JP2003270351A - Radiation imaging device - Google Patents

Abstract

(57) [Abstract] [Purpose] The coating of a protective film and a light-shielding film under a phosphor of a radiation imaging apparatus is selectively applied without performing an additional operation such as masking or other pretreatment, and large coating unevenness is caused. Even if it occurs, a high-quality and highly reliable radiation imaging apparatus can be obtained at low cost. The protective film and the light-shielding film are selectively applied to upper and lower portions of a photoelectric conversion element forming region excluding an external connection terminal formed in a process of manufacturing the photoelectric conversion element on the light-transmitting insulating substrate, respectively. Is formed larger than a region where the X-ray-visible light converter is provided, and at least smaller than a connection terminal forming region formed on the photoelectric conversion substrate, and is formed under the X-ray-visible light converter. A radiation imaging apparatus, wherein the thickness of the protective film and the light-shielding film is a coating stable region.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation image pickup device, and more particularly, to a light emission of an X-ray visible conversion layer such as a fluorescent plate using a photoelectric conversion device in which photoelectric conversion elements formed by a large area process are arranged two-dimensionally. The present invention relates to a radiation image pickup apparatus which is suitable for use in a digital image X-ray image pickup apparatus for medical equipment such as an X-ray apparatus or a nondestructive inspection apparatus, which directly reads a radiation image obtained by the method as an electric signal.

[0002]

2. Description of the Related Art X-ray inspection machines used in the medical field have mainly used a method in which X-rays are converted into visible light by a fluorescent plate, and a film adhered to the fluorescent plate is exposed to light for confirmation. However, due to the need for filmless and real-time diagnostic images, the development of a radiation imaging apparatus that directly arranges an X-ray image into an electric signal by arranging a solid-state imaging device typified by amorphous silicon in a large area in recent years Remarkable.

Generally, in order to detect an X-ray image by a photoelectric conversion device using amorphous silicon, radiation, especially,
An X-ray visible light conversion device for converting X-rays into visible light is required. In medical treatment, a large area that can withstand an X-ray examination machine for chest radiography is required, and it is practically easy to obtain and use. It consists of body powder,
A configuration is known in which a plate-shaped phosphor is attached to a two-dimensional photoelectric conversion device with an adhesive or the like.

A conventional radiation image pickup device in which a fluorescent plate is attached on a two-dimensional photoelectric conversion device will be described below.

3A and 3B are views showing the structure of a conventional radiation image pickup apparatus. FIG. 3A is a schematic plan view, and FIG. 3B is a schematic sectional view taken along the line AB in the plan view A.

In FIG. 3, reference numeral 100 denotes a photoelectric conversion device, which is used for electrical connection with an element formation region 110 in which a photoelectric conversion element or the like is formed on a substrate 101 such as glass or the like, or with an external device (not shown). Wirings and connection electrodes are formed of a conductive layer such as AL. Reference numeral 200 denotes a fluorescent plate which is an X-ray visible light conversion device. An X-ray visible light conversion substrate 210 such as PET: an X-ray visible light conversion layer 210 composed of phosphor particles for converting X-rays into visible light is provided. Has been formed. The thickness of the X-ray visible light conversion substrate 201 is generally about 0.3 mm.

The photoelectric conversion device: 100 and the X-ray visible light conversion device: 200 are manufactured by different processes. After completion of each process, they are adhered and fixed by an adhesive material (not shown), etc. Is being made.

Next, the structures of the photoelectric conversion device 100 and the X-ray visible light conversion device: 200 described in FIG. 3 will be described with reference to FIG.

FIG. 4 is an enlarged cross-sectional view of the C portion shown in FIG. 3, and is a view showing the fluorescent plate week end portion including the structure for one pixel formed on the photoelectric conversion device.

As a two-dimensional photoelectric conversion device, a two-dimensionally formed photoelectric conversion element using amorphous silicon, a thin film transistor (hereinafter referred to as TFT), and the like are used on a large-area glass substrate. . Further, as the X-ray visible light conversion device, as described above, a large-area fluorescent plate made of phosphor powder is used.

In FIG. 4, the photoelectric conversion device 100 is
A photoelectric conversion substrate: 101 made of glass or the like, a photoelectric conversion element: 120, a TFT: 130 is formed on an element forming area: 110, a photoelectric conversion device or a TFT is driven, and an image signal from the photoelectric conversion element is read out. Wiring and inspection terminal, and a connection terminal forming region in which a connection terminal 109 for connecting the wiring and an external electric circuit is formed: 19
0, and further alignment marks and the like for alignment used in each step are formed.

For each layer constituting the photoelectric conversion element and the TFT, a lower conductive layer made of Cr or the like: 102, an insulating layer made of hydrogenated amorphous silicon nitride layer: 103, an intrinsic hydrogenated amorphous silicon layer A semiconductor layer made of: 104,
Composed of N ⁺ -type hydrogenated amorphous silicon ^{n +} layer: 1
05, an upper conductive layer 106 made of Al or the like and a semiconductor protective layer 107 made of hydrogenated amorphous silicon nitride layer 107
The function is confirmed by electrical inspection by depositing and patterning by VD, sputtering, vapor deposition or the like.

Next, an organic material such as polyimide is applied onto the formed element forming region 110, and is applied with a spinner and heat-cured to form a protective layer 150.

This protective layer: 150 is a semiconductor protective layer: 1.
Like 07, it prevents moisture and metal corrosive ions (eg, chlorine ions) from entering the semiconductor elements 120 and 130, stabilizes high image quality in long-term use, and prevents defects due to wire breakage, and also performs the next step. Plays the role of a cushioning material for mechanical external force during work.

Further, an organic material such as a black resist material, which is a resin such as acrylic containing a pigment or the like, is applied to the back surface of the photoelectric conversion substrate: 101 (= opposing surface of the element formation area: 110) by a spinner to shield the light. 160 is formed, and the photoelectric conversion device: 100 is manufactured.

The light-shielding film: 160 transmits the light emitted from the X-ray visible light conversion device through the element forming region: 110 without being absorbed by the photoelectric conversion element part: 120, and further by the photoelectric conversion substrate: 101. The high S / N ratio is prevented and the high image quality is achieved by preventing the photoelectric conversion element from entering and reflecting in the photoelectric conversion substrate and returning to the element formation region: 110 to be absorbed by the photoelectric conversion element of a distant pixel.

One of the X-ray visible light converters, the fluorescent plate:
In 200, phosphor particles: 202, which is a powder of phosphor, are kneaded with a binder: 203, and this is applied to a base 201 made of PET (polyethylene terephthalate) or the like and the binder is cured to form phosphor particles. An X-ray visible light conversion layer: 210 is formed by being fixedly adhered to a base.

In this way, the photoelectric conversion device 100 and the X-ray visible light conversion device 200, which are respectively manufactured as described above, are bonded and cured with an adhesive agent (not shown) made of silicon, epoxy, or the like, and are fixedly arranged, whereby the radiation image pickup device is obtained. Is forming.

The radiation image pickup device thus manufactured has X
The X-ray visible light conversion substrate side of the X-ray visible light conversion device converts X-rays into visible light by the X-ray visible light conversion layer, and the converted visible light is converted into photoelectric light formed on the substrate of the photoelectric conversion device. The light is received by the conversion element and converted into an electric signal. The converted electric signal is read by an external drive circuit connected via a flexible wiring board connected to a TFT or a connection terminal on the substrate of the photoelectric conversion device by an anisotropic conductive film, and a two-dimensional X-ray image is read. Can be obtained by an electric signal.

[0020]

However, in the above-mentioned conventional example, since the material of the protective layer: 150 and the light-shielding film: 160 is coated by the spinner, the photoelectric conversion substrate: 101 must be coated if nothing is done. Is applied to the entire application surface. Therefore, the material is also applied on the connection terminal 109 that needs to be exposed and on the alignment mark used for alignment on the apparatus.

Therefore, the complicated work of masking the non-application area where the connection terminals and the like are formed before the material application and peeling after the application is added, and the number of steps is increased.

Further, in a roll type or slit type coater capable of line-shaped coating, although the coating area can be selectively coated in a square shape, a large thickness unevenness occurs in the peripheral portion of the coating area as shown by M1 and M2 in FIG. Then, a region where the set film thickness greatly differs occurs. Such thickness unevenness in the peripheral portion causes the X-ray visible light conversion device to be deformed and bonded at the terminal end when the X-ray visible light conversion device is bonded, so that the image quality of the terminal end is deteriorated, After the adhesive is cured, the stress with the photoelectric conversion device concentrates on the end portion and peels off at the end portion, resulting in a problem that the long-term reliability deteriorates.

[0023]

A photoelectric conversion device comprising a translucent insulating substrate on which a plurality of photoelectric conversion elements are formed, and at least X-rays on the light receiving surface of the translucent insulating substrate on which the photoelectric conversion elements are formed. In a radiation imaging device including an X-ray visible light conversion device having a visible light conversion layer formed thereon, the X-ray visible light conversion layer and a light-receiving surface of the photoelectric conversion device are provided with a protective film made of a translucent organic material, Further, a light-shielding film made of a non-light-transmitting organic material is formed on the back surface of the light-transmitting insulating substrate on which the photoelectric conversion elements are formed, and the protective film and the light-shielding film are formed on the light-transmitting insulating substrate. It is characterized in that it is selectively applied to the upper and lower portions of the photoelectric conversion element formation region excluding the external connection terminals formed in the manufacturing process of the conversion element.

The formation end of the protective film is formed to be larger than a region where the X-ray visible light conversion device is provided and at least smaller than a connection terminal formation region formed on the photoelectric conversion substrate. .

The formation end of the light shielding film is formed to be larger than a region in which the X-ray visible light conversion device is provided and at least smaller than a connection terminal formation region formed on the photoelectric conversion substrate. To do.

The film thickness of the protective film and the light-shielding film under the X-ray visible light converter is a coating stable region.

The above-mentioned coating of the protective film and the light-shielding film is provided with line-shaped coating portions arranged above and below the photoelectric conversion device, and the photoelectric conversion device moves in parallel in a direction perpendicular to the line of the coating portion. It is characterized by being applied.

[0028]

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 are views for explaining a radiation image pickup apparatus according to an embodiment of the present invention.

The parts having the same functions as those in FIGS. 3 and 4 described in the section of the conventional example are designated by the same reference numerals, and the description thereof may be omitted.

1 (a) and 1 (b) are configuration diagrams of the radiation imaging apparatus, and FIG. 1 (a) is an overall plan view and FIG.
1B is a schematic cross-sectional view taken along the line AB of FIG.

In FIGS. 1 (a) and 1 (b), reference numeral 10 denotes a photoelectric conversion device. As in FIGS. 3 (a) and 3 (b) and FIG. An element formation region: 110 in which a conversion element: 120 and a TFT: 130 are formed, a connection terminal formation region: 190 in which a connection terminal: 109 is formed, and a wiring and an inspection pad are formed therebetween.

Reference numeral 200 denotes an X-ray visible light conversion device, which is an X-ray visible light conversion substrate 201 made of PET or the like.
An X-ray visible light conversion layer 210 made of phosphor particles or the like for converting a ray into visible light is formed.

FIG. 2 shows A- in the portion C of FIG. 1 (b).
FIG. 3 is an enlarged view of a B section, that is, an enlarged view of a peripheral end portion of the X-ray visible light conversion device.

In FIG. 2, a photoelectric conversion device: 10 is an element formation region: 11 formed on a photoelectric conversion substrate: 101.
The protective layer 15 covering 0 is larger than the area to which the X-visible light converter 200 is bonded, and is applied to a region smaller than the connection terminal formation region 109 by a coater by a roll method and is heat-cured. is doing.

As is clear from the figure, the protective film of this embodiment: 1
In the element formation region 5, a portion (M1 in FIG. 2) having a large thickness unevenness generated at the end of the coating region that is parallel to the coating run that occurs at the end of the coating region or at the roll end that occurs in the present coating method is the element forming region: It is located in a region between 110 and a connection terminal formation region: 190 where wirings and inspection terminals for driving a photoelectric conversion device or a TFT and for reading an image signal from the photoelectric conversion element are provided, and X-ray visible Light conversion device: 20
The protective layer: 15 in the region where 0 is bonded is a coating stable region where the film thickness is uniform.

The light-shielding film: 16 is also formed in the same manner as the protective film: 15 in the device forming area of the photoelectric conversion substrate: 101: 110
It is formed by applying the same in the same region on the back surface of the photoelectric conversion substrate: 101, which is the opposite surface, and heating and curing. Therefore, as in the case of the protective film, a portion (M2 in FIG. 2) having a large thickness unevenness generated at the end of the coating area and at the edge of the coating area that is parallel to the coating travel occurring at the roll edge or the coating area generated by the main coating method is used as a photoelectric conversion substrate: On the back surface of the device, wiring and inspection terminals for driving the photoelectric conversion device or the TFT between the element formation region: 110 and the connection terminal formation region: 190, which are the above-described regions, or for reading out an image signal from the photoelectric conversion device. X-ray visible light converter: 20
The light-shielding film 16 in the area where 0 is bonded is a coating stable area having a uniform film thickness.

The photoelectric conversion device thus prepared: 1
0 is an X-ray visible light conversion device: 200, which is separately manufactured as in the conventional example, and is cured by adhesion and curing with an adhesive agent (not shown) made of silicon, epoxy, or the like, and a radiation imaging device is created.

The radiation image pickup device thus manufactured has X
The X-ray visible light conversion substrate side of the X-ray visible light conversion device converts X-rays into visible light by the X-ray visible light conversion layer, and the converted visible light is converted into photoelectric light formed on the substrate of the photoelectric conversion device. The light is received by the conversion element and converted into an electric signal. The converted electric signal is read by an external drive circuit connected via a flexible wiring board connected to a connection terminal on the substrate of the photoelectric conversion device by an anisotropic conductive film, and read out by the two-dimensional X-axis.
A line image can be obtained by an electric signal.

As described above, the radiation image pickup device of the present invention has the protective film: 15 formed on the photoelectric conversion device: 10.
In addition, the light shielding film 16 is selectively applied without the need for pretreatment such as masking. Therefore, simplification of the process
Man-hours can be reduced and cost can be reduced.

Further, an X-ray visible light conversion device: a coating film is formed in a uniform stable region below the region where the 200 is arranged,
Without deteriorating the image quality of the terminal part and inferior long-term reliability,
A high-quality and highly reliable radiation imaging apparatus can be obtained.

The thickness unevenness at the formation end portions of the protective films 150 and 15 described in the above-mentioned conventional example and this embodiment reaches several times to several hundred times the average film thickness at the center of the forming surface at maximum. In this example, when the average film thickness was set to 5 μm and applied, the maximum thickness of the formed end portion was 30 μm. Regarding thickness unevenness, it is a film thickness that exerts the function of the coating film, and there is no problem if it does not hinder the overall configuration thickness, but when the pixel pitch becomes smaller, the light emitted on the adjacent pixel is incident. X-ray visible light conversion layer: 210 and element formation layer:
It is necessary to bring the surface facing the 110 closer. Therefore, it is necessary to reduce the thickness of the protective film and the adhesive formed during this period, but in the present embodiment, the coating film under the X-ray visible light conversion layer is formed by the coating film with the minimum function setting. It is possible to further improve the image quality.

[0043]

According to the present invention, the protective film and the light-shielding film formed in the photoelectric conversion device are selectively coated and formed on the upper and lower sides of the photoelectric conversion element forming region, and the end where the protective film and the light-shielding film are formed is an X-ray. It is formed in a region larger than the region where the visible light conversion device is provided and smaller than the connection terminal formation region formed on the photoelectric conversion substrate, and the uneven thickness portion of each coating film is bonded to the X-ray visible light conversion device. By making it outside the portion, the protective film and the light-shielding film can be selectively applied without the need for pretreatment such as masking. Therefore, it is possible to obtain a radiation imaging apparatus that can simplify the process, reduce the number of steps, and reduce the cost.

Further, since the protective film and the light-shielding film below the region where the X-ray visible light converter is arranged are formed in a stable region where the coating film is uniform, the image quality at the end portion is deteriorated and the long-term reliability is reduced. It is possible to obtain a radiation imaging apparatus having high image quality and high reliability without being deteriorated.

[Brief description of drawings]

FIG. 1A is an overall plan view of a first embodiment according to the present invention. (B) is the illustration A- of FIG.
It is a typical sectional view of B.

FIG. 2 is an enlarged cross-sectional view taken along the line AB in the C portion of FIG. 1 (b).

FIG. 3A is an overall plan view of a conventional example according to the present invention. FIG. 1B is a schematic cross-sectional view taken along the line AB in FIG.

FIG. 4 is an enlarged cross-sectional view taken along the line A-B in a C portion of FIG.

[Explanation of symbols]

200 X-ray visible light conversion device 201 X-ray visible light conversion substrate 210 X-ray visible light conversion layer 202 Phosphor particles 203 Binder 100, 10 Photoelectric conversion device 101 Photoelectric conversion substrate 150, 15 Protective film 160, 16 Light-shielding film 102 Lower conductive Layer 103 Insulating layer 104 Semiconductor layer 105 n ⁺ layer 106 Upper conductive layer 107 Semiconductor protection 109 Connection terminal 190 Connection part formation area 110 Element formation area 120 Photoelectric conversion element 130 TFT (thin film transistor)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 5/321 H01L 27/14 KDF term (reference) 2G088 EE01 FF02 GG19 JJ05 JJ09 JJ37 4M118 AA08 AA10 AB01 BA05 CA32 CB06 CB11 FB09 FB13 GA10 GB04 HA27 HA30 HA32 5C024 AX12 CY47 5F088 BA18 HA10 HA11 JA17

Claims (5)

[Claims] 1. A photoelectric conversion device comprising a translucent insulating substrate on which a plurality of photoelectric conversion elements are formed, and at least an X-ray visible light conversion layer on the light receiving surface of the translucent insulating substrate on which the photoelectric conversion elements are formed. In a radiation imaging apparatus including an X-ray visible light conversion device formed with a transparent film, the X-ray visible light conversion layer and a light receiving surface of the photoelectric conversion device are provided with a protective film made of a light-transmissive organic material. A light-shielding film made of a non-light-transmitting organic material is formed on the back surface of the surface of the light-insulating substrate on which the photoelectric conversion element is formed, and the protective film and the light-shielding film are used to fabricate the photoelectric conversion element of the light-transmitting insulating substrate. A radiation imaging apparatus, characterized in that it is selectively applied to the upper and lower portions of the element forming regions excluding the connection terminals formed in the process. 2. The formation end of the protective film is formed to be larger than a region where the X-ray visible light conversion device is provided and at least smaller than a connection terminal formation region formed on the photoelectric conversion substrate. The radiation imaging apparatus according to claim 1. 3. The light-shielding film forming end is formed to be larger than a region where the X-ray visible light conversion device is provided and at least smaller than a connection terminal forming region formed on the photoelectric conversion substrate. The radiation imaging apparatus according to claim 1, wherein the radiation imaging apparatus is a radiation imaging apparatus. 4. The radiation imaging apparatus according to claim 1, wherein the film thickness of the protective film and the light shielding film under the X-ray visible light conversion device is a coating stable region. 5. The coating of the protective film and the light-shielding film is provided with a line-shaped coating part disposed above and below the photoelectric conversion device, and the photoelectric conversion device is relatively perpendicular to a line of the coating part. A method of manufacturing a radiation imaging apparatus, wherein the radiation imaging apparatus is applied by being moved in parallel.