JP3491610B2 - X-ray CT system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial X-ray CT apparatus, and more particularly, to a relatively small and lightweight article such as an electronic component, which can be operated easily by both CT and fluoroscopic images. The present invention relates to an X-ray CT apparatus that can be obtained.

[0002]

2. Description of the Related Art In an industrial X-ray CT apparatus, generally, as shown in a schematic perspective view of FIG.
An X-ray detector 42 is arranged on the X-ray optical axis L so as to face the line generator 41, and a sample W as an object is held between the X-ray detector 42 and the X-ray optical axis L, and an X-ray detector 42 is provided around the axis A orthogonal to the X-ray optical axis L. A configuration in which a sample stage 43 having a function of rotating is arranged is adopted. The X-ray detector 42 is made to substantially function as a line sensor by using a line sensor or by using only an output of elements arranged in a line shape among them using an area sensor. Then, while rotating the sample W around the axis A, the X-ray fluoroscopic information from the X-ray detector 42 is collected at a large number of rotation angles, and a conversion called fan-para conversion is performed to obtain a line. It is possible to reconstruct a tomographic image of the sample W sliced on the slice plane corresponding to the sensor or the elements arranged in a line.

Further, the sample stage 43 is moved along the axis A, and the X-ray fluoroscopic information from the X-ray detector 42 is acquired at a large number of rotation angles at the respective movement positions in the same manner as described above. By obtaining X-ray transmission information of all parts and all directions at an arbitrary cross-sectional position orthogonal to the axis A of, the tomographic image of the sample W at any position on the axis A can be obtained. In the conventional industrial X-ray CT apparatus, as illustrated in FIG. 4, the X-ray optical axis is set in the horizontal direction, and therefore the rotation axis A of the sample W is set vertically.

[0004]

By the way, as illustrated in FIG. 4, an X-ray CT in which the X-ray optical axis L is set horizontally.
According to the apparatus, since the sample W is rotated around the vertical rotation axis A, it is convenient to increase the rotation accuracy, but when this apparatus is used as an X-ray fluoroscopic apparatus, If you try to see through a large number of samples at one time, such as IC chips and other electronic parts that are minute,
It is necessary to stand them on a separately prepared horizontal table or tray, which poses a problem that it is difficult to fix the sample and it takes time and effort.

When considering only seeing through such a large number of small samples at once, if the X-ray optical axis is along the vertical direction, each sample is placed on a horizontal table or tray. Therefore, in the fluoroscopy device for such an application, it is advantageous in terms of operability to adopt a configuration in which the X-ray optical axis is along the vertical direction.

However, conventionally, an X-ray CT capable of functioning also as an X-ray CT apparatus without impairing the operability when seeing through a large number of electronic components such as IC chips at once. The apparatus has not been realized, and it is impossible to use the CT sample stage also as a fluoroscopic sample stage that requires a relatively large movable range. Therefore, when the X-ray CT apparatus is also used as an X-ray fluoroscope having good operability, the CT sample stage needs to be removed because it becomes an obstacle, but as the CT sample stage, If precision and rigidity are required and the design is designed for removal, each time the sample stage for CT is attached and detached, the work of calibrating its position and rotating surface is required, which is inconvenient in this respect.

The present invention has been made in view of the above circumstances, and it is an X-ray CT apparatus equipped with a CT sample stage and is suitable for relatively small samples such as IC chips and other electronic components. It is an object of the present invention to provide an X-ray CT apparatus capable of seeing through a plurality of pieces at once with excellent workability.

In order to achieve the above object, X of the present invention
The X-ray CT apparatus has a function of holding a sample between an X-ray generator and an X-ray detector arranged on the X-ray optical axis and rotating the sample around an axis orthogonal to the X-ray optical axis. An X-ray CT in which a stage is arranged, the X-ray fluoroscopic image of the sample is captured at a plurality of rotation angles while the sample is rotated by the sample stage, and a tomographic image of the sample is reconstructed using the plurality of X-ray fluoroscopic images. In the apparatus, the X-ray generator, the X-ray detector and the sample stage are arranged so that the X-ray optical axis is along the vertical direction, and the sample stage is connected to the X-ray generator and the X-ray detector. From the measurement position between
Of the two spaces including the X-ray emission port of the radiation generator and divided vertically into a plane orthogonal to the X-ray optical axis, the above X
Between the X-ray generator and the X-ray detector, a retracting mechanism for moving to a retracted position in the space not including the X-ray detector,
3D direction by detachably attaching the sample table for see-through
It is characterized by the fact that it is provided with a fluoroscopic sample stage which is moved to (1).

In the present invention, the retracting mechanism controls the sample stage to rotate between the measurement position and the retracted position, and regulates the rotation of the sample stage at each position. A configuration (claim 2) as a positioning mechanism can be preferably adopted.

According to the present invention, the X-ray optical axis is set in the vertical direction so that the operability when used as a fluoroscopic device can be made good, and when used as a fluoroscopic device, a CT sample is used. The purpose of this is not to remove the stage, but to move it to a prescribed retracted position that does not interfere with the fluoroscopic work by the retracting mechanism, thereby achieving the intended purpose.

That is, when a large number of small samples such as IC chips are seen through at the same time by setting the X-ray optical axis in the vertical direction, the samples can be set by placing them side by side on a horizontal table or tray. The workability can be improved . There
With the X-ray CT apparatus of the present invention,
Separate from the tage, between the X-ray generator and the X-ray detector,
A flat transparent sample table can be attached and detached in three dimensions
In addition to providing a fluoroscopic sample stage that moves in the same direction,
When the sample is viewed through the sample stage, the sample stage for CT is not removed, and the sample stage is moved from the measurement position to the X-ray emission port of the X-ray generator by the retracting mechanism. Of the two spaces that are divided up and down on a plane orthogonal to the line optical axis, the escape position is set in the space not including the X-ray detector, that is, it is outside the X-ray irradiation area and does not interfere at all. Move to position. As a result, when the CT sample stage is returned from the retracted position to the measurement position, its position and posture can be accurately reproduced, for example, only by providing an appropriate restriction member such as a stopper, and calibration for each measurement change. No work required, and CT
Even if the weight of the operating stage is increased to increase its rigidity, it can be positioned at the measurement position or the retracted position by a simple operation.

Further, as in the invention according to claim 2, CT
When the sample stage retracting mechanism is configured to include a mechanism for rotating the sample stage between the measurement position and the retracted position and a mechanism for positioning the sample stage at each of the two positions, the sample stage is moved linearly. In contrast, the space for moving the CT sample stage is small, and the above-described effects can be achieved without increasing the installation area.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of an embodiment of the present invention, in which a schematic diagram showing a mechanical configuration and a block diagram showing an electrical configuration are shown together.

The X-ray generator 1 is, for example, a microfocus type X-ray tube, is arranged with the X-ray emission port (window) 1a facing vertically upward, and has an X-ray optical axis L in the vertical direction (z direction).
Emit X-rays upward along the. An X-ray area sensor 2 including, for example, an image intensifier and a two-dimensional CCD is arranged vertically above the X-ray generator 1. A CT sample stage 3 is provided between the X-ray generator 1 and the X-ray area sensor 2. Further, a fluoroscopic sample stage 4 is provided above the CT sample stage 3, and each fluoroscopic sample stage 4 is made of a removable carbon by driving an individual motor (not shown). X made table 41,
It can be moved in the y and z directions. The carbon plate 41 is removed when a CT image of a sample is taken, and the fluoroscopic sample stage 4 is taken only when a fluoroscopic image is taken.
Attached to.

The sample stage 3 for CT is shown in FIG. 2 as an external view and in FIG. 3 as a front view shown by an arrow A in FIG. A rotation mechanism 31 for rotating a rod-shaped work holding member 31a having a flat surface for holding by sticking or the like and extending in the x direction around its axis (x axis) by driving a motor 31b; With the rotating mechanism 31,
The three-dimensional movement mechanism 32 is mainly configured to move in a vertical z direction and two directions (x and y directions) orthogonal to each other on a horizontal plane by a path of an individual motor (not shown).

The three-dimensional moving mechanism 32 is fixed to the surface of the support plate 33, and the support plate 33 is also provided.
Is supported on one side of the base plate 35 by a hinge mechanism 34 so as to be rotatable around the x axis.
A retracting stopper 36 (not shown in FIG. 1) is provided at a position apart from the base plate 35 in the y direction by a predetermined distance, and the CT sample stage 3 includes the retracting stopper 36 and the base plate. It can be rotated between 35 and is tilted to either side at the time of acquiring a CT image of a sample and at the time of acquiring a fluoroscopic image.

When measuring the CT image of the sample, as shown by the solid line in FIG. 3, the back surface of the support plate 33 is tilted to the side in contact with the front surface of the base plate 35. In this state, the support plate 3
The back surface of 3 adheres closely to the front surface of the base plate 35, so that
The position including the posture of the CT sample stage 3 at the time of CT image acquisition is always fixed.

On the other hand, when collecting a fluoroscopic image of a sample,
The CT sample stage 3 is tilted to the retracting stopper 36 side, as shown by the chain double-dashed line in FIG. The z-direction position of the above-mentioned hinge mechanism 34 is located below the X-ray emission port 1a of the X-ray generator 1, and the CT sample stage 3
In the state in which is tilted toward the evacuation stopper 36 side, the entire CT sample stage 3 includes the X-ray emission port 1a of the X-ray generator 1 and moves up and down on a plane P orthogonal to the X-ray optical axis L. It is in a state of being located in the space on the side not including the X-ray area sensor 2 of the two spaces divided into.

The X-ray generator 1 is driven and controlled by an X-ray control circuit 52 under the control of a computer 51, and is used for rotating a sample for rotating the work holding member 31a of the CT sample stage 3. Motor 3
1b, each motor of the three-dimensional drive mechanism 32b, and each motor of the fluoroscopic sample stage 4 are also the common motor control circuit 5 under the control of the computer 51.
Drive control is performed by the control unit 3. Motor control circuit 5
The output of 3 is supplied to each motor of the CT sample stage 3 at the time of CT image acquisition and to each motor of the fluoroscopic sample stage 4 at the time of CT image acquisition by the switch 54 also under the control of the computer 51. It has become so. A keyboard 51 connected to the computer 51 is used to select whether to acquire a CT image or a fluoroscopic image.
It is performed by the operation of a.

Each pixel output of the X-ray area sensor 2 is taken into a CT image reconstructing device 57 via a switch 55 placed under the control of a computer 51, an amplifier 56, or a capture board. It is taken in by 58. The computer 51 uses the X-ray area sensor 2
The switch 55 is driven so that the output of each pixel is captured by the CT image reconstructing device 57 when the CT image is acquired and is captured by the capture board 58 when the fluoroscopic image is acquired. C
The T image reconstructing device 57 reconstructs the CT image of the sample using the pixel output of each line of the X-ray area sensor 2 along the slice direction of the sample, and reconstructs the image by the computer 51. It is displayed on the display monitor 59 via.
Further, the capture board 58 is used for the X-ray area sensor 2
Digitize all pixel outputs from the computer 5
1, and the computer 51 displays the X-ray fluoroscopic image based on each pixel data on the display monitor 59.

When the apparatus is used as an X-ray CT apparatus in the use of the above embodiment, the support plate 33 having the CT sample stage 3 mounted thereon is positioned so as to be in close contact with the base plate 35, and the keyboard 51a is operated. And to that effect
Just point . On the other hand, when the apparatus is used as an X-ray fluoroscope, the CT sample stage 3 is retracted by the stopper 3
The table 41 made of carbon may be attached to the sample stage 4 for fluoroscopy, and the keyboard 51a may be operated to give an instruction to that effect.

When the embodiment of the present invention is used as a fluoroscope, the CT sample stage 3 is retracted below the X-ray emission port 1a of the X-ray generator 1, so that the presence thereof is completely absent. It does not get in the way, and since it is sufficient to place the sample on the horizontal carbon table 41,
For example, the work of seeing through a large number of small samples such as IC chips at one time becomes extremely easy.

When the CT sample stage 3 is used after being used as a fluoroscope, the posture and position of the CT sample stage 3 can be fixed by simply rotating the CT sample stage 3 toward the base plate 35 side, and particularly, calibration work is performed. CT immediately without
It is possible to shift to image acquisition.

In the above embodiment, the CT
As a mechanism for retracting the sample stage 3 for a test, a hinge mechanism 34 and a positioning mechanism including a base plate 35 and a retracting stopper 36 for restricting the rotation of the CT stage 3 by the hinge mechanism 34 at the CT measurement position and the retracted position are used. Configuration, which allows C with less space requirements
Although the T sample stage 3 can be retracted, the present invention is not limited to this, and a mechanism for retracting the CT sample stage 3 by a linear motion can be adopted.

In the above embodiment, the X-ray emission port 1a of the X-ray generator 1 is directed vertically upward and the X-ray area sensor 2 is arranged above the X-ray emission port 1a. Even if the configuration is reversed, that is, the X-ray emission port 1a of the X-ray generator 1 is directed vertically downward and the X-ray area sensor 2 is disposed below it, the same effect as the above is obtained. Of course, it can play.

As described above, according to the present invention, the X-ray optical axis is along the vertical direction, and the CT sample stage is arranged between the X-ray generator and the X-ray detector. , A retreating mechanism for moving to a retreat position set on the space side not including the X-ray detector among the two spaces vertically divided by the horizontal plane including the X-ray emission port of the X-ray generator , And, apart from the sample stage for CT, X
Horizontal fluoroscopy sample table between X-ray detector and X-ray detector
See through to attach and detach the bull detachably and move in three dimensions
Since a sample stage for observation is provided , when used as an X-ray fluoroscope, the sample is mounted horizontally on the sample stage for observation.
A relatively small sample such as an IC chip can be seen through at a time by placing it on the fluoroscopic sample table, and at that time, the CT sample stage does not include an X-ray detector. Since it is retracted into the space, compared with the conventional X-ray CT device in which the X-ray optical axis is horizontally aligned,
The work is greatly simplified. When the CT sample stage is returned to the measurement position when used as a CT device after being used as a fluoroscope, the CT
Compared to the case of removing the sample stage for use, it is not necessary to perform the calibration work, and the returning work is extremely easy.

Further, as a retracting mechanism for the CT sample stage, if a rotating mechanism such as a hinge mechanism and a mechanism for regulating the rotating end thereof to position the CT sample stage at the measuring position and the retracting position are adopted. The above effect can be achieved in a small required space.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, in which a schematic diagram showing a mechanical configuration and a block diagram showing an electrical configuration are shown together.

FIG. 2 is a schematic perspective view of a CT sample stage 3 in FIG.

FIG. 3 is a schematic front view showing the CT sample stage 3 in FIG.

FIG. 4 is a schematic perspective view showing a configuration example of a conventional industrial X-ray CT apparatus.

[Explanation of symbols]

1 X-ray generator 1a X-ray emission port 2 X-ray area sensor 3 CT sample stage 31 rotation mechanism 31a Work holding member 31b motor 32 3D movement mechanism 33 Support plate 34 Hinge mechanism 35 base plate 36 Evacuation stopper 4 Fluoroscopic sample stage 41 carbon table 51 computer 51a keyboard 52 X-ray control circuit 53 Motor control circuit 57 CT image reconstruction device 58 capture board 59 Display monitor

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-249948 (JP, A) JP-A-63-307341 (JP, A) JP-A-63-181742 (JP, A) JP-A-2001-21505 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 23 / 00-23 / 227

Claims (2)

(57) [Claims] 1. A sample having a function of holding a sample between an X-ray generator and an X-ray detector arranged on the X-ray optical axis and rotating the sample around an axis orthogonal to the X-ray optical axis. An X-ray CT in which a stage is arranged, the X-ray fluoroscopic image of the sample is captured at a plurality of rotation angles while the sample is rotated by the sample stage, and a tomographic image of the sample is reconstructed using the plurality of X-ray fluoroscopic images. In the apparatus, the X-ray generator, the X-ray detector and the sample stage are arranged so that the X-ray optical axis is along the vertical direction, and the sample stage is connected to the X-ray generator and the X-ray detector. From the measurement position between the two, which includes the X-ray emission port of the X-ray generator and is divided into two spaces up and down on a plane orthogonal to the X-ray optical axis, the side not including the X-ray detector. a retracting mechanism for moving to the retracted position in space, the X-ray Raw devices
Attach and detach a horizontal fluoroscopic sample table between the X-ray detector and the X-ray detector.
A fluoroscopic sample station that can be freely attached and moved in three dimensions.
X-ray CT apparatus characterized in that it comprises over-di. 2. The retracting mechanism is a mechanism for rotating the sample stage between the measurement position and the retracting position, and a mechanism for restricting and positioning the rotation of the sample stage at each position. The X-ray CT apparatus according to claim 1, wherein: