JP2003329615A - X-ray tomographic imaging method and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray tomographic imaging method capable of shortening the total photographing time required when internal structural data having the higher accuracy are desired after confirming the outline of the internal structural data of a reconstructed object to be inspected. <P>SOLUTION: When the internal structural data having the higher accuracy are acquired for the internal structural data of the object 7 to be inspected which have been reconstructed once, the projected image excluding the angle position of the projected image which is photographed previously is photographed newly. The projected image which is photographed previously is utilized. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray tomographic imaging method and apparatus for inspecting the internal structure of an object to be inspected using X-rays.

[0002]

2. Description of the Related Art In the field of research and development of semiconductor devices and the like, nondestructive three-dimensional analysis is required for inspecting cracks, disconnections and the like existing inside minute inspected objects. As a method used as one of the methods, there is an X-ray tomographic imaging method. The X-ray tomography apparatus detects, for example, an X-ray source (an X-ray generator including an X-ray tube or the like) and an X-ray that is emitted from the X-ray source through an X-ray focal point and transmitted through an object to be inspected. And a detector which is installed between the X-ray source and the detector, images the transmitted X-ray of the inspection object by the detector, processes it as image data, and inspects and observes the inside of the inspection object. it can.

In this X-ray tomographic imaging method, X-rays are emitted from various angles within a plane of an object to be inspected, and the intensity distribution of transmitted X-rays is detected and measured by a detector. A predetermined calculation is performed from this intensity distribution to obtain a tomographic image (projection image) of the object under inspection in the X-ray irradiation plane. Furthermore, by acquiring a tomographic image while switching the X-ray irradiation plane, the internal structure of the inspected object can be
It can be observed dimensionally.

In the X-ray tomographic imaging apparatus, internal structure data is calculated from the captured projected image through reconstruction calculation of the internal structure, but the number of images to be imaged is calculated by the reconstruction calculation. It greatly affects the detail level of data,
If the number of captured images is large, the degree of detail of the internal structure data tends to increase. At the same time, an increase in the number of images to be picked up increases the time required until the end of imaging, the amount of reconstruction calculation of internal configuration data, and the calculation time. Therefore, it is important to select an appropriate number of images. The appropriate number of images to be picked up by the X-ray tomographic imaging apparatus can be determined only by looking at the reconstruction result after the reconstruction calculation is completed.

[0005]

Since it takes a considerable amount of time to capture a projected image and to calculate the reconstruction of internal structure data, for example, a small number of images to be captured is set in advance, and the number of images to be captured is changed according to the number of images. The projection image of the inspection object rotated by the different angular displacement is captured, and the reconstruction calculation of the internal structure data is performed based on the captured projection data. When the internal structure data reconstructed by a display device such as a monitor is viewed and more detailed internal structure data is desired, the angular displacement pitch of the object to be inspected is finely set and the number of images to be captured is increased to re-project an image. It will be imaged.

However, at this time, since the new projection image is re-used without using the already-obtained projection data, the same projection image (angle position) is captured twice and it takes time and labor, or a fineness satisfying the requirement is obtained. There is an inconvenience that it takes a total time to obtain the internal structure data.

In view of the above point, the present invention shortens the total imaging time required when the internal structure data of the reconstructed object is confirmed and then the internal structure data of higher definition is desired. An object is to provide an X-ray tomographic imaging method and apparatus.

[0008]

According to the present invention, when finer internal structure data is acquired with respect to the internal structure data of the object to be inspected once reconstructed, the angular position of the projection image previously imaged is calculated. Except for this, a new image is picked up and the previously picked up projected image is utilized, which is performed as follows. In the X-ray tomographic imaging method of the present invention, an object to be inspected is placed between an X-ray source and a two-dimensional detection unit that captures a projected image of the object to be inspected, and the X-ray focal point of the two-dimensional detection unit is used. A rotation base portion that includes a rotation axis orthogonal to a perpendicular drawn on the light receiving surface and that rotates a predetermined rotation angle range at a predetermined angular displacement pitch,
Projection image storage means for storing a projection image of the object to be inspected for each angular displacement, reconstruction means for reconstructing internal configuration data from the projection image, and display means for displaying the reconstructed internal structure data are provided. Then, by the first rotation of the rotary base portion, a projection image is captured for each first angular displacement, and internal structure data is reconstructed from the captured projection image, and the internal structure is displayed on the display means. In order to obtain more detailed internal structure data after grasping the outline of the data, when acquiring the second angular displacement smaller than this first angular displacement by the second rotation of this rotary base part, The projection image of this inspected object is imaged except for the angular position imaged in the first rotation, and after the imaging is completed, the projection image previously imaged in the first rotation and stored in the projection image storage means. And the projection image newly captured in this second rotation , In which to perform the reconstruction of the internal structure data of the object to be inspected.

According to the present invention, when finer internal structure data is acquired for the internal structure data of the object to be reconstructed once, the angular position of the projection image previously captured is excluded. By newly capturing an image and utilizing the previously captured projection image, it is possible to reduce the total capturing time required to obtain the internal structure data having a desired definition.

The X-ray tomographic imaging apparatus of the present invention provides an X-ray source for generating X-rays, X-ray control means for controlling the X-rays generated by the X-ray source, and an X-ray projection image of an object to be inspected. A two-dimensional detecting means for imaging, and an axis of rotation which is placed between the X-ray source and the two-dimensional detecting means and which is orthogonal to a perpendicular line dropped from a focus to a light receiving surface of the two-dimensional detecting means. A rotation base part that rotates a predetermined rotation angle range at a predetermined angular displacement pitch, a mechanism control means that controls a rotation mechanism of the rotation base part, and a projection image captured by the two-dimensional detection means as projection data. The projection image storage means to be stored, the control operation means for outputting an instruction signal to the X-ray control means, the mechanism control means and the projection image storage means, and the inspection data from the projection data stored in the projection image storage means. Reconstruction hands that reconstruct internal body structure data And a display means for displaying the result of reconstructing the internal structure data. The first rotation of the rotary base section captures a projection image for each first angular displacement and the captured image. When the internal structure data is reconstructed from the projected image and the second rotation of the rotation base portion is used to capture an image with the second angular displacement smaller than the first angular displacement,
The projection image of the object to be inspected is taken except for the angular position picked up by the rotation, and after the completion of the imaging, the projection image previously taken by the first rotation and stored in the projection image storage means and the above-mentioned The projection image newly captured by the second rotation is integrated to reconstruct the internal structure data of the object to be inspected.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In this example, a tomographic imaging apparatus using X-rays, which is currently widely used among tomographic imaging apparatuses, will be described as an example. Irradiates the object with radiation from multiple directions,
Any device that reconstructs internal structure data from a plurality of projection data obtained by capturing the projection image may be used, and when a certain internal structure data is obtained and more detailed data is to be obtained, the preceding projection data is The present invention is applied to a tomographic imaging apparatus that employs an imaging method that newly captures projection data without utilizing it.

Examples of embodiments of a tomographic imaging method and apparatus according to the present invention will be described below with reference to FIGS.

1A and 1B are used for industrial purposes, for example, X used for nondestructive inspection for inspecting the internal structure of a semiconductor device.
It is a schematic diagram of an example of a line tomography device. In the figure, reference numeral 1 denotes a known X-ray source (X-ray generator) that radiates, for example, cone-beam X-rays and irradiates the entire object 7 to be inspected, and is radiated from an X-ray tube 1 of the X-ray generator. A projected image of the object 7 to be inspected is picked up by X-rays, and the transmitted X-rays of the object 7 to be inspected are captured by an X-ray two-dimensional detector 2 as two-dimensional detection means to obtain a projected image. The X-ray emitted from the X-ray tube 1 is configured to form a minimum X-ray focus having a focus size of 5 μm or less, for example. Since the resolution of the X-ray tomographic imaging apparatus is determined by the X-ray focal spot size, it is preferable that this numerical value is small so that damage of a smaller size can be observed.

The X-ray two-dimensional detector 2 is composed of, for example, a flat panel detector (FPD), and its movement to the left, right, up and down can be adjusted so that the transmitted X-ray is irradiated to the center. Regarding the FPD, Japanese Patent Laid-Open No. 6-342098
Is specifically disclosed in. X-ray transmitted through the subject
The photoconductive layer such as the Se layer absorbs the charge to generate an electric charge according to the X-ray intensity, and the amount of the electric charge is detected for each pixel. As an example of another type of FPD, Japanese Unexamined Patent Publication No. 9-
As disclosed in 90048, X-rays are absorbed in a phosphor layer such as an intensifying screen to generate fluorescence, and the intensity of the fluorescence is detected by a photodetector such as a photodiode provided for each pixel. There is. Other means for detecting fluorescence include CCD
There is also a method using a C-MOS sensor.

Particularly, in the FPD of the method disclosed in the above-mentioned Japanese Patent Laid-Open No. 6-342098, since the X-ray dose is directly converted into the charge amount for each pixel, the sharpness of the FPD is less deteriorated and the image is excellent in sharpness. Is obtained. The present invention thus provides
It is only necessary that X-rays such as lines can be captured and processed for each pixel by some means to obtain an image signal.

Reference numeral 3 denotes an entire rotary base (hereinafter referred to as a rotary base) which is composed of a rotary base on which the object 7 to be inspected is mounted, a motor for rotating the rotary base, and bearings described later. . The rotation base 3 is provided with a Z-axis drive mechanism 3a for moving the rotation base 3 in a direction parallel to the rotation axis of the rotation base 3, that is, in the Z-axis direction as shown in FIG. 1A. The object 7 to be inspected is held and fixed by a holding jig 8 on a rotary base.

The rotary base 3 is supported by an air bearing, which will be described later, and is directly connected coaxially to the air bearing by a servomotor having an angular positioning accuracy of 0.2 minutes or less and a rotational phase detecting means. The preset rotation angle range is stopped at each angular displacement corresponding to the resolution of the servo motor and the rotation phase detecting means in synchronization with the period for capturing the projection data required for reconstruction.

Reference numeral 4 is a bearing of the rotating base of the object to be inspected. The rotation axis of the bearing 4 is orthogonal to the perpendicular line from the focal point of the X-ray tube 1 to the X-ray two-dimensional detector 2. In this example, the bearing 4 is an air bearing capable of controlling the minute angular displacement of the rotary base 3, but the present invention is not limited to this, and any bearing that supports the rotary base 3 and smoothly rotates can control the minute angular displacement. Good.

Reference numeral 5 is an X-ray tube 1 serving as an X-ray source, and a bearing 4
2 is an XY table that moves on a plane orthogonal to the rotation axis of the. The turning radius of the inspection object 7 is appropriately fed back to the XY table 5 and projection data can be acquired with the inspection object 7 and the XY table 5 being extremely close to each other as necessary. The highest-order element that controls the magnification is the mutual distance between the X-ray focal point and the object to be inspected 7 held on the rotary base 3. If the magnification is large, the internal structure of a finer part is analyzed. It becomes possible to do.

Reference numeral 10 denotes an anti-vibration table on which all the devices, members, etc. constituting the X-ray tomographic imaging apparatus described above are mounted and vibrations are removed so that an error does not occur in the irradiation position. And 11
Is a shield cover made of lead or the like, which covers the entire X-ray tomography apparatus such that X-rays such as X-rays do not leak outside.

FIG. 2 is a block diagram of the X-ray tomographic imaging apparatus of this example. First, the rotation base 3 from the X-ray tube 1 which constitutes the X-ray source.
X-rays are radiated to the inspection object 7 placed on. At this time, the intensity of the X-rays irradiated, the focus size, etc. are controlled by the control console 22 which is the control operating means through the X-ray controller 20 which is the X-ray controlling means. Further, the position, rotation angle pitch, initial rotation angle, etc. of the rotary base 3 are controlled by the control console 22 through the mechanism controller 21 which is a mechanism control means for controlling the movements of the rotary base 3 and the XY stage 5. . The inspection object 7 placed on the rotary base 3 is rotated by an angle designated by the control console 22, and its projected image is X-ray.
The image is taken by the line two-dimensional detector 2.

The control console 22 is provided with input means such as a keyboard, and is composed of, for example, a personal computer, and has information processing means for processing information and display means for displaying input values. For example, X from the X-ray tube 1
Information such as the line intensity is displayed on the display unit and an appropriate control command is output to the X-ray control unit 21 via the input unit,
It is possible to output a command to the rotary base 3 for appropriately positioning the object 7 to be inspected.

The X-rays transmitted through the inspection object 7 are X-rays such as FPD.
It is captured and detected by the line two-dimensional detector 2. The X-ray two-dimensional detector 2 supplies a projected image, which is information of the detected X-ray, to a projected image storage unit 23 as a projected image storage unit, and the projected image is, for example, a digital image according to an instruction from the control console 22. The converted projection data is stored in the projection image storage unit 23 formed of a large-capacity magnetic recording medium or the like at an appropriate location according to the angle. The projection image storage means is not limited to this as long as it is a recording medium having a recording capacity capable of recording projection data, and various types such as an optical disk and a semiconductor memory are applied.

The projection data stored in the projection image storage unit 23 is supplied to a reconstruction calculation computer 24 as a reconstruction unit connected to the projection data. The projection data stored in the projection image storage unit 23 is stored by the control console 22 in association with information such as the rotation angle pitch of the projection image, the initial rotation angle, and the X-ray intensity.

The reconstruction calculation computer 24 reconstructs the internal structure data from the input projection data, and the reconstructed internal structure data is stored in the projection image storage unit 23 or another recording medium. The data is input to the reconstruction result display device 25, which is a display means, via a display memory (not shown), and is displayed on a display such as a CRT monitor. The reconstruction calculation computer 24 only needs to have an arithmetic processing capability capable of collecting input projection data and reconstructing internal structure data, and may be shared with the information processing means of the control console 22. Further, the display means of the reconstruction result display device 25 may be shared with the display means of the control console 22.

As described above, the internal structure data of the object to be inspected 7 is obtained on the reconstruction result display device 25 and the internal structure is displayed, and it is easy to check for cracks in the object to be inspected or disconnection of electronic component elements. Can be visually confirmed.

With reference to the flow chart shown in FIG. 3, for example, a case of actually reconstructing the internal structure data of the object to be inspected from 720 projected images will be described. In this example, first, the outline of the internal structure is confirmed from the projected images of 360 sheets, and thereafter, it is determined that more detailed internal structure data is necessary, and the internal structure data that is more detailed than the projection data of 720 sheets is obtained again. Is. When reconstructing the internal structure data of the DUT from the projection data of 720 sheets, the rotation base
Since 360 ° which is one rotation is divided into 720 parts, the final angular displacement per projection data is 0.5 degree.

First, as shown in FIG. 3, the initial angle of the rotary base 3 on which the object 7 to be inspected is placed is set to 0 ° (step S1). This 0 ° indicates a state in which the device under test 7 faces the front without any angular displacement with respect to the X-ray tube 1.

The image pickup is started from 0 °, and the projected image of the object 7 is picked up at an angular displacement of 1 ° (step S).
2). A total of 360 images can be picked up during one rotation of the object 7 to be inspected, and the projection data of 360 images obtained by the X-ray two-dimensional detector 2 is defined as projection data (# 1). The projection data (# 1) of the 360 sheets is stored in the projection image storage unit 23,
Reconfiguration calculation is performed by the reconfiguration calculation computer 24, and the reconfiguration calculation result is displayed on the reconfiguration result display device 25 of the internal structure of the DUT 7 (step S3).

The fineness and the detail are confirmed by looking at the internal structure displayed on the reconstruction display device 25 (step S).
4). At this point, if the reconstruction result is sufficient for the purpose of inspection, the tomographic imaging operation is terminated. However, if sufficient internal structure data cannot be obtained, imaging work is performed to obtain a further projected image.

Next, the initial angle is set to 0.5 ° (step S5), and similarly, 360 projected images are taken while the inspected body 7 makes one rotation with an angular displacement of 1 ° (step S5).
6). Then, at this time, the projection data of the 360 sheets obtained by the X-ray two-dimensional detector 2 is used as the projection data (# 2), and the projection data (# 1) and the projection data (# 2) captured previously are combined. Reconstruction calculation is performed again by the reconstruction calculation computer 24 from the obtained projection data of 720 sheets, and the reconstruction result display device 25 displays the internal structure of the DUT 7 as the calculation result (step S7). ). In this way
The internal structure data with the desired level of detail is obtained.

Projection data (# 1) and projection data (# 2)
The synthesizing method with and will be described more specifically. In the description of the present example, in FIG. 4 and FIG. 5, the place where the inspection object 7 is originally rotated is expressed as if the X-ray two-dimensional detector (projected image) side is rotated, for understanding. I tried to help.

As shown in FIG. 4, a projected image 21 when the rotary base 3 is at an angular position of 0 °, a projected image 22 when the rotary base is displaced by 0.5 ° at an angular position of 0.5 °, and the like. The projection image 23 and the projection image 24 are obtained by angularly displacing each of them by 0.5 °, and the projection data when the projection image p × 0.5 ° (p is an integer of 1 or more and 720 or less) is obtained. It is composed of a total of 720 projected images at 360 ° around one round.

As shown in FIG. 5A, first, 360 images are picked up only at odd-numbered projection image positions with an angular displacement of 1 ° per one image, and projection images 21, projection images 23, ...
., The projected image 29, the projected image 31 ,. This is the above-mentioned projection data (# 1). The internal structure data is reconstructed from the imaged projection data (# 1) of 360 sheets, and the internal structure of the reconstructed object 7 is observed and evaluated by the reconstruction result display device 25. This projection data (# 1)
Are stored in the projected image storage unit 23.

Here, in the case where the internal structure data does not have a sufficient definition in the projected images of 360 sheets, a new image shown in FIG.
As shown in FIG. 3, the projection images 22, 24, ... Are offset by 0.5 ° at the projected image positions of the remaining 360 even-numbered images, and imaged with an angular displacement of 1 ° per image.
., The projected image 30, .. This is the above-mentioned projection data (# 2), and among the 720 pieces of projection data, the odd-numbered projection images previously captured are thinned out and the even-numbered projection images are newly captured.

After the end of the image pickup, the 360 pieces of odd-numbered projection data (# 1) previously picked up and the remaining even-numbered 360 pieces of projection data (# 2) newly picked up later are integrated. That is, that is, a total of 720 projected images 21, 22, 23, 24, ..., 29, 30, 3 for every 0.5 ° of angular displacement.
The internal structure data can be reconstructed from 1, ... to obtain the internal structure data having a desired definition.

According to the present example, the rotary base is angularly displaced by 1 degree to irradiate the object 7 with X-rays, and 360 sheets (projection data (#
After capturing 1)), the internal structure data is reconstructed, and the reconstruction result display device 25 observes and evaluates the definition of the internal structure data. Then, when a higher definition is required, 360 images (projection data (# 2)) are newly imaged with the initial angle of 1 ° and the same angular displacement of 0.5 °.
Here, the projection data (# 2) newly captured by thinning out the projection data (# 1) captured earlier and the projection data (# 1) captured earlier are combined to generate 720 Since the internal structure data composed of the projection data for one sheet is reconstructed, it is possible to interpolate the intermediate angular position of the imaging position of the projection data previously imaged to obtain a desired definition and to obtain the desired definition. It is possible to reduce the total time required for imaging to obtain internal structure data having a definition to 2/3.

As another example of the embodiment of the present invention, a case where the internal structure data is reconstructed by capturing, for example, 2 ⁿ (n is a positive integer) projection images will be described. First, the initial angular phase of the rotary base 3 is 0 degree and the angular displacement is 36 degrees.
The projection image of the inspected body 7 is picked up as 2 ^n-1 sheets and stored in the projection image storage unit 23 as 0/2 ^n-1 degrees. The internal structure data of the object 7 to be inspected is reconstructed from this projected image, and the fineness of the internal structure data is observed and evaluated by the reconstruction result display device 25.

Then, the outline of the internal configuration data is grasped.
If you want to obtain more detailed internal structure data after
And the initial angular phase is 360/2ⁿDegree, angular displacement 360
/ 2 ^n-1Degree and 2^n-1Take a projection image of one sheet and take a new image
In the projected image storage unit 23, the projected image is captured in advance of the projected image.
By combining the projected image that you have memorized,
Get the structure data

It can be easily understood that the same effects as those of the examples shown in FIGS. 3 to 5 can be obtained in this example as well.

Another example of the embodiment of the present invention will be described. First, a projection image of the inspection object 7 is imaged at an equal angular displacement according to a desired degree of detail, stored in the projection image storage unit 23, and internal configuration data is reconstructed from the projection image imaged at this equal angular displacement. As configured. Next, after grasping the outline of the internal configuration data on the reconstruction result display device 25, if it is desired to obtain more detailed internal structure data, the integer displacement of the equiangular displacement is set as the angular displacement smaller than the equiangular displacement. One-half is newly set as the angular displacement, the angular position of the projection image previously captured is skipped, and the projection image is newly captured. Then, after the imaging is completed, the newly captured projection image and the projection image previously captured and stored in the projection image storage unit 23 are combined to obtain higher-definition internal structure data.

Also in this example, the angular position between the imaging angular positions of the projection image previously taken is interpolated, and the same effect as the example shown in FIGS. 3 to 5 can be obtained. Easy to understand.

Another example of the embodiment of the present invention will be described. First of all, the number of revolutions of the rotation base 3 for one rotation is N
Each of the equally divided and N equally divided regions is further divided into M equal parts, the projected images are numbered starting from 0 °, and the total (M ×
N) Image projection images are taken to obtain internal structure data. Projection images are taken every M sheets for each revolution of the rotation base 3, and the first, (M + 1) th, (2M +)
1) sheet, ..., ((N-1) M + 1) sheet is imaged, the second sheet, (M + 2) sheet, (2M +)
2) The ..., ((N-1) M + 2) th image is taken, and similarly up to the Nth round. The internal structure data of the object to be inspected 7 is reconstructed from the projection images obtained by imaging from the first round to the Nth round.

Also in this example, the angular position between the imaging angular positions of the projection image taken in advance is interpolated, and the same effect as the example shown in FIGS. 3 to 5 can be obtained. Easy to understand.

In the present invention, the rotation angle of the rotary base 3 does not necessarily have to be 360 °. When only a main part of the internal structure of the inspection object is required, for example, the rotation angle of the rotation base 3 is set to 90 °, and a projection image of the inspection object is captured with a predetermined angular displacement within the rotation angle range. Then, a new projection image is taken excluding the angular position of the previously taken projection image, and the previously taken projection image and the newly taken projection image are integrated to reconstruct the internal structure data. The configuration may be performed. In this case, only the necessary portion of the internal structure of the inspection object can be extracted, and the main part of the internal structure can be confirmed quickly.

The present invention is not limited to the examples of the above-described embodiments, and it goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0047]

According to the present invention, when finer internal structure data is acquired with respect to the internal structure data of the object to be inspected once reconstructed, the angular position of the projection image previously captured is determined. Except for this, a new image is taken, and by utilizing the previously captured projection image, the newly captured projection image and the previously captured projection image are combined to obtain internal structure data of the inspection object. Therefore, the total imaging time required to obtain the internal structure data having a desired definition can be shortened.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an embodiment of an X-ray tomographic imaging apparatus of the present invention, where A is a top view and B is a side view.

FIG. 2 is a configuration diagram of an X-ray tomographic imaging apparatus of the present invention.

FIG. 3 is a flowchart for explaining the present invention.

FIG. 4 is a diagram for explaining the present invention.

FIG. 5 is a diagram for explaining the present invention.

[Explanation of symbols]

1 ... X-ray tube, 2 ... X-ray two-dimensional detector, 3 ... Rotation base, 20 ... X-ray control unit, 21 ... Mechanism control unit, 22・ ・
..Control console, 23 ... Projection image storage unit, 24 ... Reconstruction calculation computer, 25 ... Reconstruction result display device

Continued front page    (72) Inventor Yasuo Shinohara             6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Soni             -Inside the corporation (72) Kenichi Katagai, Inventor             6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Soni             -Inside the corporation F-term (reference) 2G001 AA01 BA11 CA01 DA09 FA06                       GA06 GA08 GA13 HA07 HA12                       HA13 HA14 JA08 JA12 JA13                       KA03 LA11 PA12

Claims (8)

[Claims] 1. An object to be inspected is placed between an X-ray source and a two-dimensional detecting means for picking up a projected image of the object to be inspected, and is lowered from an X-ray focus onto a light receiving surface of the two-dimensional detecting means. From a projection image, a rotation base having a rotation axis orthogonal to the perpendicular and rotating in a predetermined rotation angle range at a predetermined angular displacement pitch, projection image storage means for storing a projection image of the inspection object taken for each angular displacement, It has a reconstructing unit for reconstructing the internal configuration data and a display unit for displaying the reconstructed internal structure data, and a projection image is obtained for each first angular displacement by the first rotation of the rotation base part. When the internal structure data is reconstructed from the captured projection image and the outline of the internal structure data is grasped by the display means, and more detailed internal structure data is acquired, The second rotation smaller than the first angular displacement in the second rotation When the image is captured by the angular displacement, the projection image of the object to be inspected is captured except for the angular position captured by the first rotation, and after the image capturing is finished, the projection image is first captured by the first rotation. The X-ray is characterized in that the projection image stored in the table and the projection image newly captured in the second rotation are integrated to reconstruct the internal structure data of the inspection object. Tomography method. 2. The X-ray tomographic imaging method according to claim 1, wherein the projection images are imaged at an equal angular displacement, and the projection images are numbered in order of imaging from a reference position as a starting point. In the first rotation, the projection image of the angular position corresponding to the odd number of the number is captured, the internal structure data is reconstructed from the captured projection image, and the outline of the internal structure data is displayed on the display means. In order to obtain more detailed internal structure data after grasping the above, in the second rotation of the rotation base part, a projection image of an angular position corresponding to the even number of the number is taken and An X-ray tomographic imaging method, characterized in that a corresponding projected image and a projected image corresponding to an odd-numbered image picked up in advance are combined to obtain internal structure data of an object to be inspected. 3. The X-ray tomographic imaging method according to claim 2, wherein when the internal structure data is reconstructed by capturing 2 × N (N is a positive integer) projected images, In the first rotation, the initial angular phase is 0 degree, N projected images are taken with an angular displacement of 360 / N degree, and the internal structure data of the object to be inspected is reconstructed from the projected images. After obtaining the outline of the internal structure data by means, when acquiring more detailed internal structure data, the initial rotation is 360 / (2N) degrees and the angular displacement is 360 / N in the second rotation. In this case, N projection images are picked up, and the newly picked up projection image and the preceding picked up projection image are combined to obtain internal structure data of the object to be inspected. X-ray tomography method. 4. The X-ray tomographic imaging method according to claim 2, wherein the internal structure data is reconstructed by capturing 2 ⁿ (n is a positive integer) projection images. In the rotation of 1, the initial angular phase is 0 degree, the angular displacement is 360/2 ^n-1 degree, and 2 ^n-1 projected images are taken,
When the internal structure data of the object to be inspected is reconstructed from the projected image and then the outline of the internal structure data is grasped by the display means, and when finer internal structure data is acquired, the second rotation , The initial angular phase is set to 360/2 ⁿ degrees, the angular displacement is set to 360/2 ^n-1 degrees, 2 ^n-1 projected images are taken, and the newly taken projected images are taken in advance. An X-ray tomographic imaging method characterized in that the internal structure data of the object to be inspected is obtained by synthesizing the projected image. 5. The X-ray tomographic imaging method according to claim 1, wherein the projection image is imaged at an equiangular displacement according to a desired degree of detail, and the inside of the projection image captured by the equiangular displacement. After reconstructing the configuration data and obtaining a more detailed internal structure data after grasping the outline of the internal configuration data on the display means, if the angular displacement is smaller than the angular displacement, the equal angular displacement in the preceding imaging is obtained. Is set as a new angular displacement, a new projection image is captured by skipping the angular position of the projection image captured previously, and the projection image is captured prior to the projection image after completion of the imaging. An X-ray tomographic imaging method characterized in that the projection image is combined to obtain internal structure data of the object to be inspected. 6. The X-ray tomographic imaging method according to claim 1, wherein one revolution of the rotation base portion is equally divided into N, and each of the N equally divided regions is further divided into M equal parts. When the projected images are numbered in the order of imaging starting from the reference position and a total of (M × N) projected images are imaged to obtain the internal structure data, every M images are obtained for each revolution of the rotary base. A projected image is captured, and first, in the first round, the first sheet, the (M + 1) th sheet, (2M +
1) Image, ..., ((N-1) M + 1) image is picked up, and on the second lap, 2nd image, (M + 2) th image, (2M + 2) th image, ... , ((N-1) M + 2) th image is captured, similarly up to the Nth round, and from the projection images obtained by capturing the first round to the Nth round, the internal structure data of the object to be inspected is obtained. The X-ray tomographic imaging method is characterized in that: 7. An X-ray source that generates X-rays, an X-ray control unit that controls the X-rays generated from the X-ray source, and a two-dimensional detection unit that captures an X-ray projection image of an object to be inspected. The object to be inspected is placed and a rotation axis orthogonal to a perpendicular line drawn from the focus to the light receiving surface of the two-dimensional detection means is provided between the X-ray source and the two-dimensional detection means, and a predetermined rotation angle range is displaced by a predetermined angle. A rotation base portion that rotates at a pitch, a mechanism control unit that controls a rotation mechanism of the rotation base portion, a projection image storage unit that stores the projection image captured by the two-dimensional detection unit as projection data, Control operation means for outputting an instruction signal to the X-ray control means, mechanism control means and projection image storage means, and reconstruction of internal structure data of the object under inspection from projection data stored in the projection image storage means. Reconstructing means, and the internal structure data Display means for displaying a reconstruction result, and a projection image is taken at each first angular displacement by the first rotation of the rotation base portion, and internal structure data is obtained from the taken projection image. When the image is reconstructed at the second rotation of the rotation base portion at the second angular displacement smaller than the first angular displacement, the object is removed except for the angular position imaged at the first rotation. The projection image of the inspection body is captured, and after the completion of the imaging, the projection image previously captured in the first rotation and stored in the projection image storage means and the projection image newly captured in the second rotation. An X-ray tomographic imaging apparatus characterized in that the internal structure data of the object to be inspected is reconstructed by integrating the above. 8. The X-ray tomographic imaging apparatus according to claim 7, wherein the rotary base portion is supported by an air bearing, and a servo motor and a rotation phase detecting unit are coaxially directly connected to the air bearing, Each of the angular displacements according to the resolution of the servo motor and the rotational phase detection means is set according to the definition of the internal structure data of the object to be inspected, and a projected image of the object to be inspected is captured. X-ray tomography apparatus.