3(a) may be set to be equal to the movement time of the X-ray source 10 when moving along the trajectory 123b shown in Fig. 3(b). That is, the speed of the movement of the one with the longer movement time is increased so that both of them complete their movements at the same time. In this way, it becomes possible for both to complete their movements at the same time and move on to the next rotational movement.

[0057] As described above, in this embodiment, the stop section when the X-ray source 10 and the X-ray camera 20 transition from the n-th rotation motion to the moving motion and transition from the moving motion to the n+1-th rotation motion is eliminated, and the X-ray source 10 and the X-ray camera 20 do not stop. This eliminates the need to add a rotation motion for acceleration and deceleration before and after the stop section in the rotation motion for capturing an X-ray image, and allows the transition to the moving motion to the next rotation motion immediately after the end of the rotation motion, and allows the transition to the next rotation motion immediately after the end of the moving motion. As a result, it is possible to shorten the inspection time in the X-ray inspection device 1.

[0058] In this embodiment, the locus of the moving motion when the n-th turning motion is shifted to the n+1-th turning motion is a curve that smoothly connects the turning circle of the n-th turning motion and the turning circle of the n+1-th turning motion at the turning end point and turning start point, and can be moved in the shortest time. This allows the X-ray source 10 and the X-ray camera 20 to shift from turning motion to moving motion, or from moving motion to turning motion, more smoothly (without excessive acceleration or impact acting on the X-ray source 10 or the X-ray camera 20). As a result, even if the speed of the turning motion is high, it is possible to perform acceleration and deceleration motion more reliably in the middle of the moving motion. Also, it is possible to more quickly shift the X-ray source 10 and the X-ray camera 20 from turning motion to moving motion, or from moving motion to turning motion.

[0059] Table 1 shows the results of comparing the times required for the nth rotation, the moving, and the n+1th rotation in the X-ray inspection device when the present invention is applied and when the present invention is not applied. Note that the rotation end point and the rotation start point of the X-ray camera 20 are set to the 0 degree position.

[0060] [Table 1] It can be seen that the elapsed time is improved by about 13% by applying the present invention to the X-ray inspection apparatus. Here, the trajectory 123a of the movement of the X-ray camera 20 and the trajectory 123b of the movement of the X-ray source 10 in FIG. 3 correspond to the specific movement trajectory in this embodiment. This point is the same for the following embodiments. In this embodiment, the trajectory 123a of the movement of the X-ray camera 20 and the trajectory 123b of the movement of the X-ray source 10 are curves that smoothly connect the turning circles and can be moved in the shortest time, but they do not necessarily have to be exactly the shortest. Any curve that smoothly connects the turning circles and can sufficiently shorten the inspection time will suffice.

[0061] In this embodiment, as described above, the trajectory of the movement movement when transitioning from the nth turning motion to the n+1th turning motion is a curve that smoothly connects the turning circle of the nth turning motion and the turning circle of the n+1th turning motion at the turning end point and turning start point, and allows movement in the shortest time. In addition to this, in this embodiment, the turning start point of the n+1th turning motion is not fixed to the 0 degree position or the 180 degree position, but is set so that the movement time when transitioning from the nth turning motion to the n+1th turning motion is the shortest.

[0062] 4, in this embodiment, for example, m points arranged on the turning circle 122n+1 of the n+1-th turning motion are set as candidate points for the turning start point on the turning circle 122n+1 of the n+1-th turning motion. At this time, it is assumed that the X-ray camera 20 turns clockwise and counterclockwise on the turning circle 122n+1 of the n+1-th turning motion. Then, for a total of 2m candidate points for the clockwise and counterclockwise cases, the turning end point on the turning circle 122n of the n-th turning motion and the turning end point on the turning circle 122n of the n+1-th turning motion are set as candidate points for the turning start point on the turning circle 122n+1 of the n+1-th turning motion. A curve that smoothly connects the turning start point on turning circle 122n+1 and the possible travel time in the shortest time is obtained, and the travel time is calculated. Then, the candidate point that provides the shortest travel time is set as the turning start point on turning circle 122n+1 of the n+1th turning motion.

[0063] According to this, for a plurality of candidate points for the turning start point on the turning circle 122n+1 of the n+1th turning motion, a curve that smoothly connects the turning circle 122n of the nth turning motion and the turning start point and allows the movement in the shortest time is calculated, and the movement time is calculated. Then, a turning start point that minimizes the movement time of the X-ray camera 20 when transitioning from the nth turning motion to the n+1th turning motion is determined. Therefore, it is possible to more reliably minimize the movement time from the turning circle 122n of the nth turning motion to the turning circle 122n+1 of the n+1th turning motion. In the explanation of FIG. 4 or the following explanation, the movement trajectory of the X-ray camera 20 may be explained as an example, but it goes without saying that the same can be said about the movement trajectory of the X-ray source 10.

[0064] Next, the effect of this embodiment will be described with reference to Figs. 5 and 6. Fig. 5 shows the transition of the turning circle and the curve (movement trajectory) connecting each turning circle in the conventional technology to which this embodiment is not applied. That is, in Fig. 5, the trajectory of the movement movement when transitioning from one turning movement to the next turning movement is not a curve that smoothly connects the turning end point and turning start point of each turning movement and can be moved in the shortest time, and the turning start point that has the shortest moving time is not selected. In Fig. 5, the dashed lines show the turning circles of each turning movement, and the solid lines show the curve (movement trajectory) connecting each turning circle. Fig. 5(a) shows the case where the turning circle for the X-ray source 10 is made to transition from the left side to the right side in the figure and further to the upper side. Fig. 5(b) also shows the case where the turning circle for the X-ray source 10 is made to transition from the lower side to the upper side in the figure and further to the right side to the left side in the figure. In FIG. 5, the curve (movement trajectory) connecting the turning end point of one turning circle and the turning start point of the next turning circle is a complex and long curve, and it can be seen that the movement efficiency is low.

[0065] FIG. 6 shows the transition of the turning circle and the curve (movement trajectory) connecting each turning circle when this embodiment is applied. That is, in FIG. 6, the trajectory of the movement movement when transitioning from the nth turning movement to the n+1th turning movement is a curve that smoothly connects each turning end point and turning start point and can be moved in the shortest time, and the turning start point in the n+1th turning movement is determined by the method of FIG. 4. In FIG. 6, the dashed lines show the turning circles of each turning movement, and the solid lines show the curve (movement trajectory) connecting each turning circle. In FIG. 6, the curve (movement trajectory) connecting one turning circle to the next turning circle is simplified and the length is also shortened. As a result, it can be understood that the movement efficiency is high.

[0066] As a result of introducing the control according to the present embodiment, the inspection tact time was shortened from 71.6 seconds to 38.7 seconds, which is a reduction effect of more than 40%. In addition, the total travel time between turning circles was shortened from 13.9 seconds to 5.2 seconds, which is a reduction effect of more than 60%. This resulted in a shortening effect.

[0067] Next, the flow of control by the calculation unit 111 and the control unit 100 in this embodiment will be described. Figures 7 and 8 show a flowchart of a movement control routine for the X-ray source 10 and the X-ray camera 20 in this embodiment. This routine is a program stored in the main storage unit 112, and is executed by the calculation unit 111 and the control unit 100. In the first half shown in Figure 7, a rotation start point in the n+1th rotation motion is determined, and in the second half shown in Figure 8, the movement control of the X-ray source 10 and the X-ray camera 20 is performed.

[0068] When this routine is executed, first, in step S01, information for calculating a trajectory that smoothly connects the movement trajectories between turning circles is obtained. More specifically, in the n+1th turning, For the turning circle 122n+1 of the motion, a trajectory that smoothly connects the turning end point and the turning start point is calculated for the 2m candidate turning start points set for both clockwise and counterclockwise turning. This is performed using a known method such as a polynomial, so a detailed description will be omitted here. When the processing of step S01 is completed, the process proceeds to step S02.

[0069] In step S02, based on the information acquired in step S01, coefficients of a polynomial for calculating a trajectory that smoothly connects the turning circle 122n of the n-th turning motion and the turning circle 122n+1 of the n+1-th turning motion and can be moved in the shortest time are calculated and acquired. When the process of step S02 ends, the process proceeds to step S03.

[0070] The processing of steps S03 to S06 is a step of calculating the travel time in parallel for 2m candidate points for the turning start point, which are set for turning circle 122n+1 of the n+1th turning motion, including both clockwise and counterclockwise turning. Here, steps S03-1 to S06-1 will be taken as an example to explain, but the same processing (steps S03-1 to S06-1, . . . , steps S03-2m to S06-2m) is performed in parallel for the 2m candidate points. In step S03-1, calculation of the travel time is started.

[0071] More specifically, the coefficients acquired in step S02 are used to calculate a curve that smoothly connects the end point of the turning circle 122n of the n-th turning motion and the first candidate point on the turning circle 122n+1 of the n+1-th turning motion, allowing movement in the shortest time, and to calculate the moving time. Note that in this embodiment, since the X-ray camera 20 turns 360 degrees in each turning motion, the end point of the turning circle 122n of the n-th turning motion is the same as the start point of the turning circle 122n of the n-th turning motion. When the process of step S03-1 is completed, the process proceeds to step S04-1.

[0072] In step S04-1, it is determined whether or not either the linear velocity or the axial velocity of the X-ray camera 20 exceeds an allowable velocity when the X-ray camera 20 moves for the movement time calculated in step S03-1. It is also determined whether or not the acceleration acting on the X-ray camera 20 exceeds an allowable acceleration, and whether or not the movement range of the rotational movement and movement movement of the X-ray camera 20 exceeds an allowable movement range.

[0073] If it is determined that either the linear velocity or the axial velocity of the X-ray camera 20 exceeds the allowable velocity, that the acceleration acting on the X-ray camera 20 exceeds the allowable acceleration, or that the motion range of the X-ray camera 20 exceeds the allowable movement range, the process proceeds to step S05-1. This is because it is determined that the allowable rotation speed of the motor or ball screw will be exceeded, that the X-ray camera 20 will deteriorate due to being unable to withstand the acceleration, or that the X-ray camera 20 may collide with a member in the X-ray inspection apparatus 1.

[0074] On the other hand, if it is determined in step S04-1 that either the linear velocity or the axial velocity of the X-ray camera 20 does not exceed the allowable velocity, the acceleration acting on the X-ray camera 20 does not exceed the allowable acceleration, and the range of motion of the X-ray camera 20 does not exceed the allowable movement range, the process proceeds to step S06-1.

[0075] In step S05-1, the travel time is recalculated until the calculated travel time value converges. More specifically, the speed of the X-ray camera 20 or the acceleration acting on the X-ray camera 20 is lowered, or the mathematical parameters of the curve are changed so that the range of motion of the X-ray camera 20 is narrowed, and then the process returns to step S03-1. Then, the routine of steps S03-1 to S05-1 is repeated until the linear speed of the X-ray camera 20 is reduced in step S04-1. This is repeated until it is determined that either the speed or the axial speed does not exceed the allowable speed, the acceleration acting on the X-ray camera 20 does not exceed the allowable acceleration, and the motion range of the X-ray camera 20 does not exceed the allowable movement range.

[0076] If it is determined in step S04-1 that either the linear velocity or the axial velocity of the X-ray camera 20 does not exceed the allowable velocity, that the acceleration acting on the X-ray camera 20 does not exceed the allowable acceleration, and that the motion range of the X-ray camera 20 does not exceed the allowable movement range, the process proceeds to step S06-1. Here, the allowable velocity is a velocity value that is predetermined as a threshold value that does not exceed the allowable rotation speed of the motor or ball screw. The allowable acceleration is an acceleration value that is predetermined as a threshold value that does not deteriorate the X-ray camera even if it acts on the X-ray camera 20. The allowable movement range is a motion range that is predetermined as a threshold value of the motion range in which the X-ray camera 20 does not collide with other members in the device.

[0077] In step S06-1, calculation of the travel time is completed. More specifically, a curve that smoothly connects the end point of turning circle 122n of the n-th turning motion and the first candidate point on turning circle 122n+1 of the n+1-th turning motion and that can be traveled in the shortest time, and the travel time are calculated. When the process of step S06-1 (and the equivalent steps S06-2 to S06-2m for the other candidate points) is completed, the process proceeds to step S07.

[0078] Next, in step S07, a time candidate that is the shortest travel time and does not exceed an allowable value is selected. More specifically, the shortest travel time is selected from the travel times calculated in steps S06-1 to S06-2m, and a candidate point corresponding to the travel time is selected. When the process of S07 ends, the selected information is passed to the control unit 100. The processes from step S01 to step S07 are executed by the calculation unit 111.

[0079] 8, the control unit 100 receives the movement time calculated in step S07. In step S09, the control unit 100 receives information necessary for the movement of the X-ray source 10 and the X-ray camera 20, such as the position coordinates (start point of rotation) to move the X-ray camera 20, the rotation speed, the rotation center, and the rotation radius. When the processes of steps S08 and S09 are completed, the process proceeds to step S10.

[0080] In step S10, a trajectory of movement to the rotation start point, which is the next movement destination, is calculated. Here, the trajectory of movement corresponding to the movement time received in S08 is calculated again. When the processing of step S10 ends, the process proceeds to step S11. In step S11, an output for moving the X-ray camera 20 and the X-ray source 10 along the trajectory to the next rotation start point is output to a drive motor (not shown) of the XY stage that controls the motion of the X-ray source 10 and the X-ray camera 20. The processing from step S08 to step S11 is executed by the control unit 100.

[0081] In this routine, in step S03-1 (to step S03-2m), a trajectory and travel time that can be moved in the shortest time by smoothly connecting the turning end point and the turning start point are calculated until it is determined in step S04-1 (to step S04-2m) that none of the speed (either linear speed or axial speed), acceleration, and moving position exceed the allowable values. However, a flow in which a trajectory and travel time that can be moved in the shortest time by smoothly connecting the turning end point and the turning start point is calculated until it is determined that none of the speed (either linear speed or axial speed), acceleration, and moving position exceed the allowable values ​​may be used.

[0082] In the above embodiment, 2m candidate points for the turning start point in the turning circle 122n+1 of the n+1th turning motion were set for both the clockwise and counterclockwise directions. However, the number of candidate points is not limited to this. The number of candidate points is determined based on the load of parallel calculation and the travel time. The accuracy of the rotation start point to be the shortest may be determined by comparing and considering the accuracy of the rotation start point to be the shortest. In the above embodiment, the present invention is applied to the X-ray inspection apparatus 1, 11 that includes the X-ray source 10, the X-ray camera 20, and the holding unit 40, and acquires and inspects a 3D image of an object to be inspected by rotating any one of the X-ray source, the X-ray camera, and the holding unit as a rotating unit. However, the technical idea of ​​the present invention can be applied to other inspection apparatuses. For example, the radiation source may irradiate electromagnetic waves (including light) other than X-rays. In that case, the camera does not need to be an X-ray camera. Furthermore, in the above embodiment, the curve that smoothly connects the rotation circle of the nth rotation motion and the rotation circle of the n+1th rotation motion at a specified point and can be moved in the shortest time is derived as a polynomial, but the curve may be derived by other methods. For example, the curve may be derived by using a calculation method that uses a parameter for a trigonometric function such as a clothoid segment.

[0083] <Comparative Example> Next, a comparative example of this embodiment will be described. In this comparative example, the turning end point of the n-th turning motion and the turning start point of the n+1-th turning motion are determined by a method different from that of the above embodiment. As shown in FIG. 9, in this modified example, for example, when calculating the turning end point of the turning circle 122n of the n-th turning motion, an intersection point between the turning circle 122n and a straight line connecting the turning circle 122n-1 of the previous n-1-th turning motion and the center of the turning circle 122n is obtained. Also, an intersection point between the turning circle 122n and a straight line connecting the turning circle 122n and the center of the turning circle 122n+1 of the next turning motion is obtained. Then, the central point Pn of the shorter arc of the arcs sandwiched between these two intersection points is set as the turning end point of the turning circle 122n of the n-th turning motion.

[0084] When calculating the turning start point of the turning circle 122n+1 of the n+1-th turning motion, the intersection point between the turning circle 122n+1 and a straight line connecting the turning circle 122n of the previous n-th turning motion and the center of the turning circle 122n+1 is obtained. The intersection point between the turning circle 122n+1 and a straight line connecting the turning circle 122n+1 and the center of the next turning circle 122n+2 is also obtained. Then, the center point Pn+1 of the shorter of the arcs sandwiched between these two intersection points is set as the turning start point of the turning circle 122n+1 of the n+1-th turning motion. Then, Pn and Pn+1 are smoothly connected by a curve 123n.

[0085] In addition, for example, when the turning circles are arranged in a horizontal line, the method according to the comparative example shown in FIG. 9 may not be able to identify the shorter arc between the two intersections. Therefore, in the comparative example, in such a case, the turning end point and turning start point in the turning motion must be set to a predetermined angle position. In this case, for example, the turning end point in the turning circle of the n-th turning motion is shifted 90 degrees counterclockwise, and the turning start point of the n+1-th turning motion is shifted 90 degrees clockwise. This avoids a situation in which the turning end point and turning start point in the turning motion cannot be calculated.

[0086] FIG. 10 is a diagram showing the effect of using the comparative example. In FIG. 10, the broken lines indicate the turning circles of each turning motion, and the solid lines indicate the curves (movement trajectories) connecting between each turning circle. FIG. 10(a) shows the case where the turning circle of the X-ray source 10 is shifted from the left side to the right side in the figure, and then shifted to the upper side. FIG. 10(b) shows the case where the turning circle of the X-ray camera 20 is shifted from the lower side to the upper side in the figure, and then shifted from the right side to the left side in the figure. In FIG. 10, the curves (movement trajectories) connecting between turning circles are simpler and shorter than the case of the conventional technology shown in FIG. 5, and it can be understood that there is an effect of improving the movement efficiency. However, compared to the case where the embodiment of the present invention shown in FIG. 6 is applied, the curves (movement trajectories) connecting between the turning circles and the next turning circle are complex and long, and it can be understood that the movement efficiency is low.

[0087] When the above comparative example is implemented, the inspection tact time is 47.4 seconds, which is shorter than the 71.6 seconds when no countermeasure is taken, but is longer than the 38.2 seconds when the embodiment of the present invention is applied.

[0088] According to the inventors' intensive research, a new finding was obtained about the trajectory of the moving motion when the distance between the turning circle of the n-th turning motion and the turning circle of the n+1-th turning motion is relatively long (for example, the distance between the centers of the turning circles is three times or more the diameter of the turning circles). That finding is that, when optimizing the turning start point of the n+1-th turning motion of the X-ray camera 20 and the X-ray source 10, the time shortening effect of the moving motion is greater if the turning end point of the n-th turning motion and the turning start point of the n+1-th turning motion are optimized for the X-ray camera 20 or the X-ray source 10 having a larger turning radius.

[0089] According to the above findings, when the distance between the turning circle of the nth turning motion and the turning circle of the n+1th turning motion is relatively long, it is preferable to optimize the turning start point of the n+1th turning motion for the one having a larger turning radius between the X-ray camera 20 and the X-ray source 10. It is also preferable to make the one of the X-ray camera 20 and the X-ray source 10 that performs a turning motion with a smaller radius reach the turning start point of the next turning motion at the same time as the one of the X-ray camera 20 and the X-ray source 10 that performs a turning motion with a larger radius.

[0090] In this way, the X-ray camera 20 or the X-ray source 10 which performs a rotational motion with a smaller radius can reach the rotation start point of the (n+1)th rotational motion simultaneously with the X-ray camera 20 or the X-ray source 10 which performs a rotational motion with a larger radius. As a result, the (n+1)th rotational motion can be started earlier, and the examination time can be more reliably shortened.

[0091] In the above embodiment, the present invention is applied to an X-ray inspection device 1 in which the position of the object to be inspected S is fixed and the X-ray camera 20 and the X-ray source 10 are rotated above and below the object to be inspected. However, the application of the present invention is not limited to an X-ray inspection device having the above-mentioned configuration. The present invention may be applied to an X-ray inspection device 11 in which the X-ray source 10 is fixed and the object to be inspected S and the X-ray camera 20 are rotated.

[0092] Fig. 11 shows an example of the arrangement of the X-ray camera 20, the object to be inspected S, and the X-ray source 10 in the X-ray inspection apparatus 11 in this embodiment. Fig. 11(a) shows an example in which the X-ray camera 20 is arranged above the object to be inspected S and the X-ray source 10 is arranged below the object to be inspected S, and Fig. 11(b) shows an example in which the X-ray source 10 is arranged above the object to be inspected S and the X-ray camera 20 is arranged below the object to be inspected S. In either case, the X-ray source 10 is fixed, and the X-ray camera 20 and the object to be inspected S perform a rotational movement.

[0093] In addition, in order to make it possible to compare the constituent elements of the present invention with the configurations of the embodiments, the constituent elements of the present disclosure will be noted below with the reference numerals in the drawings. <Appendix 1> an X-ray source (10) that generates X-rays to be irradiated onto an object to be inspected; an X-ray camera (20) that captures an X-ray image using X-rays irradiated from the X-ray source (10) onto the inspection object; A holding section (40) for holding the test object, an X-ray inspection device (1, 11) in which any one of the X-ray source (10), the X-ray camera (20), and the holding unit (40) rotates as a rotating unit (10, 20, 40) to capture the X-ray images while changing the shooting direction, thereby obtaining and inspecting a three-dimensional image of the inspection object, The rotating portion (10, 20, 40) sequentially rotates at a plurality of locations, performing a movement to move from a turning end point of one turning motion to a turning start point of the next turning motion; When the rotating unit (10, 20, 40) moves from a rotation end point of one rotation motion to a rotation start point of the next rotation motion, any one of the rotating units, that is, the X-ray source (10), the X-ray camera (20), and the holding unit (40), moves along a specific movement trajectory that is a trajectory connecting a rotation circle of the one rotation motion and a rotation circle of the next rotation motion at the rotation end point and the rotation start point; A trajectory calculation unit (111b) for calculating the turning start point in the turning circle and the specific movement trajectory, The X-ray inspection device (1, 11), characterized in that the starting point of the next rotational movement is calculated by the trajectory calculation unit (111b) as a point to which any one of the rotation parts, that is, the X-ray source (10), the X-ray camera (20), and the holding part (40), can move from the rotation circle of the one rotational movement to the rotation circle of the next rotational movement in the shortest movement time along the specific movement trajectory. <Appendix 15> an X-ray source (10) that generates X-rays to be irradiated onto an object to be inspected; an X-ray camera (20) that captures an X-ray image using X-rays irradiated from the X-ray source (10) onto the inspection object; A holding section (40) for holding the test object, an X-ray inspection method using an X-ray inspection device (1, 11) in which any one of the X-ray source (10), the X-ray camera (20), and the holding unit (40) rotates as a rotating unit (10, 20, 40) to capture the X-ray images while changing the shooting direction, thereby obtaining and inspecting a 3D image of the inspection object, The rotating unit (10, 20, 40) is rotated in sequence at a plurality of locations, and a moving motion is performed to move from a rotation end point of one rotation motion to a rotation start point of the next rotation motion; When the rotating unit (10, 20, 40) moves from a rotation end point of one rotation motion to a rotation start point of the next rotation motion, any one of the rotating units, that is, the X-ray source (10), the X-ray camera (20), and the holding unit (40), moves along a specific movement trajectory that is a trajectory connecting a rotation circle of the one rotation motion and a rotation circle of the next rotation motion at the rotation end point and the rotation start point; an X-ray inspection method, characterized in that the starting point of the next rotational movement is determined as a point to which any one of the rotation units (10, 20, 40), that is the X-ray source (10), the X-ray camera (20), and the holding unit (40), can move from the rotational circle of the one rotational movement to the rotational circle of the next rotational movement in the shortest moving time along the specific movement trajectory, among a plurality of candidate points set to be positioned on the rotational circle of the next rotational movement. [Explanation of symbols]

[0094] 1, 11: X-ray inspection equipment 10...X-ray source 20. X-ray camera 40...Holding part 100...Control section 111...Arithmetic section 111b...Trajectory calculation section 121...X-ray source orbiting motion orbiting circle 122...X-ray camera rotation movement rotation circle 123...Movement trajectory S: Inspection object (substrate)

Claims

1. an X-ray source that generates X-rays to be irradiated onto an object to be inspected; an X-ray camera that captures an X-ray image of the inspection object using X-rays irradiated from the X-ray source; A holding unit that holds the test object, An X-ray inspection device in which any one of the X-ray source, the X-ray camera, and the holding unit rotates as a rotating unit to capture the X-ray images while changing the shooting direction, thereby obtaining and inspecting a three-dimensional image of the inspection object, the rotating unit performs a sequential rotating motion at a plurality of locations and a moving motion for moving from a rotating end point of one rotating motion to a rotating start point of a next rotating motion; When the rotating unit moves from a rotation end point of one rotation motion to a rotation start point of a next rotation motion, any one of the rotating unit, that is, the X-ray source, the X-ray camera, and the holding unit, moves along a specific movement trajectory that is a trajectory connecting a rotation circle of the one rotation motion and a rotation circle of the next rotation motion at the rotation end point and the rotation start point; a trajectory calculation unit that calculates the turning start point and the specific movement trajectory of the turning motion, a rotation start point of the next rotation motion is calculated by the trajectory calculation unit as a point to which any one of the X-ray source, the X-ray camera, and the holding unit, which are the rotation units, can move from the rotation circle of the one rotation motion to the rotation circle of the next rotation motion in the shortest movement time along the specific movement trajectory, among a plurality of candidate points set to be disposed on a rotation circle of the next rotation motion; An X-ray inspection apparatus, characterized in that the specific movement trajectory is a trajectory in which the linear velocity, or the linear velocity and acceleration, or the linear velocity, acceleration and jerk of the rotating part are continuous at the rotation end point and / or the rotation start point.

2. An X-ray source that generates X-rays to be irradiated onto an object to be inspected; an X-ray camera that captures an X-ray image of the inspection object using X-rays irradiated from the X-ray source; A holding unit that holds the test object, An X-ray inspection device in which any one of the X-ray source, the X-ray camera, and the holding unit rotates as a rotating unit to capture the X-ray images while changing the shooting direction, thereby obtaining and inspecting a three-dimensional image of the inspection object, the rotating unit performs a sequential rotating motion at a plurality of locations and a moving motion for moving from a rotating end point of one rotating motion to a rotating start point of a next rotating motion; When the rotating unit moves from a rotation end point of one rotation motion to a rotation start point of a next rotation motion, any one of the rotating unit, that is, the X-ray source, the X-ray camera, and the holding unit, moves along a specific movement trajectory that is a trajectory connecting a rotation circle of the one rotation motion and a rotation circle of the next rotation motion at the rotation end point and the rotation start point; a trajectory calculation unit that calculates the turning start point and the specific movement trajectory of the turning motion, a rotation start point of the next rotation motion is calculated by the trajectory calculation unit as a point to which any one of the X-ray source, the X-ray camera, and the holding unit, which are the rotation units, can move from the rotation circle of the one rotation motion to the rotation circle of the next rotation motion in the shortest movement time along the specific movement trajectory, among a plurality of candidate points set to be disposed on a rotation circle of the next rotation motion; An X-ray inspection device characterized in that the specific movement trajectory or the movement time of the rotating part on the specific movement trajectory is determined within a range in which any of the linear or axial velocity, acceleration, and movement range of the rotating part, which is the X-ray source, the X-ray camera, and the holding part, does not exceed a predetermined allowable value.

3. 3. The X-ray inspection apparatus according to claim 1, wherein the plurality of candidate points are set for both a case where the X-ray source, which is the rotating part, the X-ray camera, or the holding part rotates around a rotation circle of the next rotational motion in a clockwise direction and a case where the candidate points are set for both a case where the X-ray source, which is the rotating part, the X-ray camera, or the holding part rotates around a rotation circle of the next rotational motion in a counterclockwise direction.

4. 4. The X-ray inspection apparatus according to claim 1, wherein the trajectory calculation unit includes a plurality of arithmetic units, and calculates the travel times for the plurality of candidate points in parallel using the plurality of arithmetic units.

5. 5. The X-ray inspection apparatus according to claim 1, wherein the rotating part does not have a stopping section during the rotating motion and the moving motion.

6. 2. The X-ray inspection apparatus according to claim 1, wherein the acceleration of the rotating part is zero at the rotation end point and / or the rotation start point.

7. 7. An X-ray inspection apparatus according to claim 1, wherein the specific movement trajectory is calculated as a polynomial or by using parameters for a trigonometric function.

8. 2. The X-ray inspection device according to claim 1, wherein the specific movement trajectory or the movement time of the rotating part on the specific movement trajectory is determined within a range in which any one of the linear or axial velocity, acceleration, and movement range of the rotating part, which is the X-ray source, the X-ray camera, and the holding part, does not exceed a predetermined allowable value.

9. 9. The X-ray inspection apparatus according to claim 1, wherein the rotating unit is the X-ray source and the X-ray camera, and the holding unit is held at a predetermined position within the X-ray inspection apparatus.

10. an X-ray source that generates X-rays to be irradiated onto an object to be inspected; an X-ray camera that captures an X-ray image based on the X-rays irradiated from the X-ray source onto the inspection object; 、 A holding unit that holds the test object, An X-ray inspection method using an X-ray inspection device, in which any one of the X-ray source, the X-ray camera, and the holding unit rotates as a rotating unit to capture the X-ray images while changing the shooting direction, thereby obtaining and inspecting a three-dimensional image of the inspection object, The rotating part is rotated in a succession of positions, and a moving motion is performed to move from a rotation end point of one rotation motion to a rotation start point of a next rotation motion; When the rotating unit moves from a rotation end point of one rotation motion to a rotation start point of a next rotation motion, any one of the rotating unit, that is, the X-ray source, the X-ray camera, and the holding unit, moves along a specific movement trajectory that is a trajectory connecting a rotation circle of the one rotation motion and a rotation circle of the next rotation motion at the rotation end point and the rotation start point; a rotation start point of the next rotation motion is determined as a point to which any one of the X-ray source, the X-ray camera, and the holding unit, which are the rotation units, can move from the rotation circle of the one rotation motion to the rotation circle of the next rotation motion in the shortest moving time along the specific movement trajectory, among a plurality of candidate points set to be disposed on a rotation circle of the next rotation motion; An X-ray inspection method characterized in that the specific movement trajectory is a trajectory in which the linear velocity, or the linear velocity and acceleration, or the linear velocity, acceleration and jerk of the rotating part are continuous at the rotation end point and / or the rotation start point.

11. 11. The X-ray inspection method according to claim 10, wherein any one of the rotating parts, that is, the X-ray source, the X-ray camera, and the holding part, is transitioned from the rotating motion to the moving motion without stopping.

12. 12. The X-ray inspection method according to claim 10, wherein the acceleration of the rotating part is zero at the rotation end point and / or the rotation start point.

13. 13. The X-ray inspection method according to claim 10, wherein the specific movement trajectory is defined by a polynomial or calculated using a parameter for a trigonometric function.

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