WO2013108475A1 - Inspection device, inspection method and inspection program - Google Patents

Description

Inspection device, inspection method, and inspection program

The present invention relates to an inspection apparatus, an inspection method, and an inspection program for inspecting an inspection object with transmitted radiation.

Conventionally, an inspection apparatus that inspects the quality of an inspection object based on transmitted radiation that has passed through the inspection object is known. For example, in Patent Document 1, the X-ray generator is fixedly installed, the inspection object is in a two-dimensionally movable state, and the area sensor that detects the transmitted radiation can be two-dimensionally moved and rotated. An apparatus is disclosed in which both the generation of an X-ray CT image and the generation of a tomographic image can be executed by entering the state.

JP 2010-2221 A

Conventionally, inspection could not be executed at high speed with a simple configuration. That is, as disclosed in Patent Document 1, in order to make an area sensor movable in two dimensions, a configuration for moving an extremely heavy area sensor along two orthogonal axes is necessary. Therefore, a large-scale device is necessary. In particular, in order to perform high-speed shooting, it is necessary to repeat the process of moving the area sensor at high speed, stopping at the shooting position, and performing shooting at high speed. The acceleration is large and it is impossible to make the device configuration simple.

In general, in order to perform high-precision inspection, it is necessary to magnify an inspection object at a high magnification, but an area sensor that can detect radiation such as X-rays in a wide area is extremely expensive. It is practically impossible to photograph an inspection object of a predetermined size such as a substrate by one photographing. Therefore, in reality, all the examination parts in the examination object are imaged by imaging the examination object a plurality of times. In this case, in order to image the inspection object at one imaging position, imaging and movement by the area sensor are repeated, but the area sensor cannot perform imaging in the process of the movement, and transmitted radiation is not transmitted. It is a complete waiting period that is not acquired. Therefore, it is practically impossible to acquire transmitted radiation at high speed using an area sensor.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique for executing an inspection at high speed with a simple configuration.

To achieve the above object, in the inspection apparatus according to the present invention, the line sensor is configured to be movable along the first straight line, and the radiation generator is configured to be movable along the second straight line. Here, the first straight line and the second straight line are not on the same plane, and are straight lines orthogonal to each other when the second straight line is translated so as to intersect the first straight line. In addition, the inspection object can be moved on a moving plane that is parallel to the first straight line and the second straight line and exists between the first straight line and the second straight line. The inspection image is generated based on the transmitted radiation.

That is, although the inspection object can move two-dimensionally on the moving plane, each of the line sensor and the radiation generator can move on one axis and does not move in directions other than the respective axial directions. In such a configuration, when the line sensor and the radiation generator are moved along each axis, the relative positional relationship between the line sensor, the radiation generator, and the inspection object is changed to various positional relationships, for example, the focal point of the radiation generator. Can be set so that the angle of the straight line extending from the center to the reference position (center point, etc.) of the line sensor is in various directions from an acute angle to a right angle, and the line is irradiated with radiation from various directions. Transmitted radiation can be acquired at the sensor. When the transmission radiation that has passed through the inspection target is acquired by the line sensor, an inspection target image is generated based on the transmission radiation, and therefore the inspection target may be inspected automatically or visually based on the inspection target image. Is possible.

In the above configuration, since the transmitted radiation is detected by the line sensor, it is possible to detect the transmitted radiation that has been transmitted from the inspection target existing in the irradiation range of the radiation irradiated from the radiation generator and reaching the line sensor. Therefore, if the inspection object is configured to pass through the irradiation range, the inspection object can be imaged two-dimensionally. For example, the line sensor and the radiation generator are moved and fixed to a predetermined imaging position, and the line sensor and the radiation generator are irradiated from the radiation generator in a state where the line sensor and the radiation generator are fixed to the imaging position. If the inspection object is moved so that the inspection object passes through the radiation irradiation range that arrives, and the inspection object image is generated based on the transmitted radiation acquired in the process of passing through the radiation irradiation range, the area sensor It is possible to generate an inspection target image equivalent to the case where transmitted radiation is acquired in step (b).

As described above, in order to make the area sensor movable in two dimensions, a configuration for moving the extremely heavy area sensor along two orthogonal axes is necessary, and a large-scale device is required. It is. However, since the inspection apparatus according to the present invention generally uses an extremely light line sensor as compared with the area sensor, the movement control for moving the sensor becomes extremely easy and has an extremely simple configuration. Realization is possible.

In addition, as described above, an area sensor that can detect radiation in a wide area is very expensive, and thus an imaging target of a predetermined size, such as a substrate on which a plurality of inspection targets are mounted, is captured by one imaging. It is virtually impossible. Therefore, in order to capture the entire area of the imaging target such as the substrate with the area sensor, it is necessary to repeat imaging a plurality of times. However, if a line sensor that includes the entire area in the width direction of the imaging target in the field of view is used, the transmitted radiation over the entire area of the substrate is acquired by moving the imaging radiation through the irradiation range as described above. Is possible. Since such a line sensor is generally cheaper than an area sensor, an inspection apparatus can be configured at a very low cost.

Furthermore, an area sensor that captures an imaging target of a certain size a plurality of times and acquires transmitted radiation over the entire area of the imaging target is heavier than a line sensor that includes the entire area in the width direction of the equivalent imaging target in the field of view. . Therefore, when shooting multiple times by repeatedly moving and stopping the area sensor, the acceleration acting on the heavy area sensor is large, and the mechanism for moving the area sensor and its surrounding housing are sturdy. It is necessary to configure, and it is impossible to make the apparatus configuration simple. However, according to the inspection apparatus of the present invention, it is possible to acquire transmitted radiation over the entire area of the imaging target using a lighter line sensor compared to the area sensor, and to perform imaging with the line sensor fixed. Transmitted radiation over the entire area of the object can be acquired. Therefore, the mechanism for moving the line sensor, the surrounding housing, and the like can be simplified.

Furthermore, since the line sensor may be moved along the first straight line even after the transmission radiation is imaged, the configuration is simple and the weight acting on the line sensor is light. It is smaller than the acceleration acting on the area sensor. Therefore, also in this sense, the mechanism for moving the line sensor, the surrounding housing, and the like can be simplified.

Furthermore, when the movement and stop of the area sensor are repeated in order to acquire transmitted radiation over the entire area to be imaged, the vibration of the area sensor converges during and after the area sensor starts moving and after the area sensor stops. Until this time, transmitted radiation cannot be acquired, and this period is a complete waiting period in which transmitted radiation is not acquired. Since the number of times the area sensor moves and stops increases as the magnification of the object to be imaged increases, the total amount of the waiting period described above increases. However, in the line sensor, it is possible to acquire the transmitted radiation of the entire area of the imaging target by fixing the line sensor having a length capable of imaging the entire width of the imaging target and moving the imaging target continuously. Therefore, there is no waiting period during which transmitted radiation is not acquired, and high-magnification transmitted radiation can be acquired at high speed.

In the inspection apparatus according to the present invention, it is necessary to move the radiation generator along the second straight line, but the movable direction is the direction along the second straight line, and the transmitted radiation is acquired by the line sensor. It is only necessary that the radiation generator is fixed while the transmission line is not acquired by the line sensor while the radiation generator is acquired. Therefore, the configuration for moving the radiation generator is a simple configuration.

In the inspection apparatus according to the present invention, the line sensor can be moved along the first straight line, the radiation generator can be moved along the second straight line, and the inspection object can be moved within the moving plane. Therefore, the relative relationship among the line sensor, the radiation generator, and the inspection object can be various. Therefore, various inspection methods such as an inspection method for transmitting radiation in a direction perpendicular to the moving plane and an inspection method for transmitting radiation in a direction inclined (≠ 90 °) with respect to the moving plane can be adopted. In addition, the movement trajectory on the moving plane of the inspection target can be a linear or circular shape, and various types of trajectories can be adopted, and various inspection methods for moving on the various types of trajectories can be adopted. is there. Furthermore, these various inspection methods can be freely combined and executed according to the inspection purpose.

Here, the line sensor moving means only needs to be able to move the line sensor along the first straight line in a state where the first straight line direction and the longitudinal direction of the line sensor coincide with each other. That is, it is sufficient that the line sensor can be moved linearly in the longitudinal direction. For example, the line sensor is moved by various mechanisms for moving an object along a linear member such as a ball screw. It can be adopted.

The line sensor is a sensor in which at least one detection element exists in a direction perpendicular to the longitudinal direction, and a large number of detection elements are arranged in the longitudinal direction. The detection element of several pixels is arranged in the direction perpendicular to the longitudinal direction. Although they may be arranged, a low-cost and light-weight sensor is adopted as the line sensor of the inspection apparatus according to the present invention as compared with an area sensor in which a large number (for example, several thousand) of detection elements are arranged two-dimensionally. The Furthermore, the first straight line only needs to be parallel to the movement plane of the inspection object, but when the inspection object can move along two directions within the movement plane, it is preferable that the first straight line be parallel to one of them.

The radiation generator moving means only needs to be able to move the radiation generator that emits radiation toward the line sensor along the second straight line. Again, various configurations can be employed as a configuration for linearly moving the radiation generator, and for example, a mechanism for moving an object along a linear member such as a ball screw can be employed. . The radiation generator may be configured such that radiation such as X-rays output from the focal point passes through the moving plane and reaches the line sensor. The beam shape is preferably a fan beam, but the cone It may be a beam.

Furthermore, the second straight line is parallel to the moving plane to be inspected, and the second straight line is provided at a position that is not on the same plane as the first straight line in relation to the first straight line. It is set so as to be orthogonal to the first straight line when it is translated so as to cross the first straight line. In other words, the first straight line and the second straight line are set to have a twisted relationship, and the first straight line and the second straight line are set to be orthogonal to each other when projected onto the moving plane to be inspected. Is done. In addition, when the test object is movable in two directions within the moving plane, it is preferable that the first straight line is parallel to one and the second straight line is parallel to the other.

Furthermore, the radiation generator moving means may be configured to move the radiation generator while adjusting the position and orientation of the radiation generator. For example, the radiation generator may be moved along the second straight line while being inclined so that the optical axis passing through the focal point of the radiation generator (a straight line passing through the center of the radiation irradiation range) always faces the line sensor.

The inspection object moving means only needs to be able to move the inspection object on a moving plane parallel to the first straight line and the second straight line within the radiation irradiation range. For example, X− that moves along two orthogonal axes A Y stage or the like can be used. Further, in order to continuously inspect a large number of inspection objects, it is preferable that the inspection apparatus is configured to be interlocked with a conveyance mechanism of the inspection objects.

The inspection target image generation unit only needs to be able to generate the inspection target image based on the transmitted radiation that has passed through the inspection target acquired by the line sensor, and generates a fluoroscopic image that indicates the intensity distribution of the two-dimensional transmitted radiation. The image may be the inspection target image, or may be the inspection target image by performing various types of image processing (for example, three-dimensional reconstruction, tomographic image generation, etc.).

As an example of the relative relationship among the line sensor, the radiation generator, and the inspection target, a configuration example in which the line sensor and the radiation generator are fixed at a specific place and the inspection target is moved can be adopted. Specifically, the line sensor is moved to a specific location and fixed, and the radiation generator is moved to a specific location and fixed to fix the line sensor and the radiation generator at the imaging position. In a state where the line sensor and the radiation generator are fixed at the imaging position, it is possible to adopt a configuration in which the inspection object is moved so that the inspection object passes through the radiation irradiation range. In this configuration, the transmitted radiation acquired in the process in which the inspection object passes through the radiation irradiation range is transmitted radiation obtained by irradiating the inspection object with radiation from a specific angle. Therefore, a fluoroscopic image to be inspected can be generated from the transmitted radiation, and the fluoroscopic image can be used as the inspection target image.

Furthermore, as an example of the relative relationship between the line sensor, the radiation generator, and the inspection object, one of the line sensor and the radiation generator is fixed at a specific position and the other is fixed at a plurality of specific positions. It is possible to adopt a configuration example in which the inspection object is moved while the generator is fixed at each position. For example, with the line sensor moved to a specific position and fixed, the radiation generator may be moved and fixed to a plurality of imaging positions along the second straight line. In this case, in a state where the line sensor is fixed at a specific position and the radiation generator is fixed at each of a plurality of imaging positions, the inspection object is moved so that the inspection object passes through the radiation irradiation range. The transmitted radiation that has passed through the inspection object is acquired by the sensor. That is, by performing imaging at a plurality of imaging positions where the positions of the radiation generators are different, transmitted radiation is acquired in a state where the radiation to be examined is irradiated at a plurality of angles.

In this case, a three-dimensional reconstructed image or a cross-sectional image in a direction parallel to the moving plane is generated based on the transmitted radiation acquired in the process of passing the inspection target through the radiation irradiation range, and used as the inspection target image. That is, since data of transmitted radiation acquired by irradiating the inspection object with radiation at a plurality of angles is obtained, the inspection can be performed by generating a three-dimensional reconstructed image or a cross-sectional image. Of course, here, it is also possible to generate a fluoroscopic image based on transmitted radiation acquired by irradiating the inspection target with radiation at a plurality of angles to obtain the inspection target image. In this example, the line sensor is fixed at one location and the radiation generator is fixed at multiple locations. However, the radiation generator is fixed at one location and the line sensor is fixed at multiple locations. You may do it.

Furthermore, as an example of the relative relationship between the line sensor, radiation generator, and inspection object, the line sensor and radiation generator are fixed at a plurality of locations, and the line sensor and radiation generator are fixed at each location. A configuration example that moves the object can be adopted. For example, the line sensor and the radiation generator are placed at a plurality of imaging positions such that a third straight line connecting the reference position of the line sensor and the focal point of the radiation generator intersects a predetermined figure provided on the moving plane to be inspected. It is good also as moving and fixing. In this case, in the state where the line sensor and the radiation generator are fixed at each of the imaging positions, the inspection is performed by the line sensor by moving the inspection object so that the inspection object passes through the radiation irradiation range including the third straight line. The transmitted radiation that has passed through the object is acquired. That is, by performing imaging at a plurality of imaging positions where the position of the line sensor and the position of the radiation generator are different, the transmitted radiation is acquired in a state where the radiation to be examined is irradiated at a plurality of angles.

In this case as well, a three-dimensional reconstructed image or a cross-sectional image in a direction parallel to the moving plane is generated based on the transmitted radiation acquired in the process of passing the irradiation target through the radiation irradiation range, and used as the inspection target image. That is, since data of transmitted radiation acquired by irradiating the inspection object with radiation at a plurality of angles is obtained, the inspection can be performed by generating a three-dimensional reconstructed image or a cross-sectional image. Of course, here, it is also possible to generate a fluoroscopic image based on transmitted radiation acquired by irradiating the inspection target with radiation at a plurality of angles to obtain the inspection target image.

Although the case where the present invention is realized as an apparatus has been described above, the present invention can also be realized as a method and program for realizing the apparatus and a medium recording the program. In addition, the inspection apparatus as described above may be realized by itself, applied to a certain method, or may be used in a state of being incorporated in another device. Is not limited to this, but includes various aspects. Therefore, it can be changed as appropriate, such as software or hardware. The software recording medium may be a magnetic recording medium, a magneto-optical recording medium, or any recording medium to be developed in the future.

It is a block diagram of an inspection device. (2A), (2B) is a figure which shows the positional relationship of the component of an inspection apparatus. (3A) is a flowchart of fluoroscopic image inspection processing, and (3B) is a flowchart of cross-sectional image inspection processing or three-dimensional reconstructed image inspection processing. (4A) and (4B) are diagrams showing the positional relationship of the components of the inspection apparatus. (5A) to (5L) are diagrams showing the positional relationship of the components of the inspection apparatus. (6A) to (6L) are diagrams showing the positional relationship of the components of the inspection apparatus.

Here, embodiments of the present invention will be described in the following order.
(1) Configuration of the inspection device:
(2) Perspective image inspection processing:
(3) Cross-sectional image inspection processing:
(4) Three-dimensional reconstructed image inspection process:
(5) Other embodiments:

(1) Configuration of the inspection device:
FIG. 1 is a schematic block diagram of an inspection apparatus 1 according to an embodiment of the present invention. The inspection apparatus 1 shown in FIG. 1 includes a line sensor moving mechanism 10, a line sensor control unit 11, a stage 12, a stage control unit 13, a radiation generator moving mechanism 14, a radiation control unit 15, an input unit 16, an output unit 17, and a memory. 18 and CPU 19 are provided. The inspection apparatus 1 is an apparatus that inspects the shape of solder as an inspection target formed on a substrate W, wiring between layers of a multilayer substrate, components, and the like. The substrate W is planar, and the inspection apparatus 1 holds the substrate W so that the planar direction of the substrate W is ideally horizontal and the thickness direction of the substrate W is vertical.

The stage 12 has a holding mechanism for holding the substrate W, and can move the substrate W in a plane parallel to the horizontal plane while holding the substrate W. Accordingly, the stage 12 moves the inspection target in a plane parallel to the horizontal plane along with the movement of the substrate W, and the plane parallel to the horizontal plane is referred to as the movement plane of the inspection target. In the present embodiment, the stage 12 can move the substrate W along two orthogonal axes. In this specification, directions parallel to each axis are defined as an X-axis direction and a Y-axis direction. To do. A direction perpendicular to the X axis and the Y axis is defined as a Z axis direction. In FIG. 1, the movable direction of the substrate W is indicated by dashed-dotted arrows Dx and Dy around the stage 12.

The stage control unit 13 is a circuit that outputs a control signal to the stage 12 in response to a control instruction output from the CPU 19. When the CPU 19 instructs an arbitrary position, the stage controller 13 moves the substrate W to the position. The control signal is output. As a result, the stage 12 can move the substrate W (or the inspection target on the substrate W) to an arbitrary position designated by the CPU 19.

The line sensor control unit 11 includes a rail 10a and a line sensor 10b. The line sensor 10b is a sensor in which a plurality of detection elements are arranged in a line along one direction, detects the intensity of X-rays reaching each detection element, and the intensity of X-rays detected by each detection element. The information indicating is output. That is, the line sensor 10b is an X-ray sensor configured by arranging a plurality of detection elements in the longitudinal direction. The rail 10a is a linear member that is long in one direction, and includes a groove that moves the line sensor 10b along the one direction. That is, the line sensor 10b is provided with a projection (not shown), and the line sensor 10b is moved with the projection inserted into the rail 10a, thereby moving the line sensor 10b along the direction in which the rail 10a extends. It is configured to be able to. In the present embodiment, the moving direction of the line sensor 10b is set to be parallel to the longitudinal direction of the line sensor 10b and parallel to the Y-axis direction. Here, a straight line extending in the longitudinal direction of the line sensor 10b is defined as a first straight line. In FIG. 1, the movable direction of the line sensor 10 b is indicated by a one-dot chain line arrow D _{1 at} the lower right of the line sensor 10 b.

The line sensor control unit 11 is a circuit that outputs a control signal to the rail 10a and the line sensor 10b in response to a control instruction from the CPU 19, and the CPU 19 instructs an imaging position for acquiring transmitted X-rays. In this case, the line sensor 10b is moved to the imaging position, and transmitted X-rays detected by the detection elements included in the line sensor 10b are acquired from the line sensor 10b and transferred to the CPU 19.

The radiation generator moving mechanism 14 includes a radiation generator 14a and a rail 14b. The radiation generator 14a emits X-rays as radiation in a fan beam shape from a focal point determined by the optical system of the radiation generator 14a. The rail 14b is a linear member that is long in one direction, and includes a mechanism for moving the radiation generator 14a along the one direction. In the present embodiment, the movement direction of the radiation generator 14a is set to be parallel to the X-axis direction. Here, the moving direction of the radiation generator 14a is defined as the second straight line.

In the present embodiment, the line sensor moving mechanism 10 and the radiation generator moving mechanism 14 are arranged so as to sandwich the moving plane of the substrate W as shown in FIG. When there is an inspection target on the substrate W within the X-ray irradiation range, the transmitted X-ray transmitted through the inspection target reaches the line sensor 10b, and the transmitted X-ray transmitted through the inspection target by the line sensor 10b. Will be detected.

Further, in the present embodiment, the radiation generator moving mechanism 14 includes an inclination mechanism (not shown) for inclining the radiation generator 14a, and in the process of moving the radiation generator 14a along the second straight line, radiation generation is performed. The optical axis of the detector 14a (the straight line O passing through the focal point at the center of the X-ray output range) is always tilted so as to face the direction of the line sensor 10b. Further, the tilt and movement are performed so that the position of the focal point of the radiation generator 14a in the Z-axis direction does not change. Therefore, in an arbitrary straight line that reaches the line sensor 10b from the focal point of the radiation generator 14a, the ratio of the distance from the focal point of the radiation generator 14a to the moving plane and the distance from the moving plane to the line sensor 10b is constant. The transmission X-ray of the inspection object can be acquired in a state where the inspection object is enlarged at a magnification of. In FIG. 1, the moving direction of the radiation generator 14 a is indicated by a one-dot chain line arrow D _{2 on} the left and right of the radiation generator 14 a, and the radiation generator 14 a moved while being inclined is indicated by a broken line.

That is, in this embodiment, the radiation generator 14a is configured such that the optical axis is parallel to the Z axis at the center of the movable range, and in this state, the optical axis is the center of the movable range of the line sensor 10b. It is comprised so that it may cross (the center of the rail 10a). The radiation control unit 15 is a circuit that outputs a control signal to the radiation generator 14a and the rail 14b in accordance with a control instruction output from the CPU 19, and instructs the imaging position for the CPU 19 to acquire transmitted X-rays. In this case, the radiation generator 14a is moved to the imaging position, and X-rays having a predetermined intensity are irradiated from the radiation generator 14a.

2A shows a state in which the line sensor moving mechanism 10, the substrate W, and the radiation generator moving mechanism 14 are viewed from a direction parallel to the Y axis, and FIG. 2B shows the line sensor moving mechanism 10 from a direction parallel to the X axis. And the substrate W and the radiation generator moving mechanism 14 are viewed. As shown in FIG. 2A, the second straight line L _2, which is the movement direction of the radiation generator 14a is parallel to the X-axis direction. As shown in FIG. 2B, the first straight line L ₁ that is the moving direction of the line sensor 10b is parallel to the Y-axis direction. Since the first straight line L ₁ exists above the movement plane of the substrate W and the second straight line L ₂ exists below the track plane of the substrate W, the first straight line L ₁ and the second straight line L ₂ are There is a so-called twisted relationship that does not intersect. Further, when the second straight line L ₂ is translated along the Z-axis direction so as to intersect the first straight line L ₁ , the two are in a relationship orthogonal to each other.

In this embodiment, the radiation generator 14a has a movable range on the rail 14b in a state where the optical axis of the radiation generator 14a is perpendicular to the Z-axis direction as shown in FIGS. The position where the optical axis intersects with the rail 10a when the optical axis of the radiation generator 14a is parallel to the Z-axis direction is the center of the movable range of the line sensor 10b on the rail 10a. The fan beam irradiated from the radiation generator 14a is set so that at least the broken line range R shown in FIG. Therefore, as shown in FIG. 2B, the line sensor 10b can move within the irradiation range of the fan beam.

2B, when the inspection apparatus 1 is viewed from the X-axis direction, the X-ray irradiation range extends over a wide range R, but as illustrated in FIG. 2A, the inspection apparatus 1 is viewed from the Y-axis direction. , The X-ray irradiation range is limited to a narrow range R. That is, in FIG. 2A, since the solid line R extending from the focal point of the radiation generator 14a to the line sensor 10b is an irradiation range when viewed from the Y-axis direction, when the substrate W and the solid line R intersect, Transmitted X-rays that pass through the inspection object of the part are obtained. For this reason, by moving the substrate W along the X-axis direction, transmitted X-rays transmitted through the inspection object existing in the entire area of the substrate W can be obtained. In the present embodiment, the length of the line sensor 10b in the direction parallel to the Y-axis direction is such that the entire range in the direction parallel to the Y-axis direction of the substrate W can be photographed at a time. It is configured. That is, the transmission X-rays in the range indicated by the alternate long and short dash line in FIG. 2B are configured to have such a length that can be detected without moving the line sensor 10b.

The input unit 16 includes an input device for accepting an operation of an inspection operator or the like, and generates an operation signal corresponding to the operation of the inspection operator using an input device such as a mouse or a keyboard. The output unit 17 includes an output device for outputting the inspection progress of the substrate W, inspection results, images, and the like, and includes, for example, a display or a printer as an output device. The memory 18 records execution data for executing a board inspection program A described later. The memory 18 also records intermediate data and intermediate image data generated and acquired during execution of the board inspection program A. The CPU 19 is an arithmetic device that reads out execution data from the memory 18 and executes the board inspection program A.

The board inspection program A includes a line sensor moving part A1, a radiation generator moving part A2, an inspection object moving part A3, an inspection object image generating part A4, and an inspection part A5. The line sensor moving unit A1 is a module that causes the CPU 19 to realize a function of moving the line sensor 10b along the first straight line. That is, the CPU 19 outputs a control instruction indicating a predetermined photographing position to the line sensor control unit 11 by the processing of the line sensor moving unit A1. As a result, the line sensor control unit 11 outputs a control signal for moving the line sensor 10b to the photographing position with respect to the rail 10a, and moves the line sensor 10b to the photographing position and fixes it.

The radiation generator moving unit A2 is a module that causes the CPU 19 to realize a function of moving the radiation generator 14a along the second straight line. That is, the CPU 19 outputs a control instruction indicating a predetermined imaging position to the radiation control unit 15 by processing of the radiation generator moving unit A2. As a result, the radiation control unit 15 outputs a control signal for moving the radiation generator 14a to the rail 14b, and moves and fixes the radiation generator 14a to the imaging position.

The inspection object moving unit A3 is a module that causes the CPU 19 to realize a function of moving the inspection object on the substrate W on the movement plane. That is, the CPU 19 irradiates the X-rays that are irradiated from the radiation generator 14a and reach the line sensor 10b with the line sensor 10b and the radiation generator 14a fixed at the imaging position by the processing of the inspection object moving unit A3. A control signal for moving the substrate W so that the inspection object on the substrate W passes through the range is output to the stage controller 13. As a result, the stage control unit 13 outputs a control signal for moving the substrate W to the stage 12, moves the substrate W to the vicinity of the X-ray irradiation range, and is irradiated with the X-rays. The substrate W is moved so as to pass through the X-ray irradiation range. As a result, the inspection object passes through the X-ray irradiation range.

The inspection target image generation unit A4 is a module that causes the CPU 19 to realize a function of generating an inspection target image based on the transmitted X-rays acquired by the line sensor 10b. That is, the CPU 19 acquires transmitted X-rays output from the line sensor control unit 11 by the processing of the inspection target image generation unit A4. As a result, the CPU 19 acquires transmitted X-rays acquired when the inspection target on the substrate W passes through the X-ray irradiation range, that is, information indicating the two-dimensional distribution of transmitted X-ray intensity. Therefore, the CPU 19 acquires any or a combination of a fluoroscopic image, a cross-sectional image, and a three-dimensional reconstructed image to be inspected as an inspection target image based on the two-dimensional distribution of the intensity of the transmitted X-ray.

The inspection unit A5 is a module that causes the CPU 19 to realize a function of inspecting an inspection object based on an inspection object image. That is, the CPU 19 extracts a feature amount for determining the quality of the inspection target from the inspection target image, and determines the quality of the inspection target by comparing the feature amount with a predetermined quality determination criterion.

As described above, in the inspection apparatus 1 according to the present embodiment, when the line sensor 10b is moved along the first straight line and the radiation generator 14a is moved along the second straight line, from the focal point of the radiation generator 14a. The angle of the straight line extending to the reference position of the line sensor 10b (for example, the position of the element existing in the center among the detection elements arranged in the longitudinal direction) can be set so as to be in various directions from an acute angle to a right angle ( Specific examples will be described later). Therefore, transmission X-rays can be acquired by the line sensor 10b in a state in which X-rays are irradiated from various directions to the inspection object, and the inspection object is imaged from various directions using the single inspection apparatus 1. can do. Therefore, various inspection methods can be inspected using one inspection apparatus 1.

Further, in the inspection apparatus 1 according to the present embodiment, the two-dimensional distribution of the intensity of transmitted X-rays is obtained using the line sensor 10b by moving the inspection target so as to pass through the X-ray irradiation range. Can be acquired. Therefore, a two-dimensional distribution of transmitted X-ray intensity can be acquired without using an area sensor.

Note that, as an apparatus that is currently used as a sensor for detecting X-rays, for example, an area sensor having a detection element of 6 million pixels can be cited. Here, it is assumed that the effective pixels of the area sensor are 2000 pixels × 3000 pixels, the area on the moving plane that can be imaged by the effective pixels is 80 × 120 mm, and the frame rate is 1 fps. Further, it is assumed that an area to be photographed on the substrate W on which an inspection target such as solder is placed has a size of 320 mm × 240 mm.

In this case, in order to photograph the entire area of 320 mm × 240 mm with the area sensor, it is necessary to repeat the movement and photographing of the area sensor eight times (= (320/80) × (240/120)). Here, assuming that a realistic time of 0.5 seconds is assumed as the time from when the shooting by the area sensor is completed to when the movement is performed and the shooting can be performed again, the frame rate is 1 fps, and 1 for one shooting. Since a time of 2 seconds is required, 12 seconds (= 1.5 × 8) are required to shoot all 8 times.

On the other hand, a sensor with 8000 pixels and a capturing speed of 2000 Hz is assumed as the line sensor 10b according to the present embodiment. That is, a sensor is assumed in which the length of the line sensor 10b in the longitudinal direction is four times as long as one side of the area sensor and can capture 2000 lines per second. Since the pixel pitch of the area sensor described above is 40 μm (= 80/2000), when capturing with the same resolution of 40 μm, the moving speed of the substrate W on which the inspection object is placed is 80 mm / second (= 40 μm × 2000 Hz). It becomes.

In this case, in order to image the entire area of 320 mm × 240 mm by the line sensor 10b, the X-ray irradiation range may be moved so that the substrate W having a width of 320 mm passes once. It takes 3 seconds (= 240/80) to acquire transmitted X-rays for the whole. Therefore, the time required for imaging at the same imaging position on the same substrate W is ¼ in the present embodiment using the line sensor 10b as compared with the apparatus using the area sensor, and the high speed. You can shoot. For this reason, in the three-dimensional reconstruction analysis and cross-sectional analysis in which images are taken at a plurality of shooting positions, it is possible to perform a plurality of times of shooting at a very high speed compared to the case of using an area sensor.

Furthermore, when the movement and stop of the area sensor are repeated, the time from the start of the movement of the area sensor to the convergence of the vibration of the area sensor after the movement stops, that is, 0.5 seconds in the above example. Transmission X-rays cannot be acquired, and this period is a complete standby period during which transmission X-rays are not acquired. When an area sensor is used, a large sensor capable of photographing the substrate W at a time is extremely expensive and unrealistic, so it is practically necessary to repeat photographing. However, in this case, the above-described standby period occurs, and the standby period becomes longer and the inefficiency is increased as the number of photographing is increased. However, in the line sensor 10b, since a standby period does not occur when the substrate W is imaged at one imaging position, it is possible to efficiently perform imaging.

Furthermore, comparing the 6 million pixel area sensor with the 8000 pixel line sensor 10b, the area sensor is extremely expensive. Therefore, the inspection apparatus according to the present embodiment can be configured at a low cost. Furthermore, when comparing an area sensor with 6 million pixels and a line sensor 10b with 8000 pixels, the area sensor is much heavier. Therefore, in the case where the area sensor is moved and stopped for repeated shooting, a configuration for moving the area sensor along two orthogonal axes is necessary. Further, the acceleration acting on the heavy area sensor is large. Therefore, the mechanism for moving the area sensor is complicated, and it is necessary to make the mechanism and its surrounding casing robust, and it is impossible to make the device configuration simple.

However, in the inspection apparatus according to the present invention, the line sensor 10b may be movable along the first straight line, and the radiation generator 14a may be movable along the second straight line. Further, it is possible to acquire transmitted X-rays over the entire area of the substrate W on which the inspection target is placed by using the line sensor 10b which is lighter than the area sensor, and the inspection target is in a state where the line sensor 10b is fixed. It is possible to acquire transmitted X-rays over the entire area of the substrate W on which the is placed. Therefore, the mechanism for moving the line sensor 10b and the like is simple, and the mechanism and the surrounding housing can be configured simply.

Furthermore, in the inspection apparatus according to the present invention, the line sensor 10b can be moved along the first straight line, the radiation generator 14a can be moved along the second straight line, and the inspection object can be moved within the moving plane. Therefore, the relative relationship among the line sensor 10b, the radiation generator 14a, and the inspection object can be various. Accordingly, various inspection methods such as an inspection method that transmits X-rays in a direction perpendicular to the moving plane and an inspection method that transmits X-rays in a direction inclined (≠ 90 °) with respect to the moving plane can be adopted. . Hereinafter, specific examples of inspection by various inspection methods will be described.

(2) Perspective image inspection processing:
In the inspection apparatus 1 according to the present embodiment, the fluoroscopic image inspection can be performed by fixing the line sensor 10b and the radiation generator 14a at a specific location and moving the inspection target to acquire transmitted X-rays. it can. FIG. 3A is a flowchart showing a fluoroscopic image inspection process. The operator can designate the inspection method in advance by the input unit 16 and cause the CPU 19 to execute the board inspection program A. When the board inspection program A is executed by designating inspection based on the fluoroscopic image, the CPU 19 The fluoroscopic image inspection process shown in 3A is executed.

In the fluoroscopic image inspection processing, the CPU 19 sets the substrate W including the inspection target on the stage 12 by the processing of the substrate inspection program A (step S100). That is, the CPU 19 controls a transport mechanism (not shown) to transport the substrate W to the stage 12, deliver the substrate W to the stage 12, and output a control instruction for supporting the substrate W to the stage control unit 13. Thus, the substrate 12 is supported on the stage 12. As a result, the stage 12 can move the substrate W on the moving plane.

Next, the CPU 19 moves the line sensor 10b and the radiation generator 14a to the imaging position by the processing of the line sensor moving unit A1 and the radiation generator moving unit A2 (step S110). In the fluoroscopic image inspection process, there is one photographing position, and in this embodiment, the CPU 19 performs the processing of the line sensor moving unit A1 to the line sensor control unit 11 so that the line sensor 10b is positioned at the center of the movable range. Output a control instruction. As a result, the line sensor control unit 11 moves and fixes the line sensor 10b to the center of the movable range as shown in FIG. 2B. Further, the CPU 19 outputs a control instruction to the radiation control unit 15 so that the radiation generator 14a is positioned at the center of the movable range by the processing of the radiation generator moving unit A2. As a result, the radiation control unit 15 moves and fixes the radiation generator 14a to the center of the movable range as shown in FIG. 2A. That is, in the fluoroscopic image inspection processing according to the present embodiment, the optical axis extending from the radiation generator 14a to the line sensor 10b side is parallel to the Z-axis direction, and the optical axis is located at the center of the line sensor 10b. The line sensor 10b and the radiation generator 14a are moved and fixed at the imaging positions where they intersect.

Next, the CPU 19 moves the substrate W including the inspection target to the imaging preparation position by the processing of the inspection target moving unit A3 (step S120). That is, the CPU 19 outputs a control signal to the stage control unit 13 and drives the stage 12 to position P (FIG. 2A) where one side of the substrate W is in contact with the X-ray irradiation range (solid line R shown in FIG. 2A). The substrate W is moved to the broken line shown in FIG.

Next, the CPU 19 causes the radiation generator 14a to output X-rays by the processing of the substrate inspection program A (step S130). That is, the CPU 19 outputs a control instruction to the radiation control unit 15 and causes the radiation generator 14a to emit X-rays having a predetermined intensity. As a result, X-rays of the fan beam are irradiated within the irradiation range R as shown in FIGS. 2A and 2B.

Next, the CPU 19 scans the substrate W by the processing of the inspection object moving unit A3 (step S140). That is, the CPU 19 outputs a control instruction to the stage controller 13 and drives the stage 12 so that the substrate W passes through the X-ray irradiation range. As a result, for example, in the example shown in FIG. 2A, one side of the substrate W existing at the position P and opposite to the side in contact with the X-ray irradiation range R reaches the X-ray irradiation range R. The substrate W is moved rightward in parallel with the X-axis direction. In the process of moving the substrate W, since X-rays are continuously output, the X-rays that have passed through the inspection target on the substrate W reach the line sensor 10b. Therefore, the detection element of the line sensor 10b sequentially detects transmitted X-rays transmitted through the respective positions of the substrate W and outputs data indicating the detection result to the line sensor control unit 11.

Therefore, the CPU 19 acquires the data from the line sensor control unit 11 by the processing of the inspection target image generation unit A4, and generates a fluoroscopic image showing the distribution of transmitted X-ray intensity over the entire area of the substrate W as the inspection target image. (Step S150). That is, the CPU 19 generates a fluoroscopic image showing a two-dimensional distribution of the intensity of transmitted X-rays based on the data acquired by the line sensor control unit 11 and records it in the memory 18 as an inspection target image. Of course, the inspection object image may be generated for each individual inspection object (for example, for each solder bump), or may be generated for a substrate W including a plurality of inspection objects.

Next, the CPU 19 performs inspection by the processing of the inspection unit A5 (step S160). That is, the CPU 19 extracts a feature amount determined in advance to determine the quality of the inspection target from the inspection target image, and determines the quality of the inspection target by comparing the feature amount with a quality determination criterion. Further, the CPU 19 causes the output unit 17 to output the determination result. As a result, an inspection based on the fluoroscopic image is performed.

(3) Cross-sectional image inspection processing:
In the inspection apparatus 1 according to the present embodiment, the line sensor 10b is fixed at one specific position, the radiation generator 14a is fixed at a plurality of specific imaging positions, and the inspection target is moved at each position to transmit X-rays. By acquiring, cross-sectional image inspection can be performed. FIG. 3B is a flowchart showing the cross-sectional image inspection process. The operator can designate the inspection method in advance by the input unit 16 and cause the CPU 19 to execute the board inspection program A. When the inspection based on the cross-sectional image is designated and the board inspection program A is executed, the CPU 19 The cross-sectional image inspection process shown in 3B is executed. In the cross-sectional image inspection process, the CPU 19 sets the substrate W including the inspection object on the stage 12 by the process of the substrate inspection program A (step S200). Step S200 is the same as step S100 described above.

Next, the CPU 19 moves the line sensor 10b and the radiation generator 14a to the imaging position by the processing of the line sensor moving unit A1 and the radiation generator moving unit A2 (step S210). In the cross-sectional image inspection process, the radiation generator 14a is moved to a plurality of imaging positions. Here, it is assumed that there are N shooting positions (N is an integer equal to or greater than 2), and the N shooting positions are referred to as shooting positions Ps ₁ to Ps _N. In the cross-sectional image inspection process, the line sensor 10b is fixed, and only the radiation generator 14a is moved and fixed at a plurality of imaging positions. In the present embodiment, since the radiation generator 14a is fixed at a plurality of imaging positions existing over the entire movable range, N radiation generators 14a arranged from one side to the other side in the X-axis direction. Are fixed positions of the radiation generator 14a at the imaging positions Ps ₁ to Ps _N , respectively. FIG. 4A shows a state in which the inspection apparatus 1 according to the present embodiment is viewed from a direction parallel to the Y-axis direction. In FIG. 4A, the radiation generator 14a at the imaging positions Ps ₁ , Ps _M , and Ps _N is shown. Is indicated by a one-dot chain line, a solid line, and a broken line (M is (1 + N) / 2, where N is an odd number in this example).

In order to move and fix the radiation generator 14a to each of the imaging positions as described above, in the process of the loop processing of steps S210 to S250, the imaging position of the radiation generator 14a every time the loop processing is executed. In this embodiment, each of the photographing positions Ps ₁ to Ps _N is sequentially selected as a photographing position to be processed. As for the line sensor 10b, one specific predetermined place is set as a photographing position and fixed. That is, in step S210, the CPU 19 outputs a control instruction to the line sensor control unit 11 so that the line sensor 10b is positioned at the center of the movable range by the processing of the line sensor moving unit A1. As a result, the line sensor control unit 11 moves and fixes the line sensor 10b to the center of the movable range as shown in FIG. 4B. Further, the CPU 19 outputs a control instruction to the radiation control unit 15 so that the radiation generator 14a is positioned at the imaging position to be processed by the processing of the radiation generator moving unit A2. As a result, the radiation control unit 15 moves and fixes the radiation generator 14a to the imaging position to be processed. For example, if the step S210 is executed for the first time, CPU 19 is fixed by moving the radiation generator 14a to the photographing position Ps ₁ shown in FIG. 4A.

Next, the CPU 19 moves the substrate W including the inspection target to the imaging preparation position by the processing of the inspection target moving unit A3 (step S220). That is, the CPU 19 outputs a control signal to the stage controller 13 and drives the stage 12 to move the substrate W to a position where one side of the substrate W is in contact with the X-ray irradiation range. For example, when the imaging position to be processed is the imaging position Ps ₁ shown in FIG. 4A, the substrate W is moved to the position P ₁ where one side of the substrate W is in contact with the X-ray irradiation range R ₁ indicated by the alternate long and short dash line.

Next, the CPU 19 causes the radiation generator 14a to output X-rays by the processing of the substrate inspection program A (step S230). That is, the CPU 19 outputs a control instruction to the radiation control unit 15 and causes the radiation generator 14a to emit X-rays having a predetermined intensity. For example, if the radiation generator 14a to the photographing position Ps ₁ shown in FIG. 4A is fixed, X-rays of the fan beam is irradiated in the irradiation range R ₁ shown by the one-dot chain line.

Next, the CPU 19 scans the substrate W by the processing of the inspection object moving unit A3 (step S240). That is, the CPU 19 outputs a control instruction to the stage controller 13 and drives the stage 12 so that the substrate W passes through the X-ray irradiation range. For example, in the example shown in FIG. 4A, when the imaging position to be processed is the imaging position Ps ₁ , the side opposite to the side of the substrate W in contact with the X-ray irradiation range R ₁ is the X-ray irradiation range R. _The substrate W is moved in the right direction parallel to the X-axis direction until ₁ is reached. As a result, transmitted X-rays that have passed through the detection target are sequentially detected by the detection element of the line sensor 10 b, and data indicating the detection result is output to the line sensor control unit 11. The data is recorded in the memory 18 under the control of the CPU 19.

Next, the CPU 19 determines whether or not scanning has been completed at all photographing positions (step S250). That is, the CPU 19 determines whether or not scanning of the substrate W has been completed at all of the predetermined shooting positions, for example, at the shooting positions Ps ₁ to Ps _N in the example shown in FIG. 4A. If it is not determined in step S250 that scanning has been completed at all shooting positions, the CPU 19 changes the shooting position to be processed (increments the shooting position numbers 1 to N by 1), and repeats the processing from step S210 onward.

When it is determined in step S250 that scanning has been completed at all photographing positions, the CPU 19 obtains data recorded in the memory 18 by processing of the inspection target image generation unit A4, and generates a cross-sectional image as an inspection target image ( Step S260). That is, the CPU 19 superimposes a plurality of fluoroscopic images showing a two-dimensional distribution of transmitted X-ray intensity based on the data acquired by the line sensor control unit 11, thereby obtaining a cross-sectional image at an arbitrary position in the Z-axis direction. The image is generated as an inspection target image and recorded in the memory 18. Of course, the inspection object image may be generated for each individual inspection object (for example, for each solder bump), or may be generated for a substrate W including a plurality of inspection objects. Note that the cross-sectional image can be generated using a known technique in tomosynthesis, such as a shift addition method.

Next, the CPU 19 performs inspection by the processing of the inspection unit A5 (step S270). That is, the CPU 19 extracts a feature amount determined in advance to determine the quality of the inspection target from the inspection target image, and determines the quality of the inspection target by comparing the feature amount with a quality determination criterion. Further, the CPU 19 causes the output unit 17 to output the determination result. As a result, an inspection based on the cross-sectional image is performed.

In the cross-sectional image inspection process as described above, the entire region of the substrate W is scanned by scanning the substrate W in the X-axis direction with the radiation generator 14a fixed to each of the plurality of imaging positions Ps ₁ to Ps _N. Obtain transmitted X-rays. Accordingly, the substrate W does not move in the Y-axis direction during the scanning process, and the X-ray irradiation angle with respect to each position on the substrate W having the same position in the Y-axis direction and different positions in the X-axis direction is always constant. is there. That is, when a straight line extending in the X-axis direction is assumed on the substrate W, the X-ray irradiation angle with respect to a portion existing on the straight line is always constant. Therefore, the detection element that detects transmitted X-rays that have passed through a portion that exists on a straight line parallel to the X-axis direction is a specific detection element, and can be accurately specified in advance. Since scanning is performed by moving the substrate W in a direction parallel to the X-axis direction, a detection element that detects transmitted X-rays transmitted through a portion existing on the straight line in the scanning process is provided in the Y-axis direction. There is no deviation in the parallel direction. Therefore, it is possible to accurately specify the inspection target image existing on the substrate W and perform the inspection, and it is possible to perform the inspection with high accuracy.

(4) Three-dimensional reconstructed image inspection process:
In the inspection apparatus 1 according to the present embodiment, the line sensor 10b and the radiation generator 14a are fixed at a plurality of specific imaging positions, and the inspection target is moved at each position to acquire transmitted X-rays, thereby obtaining a three-dimensional view. A reconstructed image inspection can be performed. The operator can specify the inspection method in advance by the input unit 16 and cause the CPU 19 to execute the board inspection program A. When the board inspection program A is executed by specifying inspection based on the three-dimensional reconstructed image, The CPU 19 executes a three-dimensional reconstructed image inspection process shown in FIG. 3B. The three-dimensional reconstructed image inspection process can be realized by the flowchart shown in FIG. 3B as in the cross-sectional image inspection process. However, in the flowchart shown in FIG. The dimension reconstruction image inspection process and the cross-sectional image inspection process are different.

Here, the difference between the three-dimensional reconstruction image inspection process and the cross-sectional image inspection process will be described. Assume that there are N shooting positions (N is an integer of 2 or more) in the three-dimensional reconstructed image inspection process, and the N shooting positions are called shooting positions Pt ₁ to Pt _N. In the three-dimensional reconstruction image inspection process, since both the line sensor 10b and the radiation generator 14a are moved to a plurality of imaging positions, the relative relationship between the line sensor 10b and the radiation generator 14a at the imaging positions Pt ₁ to Pt _N is obtained. The positional relationship is a different positional relationship.

5A to 5L and 6A to 6L show an example in which there are eight shooting positions. FIGS. 5A to 5C show the shooting position Pt ₁ , FIGS. 5D to 5F show the shooting position Pt ₂ , and FIGS. 5G to 5I show the shooting positions. Position Pt ₃ , FIGS. 5J to 5L are shooting positions Pt ₄ , FIGS. 6A to 6C are shooting positions Pt ₅ , FIGS. 6D to 6F are shooting positions Pt ₆ , FIGS. 6G to 6H are shooting positions Pt ₇ , and FIGS. Position Pt ₈ is shown. 5A to 5C, reference numerals indicating the respective devices are shown, but these reference numerals are omitted in other drawings. 5A to 6L, the upper stage (FIG. 5A, etc.) is a view of the inspection apparatus 1 viewed from the Y-axis direction, the middle stage (FIG. 5B, etc.) is the inspection apparatus 1 viewed from the X-axis direction, and the lower stage (FIG. 5C). Is a view of the inspection apparatus 1 viewed from the Z-axis direction. In the three-dimensional reconstructed image inspection process in this example, steps S210 to S250 are repeated eight times, so that the substrate is sequentially taken from the photographing position Pt ₁ at each of the photographing positions Pt ₂ , Pt ₃ ,, Pt ₇ , Pt _8. W is scanned, and fluoroscopic images photographed at eight photographing positions are acquired.

In the three-dimensional reconstructed image inspection process in the present embodiment, each photographing is performed so that the third straight line L ₃ connecting the focal point of the radiation generator 14a and the detection element at the center of the line sensor 10b passes through a circle set on the moving plane. Positions Pt ₁ to Pt _N are set. Figure 5A ~ 5C and FIG. 5F, 5I, 5L, 6C, 6F, 6I, in 6L is dashed shows a circle on movement plane by illustrates a third straight line L ₃ by a dashed line in FIG. 5A .

At the imaging positions Pt ₁ to Pt _N , the third straight line L ₃ connecting the focal point of the radiation generator 14a and the center detection element of the line sensor 10b satisfies the upper limit of passing through a circle set on the moving plane, while The photographing positions Pt ₁ to Pt _N are set so that the intersection of the three straight lines L ₃ and the circle makes one round of the circle. Since the third straight line L ₃ is included in the X-ray irradiation range irradiated from the radiation generator 14a, when the substrate W is scanned, the substrate W is within the irradiation range including the third straight line L _3. Scanned. In FIG. 5A ~ 6L, illustrate the position of the substrate W in the process of being scanned in the vicinity of the intersection of the third straight line L ₃ and the circle. Since the photographing positions Pt ₁ to Pt ₈ are set so that the intersection of the third straight line L ₃ and the circle makes one round of the circle, FIGS. 5C, 5F, 5I, 5L, 6C, 6F, 6I, and 6L are compared. Then, the position of the substrate W changes so as to rotate on a circle indicated by a broken line in each figure.

Note that since the shooting positions Pt ₁ to Pt ₈ are set so that the intersection of the third straight line L ₃ and the circle makes one round of the circle, in the process of changing the shooting position to Pt ₁ to Pt ₈ , As shown in FIGS. 5A, 5D, 5G, 5J, 6A, 6D, 6G, and 6J, the position of the radiation generator 14a changes from one end of the rail 14b to the other end, and again from the other end to the other. Changes to the end of Further, in the process of changing the photographing position as Pt ₁ to Pt ₈ , the position of the line sensor 10 b is set at the center of the rail 10 a as shown in FIGS. 5B, 5E, 5H, 5K, 6B, 6E, 6H, and 6K. From one end to the other end, and again from the other end toward the center of the rail 10a.

In photographing position Pt ₁ ~ Pt ₈ as described above, when the radiation generator 14a is assumed to view the substrate W and the line sensor 10b, the radiation generator 14a when the imaging position is changed as Pt ₁ ~ Pt ₈ The positions of the substrate W and the line sensor 10b appear to move while drawing a circular trajectory. Therefore, the two-dimensional distribution of transmitted X-rays imaged at such imaging positions Pt ₁ to Pt ₈ is equivalent to the two-dimensional distribution of transmitted X-rays imaged by normal three-dimensional CT.

Therefore, if it is determined in step S250 that scanning has been completed at all photographing positions, the CPU 19 acquires the data from the line sensor control unit 11 by the processing of the inspection target image generation unit A4, and three-dimensional reconstruction of the inspection target An image is generated as an inspection target image (step S260). That is, the CPU 19 generates a three-dimensional image to be inspected by performing a known three-dimensional reconstruction process.

Next, the CPU 19 performs inspection by the processing of the inspection unit A5 (step S270). That is, the CPU 19 extracts a feature amount determined in advance to determine the quality of the inspection target from the inspection target image, and determines the quality of the inspection target by comparing the feature amount with a quality determination criterion. Further, the CPU 19 causes the output unit 17 to output the determination result. As a result, an inspection based on the three-dimensional reconstructed image is performed.

(5) Other embodiments:
In the present invention, it is only necessary that the line sensor is moved along one axis and the radiation generator is moved along one axis so that transmission X-rays can be imaged. Is possible. For example, the position where the line sensor 10b is fixed in the cross-sectional image inspection process described above is not limited to the center of the movable range, and may be an arbitrary position within the movable range. In addition, the inspection target image generated in the inspection method in which the radiation generator 14a is moved to a plurality of imaging positions with the line sensor 10b fixed at one place is not limited to a cross-sectional image, and other images, for example, three-dimensional reproduction. It may be a constituent image.

Furthermore, in the above-described three-dimensional reconstruction image inspection process, the figure through which the intersection of the third straight line and the moving plane passes is not limited to a circle, and may be another shape, for example, a straight line or a polygon. In addition, the inspection target image generated in the inspection method in which the line sensor 10b and the radiation generator 14a are moved to a plurality of imaging positions is not limited to a three-dimensional reconstructed image, and may be another image, for example, a cross-sectional image. .

Further, as in the above-described embodiment, the fluoroscopic image inspection process, the cross-sectional image inspection process, and the three-dimensional reconstructed image inspection process are not separately performed, but these inspection methods are freely combined depending on the inspection purpose. May be executed. Furthermore, the number of inspection objects existing on an imaging object such as a substrate is arbitrary, and the shape and size thereof are also arbitrary.

DESCRIPTION OF SYMBOLS 1 ... Inspection apparatus, 10 ... Line sensor moving mechanism, 10a ... Rail, 10b ... Line sensor, 11 ... Line sensor control part, 12 ... Stage, 13 ... Stage control part, 14 ... Radiation generator moving mechanism, 14a ... Radiation generation 14b ... rail, 15 ... radiation control unit, 16 ... input unit, 17 ... output unit, 18 ... memory

Claims (7)

A line sensor moving means for moving a line sensor in which the first linear direction and the longitudinal direction coincide with each other along the first straight line;
A second straight line that is not on the same plane as the first straight line and is directed to the line sensor along a second straight line that is orthogonal to the first straight line when translated to intersect the first straight line. A radiation generator moving means for moving the radiation generator for emitting radiation,
Inspection object moving means for moving the inspection object on a moving plane that is parallel to the first straight line and the second straight line and exists between the first straight line and the second straight line;
An inspection object image generating means for generating an inspection object image based on the transmitted radiation transmitted through the inspection object acquired by the line sensor;
An inspection apparatus comprising: The line sensor moving means and the radiation generator moving means move and fix the line sensor and the radiation generator to a predetermined imaging position,
The inspection object moving means is configured to determine an irradiation range of the radiation that is irradiated from the radiation generator and reaches the line sensor in a state where the line sensor and the radiation generator are fixed at the imaging position. Move the test object so that the
The inspection target image generating means generates the inspection target image based on the transmitted radiation acquired in the process of passing the inspection target through the radiation range,
The inspection apparatus according to claim 1. The line sensor moving means and the radiation generator moving means move the line sensor to a specific one place and fix the line sensor, and move the radiation generator to a specific one place and fix the line sensor. Fixing the radiation generator to the imaging position;
The inspection object moving means moves the inspection object so that the inspection object passes through an irradiation range of the radiation in a state where the line sensor and the radiation generator are fixed at the imaging position.
The inspection target image generation means generates a fluoroscopic image of the inspection target based on the transmitted radiation acquired in the process of passing the inspection target through the radiation irradiation range, and sets the inspection target image.
The inspection apparatus according to claim 2. The radiation generator moving means moves the radiation generator to a plurality of imaging positions along the second straight line with the line sensor moving means moving and fixing the line sensor to a specific position. Fixed,
The inspection object moving means is configured such that the inspection object passes through the radiation irradiation range in a state where the line sensor is fixed at the specific position and the radiation generator is fixed at each of the plurality of imaging positions. Move the inspection object so that
The inspection object image generation unit generates a three-dimensional reconstruction image or a cross-sectional image in a direction parallel to the moving plane based on the transmitted radiation acquired in the process of passing the inspection object through the radiation irradiation range. The inspection target image,
The inspection apparatus according to claim 2. The line sensor moving means and the radiation generator moving means include a plurality of lines such that a third straight line connecting a reference position of the line sensor and a focal point of the radiation generator intersects a predetermined figure provided on the moving plane. The line sensor and the radiation generator are moved and fixed to the imaging position of
The inspection object moving means is configured so that the inspection object passes through the radiation irradiation range including the third straight line in a state where the line sensor and the radiation generator are fixed to each of the imaging positions. Move the inspection object,
The inspection object image generation unit generates a three-dimensional reconstruction image or a cross-sectional image in a direction parallel to the moving plane based on the transmitted radiation acquired in the process of passing the inspection object through the radiation irradiation range. The inspection target image,
The inspection apparatus according to any one of claims 2 to 4. A line sensor moving step of moving a line sensor whose first linear direction and longitudinal direction coincide with each other along the first straight line;
A second straight line that is not on the same plane as the first straight line and is directed to the line sensor along a second straight line that is orthogonal to the first straight line when translated to intersect the first straight line. A radiation generator moving step for moving the radiation generator for irradiating the radiation;
An inspection object moving step of moving the inspection object on a moving plane that is parallel to the first straight line and the second straight line and exists between the first straight line and the second straight line;
An inspection object image generating step for generating an inspection object image based on the transmitted radiation transmitted through the inspection object acquired by the line sensor;
Including inspection methods. A line sensor moving function for moving a line sensor in which the first linear direction and the longitudinal direction coincide with each other along the first straight line;
A second straight line that is not on the same plane as the first straight line and is directed to the line sensor along a second straight line that is orthogonal to the first straight line when translated to intersect the first straight line. A radiation generator moving function for moving the radiation generator that emits radiation,
An inspection object moving function that moves the inspection object on a moving plane that is parallel to the first straight line and the second straight line and exists between the first straight line and the second straight line;
An inspection object image generation function for generating an inspection object image based on the transmitted radiation transmitted through the inspection object acquired by the line sensor;
Inspection program that causes a computer to execute.

Images