JP7643104B2 - X-ray inspection device and X-ray inspection method - Google Patents

Description

The present invention relates to an X-ray inspection device that acquires multiple X-ray images of an object to be inspected and creates three-dimensional data.

Conventionally, there has been a technique for taking X-ray images of an object to be inspected, such as the surface of a circuit board, from multiple directions, creating three-dimensional data from the multiple X-ray images taken, and inspecting the internal structure of the inspection point. Examples of this technique include tomosynthesis and CT. In this technique, 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, object to be inspected, and X-ray camera.

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 their relative positions, and when one rotation is completed and the inspection point is photographed, a movement is made to the photographing position for photographing the next inspection point, and then a further rotation is made. Therefore, in order to shorten the inspection time of the object to be inspected, it is necessary to perform the above-mentioned rotation and movement movements efficiently. Here, rotation refers to a movement that turns in a circle at a constant speed, and does not include an accelerating run-up movement before the circle, or a decelerating braking movement after the circle. On the other hand, a movement movement refers to a movement from one turning circle to the next turning circle. For example, the movement distance related to the movement movement is the movement distance between the turning circles.

To address this issue, a known technology is used to find an imaging path that shortens the time required to capture multiple 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 emitted by the radiation generator to stabilize, the time required to move the radiation generator, the time required to translate the substrate holder on the plane along the substrate rotation orbit, the time required by the detector driver to move the detector and the substrate holder in conjunction with the detector, etc.) (see, for example, Patent Document 1).

However, in conventional technology, there was no sufficient consideration given to optimizing the movement trajectories and movement times of the X-ray source, the object to be inspected, and the X-ray camera.

JP 2011-209054 A JP 2013-247228 A

The present invention was made in consideration of the above problems, and its purpose is to provide a technology that can shorten the inspection time of an object to be inspected in an X-ray inspection device.

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 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 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, among a plurality of candidate points set to be placed on the rotation circle of the next rotational movement.

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 that can be moved to in the shortest moving time can be selected from among multiple candidate points arranged on the rotation circle of the next rotational motion. As a result, the rotating part can move from the end point of one rotational motion to the start point of the next rotational motion more reliably. As a result, it is possible to more reliably shorten the inspection time of the object to be inspected in the X-ray inspection device. Here, the rotating part (the radiation source, the camera, and the holding part that rotates) is controlled so that it arrives at the same time at the start point of the next rotational motion during the moving motion. And the shortest moving time in the above case is, for example, the time candidate for the moving time at which the radiation source and the camera, which are the rotating part, arrive at the same time at the start point of the next rotational motion is calculated for each candidate point, and the shortest moving time among the calculated time candidates is selected.

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

In addition, in the present invention, the trajectory calculation unit may include multiple arithmetic devices, and the movement times for the multiple candidate points may be calculated in parallel using the multiple arithmetic devices. This allows the movement times of the turning part for the multiple candidate points to be calculated in parallel using the multiple arithmetic devices, making it possible to determine the turning start point for the next turning motion more quickly. Note that here, multiple arithmetic devices includes cases where there are multiple independent arithmetic devices, as well as cases where multiple arithmetic functions are used inside a single arithmetic device.

In addition, in the present invention, the rotating unit may be configured so that there is no stop section in the middle of the rotating motion and the moving motion. Here, in the conventional technology, when transitioning from the rotating motion to the moving motion or from the moving motion to the rotating motion, the rotating unit had to stop once. And, a run-up distance and a braking distance were required for accelerating and decelerating motions in the middle of the rotating motion. In contrast, in the present invention, the rotating unit is configured so that there is no stop section in the middle of the rotating motion and the moving motion, so that the rotating unit does not need to perform accelerating and decelerating motions for stopping between the rotating motion and the moving motion. As a result, there is no need to perform additional rotating motions for accelerating and decelerating before and after the rotating motion for taking an X-ray image. Therefore, it is possible to reduce the total motion time of multiple rotating motions and moving motions, and shorten the examination time.

In addition, 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. In addition, 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 a trajectory in which 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.

In other words, the specific movement trajectory of the present invention requires that the linear velocity of the turning part is continuous at the turning end point and/or turning start point. It is also desirable that the linear velocity and acceleration are continuous. It is also ideal that the linear velocity, acceleration, and jerk are continuous. In addition, when acceleration is continuous, it is also ideal that the acceleration is 0.

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, a 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 one turning circle to the next turning circle.

In addition, in the present invention, the specific movement trajectory may be defined by a polynomial. Alternatively, it may be calculated 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.

In the present invention, the rotating part may be any two of the X-ray source, the X-ray camera, and the holding part, and the specific movement trajectory may be a trajectory that connects the rotation circle of the first rotation and the rotation circle of the next rotation of the one of the two of the X-ray source, the X-ray camera, and the holding part that performs a rotation with a larger radius, at the rotation end point and the rotation start point.

Here, when the rotating part is any two of the X-ray source, the X-ray camera, and the holding part, the circle of the rotation of one of the rotating parts is often different from the circle of the rotation of the other 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 the larger radius of rotation of the X-ray source, the X-ray camera, and the holding part is defined as a trajectory that smoothly connects the circle of one rotation movement and the circle of the next rotation movement at the end point of the rotation and the start point of the rotation. 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.

In addition, in the present invention, of any two of the X-ray source, the X-ray camera, and the holding unit, the one that performs a rotational motion with a smaller radius may reach the rotation start 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 that performs a rotational motion with a larger radius.

In this way, any two of the X-ray source, the X-ray camera, and the holding unit that perform a rotational motion with a smaller radius can reach the rotation start point of the next rotational motion simultaneously with any two of the X-ray source, the X-ray camera, and the holding unit that perform a rotational motion with a larger radius, thereby enabling the rotation unit to start the next rotational motion earlier.

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, the speed and acceleration of the X-ray source, the X-ray camera, the holding part, etc. can be prevented from becoming excessive, and it is possible to prevent equipment failure and improve reliability.

In addition, in the present invention, the specific movement trajectory may be determined so that the movement range of any of the rotating parts, the X-ray source, the X-ray camera, and the holding part, does not exceed a predetermined allowable movement range. Alternatively, the movement time of the rotating part on the specific movement trajectory may be determined so that the movement range of any of the rotating parts, the X-ray source, the X-ray camera, and the holding part, 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 part, etc. colliding with structures within the device when the rotating part moves along the specific movement trajectory, or errors occurring due to exceeding a limit range set by software, thereby improving reliability.

In addition, 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 within 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 movement mechanism, loading mechanism, etc. of the object not to be inspected within the X-ray inspection device.

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 three-dimensional image of the inspection object,
The rotating unit 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;
This may be an X-ray inspection method, characterized in that the starting point of the next rotational movement is determined 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 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.

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.

In addition, at that time, when the rotating unit moves from the rotation end point of one rotation motion to the rotation start point of the next rotation motion, any one of the rotating unit, that is, the X-ray source, the X-ray camera, and the holding unit, is moved along a specific movement trajectory that is a trajectory connecting the rotation circle of the one rotation motion and the 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.

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. Furthermore, if the acceleration is continuous at the turning end point and/or the turning start point, the acceleration may be set to 0.

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

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.

As described above, the present invention can be understood as an X-ray inspection device including at least some of the above 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 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 contradictions arise.

The present invention makes it possible to shorten the inspection time of non-inspected objects in an X-ray inspection device.

1 is a diagram showing an overview of an X-ray inspection apparatus according to an embodiment of the present invention. 4A and 4B are diagrams illustrating the relationship between the rotational motion and the translational motion of an X-ray source or an X-ray camera in an embodiment of the present invention. 1A to 1C are diagrams illustrating examples of trajectories of rotation and translation of an X-ray source or an X-ray camera in an embodiment of the present invention. 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. 1A to 1C are diagrams showing examples of trajectories of rotation and translation of an X-ray source or an X-ray camera in the prior art; 1A to 1C are diagrams illustrating examples of trajectories of rotation and translation of an X-ray source or an X-ray camera in an embodiment of the present invention. 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. 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. 11A and 11B are diagrams for explaining a method for determining a turning start point of the next turning motion in the comparative example. 11A and 11B are diagrams illustrating examples of trajectories of rotation and movement of an X-ray source or an X-ray camera in a comparative example. FIG. 13 is a diagram showing a modified example of the X-ray inspection apparatus according to the present invention.

[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 object S to be inspected 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 revolve on revolving circles 121 and 122, respectively, and take X-ray images of the object S to be inspected at a plurality of positions on the trajectory. Thereafter, in order to inspect another inspection point, both the X-ray source 10 and the X-ray camera 20 move to the next revolving circle, and take X-ray images while revolving further on the revolving circle.

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, acceleration and deceleration motions on the 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.

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) arranged on the n+1th turning circle 122n+1 are set. 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 candidate points (twice m) for the clockwise and counterclockwise cases, a curve that smoothly connects the turning end point on the nth turning circle 122n and the turning start point on the n+1th turning circle 122n+1 and allows movement in the shortest time is obtained, and the moving time is calculated. Then, the candidate point with the shortest moving time is set as the turning start point on the n+1th turning circle 122n+1. This makes it possible to minimize the moving 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.

As shown in FIG. 1, the present invention can be applied to an X-ray inspection device 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. 11, the present invention can also be applied to an X-ray inspection device 11 in which an X-ray source 10 is fixed and an X-ray camera 20 and an inspection object S are rotated.

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

The X-ray inspection device according to the first embodiment of the present invention is a device that judges the quality of, for example, the soldering condition of electronic components soldered to a printed circuit board or the bumps of a ball grid array (BGA). More specifically, the X-ray source and the object to be inspected are moved relative to each other to perform multiple X-ray photographs, obtain the internal condition of the area to be inspected, generate a cross-sectional image at an appropriate position, and inspect the quality based on the cross-sectional image.

<Device Configuration>
FIG. 1 shows an arrangement diagram of an X-ray source 10, a holding unit 40 for holding an object S to be inspected, and an X-ray camera 20 in an X-ray inspection device 1 according to a first embodiment of the present invention. In the X-ray inspection device 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 a transport roller (not shown) and held by the holding unit 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 can be moved by a stage (not shown). The X-ray source 10 and the X-ray camera 20 move on rotation circles 121 and 122, respectively, by these stages, and images are taken at multiple positions on the rotation circles.

The control of each part in the X-ray inspection device 1 is performed based on a control signal from the control unit 100. The X-ray inspection device 1 includes, as the control unit 100, an XY stage control unit for camera 101, a camera control unit 102, and an XY stage control unit for X-ray source 107. In addition, the device includes a height measurement unit 103, an inspection target position control unit 104, an X-ray source control unit 105, and an imaging height control unit 106. Furthermore, the X-ray inspection device 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.

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 with 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 transport rollers and the holding unit 40 for the inspection object S, and controls the horizontal and vertical positions of the inspection object S to the optimal positions for imaging.

The X-ray source control unit 105 transmits signals to start and end irradiation of X-rays by the X-ray source 10, as well as to adjust 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 XY stage control unit for X-ray source 107 transmits signals for driving the XY stage for X-ray source (not shown) and moving the X-ray source 10 in the horizontal direction. The signals output from the camera XY stage control unit 101, the camera control unit 102, the inspection target position control unit 104, the X-ray source control unit 105, the imaging height control unit 106, and the XY stage control unit for X-ray source 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.

In particular, the imaging command unit 111a of the calculation unit 111 transmits information necessary 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 starting point of the rotational motion, using a method described below. In addition, the exchange of information such as setting information and examination results with the user is performed via the input unit 114 and output unit 115.

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 inspection object S. An image intensifier (I.I.) tube or a flat panel detector (FPD) can be used as the X-ray camera 20. Here, only one X-ray camera 20 is used, but multiple X-ray cameras may be used.

The displacement meter 30 measures the distance to the object to be inspected S at multiple positions on the object to be inspected S. Therefore, the displacement meter 30 can measure the warping and tilt of the object to be inspected S. During the manufacturing process of the object to be inspected S, warping and tilting may occur, and the amount of warping and tilting varies from object to object. Therefore, the warping and tilting of each object to be inspected S is measured, and the height position of the holding part 40 is adjusted so that appropriate X-ray imaging can be performed.

With the above configuration, the X-ray inspection apparatus 1 can control the positions of the X-ray source 10 and the X-ray camera 20 so as to capture images of the board from various directions. In this embodiment, based on the results of capturing images from various directions, three-dimensional data of the inspection location of the inspection object S is generated using a three-dimensional data generation method called CT (Computed Tomography).

The calculation unit 111 may be a general-purpose calculation unit 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. In other words, these functions can be realized using a general computer system. The calculation unit 111 reads and executes a program stored in the auxiliary storage unit 113, thereby controlling the movement of the X-ray source 10 and the X-ray camera 20, as described below. The calculation unit 111 in this embodiment is capable of parallel calculation and may include multiple CPUs, or may include multiple parallel calculation functions in one CPU.

As shown in FIG. 1, the X-ray source 10 and the X-ray camera 20 move on the rotation 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 rotating on the rotation circles 121 and 122 for each inspection point on the inspection object S, it is possible to create a three-dimensional image of the inspection point. 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 rotation movement over 360 degrees (also called the nth rotation movement) 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 rotation movement over 360 degrees (also called the n+1th rotation movement) is started.

Figure 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 Figure 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.

Similarly, after the X-ray source 10 or the X-ray camera 20 has finished moving and stopped, the X-ray source 10 or the X-ray camera 20 accelerates to a predetermined speed before reaching the starting point of the rotation, and then starts the n+1th rotation (360 degrees). In other words, the X-ray source 10 or the X-ray camera 20 stops once after the image capture in the nth rotation is completed, with a deceleration braking distance provided, and performs a moving motion with acceleration and deceleration in preparation for the n+1th rotation, and stops after the movement. After that, acceleration is performed along the rotation path so that n+1th imaging can be performed. In this way, 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 is inconvenient as it lengthens the inspection time.

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 in addition to the rotation for taking X-ray images, no rotation for acceleration or deceleration before and after stopping is performed.

In this embodiment, the trajectory of the moving motion is set to the trajectory that can move in the shortest time among the trajectories 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 trajectory that smoothly connects the turning circle of the nth turning motion and the turning circle of the n+1th turning motion may be a trajectory in which the linear velocity of the X-ray source 10 or the X-ray camera 20 is continuous at the turning end point and/or the turning start point. Alternatively, it is preferable that the trajectory is a trajectory in which 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.

Figure 3 shows an example of the trajectory of the movement in this case. The arrows and the numbers in circles 1 to 3 in the figure correspond to the nth rotation, movement, and n+1th rotation, respectively. Figure 3(a) shows an example of the trajectory of the movement of the X-ray camera 20. As shown in Figure 3(a), the trajectory 123a of the 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 nth rotation and the rotation circle 122b of the n+1th rotation at the top point of both (hereinafter, this point is also referred to as the 0 degree position or the 360 degree position).

3(b) also 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), forming 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 positioned in point symmetry with respect to the inspection point of the inspection object S. In this case, when the X-ray camera 20 is positioned at the 0-degree position or the 360-degree position, the X-ray source 10 needs to be positioned at the 180-degree position.

Note that, as shown in FIG. 3, a curve that smoothly connects the turning circle of the nth turning motion and the turning circle of the n+1th turning motion at a specified point and allows travel in the shortest time can be derived as a polynomial using known mathematical techniques, so the method of deriving the curve will not be described here in particular. In addition, a method of deriving a curve that allows travel in the shortest time among the curves that smoothly connect the turning end point of the nth turning motion and the turning start point of the n+1th turning motion may be to assign mathematical parameters such as the coefficients of each term of the polynomial curve obtained by a known method and select the one with the shortest travel time by repeated calculations.

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 the same as the movement time of the X-ray source 10 when moving along the trajectory 123b shown in FIG. 3(b). In other words, the speed of the movement of the one with the longer movement time is increased so that both complete their movements at the same time. This allows both to complete their movements at the same time and move on to the next rotational movement.

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

In addition, in this embodiment, the trajectory of the moving motion 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 the movement in the shortest time. This allows the X-ray source 10 and the X-ray camera 20 to transition more smoothly (without excessive acceleration or impact acting on the X-ray source 10 or the X-ray camera 20) from turning motion to moving motion, or from moving motion to turning motion. As a result, even if the speed of the turning motion is high, it is possible to more reliably perform acceleration and deceleration motion during the moving motion. Also, it is possible to more quickly transition the X-ray source 10 and the X-ray camera 20 from turning motion to moving motion, or from moving motion to turning motion.

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

本発明をＸ線検査装置に適用することで、経過時間が１３％程度改善されていることが分かる。ここで、図３におけるＸ線カメラ２０の移動運動の軌跡１２３ａ及びＸ線源１０の移動運動の軌跡１２３ｂは、本実施例において特定移動軌跡に相当する。この点は以下の実施例についても同じである。また、本実施例においては、Ｘ線カメラ２０の移動運動の軌跡１２３ａ及びＸ線源１０の移動運動の軌跡１２３ｂは、旋回円どうしを滑らかに結び最短の時間で移動可能な曲線としたが、必ずしも正確に最短である必要はない。旋回円どうしを滑らかに結ぶ曲線のうち充分に検査時間を短縮できるものであれば良い。

It can be seen that the application of the present invention to the X-ray inspection apparatus improves the elapsed time by about 13%. Here, the locus 123a of the movement of the X-ray camera 20 and the locus 123b of the movement of the X-ray source 10 in FIG. 3 correspond to the specific movement locus in this embodiment. This point is the same for the following embodiments. In this embodiment, the locus 123a of the movement of the X-ray camera 20 and the locus 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 need to be exactly the shortest. Any curve that smoothly connects the turning circles and can sufficiently shorten the inspection time will suffice.

In this embodiment, as described above, 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 the turning circle of the nth turning movement and the turning circle of the n+1th turning movement at the turning end point and turning start point, allowing movement in the shortest time. In addition to this, in this embodiment, the turning start point of the n+1th turning movement 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 movement to the n+1th turning movement is the shortest.

As shown in FIG. 4, in this embodiment, for example, m points arranged on the turning circle 122n+1 of the n+1th turning motion are set as candidate points for the turning start point on the turning circle 122n+1 of the n+1th 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+1th turning motion. Then, for a total of 2m candidate points in the clockwise and counterclockwise cases, a curve that smoothly connects the turning end point on the turning circle 122n of the nth turning motion and the turning start point on the turning circle 122n+1 of the n+1th turning motion and that can be moved in the shortest time is obtained, and the moving time is calculated. Then, the candidate point with the shortest moving time is set as the turning start point on the turning circle 122n+1 of the n+1th turning motion.

According to this, for multiple candidate points for the start point of rotation on the rotation circle 122n+1 of the n+1th rotation, a curve that smoothly connects the rotation circle 122n of the nth rotation and the start point of rotation and that can be moved in the shortest time is calculated, and the movement time is calculated. Then, a start point of rotation is determined that minimizes the movement time of the X-ray camera 20 when transitioning from the nth rotation to the n+1th rotation. Therefore, it is possible to more reliably minimize the movement time from the rotation circle 122n of the nth rotation to the rotation circle 122n+1 of the n+1th rotation. In the explanation of FIG. 4 or the following explanation, the trajectory of the movement 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 trajectory of the movement of the X-ray source 10.

Next, the effect of this embodiment will be described with reference to Figures 5 and 6. Figure 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 Figure 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 Figure 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. Figure 5(a) shows the case where the turning circle for the X-ray source 10 is transitioned from the left side to the right side in the figure and then transitioned to the upper side. Also, Figure 5(b) shows the case where the turning circle for the X-ray source 10 is transitioned from the lower side to the upper side in the figure and then transitioned from the right side to the left side in the figure. In Figure 5, the curve (movement trajectory) connecting the end point of one turning circle and the start point of the next turning circle is a complex and long curve, and it can be seen that the movement efficiency is low.

Figure 6 shows the transition of the turning circle and the curves (movement trajectories) connecting each turning circle when this embodiment is applied. That is, in Figure 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 allows movement in the shortest time, and the turning start point in the n+1th turning movement is determined by the method of Figure 4. In Figure 6, the dashed lines show the turning circles of each turning movement, and the solid lines show the curves (movement trajectories) connecting each turning circle. In Figure 6, the curves (movement trajectories) connecting one turning circle to the next turning circle are simplified and are shorter in length. As a result, it can be seen that the movement efficiency is increased.

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%.

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 the 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 memory unit 112, and is executed by the calculation unit 111 and the control unit 100. In the first half shown in Figure 7, the rotation start point for 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.

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

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

The processing in steps S03 to S06 is for calculating the travel time in parallel for 2m candidate turning start points set for both clockwise and counterclockwise turning for turning circle 122n+1 of the n+1th turning motion. Here, steps S03-1 to S06-1 will be used as a representative example, 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 begins.

More specifically, using the coefficients obtained in step S02, a curve that smoothly connects the end point of the turning circle 122n of the nth turning motion and the first candidate point on the turning circle 122n+1 of the n+1th turning motion and allows movement in the shortest time is calculated, and the movement time is calculated. 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 nth turning motion is the same as the start point of the turning circle 122n of the nth turning motion. When the processing of step S03-1 is completed, proceed to step S04-1.

In step S04-1, it is determined whether either the linear velocity or the axial velocity of the X-ray camera 20 exceeds the allowable velocity when moving for the movement time calculated in step S03-1. It is also determined whether the acceleration acting on the X-ray camera 20 exceeds the allowable acceleration, and whether the range of motion in the rotational and translational movements of the X-ray camera 20 exceeds the allowable range of motion.

If it is determined that either the linear velocity or 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 range of motion 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 there is a risk that the X-ray camera 20 will collide with a component within the X-ray inspection device 1.

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 range of movement, the process proceeds to step S06-1.

In step S05-1, the movement time is recalculated until the calculated movement time value converges. More specifically, the speed of the X-ray camera 20 or the acceleration acting on the X-ray camera 20 is reduced, 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 again. Then, the routine of steps S03-1 to S05-1 is repeatedly executed until 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 range of motion of the X-ray camera 20 does not exceed the allowable movement range.

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 permissible velocity, that the acceleration acting on the X-ray camera 20 does not exceed the permissible acceleration, and that the range of motion of the X-ray camera 20 does not exceed the permissible movement range, the process proceeds to step S06-1. Here, the permissible velocity is a speed value that is predetermined as a threshold value that does not exceed the permissible rotation speed of the motor or ball screw. The permissible 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 permissible movement range is a range of motion that is predetermined as a threshold value of the range of motion within which the X-ray camera 20 will not collide with other components within the device.

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 nth turning motion and the first candidate point on turning circle 122n+1 of the n+1th turning motion and that can be traveled along in the shortest time is calculated, along with the travel time. When the processing of step S06-1 (and the equivalent steps S06-2 to S06-2m for the other candidate points) is completed, proceed to step S07.

Next, in step S07, a time candidate that is the shortest travel time and does not exceed the 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 that travel time is selected. When the processing in S07 ends, the selected information is passed to the control unit 100. Note that the processing from step S01 to step S07 is executed by the calculation unit 111.

In step S08 of FIG. 8, the control unit 100 receives the movement time calculated in step S07. In addition, 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 (starting point of rotation) to which the X-ray camera 20 is to be moved, the rotation speed, the center of rotation, and the rotation radius. When the processing of steps S08 and S09 is completed, the process proceeds to step S10.

In step S10, the trajectory of movement to the rotation start point, which is the next 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 XX-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 movement of the X-ray source 10 and the X-ray camera 20. Note that the processing from step S08 to step S11 is executed by the control unit 100.

In this routine, in step S03-1 (to step S03-2m), a trajectory and travel time that can be traveled in the shortest time smoothly connecting the turning end point and 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 traveled in the shortest time smoothly connecting the turning end point and turning start point are 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 also be used.

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 in total for the clockwise and counterclockwise cases. However, the number of candidate points is not limited to this. The number of candidate points may be determined by comparing and considering the load of parallel calculation and the accuracy of the turning start point that minimizes the moving time. In the above embodiment, an example was described in which the present invention is applied to the X-ray inspection device 1, 11 that includes the X-ray source 10, the X-ray camera 20, and the holding unit 40, and obtains and inspects a three-dimensional image of the inspection object by turning any one of the X-ray source, the X-ray camera, and the holding unit as a turning unit. However, the technical idea of the present invention can be applied to other inspection devices. 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 turning circle of the nth turning motion and the turning circle of the n+1th turning motion at a predetermined point and enables movement 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.

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.

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

Note that, for example, when the turning circles are lined up horizontally, the method according to the comparative example shown in FIG. 9 may not be able to identify the shorter of the two arcs sandwiched between the two intersections. Therefore, in such cases, the comparative example must set the turning end point and turning start point of the turning motion at a predetermined angle position. In this case, for example, the turning end point of the turning circle of the nth turning motion is shifted 90 degrees counterclockwise, and the turning start point of the n+1th turning motion is shifted 90 degrees clockwise. This avoids a situation in which the turning end point and turning start point of the turning motion cannot be calculated.

Figure 10 is a diagram showing the effect of using the comparative example. In Figure 10, the dashed lines indicate the turning circles of each turning motion, and the solid lines indicate the curves (movement trajectories) connecting the turning circles. Figure 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. Also, Figure 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 Figure 10, the curves (movement trajectories) connecting the turning circles are simpler and shorter than those in the case of the conventional technology shown in Figure 5, and it can be seen that there is an effect of improving the movement efficiency. However, compared to the case where the embodiment of the present invention shown in Figure 6 is applied, the curves (movement trajectories) connecting the turning circles and the next turning circle are complex and long, and it can be seen that the movement efficiency is low.

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 countermeasures are taken, but longer than the 38.2 seconds when the embodiment of the present invention is applied.

In addition, according to the inventors' intensive research, new knowledge has been obtained about the trajectory of the movement movement when the distance between the turning circle of the nth turning movement and the turning circle of the n+1th turning movement is relatively long (for example, the distance between the centers of the turning circles is three times the diameter of the turning circle or more). This is that, when optimizing the starting point of the turning movement of the n+1th turning movement of the X-ray camera 20 and the X-ray source 10, the time reduction effect of the movement movement is greater if the ending point of the turning movement of the nth turning movement and the starting point of the turning movement of the n+1th turning movement are optimized for the X-ray camera 20 or the X-ray source 10 with the larger turning radius.

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 advisable to optimize the turning start point of the n+1th turning motion for the X-ray camera 20 or the X-ray source 10 that has a larger turning radius. In addition, it is advisable to make the X-ray camera 20 or the X-ray source 10 that makes a turning motion with a smaller radius reach the turning start point of the next turning motion at the same time as the X-ray camera 20 or the X-ray source 10 that makes a turning motion with a larger radius.

In this way, the X-ray camera 20 or the X-ray source 10 that performs a rotational motion with a smaller radius can reach the starting point of the n+1th rotational motion at the same time as the X-ray camera 20 or the X-ray source 10 that performs a rotational motion with a larger radius. As a result, the n+1th rotational motion can be started earlier, and the examination time can be more reliably shortened.

In the above embodiment, an example was described in which the present invention was 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 X-ray inspection devices having the above-mentioned configuration. The present invention may also 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.

Figure 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 device 11 in this embodiment. Figure 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 Figure 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 rotating movement.

In addition, in the following, 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 with the reference numerals in the drawings.
<Appendix 1>
an X-ray source (10) for generating X-rays to be irradiated onto an object to be inspected;
an X-ray camera (20) for capturing 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), thereby capturing the X-ray images while changing the shooting direction, and acquiring 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 movement for moving from a turning end point of one turning movement to a turning start point of the next turning movement;
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 motion is calculated by the trajectory calculation unit (111b) as a point to which any 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 motion to the rotation circle of the next rotational motion in the shortest movement time along the specific movement trajectory.
<Appendix 15>
an X-ray source (10) for generating X-rays to be irradiated onto an object to be inspected;
an X-ray camera (20) for capturing 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 three-dimensional 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 of the rotating parts (10, 20, 40), namely the X-ray source (10), the X-ray camera (20), and the holding part (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.

Reference Signs List 1, 11: X-ray inspection device 10: X-ray source 20: X-ray camera 40: Holding unit 100: Control unit 111: Calculation unit 111b: Trajectory calculation unit 121: X-ray source rotational motion rotation circle 122: X-ray camera rotational motion rotation circle 123: Movement motion trajectory S: Inspection object (substrate)

Claims (13)

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. 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 sequentially rotates at a plurality of locations and performs a moving motion for moving 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 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 any of the rotating parts, which are the X-ray source, the X-ray camera, and the holding part, does not exceed a predetermined allowable value. 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 clockwise and a case where the ... counterclockwise . 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. 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. 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. The X-ray inspection device according to any one of claims 1 to 6, characterized in that the specific movement trajectory is calculated as a polynomial or by using a parameter for a trigonometric function. The X-ray inspection device according to claim 1, 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 speed, 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. The X-ray inspection device according to any one of claims 1 to 8, characterized in that the rotating part is the X-ray source and the X-ray camera, and the holding part is held at a predetermined position within the X-ray inspection device. 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 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 unit 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 end point of rotation and /or the start point of rotation. The X-ray inspection method according to claim 10, characterized in that any one of the rotating parts, the X-ray source, the X-ray camera, and the holding part, is shifted from the rotating motion to the moving motion without stopping. 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. 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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