JP2002228759A - Image detector and solid imaging system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of crosstalk, or to reduce the influence of the crosstalk by reading image information having the predetermined number of pixels even if a positional displacement is generated in a sticking process of an X-ray sensing unit to a reading unit. SOLUTION: This image detector is formed by sticking a first substrate having a semiconductor layer for converting the incident energy to electrical charge and several first electrodes for outputting the electrical charge to a second substrate having several second electrodes, in which the electrical charge outputted from the several first electrodes is inputted, and electrically connecting the first substrate to the second substrate. The number of the first electrode and the number of the second electrodes are different.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image detecting apparatus and a solid-state imaging system for detecting an image obtained from incident energy such as light and radiation, and more particularly, to an image detecting apparatus for detecting an X-ray image. The present invention relates to an image detection device and a solid-state imaging system.

[0002]

2. Description of the Related Art In recent years, with the development of a photoelectric conversion semiconductor material represented by amorphous silicon (a-Si), the development of a two-dimensional sensor in which a large number of photoelectric conversion elements are formed two-dimensionally on a large-area substrate has been advanced. Has been put to practical use. Among such two-dimensional sensors, there is an X-ray two-dimensional sensor for imaging an X-ray image mainly as a medical diagnostic device.

The two-dimensional X-ray sensor mainly has two types, an indirect conversion method and a direct conversion method, depending on the difference in the X-ray conversion method.
Divided into methods. In the indirect conversion method, X-rays are converted into visible light by an X-ray sensing unit, the visible light is converted into charges by a photoelectric conversion element, and the stored charges are read out via a transistor. On the other hand, in the direct method, an X-ray sensing unit converts X-rays into electric charges and reads out the stored electric charges via a transistor.

FIG. 3 is a schematic cross-sectional view schematically showing a cross section in the arrangement direction of a direct conversion type two-dimensional sensor in which pixels are arranged in a matrix. 3, an X-ray sensing unit 10 includes an insulating substrate 11, an upper electrode 1 serving as a common electrode.
2. Pin as a semiconductor layer that converts incident X-rays into charges
It has a diode 13, a protective film 14, and a lower electrode 15.

The read section 20 has a conductive electrode 21, a capacitor section 22, a TFT (thin film transistor section) 23, and an insulating substrate 24.

The lower electrode 1 of the X-ray sensing unit 10
5 and the conductive electrode 21 of the reading unit 20 are connected to the lower electrode 15.
And electrically connected by a conductive member 8 such as an anisotropic conductive adhesive over a width R in the arrangement direction of the conductive electrodes 21.
A pixel. There is a non-conductive portion having a width Q in the arrangement direction between the adjacent lower electrodes 15 and between the conductive electrodes 21 and is electrically separated.

Next, referring to FIG.
The operation of the dimensional sensor will be described. When the X-ray transmitted through the insulating substrate 11 is applied to the pin diode 13, electric charges are generated inside. At this time, when a voltage is applied between the upper electrode 12 and the capacitor unit 22, the electric charge generated in the pin diode 13 is electrically connected to the pin diode 13 via the lower electrode 15, the conductive member 8, and the conductive electrode 21. Are stored in the capacitor unit 22 connected in series with the.
The charge stored in the capacitor unit 21 is read out to the outside via the source / drain electrodes by turning on the gate of the TFT unit 23. This operation is performed for all pixels arranged two-dimensionally, so that two-dimensional image data can be obtained.

FIG. 4 is a diagram schematically showing a cross section of the X-ray sensing unit and the reading unit. In FIG. 4, the upper substrate alignment mark 19 is provided on the X-ray sensing unit 10, and the lower substrate alignment mark 29 is provided on the reading unit 20. The lower electrode 15 and the conductive electrode 21 are both arranged at a pixel pitch m, and the numbers thereof are equal. In FIG. 4, six are arranged in each case. FIG.
In FIG. 7, the same parts as those in FIG. 3 are denoted by the same reference numerals, and the description thereof will be omitted.

Here, the step of bonding the X-ray sensing unit and the reading unit will be described with reference to FIG.

First, in the bonding step, the substrates of the X-ray sensing unit 10 and the reading unit 20 are fixed to a stage (not shown) by a method such as vacuum adhesion. At this time, FIG.
As shown in (a), each lower electrode 15 and the conductive electrode 21 face each other, and a conductive member such as an anisotropic conductive adhesive (not shown) is disposed between the lower electrode 15 and the conductive electrode 21. I have. Next, the upper substrate alignment mark 19 is
Then, the alignment is performed by moving the stage on which each substrate is fixed so that the lower substrate alignment mark 29 matches.

After the alignment, the X-ray sensing unit 10 and the readout unit 20 are brought closer to each other, and the lower electrode 15 and the conductive electrode 21 sandwich a conductive member.
The line sensing unit 10 and the reading unit 20 are attached.
At this time, one of the conductive electrodes 21 of the reading unit 20 is electrically connected to one of the lower electrodes 15 of the X-ray sensing unit 10 via a conductive member.

[0012]

However, when bonding is performed by pressure bonding or heat treatment as in the past,
In some cases, displacement of the electrical connection portion may occur due to uneven pressure in the plane, thermal expansion of the sensor member, or the like. In addition, misalignment also occurs due to an alignment error.

Here, consider the effect of a position shift.

FIG. 4B is a diagram when the X-ray sensing unit 10 and the reading unit 20 are displaced by a half of the pixel pitch m. In this case, for example, the reading unit 2
The zero conductive electrodes 21a and 21b are electrically connected via the lower electrode 15b of the X-ray sensing unit 10, and the conductive electrodes 21b and 21c are electrically connected via the lower electrode 15c. . As described above, in the configuration in which the pair of conducting electrodes of the reading unit are electrically connected to each other through the conductive member via the lower electrode having the X-ray sensing unit, the conducting electrode 2 is connected to one of the lower electrodes due to displacement. If the two are electrically connected, a short circuit occurs between the conductive electrodes, and true image data cannot be obtained.

When a displacement occurs by a pixel pitch m as shown in FIG. 4C, the lower electrode 15a is not electrically connected to the read section 20. For this reason, there arises a problem that the image information in the effective pixel area cannot be partially read, such that the image information of the lower electrode 15a which is originally an effective pixel cannot be read. In the above-described conventional example, when a positional deviation that satisfies the relationship of positional deviation amount> R occurs, a part of the image information cannot be read.

Further, in recent years, the pixel pitch has become smaller as the definition of an image has become higher, and accordingly, the requirements for alignment accuracy in the bonding step have become stricter. If the requirement for alignment accuracy is strict, that is, if the allowable amount of displacement is small, problems such as a decrease in manufacturing yield occur.

In order to prevent such a problem caused by misalignment at the time of bonding, a high-precision member, a bonding apparatus or the like is used to strictly control the process and reduce the amount of misalignment.
That is, raising the alignment accuracy can be mentioned.
However, high-precision members and devices are expensive, and a new problem of increasing manufacturing costs arises. If the process control is strict, problems such as an increase in manufacturing cost and a decrease in the throughput of the process will occur.

An object of the present invention is to provide a two-dimensional image detecting apparatus which minimizes deterioration of image quality even when a positional shift occurs in a bonding step between a sensing unit and a reading unit.

It is another object of the present invention to provide a two-dimensional image detecting apparatus capable of reading out all image information in an effective pixel area even when a position shift occurs.

It is still another object of the present invention to provide a two-dimensional image detecting device which increases the allowable amount of displacement and improves the production yield.

[0021]

In order to achieve the above object, a first substrate having a semiconductor layer for converting incident energy into electric charges and a plurality of first electrodes for outputting the electric charges is provided. A second substrate having a plurality of second electrodes to which electric charges output from the plurality of first electrodes are input; and bonding the plurality of first electrodes to the plurality of second electrodes. Wherein the number of the plurality of first electrodes is different from the number of the plurality of second electrodes.

In one embodiment of the present invention, the plurality of first electrodes and the plurality of second electrodes are arranged in a line or a matrix.

In one embodiment of the present invention, the smaller number of the electrodes among the plurality of first electrodes and the plurality of second electrodes is x, and the plurality of first electrodes Assuming that the larger number of electrodes among the electrodes and the plurality of second electrodes is y, the x electrodes are connected to x of y electrodes, respectively. The first substrate and the second substrate are attached to each other.

In one embodiment of the present invention, the number of the plurality of first electrodes is larger than the number of the plurality of second electrodes.

In one embodiment of the present invention, in the arrangement direction, the width of the first electrode is smaller than the width between the adjacent second electrodes.

In one embodiment of the present invention, a plurality of the first electrodes are electrically connected to one second electrode.

In one embodiment of the present invention, five or more first electrodes are electrically connected to one second electrode.

[0028] In one embodiment of the present invention, the second substrate further includes a capacitor portion for accumulating electric charge and a thin film transistor portion, and the electric charge converted by the semiconductor layer is the first electric charge. The charge is stored in the capacitor unit via the electrode and the second electrode, and the stored charge is read out via the thin film transistor unit.

In one aspect of the present invention, the above-described image detection device, signal processing means for processing a signal from the radiation imaging apparatus, recording means for recording a signal from the signal processing means, Display means for displaying a signal from the signal processing means, transmission processing means for transmitting a signal from the signal processing means, and a radiation source for generating the radiation. This is a solid-state imaging system.

According to the present invention, it is possible to read out all pieces of image information of a desired number of pixels even if displacement occurs during bonding.

Further, according to the present invention, the number n of the lower electrodes,
Since the number N of conducting electrodes is n> N, image information of all desired number of pixels can be read out even if misalignment occurs at the time of bonding, and the amplifier at the subsequent stage can be compared with the case where many conducting electrodes are arranged. It is not necessary to arrange many electric circuits for A / D conversion and the like, and it can be manufactured at low cost.

Further, according to the present invention, the length S of the lower electrode in the arrangement direction and the length Q between the adjacent conductive electrodes are S
Because of <Q, even if a displacement occurs, one electrode is not electrically connected to two other electrodes, and image quality degradation such as resolution and contrast degradation due to crosstalk occurs. Absent. For this reason, the allowable amount of displacement can be increased, and the manufacturing yield can be improved.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an image detecting device according to the present invention will be described. In the following embodiments, a two-dimensional image detection device having a configuration in which lower electrodes and conductive electrodes are arranged in a matrix is applied, but the image detection device of the present invention is not limited to a two-dimensional image detection device. The present invention is also applicable to a one-dimensional image detecting device such as a line sensor.

(First Embodiment) Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram schematically showing a cross section of an X-ray sensing section and a reading section according to a first embodiment of the present invention. The same members or parts as those in the conventional example shown in FIG. And description thereof is omitted here.

4 is different from FIG. 4 in that the number of lower electrodes 15 of the X-ray sensing unit 10 and the number of conducting electrodes 21 of the reading unit 20 are equal in FIG. The number of the lower electrodes 15 as the first electrodes of the sensing unit 10 and the number of the conductive electrodes 21 as the second electrodes of the reading unit 20 as the second substrate are different. Is a large number of

In the example shown in FIG. 1, the lower electrodes are lower electrodes 15a to 15a.
f (that is, x, which is the smaller number of electrodes among the number of lower electrodes and the number of conductive electrodes, is six), and the number of conductive electrodes is eight of conductive electrodes 21a to 21h (ie, lower electrode). The number y of the larger number of the electrodes is 8 among the number of the conductive electrodes 21 and the number of the conductive electrodes 21), and the six lower electrodes 15a to 15f are the six of the eight conductive electrodes 21a to 21h. Conducting electrode 21a
To 21f.

Therefore, as shown in FIG. 1A, the upper substrate alignment mark 19 and the lower substrate alignment mark 29
Are substantially the same, there is no lower electrode facing the conductive electrodes 21a and 21h. That is, in this embodiment, many conductive electrodes are arranged outside the effective pixel area. Therefore, as shown in FIG. 1B, the X-ray sensing unit 10
Is shifted by a pixel pitch m in the arrangement direction, X
All the lower electrodes 15 of the line sensing unit 10 are readout units 2
0, and can read all image information in the effective pixel area.

As described above, in the present embodiment, the lower electrode 15 of the X-ray sensing unit 10 and the conductive electrode 2 of the readout unit 20
By disposing the conductive electrodes 21 of the reading unit 20 in large numbers, the entire number of image information can be read even if a positional shift occurs.

It should be noted that the number of conductive electrodes arranged in large numbers may be appropriately determined according to the alignment accuracy in the bonding step.

In the first embodiment, a large number of conductive electrodes 21 of the reading unit 20 are provided. However, as another embodiment, a configuration in which a large number of lower electrodes 15 of the X-ray sensing unit 10 are provided. You may. In this case, contrary to the above configuration, many lower electrodes 15 are arranged outside the effective pixel area. Assuming that the number of lower electrodes 15 of the X-ray sensing unit 10 as the first substrate is n and the number of conductive electrodes 21 of the readout unit 20 as the second substrate is N, n> N. The number may be larger than the number of conductive electrodes. In this case, not only the same effects as in the first embodiment are obtained, but also more electric circuits such as amplifiers and A / D converters in the subsequent stage are arranged than in the case where more conductive electrodes 21 of the reading unit 20 are arranged. There is no need to make it inexpensively.

(Second Embodiment) Next, a second embodiment as one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a diagram schematically showing a cross section of an X-ray sensing unit and a reading unit according to a second embodiment of the present invention. The same members and parts as those in FIG. The description here is omitted. In the present embodiment,
S is the width of the lower electrode in the arrangement direction, Q is the width between adjacent conductive electrodes, and m is the pitch between the conductive electrodes.

The difference from FIG. 4 is that the number of the lower electrodes 15 of the X-ray sensing unit 10 and the number of the conductive electrodes 21 of the reading unit 20 are equal, whereas in the present embodiment, the X-ray sensing unit 10 as the first substrate is The number of the lower electrodes 15 as the first electrodes of the X-ray sensing unit 10 is different from the number of the lower electrodes 15 of the X-ray sensing unit 10 because the number of the lower electrodes 15 as the first electrodes and the number of the conductive electrodes 21 as the second electrodes of the reading unit 20 as the second substrate differ And the point that the width of the lower electrode and the width of the conductive electrode in the arrangement direction and the width between the adjacent lower electrodes and the width between the conductive electrodes are different.

That is, assuming that the number of lower electrodes 15 of the X-ray sensing unit 10 as the first substrate is n and the number of conducting electrodes 21 of the readout unit 20 as the second substrate is N, n> N And the lower electrode 1 is smaller than the number of conductive electrodes.
The number of 5 is large.

In the present embodiment, when the upper substrate alignment mark 19 and the lower substrate alignment mark 29 substantially coincide with each other as shown in FIG.
, Five lower electrodes 15a to 15e are electrically connected. The number is not particularly limited, and two or more lower electrodes can be connected as long as space permits.

Further, in this embodiment, the width Q between the adjacent conductive electrodes 21 in the arrangement direction and the width S of the lower electrode 15
Has a relationship of Q> S, and the width of the lower electrode 15 in the arrangement direction is smaller than the width between the adjacent conductive electrodes 21.

Here, with reference to FIG. 2B, description will be given of a case where a displacement has occurred by a half of the pixel pitch m in the present embodiment.

FIG. 2B shows that the X-ray sensing unit 10 is displaced in the right direction on the paper by 1/2 of the pixel pitch m. At this time, for example, the lower electrode 1 is connected to the conductive electrode 21a.
Four of 5d-g are electrically connected. At this time, the lower electrode 15h is not electrically connected to either of the conductive electrodes 21a and 21b.

As described above, in this embodiment, the length Q of the non-conductive portion between the adjacent conductive electrodes 21 and the length of the lower electrode 15
Since the length S has a relationship of Q> S, two conductive electrodes are not electrically connected to one lower electrode even if a positional shift occurs. Therefore, although the aperture ratio is reduced due to the decrease in the number of lower electrodes of the X-ray sensing unit electrically connected to one conductive electrode of the readout unit, the image quality does not deteriorate due to the short circuit between the conductive electrodes. .

As described above, according to the present embodiment, a short circuit between the conductive electrodes due to a displacement during bonding does not occur, so that the allowable displacement can be increased, and the manufacturing yield can be improved. .

In the above description, the effective pixel area means the area of the image detecting device where the lower electrode and the conductive electrode are connected, and in the first and second embodiments,
Which area is to be an effective pixel area is determined at the time of bonding. In FIGS. 1 and 2, the area is indicated by A.

(Third Embodiment) Hereinafter, a third embodiment according to the present invention will be described with reference to FIG. FIG.
1 is a configuration diagram of a solid-state imaging system using an image detection device described in the first and second embodiments. In the present embodiment, the image detecting device is an image detecting device 6040.
Applied as

X-ray 60 generated in X-ray tube 6050
Reference numeral 60 denotes an image detection device 6 which transmits through a chest 6062 of a patient or a subject 6061 and has a scintillator mounted on an upper portion thereof.
040. This incident X-ray contains the patient 6061
Contains information about the inside of the body. The scintillator emits light in response to the incidence of X-rays, and photoelectrically converts the light to obtain electrical information. This information is converted into digital data, image-processed by an image processor 6070, and can be observed on a display 6080 in the control room.

This information can be transferred to a remote place by a transmission means such as a telephone line 6090, displayed on a display 6081 such as a doctor's room in another place, or stored in a storage means such as an optical disk. It is also possible to make a diagnosis. Also film processor 6
100 can also be recorded on the film 6110.

Note that radiation refers to X-rays, α, β, γ-rays, and the like, and light is electromagnetic waves in a wavelength range that can be detected by a photoelectric conversion element, and includes visible light.

[0057]

As described above, according to the present invention,
Since the number of lower electrodes is different from the number of conductive electrodes, all image information in the effective pixel area can be read even if a positional shift occurs during bonding, and a desired pixel output can be obtained.

Further, according to the present invention, since the number of lower electrodes is larger than the number of conductive electrodes, all image information in the effective pixel area can be read out even if displacement occurs during bonding. Compared to the case where a large number of conductive electrodes are provided, there is no need to provide a large number of electric circuits such as amplifiers and A / D converters at the subsequent stage, and the device can be manufactured at low cost.

Further, according to the present invention, since the width between adjacent conductive electrodes is larger than the width of the lower electrode in the arrangement direction, two conductive electrodes are electrically connected to one lower electrode even if a positional shift occurs. The image quality is not degraded due to the short circuit between the conductive electrodes. Therefore, the allowable amount of displacement can be increased, and the manufacturing yield can be improved.

The present invention is not limited to an image detecting apparatus for detecting an X-ray image, but may be an image detecting apparatus for detecting an image such as visible light, infrared light, or other radiation (α, β, γ-ray). Similar effects can be obtained in the detection device.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a cross section in an arrangement direction of an X-ray sensing unit and a read-out unit of a first embodiment of an image detection device according to the present invention.

FIG. 2 is a diagram schematically illustrating a cross section of an image detection apparatus according to a second embodiment of the present invention in an arrangement direction of an X-ray sensing unit and a reading unit.

FIG. 3 is a schematic cross-sectional view schematically illustrating a cross-section of a direct conversion type two-dimensional sensor.

FIG. 4 is a diagram schematically showing a cross section in the arrangement direction of a conventional X-ray sensing unit and a reading unit.

FIG. 5 shows an application example of an image detection device according to the present invention to an X-ray diagnostic system.

[Explanation of symbols]

 Reference Signs List 8 Conductive member 10 X-ray sensing unit 15 Lower electrode 19 Upper substrate alignment mark 20 Readout unit 21 Conductive electrode 29 Lower substrate alignment mark 6040 Image detector 6050 X-ray tube 6060 X-ray 6061 Subject 6062 Chest 6070 Image processor 6080 Control room Display 6090 Telephone line 6081 Doctor's room display 6100 Film processor 6110 Film

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 31/09 H01L 27/14 F H04N 5/32 31/00 A F term (Reference) 2G088 EE02 FF02 FF04 FF05 FF06 GG19 GG21 JJ04 JJ05 JJ31 JJ33 4M118 AA10 AB01 BA05 BA19 CA05 CB06 FB13 FB16 GA10 HA24 HA32 5C024 AX12 CY47 CY49 GX09 GX16 GX18 5F088 AA03 AB05 BA18 BB03 BB07 EA03 LA07

Claims (9)

[Claims] 1. A first substrate having a semiconductor layer for converting incident energy into electric charge and a plurality of first electrodes for outputting the electric charge, and a first substrate output from the plurality of first electrodes. And a second substrate having a plurality of second electrodes to which the charged electric charges are input, and the plurality of first electrodes and the plurality of second electrodes are electrically connected to each other. An image detection device, wherein the number of the plurality of first electrodes is different from the number of the plurality of second electrodes. 2. The image detection device according to claim 1, wherein the plurality of first electrodes and the plurality of second electrodes are arranged in a line or a matrix. 3. The number of the plurality of first electrodes and the number of the second electrodes, the smaller of the number of electrodes being x
And the number of the plurality of first electrodes and the number of the second electrodes
When the number of the electrodes having the larger number of the electrodes is y, the first or the second electrode having the number of the electrodes x is equal to the number of the second or the first electrode having the number y of the electrodes. The image detection device according to claim 1, wherein the first substrate and the second substrate are attached to each other so as to be connected to x electrodes. 4. The image detection apparatus according to claim 1, wherein the number of the plurality of first electrodes is larger than the number of the plurality of second electrodes. 5. The image detection device according to claim 2, wherein a width of the first electrode is smaller than a width between the adjacent second electrodes in the arrangement direction. 6. The image detection device according to claim 5, wherein a plurality of said first electrodes are electrically connected to one said second electrode. 7. The image detection apparatus according to claim 5, wherein five or more first electrodes are electrically connected to one second electrode. 8. The second substrate further includes a capacitor unit for accumulating electric charge and a thin film transistor unit, and the electric charge converted in the semiconductor layer is applied to the first electrode and the second electrode. The image detection device according to claim 1, wherein the charge is stored in the capacitor unit via an electrode, and the stored charge is read out via the thin film transistor unit. 9. An image detecting apparatus according to claim 1, a signal processing unit for processing a signal from the radiation imaging apparatus, and a signal processing unit for recording a signal from the signal processing unit. Recording means; display means for displaying a signal from the signal processing means; transmission processing means for transmitting a signal from the signal processing means; and a radiation source for generating the radiation. A solid-state imaging system, characterized in that: