JP2009036569A - Sheet, radiation detector, and sheet sticking method - Google Patents

Abstract

An object of the present invention is to improve the pasting performance of a sheet to be pasted on a radiation detection device.
A sheet (300) having a reinforcing film (306) affixed with increased rigidity is previously processed into a rectangular shape, and two end faces (102B, 102D) are used as positioning references, so that positioning with the radiation detection device (102) is achieved. Easily made possible. Further, by processing the outer shape into a rectangular shape after increasing the rigidity, the outer shape of the protective film 200 can be processed with higher accuracy than when the protective film 200 is processed alone. Further, since the reinforcing film 306 is stuck and the overall rigidity is improved, the sticking property is improved and the cut portion 306A is formed in the reinforcing film 306, so that it straddles the chest wall side surface 102B and the surface 102A. It becomes easy to stick.
[Selection] Figure 3

Description

  The present invention relates to a sheet attached to a radiation detection device, a radiation detector, and a sheet attaching method.

An insulation film is usually attached to the radiation detection device mainly for the purpose of insulation. Since the insulating film is thin, it will wrinkle when it is attached to the radiation detection device. Therefore, a method has been proposed in which an insulating film is pasted on an insulating film, the sheet is pasted on a radiation detection device, and the pasting film is peeled off after the pasting, whereby the insulating film is pasted without wrinkles (for example, , See Patent Document 1)
JP 2005-172800 A

  However, in the method as disclosed in Patent Document 1, after the sheet is attached and the peeling film is peeled off, the outer shape of the insulating film is cut along the outer shape of the radiation detection device. For this reason, the process for cutting is needed. Furthermore, since the insulating film is thin, it may be difficult to ensure the accuracy of the outer shape.

  Alternatively, when the re-peeling film is thickened and the rigidity of the re-peeling film is increased in order to improve the pasting performance, it is difficult to stick the radiation detecting device to the bent portion.

  Therefore, improvement of the sticking performance of such a sheet is desired.

  In view of the above facts, an object of the present invention is to provide a sheet to be attached to a radiation detecting device with improved attaching performance, a radiation detector to which the sheet is attached, and a sheet attaching method.

  In order to achieve the above object, the sheet according to claim 1 is folded over a surface of the radiation detection layer from a side surface of the radiation detection device in which a radiation detection layer for converting radiation into electric charges is formed on a substrate. A protective film that is bonded to the radiation detection device, and a reinforcing film that is bonded to the protective film and has a cut portion formed in a bent portion. It is said.

  In the sheet according to the first aspect, the positioning with the radiation detection device is facilitated by using the end face of the sheet to which the peeling film is bonded and the rigidity is increased as a positioning reference. Further, since the reinforcing film is applied and the rigidity is increased, it is easy to apply the film without wrinkles. Furthermore, since the cut portion is formed in the reinforcing film, the folding becomes easy. As a result, for example, attachment to a curved surface or a corner is facilitated.

  Accordingly, the sheet sticking performance is improved. Therefore, for example, the accuracy of the pasting position of the sheet after pasting is improved.

  According to a second aspect of the present invention, in the configuration of the first aspect, the reinforcing film is peeled off after being attached to the radiation detection device.

  In the sheet according to claim 2, since the reinforcing film is peeled off after being attached to the radiation detection device, the sensitivity of radiation detection in the radiation detection layer is improved.

  According to a third aspect of the present invention, in the configuration of the second aspect, the adhesive force between the reinforcing film and the protective film is greater than the adhesive force between the protective film and the radiation detection device. Is also characterized by weakness.

  In the sheet according to claim 3, since the adhesive force between the reinforcing film and the protective film is weaker than the adhesive force between the protective film and the radiation detection device, the adhesive film is attached to the radiation detection device. The reinforcing film is easily peeled off.

  The sheet according to claim 4 is the separator according to any one of claims 1 to 3, wherein the separator is peeled off before being attached to the radiation detection device on the adhesive surface of the protective film. It is characterized in that a sheet is pasted.

  In the sheet according to claim 4, since the separator sheet is affixed to the adhesive surface of the protective film, the handleability before being affixed to the radiation detection device is improved.

  The sheet according to claim 5 is the structure according to claim 4, wherein an adhesive force between the separator sheet and the protective film is greater than an adhesive force between the reinforcing film and the protective film. It is characterized by weakness.

  In the sheet according to the fifth aspect, the adhesive force obtained by adhering the separator sheet and the protective film is weaker than the adhesive force obtained by adhering the reinforcing film and the protective film, so that the separator sheet is easily peeled off.

  The radiation detector according to claim 6 extends from the side surface of the radiation detection device, on which the radiation detection layer for converting radiation into electric charges is formed on the substrate, across the surface of the radiation detection layer. The sheet according to any one of the above is attached.

  In the radiation detector of Claim 6, the sheet | seat of any one of Claims 1-5 with which the affixing performance was improved is affixed. Therefore, for example, the accuracy of the application position of the attached sheet or protective film is improved. As a result, for example, the moisture-proof performance and insulation performance of the radiation detector can be improved.

The sheet sticking method according to claim 7, wherein the sheet sticking is performed by sticking a sheet from the first side surface of the radiation detection device, on which a radiation detection layer for converting radiation to electric charge is formed on a substrate, across the surface of the radiation detection layer. A method,
The sheet has a protective film that is bonded to the radiation detection device, and a reinforcing film that is bonded to the protective film and has a cut portion formed in a bent portion.
The first end surface of the sheet is positioned with respect to the back surface opposite to the surface on which the radiation detection layer is formed, and the second end surface of the sheet orthogonal to the first end surface is positioned on the first side surface of the radiation detection device. A positioning step for positioning with respect to the second side of the radiation detection device orthogonal to
After the positioning step, the sheet is attached to the first side surface of the radiation detection device, and is attached to the surface of the radiation detection layer after being bent at the cut portion.

  In the sheet sticking method according to claim 7, as the positioning step, the first end surface of the sheet is positioned with respect to the back surface of the radiation detection device, and the second end surface orthogonal to the first end surface of the sheet is the first end surface of the radiation detection device. Positioning is performed with respect to a second side surface orthogonal to the one side surface.

  And as a sticking process after a positioning process, a sheet | seat is affixed on the 1st side surface of a radiation detection device, it bends in a notch part, and is affixed on the surface of a radiation detection layer.

  Since a sheet | seat is affixed on a radiation device at such a process, the sticking performance of a sheet | seat is improved. Therefore, for example, the accuracy of the application position of the attached sheet is improved.

  The sheet sticking method according to an eighth aspect is characterized in that, in the method according to the seventh aspect, a peeling step of peeling the reinforcing film is provided after the sticking step.

  In the sheet sticking method according to the eighth aspect, since the reinforcing film is peeled in the peeling step after the sticking step, the radiation detection intensity is improved.

  The sheet sticking method according to claim 9 is the structure according to claim 8, wherein the adhesive force obtained by adhering the reinforcing film and the protective film is an adhesion obtained by adhering the protective film and the radiation detection device. It is characterized by being weaker than power.

  In the sheet affixing method according to claim 9, the adhesive force between the reinforcing film and the protective film is weaker than the adhesive force between the protective film and the radiation detecting device. Easy to peel off.

  The sheet sticking method according to claim 10 is the method according to any one of claims 7 to 9, wherein a separator sheet is stuck to the adhesive surface of the protective film in the sheet, Before the sticking step, a pre-peeling step for peeling the separator is provided.

  In the sheet sticking method according to claim 10, since the separator attached to the adhesive surface of the protective film is peeled off in the pre-peeling step before the sticking step, the handling property of the sheet before the pre-peeling step is improved. .

  The sheet sticking method according to claim 11 is the method according to claim 10, wherein an adhesive force obtained by adhering the separator sheet and the protective film is an adhesive force obtained by adhering the reinforcing film and the protective film. It is characterized by being weaker than.

  In the sheet sticking method according to claim 11, since the adhesive force between the separator sheet and the protective film is weaker than the adhesive force between the reinforcing film and the protective film, the separator sheet can be easily used in the pre-peeling step. Is peeled off.

  As described above, according to the present invention, there is an excellent effect that the pasting performance of the sheet to be pasted on the radiation detection device can be improved.

  Below, an example of an embodiment of a radiation detector concerning the present invention is explained based on a drawing.

  The radiation detector according to the present embodiment is used in an X-ray imaging apparatus or the like, and includes an electrostatic recording unit including a photoconductive layer that exhibits conductivity when irradiated with radiation. The image information is recorded upon receiving the irradiation of the radiation carrying the image, and the image signal representing the recorded image information is output.

  As shown in FIGS. 1B and 2, the radiation detector 100 in the present embodiment has a rectangular plate shape in plan view. In this embodiment, the radiation detector 100 (mammography) for mammography is used. Therefore, as schematically shown in FIG. 1A, the plate-like radiation detector 100 is disposed substantially horizontally and is disposed below the breast 902. In addition, the chest wall surface 100 </ b> B that is the side surface on one side of the long side is brought into contact with the chest wall 904.

  The radiation detector 100 includes a surface 102A of the radiation detection device 102 (surface 106B of the radiation detection layer 106) and a chest wall side surface 102B in which the radiation detection layer 106 is formed on the upper surface of a plate-like glass substrate 104 having a rectangular shape in plan view. In addition, an insulating protective film 200 is attached by an adhesive layer 202. The chest wall side surface 102B corresponds to the first side surface of the present invention.

  The radiation detection device 102 has a charge conversion layer (see the charge conversion layer 604 in FIG. 9) that generates charges when radiation is incident from the surface 104A of the substantially rectangular glass substrate 104 in plan view. ) And the like are formed. In addition, the upper surface of the radiation 106 (the surface opposite to the glass substrate 104) is a surface 106B, and the entire surface on which the radiation detection layer 106 is formed is a surface 102A of the radiation detection device 102. An example of a detailed structure of the radiation detection device 102 and the like will be described later.

  Next, the sheet 300 having the protective film 200 attached to the radiation detection device 102 will be described.

  As schematically shown in FIG. 2A, a sheet 300 is configured by laminating (adhering) a separator sheet 302, an adhesive layer 202, a protective film 200, a slightly adhesive layer 304, and a reinforcing film 306 in order from the lower layer. Has been. The reinforcing film 306 preferably has higher rigidity than the protective film 200.

  The specifications of each layer in this embodiment are shown in the table of FIG. This table is merely an example in the present embodiment, and the present invention is not limited to this specification.

  Further, as can be seen from this table, the reinforcing film 306 is thicker and more rigid than the protective film 200.

  It should be noted that the adhesive force between the reinforcing film 306 and the protective film 200 is weaker than the adhesive force between the protective film 200 and the radiation detection device 102. Further, the adhesive force between the separator sheet 302 and the protective film 200 is weaker than the adhesive force between the reinforcing film 306 and the protective film 200.

  As shown in FIG. 2B, the sheet 300 is cut into a final outer shape (rectangular shape in plan view) by die cutting. The final outer shape is an outer shape (rectangular shape) in which the protective film 200 (sheet 300) is accurately attached to the surface 102A and the chest wall side surface 102B of the radiation detection device 102.

  Therefore, as shown in FIG. 2, the first end surface 300C of the sheet 300 is used as a positioning reference with respect to the back surface 102C (see FIG. 1) of the radiation detection device 102, and the second end surface 300D (FIG. 2 (FIG. 2 (2) orthogonal to the first end surface 300C). (B) only) is a positioning reference for the side surface 102D (see FIG. 1B) orthogonal to the chest wall side surface 102B of the radiation detection device 102 (details regarding the positioning reference will be described later). The side surface 102D corresponds to the second side surface of the present invention.

  Further, a cut portion 306A is formed in the reinforcing film 306 at a position parallel to the first end surface 300C and separated by a predetermined distance.

  In addition, you may affix the reinforcement film 306 in the state in which the cut | notch part 306A was formed to the protective film 200. FIG. When the cut portion 306A is inserted in advance as described above, a peeling film (not shown) is attached to the reinforcing film 306, and even if the cut portion 306A is formed, the cut portion 306A is not divided and is reinforced to the protective film 200. The peeling film may be peeled off after the film 306 is pasted.

  Next, an outline of the attachment of the sheet 300 to the radiation detection device 102 will be described with reference to FIG.

  As shown in FIG. 3A, the first end surface 300C of the sheet 300 is positioned with respect to the back surface 102C of the radiation detection device 102, and the second end surface 300D (see FIG. 2B) is positioned on the radiation detection device 102. Positioning with respect to the side surface 102D (see FIG. 1B). The reinforcing film 306 of the sheet 300 is sucked and held (details will be described later). Then, the separator sheet 302 (see FIG. 2B) is peeled off to expose the adhesive layer 202. FIG. 3A shows a state where the separator sheet 302 is peeled off. Further, the sheet 300 is shown and described even when the separator sheet 302 is peeled off.

  As shown in FIGS. 3B and 3C, after the sheet 300 is attached to the chest wall side surface 102B of the radiation detection device 102, suction holding is released, and the radiation detection device 102 is bent at the notch 306A. The surface 102A (the surface 106B of the radiation detection layer 106) is attached.

  Then, as shown in FIG. 3D, the reinforcing film 306 (and the slightly adhesive layer 304) are peeled off.

  In addition, as shown in FIG. 8, it is good also as a structure by which the two protective films 200 were laminated | stacked. Although not shown in the drawings, three or more protective films 200 may be laminated. That is, in the same process as described above, a process of attaching another (or more) sheet 300 on the protective film 200 and peeling the reinforcing film 306 may be added.

  Next, the operation of this embodiment will be described.

  By sticking the reinforcing film 306 in this way and processing the sheet 300 with increased rigidity into a rectangular shape having a final outer shape in advance, the two orthogonal end faces 300B and 300D are used as positioning references, so that the radiation detection device 102 can be used. Can be easily positioned. Further, by performing the outer shape processing after increasing the rigidity, the outer shape of the protective film 200 can be processed with higher accuracy than when the protective film 200 is processed alone.

  Further, since the reinforcing film 306 is stuck and the overall rigidity is improved, the sticking property is improved, and the notch 306A is formed in the reinforcing film 306. Therefore, the chest wall side surface 102B and the surface of the radiation detection layer 106 are formed. It becomes easy to paste across 106B (see FIG. 3).

  Therefore, the pasting performance of the sheet 300 is improved. Therefore, for example, the pasting position accuracy of the protective film 200 after pasting is improved. As a result, the moisture resistance and insulation of the radiation detector 100 can be improved. In particular, in the present embodiment, as shown in FIG. 1A, the upper surface 100A and the chest wall surface 100B of the radiation detector 100 are brought into contact with the human body. It is preferable that is secured.

  Since the thick and stiff reinforcing film 306 is peeled last, the sensitivity of radiation detection is improved (the thickness and material of the reinforcing film 306 do not affect the radiation detection). Further, since the adhesive force obtained by bonding the reinforcing film 306 and the protective film 200 is weaker than the adhesive force obtained by bonding the protective film 200 and the radiation detecting device 102, the reinforcing film 306 is easily peeled off.

  Moreover, since the separator sheet 302 is affixed to the protective film 200 (adhesive layer 202), the handleability of the sheet 300 before being affixed to the radiation detection device 102 is improved. In addition, since the adhesive force with which the separator sheet 302 and the protective film 200 are bonded is weaker than the adhesive force with which the reinforcing film 306 and the protective film 200 are bonded, in the state where the reinforcing film 306 of the sheet 300 is held by suction, Separator sheet 302 is easily peeled off.

  In the above embodiment, the sheet 300 and the radiation detection device 102 have a rectangular sheet shape and a plate shape in plan view, but are not limited thereto. For example, the end face of the sheet 300 that is not used for positioning or that is not important and the side face of the radiation device 102 may be rounded or cut.

  Next, an example of details regarding the attachment of the sheet 300 to the radiation detection device 102 is shown in FIGS. 4 (A) to (H), FIGS. 5 (A) to (F), and FIGS. 6 (A) to (B). It explains using. 4 is a diagram schematically showing, FIG. 5 is a diagram showing in more detail including a jig, and FIG. 6 is a diagram seen from the side.

  As illustrated in FIG. 5A, the sheet 300 is set on the jig 400 while being guided by the left and right guide plates 403 and 404. Then, as shown in FIGS. 4A and 5B, the reinforcing film 306 of the sheet 300 is sucked and held on the suction base 402 of the jig 400.

  As shown in FIG. 4B, the first end surface 300C and the second end surface 300D of the sheet 300 are abutted and positioned at predetermined locations corresponding to abutting positions Y1, Y2, Y3, and Y4 described later. .

  As shown in FIG. 5-1 (B), the guide plates 403 and 404 are slid left and right and removed, and as shown in FIGS. 5-1 (B) and 4-1 (C), the separator sheet 302 is removed. The separator tag 302 is peeled off by holding the peeling tag 302A. Even after the separator sheet 302 is peeled off, it is referred to as a sheet 300.

  The radiation detection device 102 is set on the jig 400 as shown in FIGS. At that time, as shown in FIG. 4-1 (D), X1 and X2 at both ends of the chest wall side surface 102B of the radiation detection device 102 and both ends X3 and X4 of the side surface 102D are connected as shown in FIG. The abutting positions Y1, Y2, Y3, and Y4 are brought into contact with each other for positioning.

  As shown in FIGS. 5-2 (D) and 4-2 (E), the sheet 300 (suction base 402) is slid to attach the sheet 300 to the chest wall side surface 102B of the radiation detection device 102.

  As shown in FIGS. 4-2 (E) and 5-3 (E), after attaching the tensioner 410 to the upper end of the sheet 300, the suction base 402 is removed.

  As shown in FIGS. 5-3 (F), 4-2 (F), and 6 (A), a sponge roll 420 that contacts the reinforcing film 306 is attached, and a metal roll 422 is attached on the sponge roll 420. .

  As shown in FIG. 6A, FIG. 6B, and FIG. 4-2G, the sponge roll 420 and the metal roll 422 are slid in the direction of arrow S, and the surface 102A (radiation detection) of the radiation detection device 102 is detected. The sheet 300 is applied to the surface 106B) of the layer 106.

  Finally, as shown in FIG. 4-2 (H), the tensioner 410 (see FIG. 4-2 (G) and the like) is removed, and the reinforcing film 306 is peeled off.

  In addition, the said process is performed again and it is set as the structure by which the two protective films 200 shown in FIG. 8 were laminated | stacked.

  Next, an example of the detailed structure of the radiation detector in the above-described embodiment will be described with [light reading radiation detector] and [TFT radiation detector].

[Detailed structure of optical reading radiation detector]
FIG. 9 shows a schematic diagram of a radiation detection device 500 (corresponding to the radiation detection device 102 in the above embodiment). The radiation detection device 500 is connected to TCPs 802 and 803, readout devices 804 and 805 connected through the TCPs 802 and 803, and a high voltage application wiring 806 for applying a high voltage. Note that TCP (Tape Carrier Package) is a flexible wiring board on which a signal detection IC (charge amplifier IC) is mounted. The TCPs 802 and 803 are connected by thermocompression bonding using an ACF (Anisotropic Conductive Film anisotropic conductive film).

  A radiation detection layer 600 for detecting radiation (corresponding to the radiation detection layer 106 in the above embodiment) is a lower electrode 606 for signal readout and application of a high voltage, a charge conversion layer 604 for converting radiation into charges, and a high voltage is applied. The upper electrode 602 and the like. The upper electrode 602 in the upper part constituting the radiation detection layer 600 is led out to the high voltage extraction portion 808 and fixed to the high voltage application wiring 806 with a conductive adhesive.

  The manufacture of the radiation detection device 500 is roughly divided into the manufacture of the radiation detection lower substrate 502, the formation of the charge conversion layer 604 and the upper electrode 602, and the connection of the high voltage application wiring 806.

  Next, the structure of the radiation detection lower substrate will be described.

  FIG. 10 shows a schematic structure of the radiation detection lower substrate 502. In FIG. 10, TCPs 802 and 803 are simplified to one on each side, and the number of channels is 3 for each channel, for a total of 6 channels.

  The radiation detection lower substrate 502 includes a radiation detection unit 700, a pitch conversion unit 504, TCP connection units 810 and 811, a high voltage extraction unit 802, and the like. In the radiation detection unit 700, a lower electrode 606 for signal extraction is arranged on a stripe. In addition, a color filter layer 704 that partially transmits only light having an arbitrary wavelength is formed under the transparent organic transparent insulating layer 702.

  Note that a layer above the color filter layer 704 is called a common B line, and a signal S line in a portion without the color filter layer 704. The B line is shared outside the radiation detection unit 700 and has a comb-shaped electrode structure. The S line is used as a signal line. The widths of the B line and the S line are, for example, 20, 10 μm and the interval is 10 μm (see (C) of FIG. 10).

  The width of the color filter layer 704 is 30 μm. The lower electrode 606 is transparent to irradiate light from the back surface, and needs flatness to avoid breakdown due to electric field concentration when a high voltage is applied. For example, IZO or ITO is used. When IZO is used, the thickness is 0.2 μm and the flatness is about Ra = 1 nm.

  The color filter layer 704 is a photosensitive resist in which a pigment is dispersed, for example, a red resist used for an LCD color filter. In addition, a photosensitive organic organic transparent insulating layer 702, for example, PMMA is used to eliminate the step of the color filter layer 704. Further, a substrate 706 (corresponding to the glass substrate 104 in the above embodiment) serving as a supporting member is preferably transparent and rigid glass, and more preferably soda lime glass.

  As an example of the thickness of each layer, IZO is 0.2 μm, red resist is 1.2 μm, transparent insulating layer PMMA is 1.8 μm, and glass is 1.8 mm. The color filter layer 704 and the organic transparent insulating layer 702 are only in the radiation detection unit 700, and the boundaries are in the radiation detection unit 700 and the pitch conversion unit 504. For this reason, the IZO wiring is formed on the substrate 706 (glass) in the TCP connection portions 810 and 811 through the boundary step portion of the organic transparent insulating layer 702.

  In the radiation detection unit 700, wirings to the left and right TCPs 802 and 803 are taken out in units of a predetermined number. In the figure, the unit is 3 lines. An example of the number of lines is 256 lines. The line width in the radiation detection unit 700 is different from the line width in the TCP connection units 810 and 811 and is adjusted to adjust the line width in the pitch conversion unit in order to route the wiring to a predetermined TCP connection position. Also, the B line is shared and drawn out to the TCP connection units 810 and 811 in the same manner.

  In the TCP connection units 810 and 811, the signal S line and the common B line shared outside the radiation detection unit 700 are arranged. The common B line is arranged outside the signal S line. As an example of the number, the signal line 256 and the common line are connected to the TCPs 802 and 803 using five lines above and below the common line. The electrode line / space is 40/40 μm. Further, in order to connect the TCPs 802 and 803 with the TCP connection units 810 and 811, a TCP alignment mark is necessary. Although it is desirable to form it with a transparent electrode, it is difficult to recognize it because it is transparent. Therefore, as an opaque material, for example, a color filter layer 704 that is a constituent member is used to form an alignment mark.

  Next, although a configuration example of a preferable layer configuration is shown, the present invention is not limited to this.

  FIG. 11 is a cross-sectional view modeling a preferred layer structure. Note that the radiation detection layer 600 (corresponding to the radiation detection layer 106 in the above embodiment) extends from “upper electrode” to “undercoat layer” in FIG.

<Configuration example 1>
A layer structure was fabricated in the following order on a (glass) substrate 706 (see FIG. 10) having a comb-shaped electrode structure as shown in FIGS. As the comb electrode, a flat IZO electrode having a surface roughness Ra <1 nm was used.

Undercoat layer 1050: CeO ₂ thickness 20 nm
Lower electrode interface layer 1048A: As 10% doped amorphous selenium: LiF 500 ppm doped, thickness 0.1 μm
Photoelectric conducting layer 1046 for reading: amorphous selenium, thickness 7 μm
Charge storage layer 1044: As ₂ Se ₃ , thickness 1 μm
Photoconductive layer 1042 for recording: 0.001 ppm of amorphous selenium Na, thickness 200 μm
Upper electrode interface layer 1048B: As10% doped amorphous selenium, thickness 0.2 μm
Overcoat layer 1052: Sb ₂ S ₃ , thickness 0.5 μm
Upper electrode 602: Aμ thickness 70nm

<Configuration example 2>
A layer structure was fabricated in the following order on a (glass) substrate 706 (see FIG. 10) having a comb-shaped electrode structure as shown in FIGS. As the comb electrode, a flat IZO electrode having a surface roughness Ra <1 nm was used.

Undercoat layer 1050: None Lower electrode interface layer 1048A: As3% doped amorphous selenium, thickness 0.15 μm
Photoconductive layer 1046 for reading: amorphous selenium, thickness 15 μm
Charge storage layer 1044: As ₂ Se ₃ , thickness 2 μm
Photoconductive layer 1042 for recording: 0.001 ppm of amorphous selenium Na, thickness 180 μm
Upper electrode interface layer 1048B: As10% doped amorphous selenium, thickness 0.1 μm
Overcoat layer 1052: Sb ₂ S ₃ , thickness 0.2 μm
Upper electrode 602: Au thickness 150 nm

<Configuration example 3>
A layer structure was fabricated in the following order on a (glass) substrate 706 (see FIG. 10) having a comb-shaped electrode structure as shown in FIGS. As the comb electrode, a flat IZO electrode having a surface roughness Ra <1 nm was used.

Undercoat layer 1050: CeO ₂ , thickness 30 nm
Lower electrode interface layer 1048A: As6% doped amorphous selenium, thickness 0.25 μm
Photoconductive layer 1046 for reading: amorphous selenium, thickness 10 μm
Charge storage layer 1044: As ₂ Se ₃ , thickness 0.6 μm
Photoconductive layer for recording 1042: 0.001 ppm of amorphous selenium Na, thickness 230 μm
Upper electrode interface layer 1048B: As10% doped amorphous selenium, thickness 0.3 μm
Overcoat layer 1052: Sb ₂ S ₃ , thickness 0.3 μm
Upper electrode 602: Au, thickness 100 nm
Next, each layer will be described in detail (see FIG. 11).

<Surface protective layer 1100>
In order to form a latent image on the radiation detection device by irradiation, a high voltage of several kV is applied to the upper electrode. There is a risk that a creeping discharge occurs between the upper electrode and the lower electrode and the device is destroyed. Therefore, in order to prevent creeping discharge in the upper electrode, the electrode is subjected to insulation treatment (see FIG. 12). Note that the insulation treatment has a structure in which the electrode surface is covered with an insulator.

  Insulation treatment requires a structure in which the electrode surface does not come into contact with the atmosphere at all, and a structure in which the electrode surface is tightly covered with an insulator. In addition, this insulator needs to have a dielectric breakdown strength exceeding the applied potential. Furthermore, it is necessary for the function of the radiation detection device to be a member that does not interfere with radiation transmission. As a material and manufacturing method of these required covering properties, dielectric breakdown strength and radiation transmittance, vapor deposition of insulating polymer or solvent coating is preferable. Specific examples include a room temperature curing type epoxy resin, a polycarbonate resin, a polyvinyl butyral resin, a polyvinyl alcohol resin, an acrylic resin, and a method of forming a polyparaxylene derivative by a CVD method. Among these, a room temperature curing type epoxy resin and polyparaxylylene are preferably formed by a CVD method, and a method of forming a polyparaxylylene derivative by a CVD method is particularly preferable. A preferable film thickness is 10 μm or more and 1000 μm or less, and more preferably 20 μm or more and 100 μm or less.

  A polyparaxylylene film can be formed at room temperature, so that an insulating film with extremely high step coverage can be obtained without applying thermal stress to the adherend, but it is chemically very stable. In general, the adhesion is often not preferred. In order to increase the adhesion with the adherend, as a treatment to the adherend before the formation of polyparaxylylene, physical, such as a coupling agent, corona discharge, plasma treatment, ozone cleaning, acid treatment, surface treatment, Chemical treatment is generally known and can be used. In particular, a polyparaxylylene film is formed after applying a silane coupling agent or a solution obtained by diluting a silane coupling agent with an alcohol or the like if necessary to at least improve the adhesion to the adherend. A method of improving the adhesion with the adherend is preferable.

  Furthermore, in order to prevent deterioration of the radiation detection device with time, it is preferable to perform a moisture-proof treatment. Specifically, the structure is covered with a moisture-proof member (corresponding to the insulating protective film 200 in the above embodiment). As the moisture-proof member, the resin alone such as the insulating polymer is insufficient in function, and at least an inorganic material layer such as glass or an aluminum laminate film is effective. However, since glass attenuates radiation transmission, the moisture-proof member is preferably a thin aluminum laminate film. For example, as an aluminum laminate film generally used as a moisture-proof packaging material, there is a laminate of PET 12 μm / rolled aluminum 9 μm / nylon 15 μm. The thickness of aluminum is preferably 5 μm or more and 30 μm or less, and the front and rear PET thicknesses and nylon thicknesses are each preferably 10 μm or more and 100 μm or less. This film has an X-ray attenuation of about 1%, and is optimal as a member that achieves both a moisture-proof effect and X-ray transmission. The entire surface of the radiation detection device subjected to insulation treatment with polyparaxylylene is covered with a moisture-proof film, and the periphery of the moisture-proof film is adhered and fixed to the substrate with an adhesive outside the radiation detection device region. Thus, the radiation detection device is sealed with the substrate and the moisture-proof film.

  At the time of this adhesion fixation, polyparaxylylene is chemically very stable, and thus generally has poor adhesion to other members by an adhesive, but is subjected to light irradiation treatment with ultraviolet light prior to adhesion. Thus, the adhesiveness can be improved. The necessary irradiation time is appropriately adjusted to the optimum time depending on the wavelength and wattage of the ultraviolet light source to be used, but it is preferably 1 to 50 W with a low-pressure mercury lamp, and the light irradiation is preferably performed for 1 to 30 minutes. Note that the radiation detection device of the present application uses amorphous selenium, and amorphous selenium crystallizes at a high temperature of 40 ° C. or higher, so that a latent image forming function cannot be obtained. Therefore, a room temperature curable adhesive is desirable, and a two-component mixed room temperature curable epoxy adhesive having a high adhesive strength is optimal. This epoxy adhesive is applied to the outer periphery of the radiation detection device and covered with a moisture-proof film. The adhesive part is pressed and fixed uniformly from the upper surface of the protective film, and is left in this state for 12 hours or more in a room temperature environment to be cured. After the adhesive is cured, the pressure is released to complete the sealing structure.

  It supplements about a sealing structure member. When a radiation detection device is used for mammography, imaging detection at a low dose is desired in order to suppress exposure in X-ray imaging. In order to detect a change in shadow caused by low-dose irradiation, it is desirable that members other than the subject (mammo) in the path from the radiation source to the device have a high X-ray transmittance, thereby obtaining a clear image.

  An example of a preferred protective layer / sealing structure is shown in FIG. 12, but the present invention is not limited to this. It is preferable that the humidity environment of the device is maintained at 30% or less, more preferably 10% or less by forming the surface protective layer. In FIG. 11, as shown in FIG. 12, the surface protective layer 1100 is configured by the protective film 200 and the insulating treatment layer 1102.

<Upper electrode 602>
A metal thin film is preferably used as the upper electrode 602 formed on the upper surface of the recording photoconductive layer. Materials include Au, Ni, Cr, Au, Pt, Ti, Al, Cu, Pd, Ag, Mg, MgAg3-20% alloy, Mg-Ag intermetallic compound, MgCu3-20% alloy, Mg-Cu metal What is necessary is just to make it form from metals, such as an intermetallic compound.
In particular, Au, Pt, and Mg—Ag intermetallic compounds are preferably used. For example, when Au is used, the thickness is preferably 15 nm to 200 nm, more preferably 30 nm to 100 nm. For example, when an MgAg3-20% alloy is used, it is more preferable to use a thickness of 100 nm to 400 nm.

Although the preparation method is arbitrary, it is preferably formed by vapor deposition by a resistance heating method.
For example, after a metal lump is melted in a boat by a resistance heating method, the shutter is opened, vapor deposition is performed for 15 seconds, and cooling is performed once. It is formed by repeating a plurality of times until the resistance value becomes sufficiently low.

<Recording Photoconductive Layer 1042>
The recording photoconductive layer 1042 (corresponding to the X-ray photocon layer in FIG. 11) is a photoconductive material that absorbs electromagnetic waves and generates charges, and is an amorphous selenium compound, Bi ₁₂ MO20 (M: Ti, Si, Ge). , Bi ₄ M3O12 (M: Ti, Si, Ge), Bi ₂ O ₃ , BiMO4 (M: Nb, Ta, V), Bi ₂ WO6, Bi ₂₄ B2O39, ZnO, ZnS, ZnSe, ZnTe, MNbO3 (M: Li, Na, K), PbO, HgI ₂ , PbI ₂ , CdS, CdSe, CdTe, BiI ₃ , GaAs, and the like. Of these, an amorphous selenium compound is particularly preferable.

In the case of an amorphous selenium compound, the layer is doped with a small amount of alkali metal such as Li, Na, K, Cs, Rb between 0.001 ppm and 1 ppm, LiF, NaF, KF, CsF, RbF, etc. A small amount of fluoride of 10ppm to 10000ppm, P, As, Sb, Ge added from 50ppm to 0.5%, As doped from 10ppm to 0.5%, Cl, Br , I doped in a slight amount between 1 ppm and 100 ppm can be used.
In particular, amorphous selenium containing about 10 ppm to 200 ppm of As, amorphous selenium containing about 0.2% to 1% of As and further containing 5 ppm to 100 ppm of Cl, and alkali metal of about 0.001 ppm to 1 ppm were contained. Amorphous selenium is preferably used.

Also, Bi ₁₂ MO20 (M: Ti, Si, Ge), Bi ₄ M3O12 (M: Ti, Si, Ge), Bi ₂ O ₃ , BiMO4 (M: Nb, Ta, V) of several nano to several microns, _{Bi 2 WO6, Bi 24 B2O39,} ZnO, ZnS, ZnSe, ZnTe, MNbO3 (M: Li, Na, K), PbO, HgI 2, PbI 2, CdS, CdSe, CdTe, BiI 3, photoconductive such GaAs Those containing substance fine particles can also be used.

  In the case of amorphous selenium, the thickness of the recording photoconductive layer is preferably 100 μm or more and 2000 μm or less. In particular, it is particularly preferably in the range of 150 μm or more and 250 μm or less for mammography applications and in the range of 500 μm or more and 1200 μm or less for general imaging applications.

<Charge storage layer 1044>
The charge storage layer 1044 (corresponding to the latent image storage layer in FIG. 11) may be any film that is insulative with respect to the polar charge to be stored, such as acrylic organic resin, polyimide, BCB, PVA, acrylic, polyethylene, and polycarbonate. It is composed of polymers such as polyetherimide, sulfides such as As ₂ S ₃ , Sb ₂ S ₃ and ZnS, oxides and fluorides. Furthermore, it is more preferable to be insulative with respect to the charge of the polarity to be accumulated, and to be conductive with respect to the charge with the opposite polarity. Substances with differences are preferred.

As a preferred compound, As ₂ Se ₃ , As ₂ Se ₃ doped with Cl, Br, I from 500 ppm to 20000 ppm, As ₂ Se ₃ Se substituted with Te to about 50% (SexTe1-x) 3 (0.5 <x <1), As ₂ Se _{3 with} As concentration changed about ± 15%, Amorphous Se-Te system with Te of 5-30wt%, As ₂ Se ₃ Se In which S is substituted to about 50% by S.

  When such a material containing a chalcogenide element is used, the thickness of the charge storage layer is preferably 0.4 μm or more and 3.0 μm or less, more preferably 0.5 μm or more and 2 μm or less. Such a charge storage layer may be formed by a single film formation or may be laminated in a plurality of times.

As a preferable charge storage layer using an organic film, a compound obtained by doping a charge transport agent with a polymer such as an acrylic organic resin, polyimide, BCB, PVA, acrylic, polyethylene, polycarbonate, polyetherimide, or the like is preferably used. Preferred charge transport agents include tris (8-quinolinolato) aluminum (Alq ₃ ), N, N-diphenyl-N, N-di (m-tolyl) benzidine (TPD), polyparaphenylene vinylene (PPV), polyalkyl Thiophene, polyvinylcarbazole (PVK), triphenylene (TNF), metal phthalocyanine, 4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran (DCM), liquid crystal molecules, hexapentyloxy Examples include molecules selected from the group consisting of triphenylene, discotic liquid crystal molecules whose central core contains a π-conjugated condensed ring or a transition metal, carbon nanotubes, and fullerenes. The doping amount is set between 0.1 and 50 wt.%.
<Reading Photoconductive Layer 1046>
Reading photoconductive layer 1046 (in FIG. 11, the reading layer is a photoconductive material that absorbs electromagnetic waves, particularly visible light, and generates electric charges, and has an energy gap of amorphous selenium compound, amorphous Si: H, crystalline Si, GaAs, etc. Can be used in the range of 0.7-2.5 eV, particularly preferably amorphous selenium).

In the case of an amorphous selenium compound, the layer is doped with a small amount of alkali metal such as Li, Na, K, Cs, Rb between 0.001 ppm and 1 ppm, LiF, NaF, KF, CsF, RbF, etc. A small amount of fluoride of 10ppm to 10000ppm, P, As, Sb, Ge added from 50ppm to 0.5%, As doped from 10ppm to 0.5%, Cl, Br , I doped in a slight amount between 1 ppm and 100 ppm can be used.
In particular, amorphous selenium containing about 10 ppm to 200 ppm of As, amorphous selenium containing about 0.2% to 1% of As and further containing 5 ppm to 100 ppm of Cl, and alkali metal of about 0.001 ppm to 1 ppm were contained. Amorphous selenium is preferably used.

  The thickness of the reading photoconductive layer only needs to be able to sufficiently absorb the reading light and to drift the charge excited by the electric field generated by the charge accumulated in the charge accumulation layer, and is preferably about 1 μm to 30 μm.

<Electrode interface layer 1048A, B>
The electrode interface layers 1048A, B (corresponding to the interface crystallization preventing layer in FIG. 11) are laid between the recording photoconductive layer 1042 and the upper electrode 602, or between the reading photoconductive layer 1046 and the lower electrode layer 606. The For the purpose of preventing crystallization, amorphous selenium with As added in the range of 1% -20%, S, Te, P, Sb, Ge added in the range of 1% to 10%, the above What added the combination of an element and another element is preferable. Alternatively, As ₂ S ₃ or As ₂ Se ₃ having a higher crystallization temperature can also be preferably used. Furthermore, in addition to the above-mentioned additive elements for the purpose of preventing charge injection from the electrode layer, in particular, alkali metals such as Li, Na, K, Rb, Cs, LiF, NaF, KF to prevent hole injection It is also preferable to dope molecules such as RbF, CsF, LiCl, NaCl, KCl, RbF, CsF, CsCl, CsBr in the range of 10 ppm to 5000 ppm. Conversely, in order to prevent electron injection, it is also preferable to dope a halogen element such as Cl, I, or Br, or a molecule such as In2O3 in the range of 10 ppm to 5000 ppm. The thickness of the interface layer is preferably set between 0.05 μm and 1 μm so as to sufficiently fulfill the above purpose.

The lower electrode interface layer, the reading photoconductive layer, the charge storage layer, the recording photoconductive layer, and the upper electrode interface layer are formed in a vacuum chamber with a degree of vacuum of 10 ⁻³ to 10 ⁻⁷ Torr. A boat or a crucible containing the above alloys is heated between resistance and electron beams while being heated between 70 ° C. and 70 ° C., and laminated on the substrate by evaporating or sublimating the alloys and compounds.

When the evaporation temperatures of the alloy and the compound are greatly different, it is also preferable to control the addition concentration and the dope concentration by simultaneously heating and individually controlling a plurality of boats corresponding to a plurality of evaporation sources. For example, As ₂ Se ₃ / Amorphous selenium / LiF are put in a boat, As ₂ Se ₃ boat is 340 ° C, Amorphous selenium (a-Se) boat is 240 ° C, LiF boat is 800 ° C, and each boat By opening and closing the shutter, a layer of As10% doped amorphous selenium doped with 5000 ppm LiF can be formed.

<Undercoat layer 1050>
An undercoat layer 1050 can be provided between the recording photoconductive layer 1046 and the charge collection electrode (lower electrode 606). When there is an anti-crystallization layer (A layer) 1048, it is preferably provided between the anti-crystallization layer 1048 and the charge collection electrode. The undercoat layer 1050 preferably has rectification characteristics from the viewpoint of reducing dark current and leakage current. It is preferable to have an electron blocking property when a positive bias is applied to the upper electrode, and a hole blocking property when a negative bias is applied.

The resistivity of the undercoat layer is preferably 10 ⁸ Ωcm or more, and the film thickness is preferably 0.01 μm to 10 μm. As a layer having an electron blocking property, that is, an electron injection blocking layer, a layer made of a composition such as Sb2S3, SbTe, ZnTe, CdTe, SbS, AsSe, As2S3, or an organic polymer layer is preferable. As the organic polymer layer, a film in which NPD or TPD is mixed with a hole transporting polymer such as PVK or an insulating polymer such as polycarbonate, polystyrene, polyimide, or polycycloolefin can be preferably used.

  As a layer having a hole blocking property, that is, a hole injection blocking layer, a film of CdS, CeO2, or the like, or an organic polymer layer is preferable. As the organic polymer layer, a film obtained by mixing a carbon cluster such as C60 (fullerene) or C70 with an insulating polymer such as polycarbonate, polystyrene, polyimide, or polycycloolefin can be preferably used.

  On the other hand, a thin insulating polymer layer can also be preferably used. For example, parylene, polycarbonate, PVA, PVP, PVB, a polyester resin, an acrylic resin such as polymethyl methacrylate is preferable. The film thickness at this time is preferably 2 μm or less, and more preferably 0.5 μm or less.

<Overcoat layer 1052>
An overcoat layer 1052 can be provided between the recording photoconductive layer 1042 and the voltage application electrode (upper electrode 602). When there is a crystallization prevention layer (C layer) 1048B, it is preferably provided between the crystallization prevention layer 1048B and the voltage application electrode. The overcoat layer 1052 preferably has rectification characteristics from the viewpoint of reducing dark current and leakage current, and from the viewpoint of reducing dark current and leakage current. It is preferable to have a hole blocking property when a positive bias is applied to the upper electrode, and an electron blocking property when a negative bias is applied. The resistivity of the overcoat layer is preferably 10 ⁸ Ωcm or more, and the film thickness is preferably 0.01 μm to 10 μm.

Layer having an electron blocking ability, that is, as the electron injection blocking layer, Sb2S3, SbTe, ZnTe, CdTe , SbS, AsSe, composition or comprising layers such as _As 2 _{S 3,} or an organic polymer layer is preferred. As the organic polymer layer, a film in which NPD or TPD is mixed with a hole transporting polymer such as PVK or an insulating polymer such as polycarbonate, polystyrene, polyimide, or polycycloolefin can be preferably used.

  As a layer having a hole blocking property, that is, a hole injection blocking layer, a film of CdS, CeO2, or the like, or an organic polymer layer is preferable. As the organic polymer layer, a film obtained by mixing a carbon cluster such as C60 (fullerene) or C70 with an insulating polymer such as polycarbonate, polystyrene, polyimide, or polycycloolefin can be preferably used.

  On the other hand, a thin insulating polymer layer can also be preferably used. For example, parylene, polycarbonate, PVA, PVP, PVB, a polyester resin, an acrylic resin such as polymethyl methacrylate is preferable. The film thickness at this time is preferably 2 μm or less, and more preferably 0.5 μm or less.

<Comb type electrode>
As described with reference to FIGS. 9 and 10, the radiation detection unit has a comb-shaped electrode structure in which lower electrodes for signal extraction are alternately arranged on a stripe. In addition, a color filter layer that partially transmits only light having an arbitrary wavelength is formed under the transparent organic insulating layer. In the lower electrode having the comb-shaped electrode structure, a layer above the color filter layer is called a common B line, and a signal S line in a portion without the color filter layer. The B line is shared outside the radiation detector. The S line is used as a signal line. The widths of the B and S lines are, for example, 20, 10 μm, the interval is 10 μm, and are continuous at a pitch of 50 μm. The width of the color filter layer is 30 μm. The lower electrode is transparent because it irradiates light from the back surface, and needs flatness to avoid breakdown due to electric field concentration when a high voltage is applied. For example, IZO or ITO is used. An example of the thickness and flatness of the lower electrode is IZO, 0.2 μm, Ra = 1 nm.

<Charge extraction amplifier>
The electric charge is amplified through an amplifier and then AD converted. FIG. 13 shows details of the current detection means 30 and the high-voltage power supply unit 45, and these and the image detector 10 (corresponding to the radiation detector 100 of the above embodiment), the current detection means 30, and the outside of the apparatus 1. 3 is a block diagram illustrating a connection mode with the image processing apparatus 150 and the like. The charge amplifier IC 33 provided on the TCP multiplexes a number of charge amplifiers 33a and sample hold (S / H) 33b connected to each element 15a of the image detector 10 and signals from the sample hold 33b. A multiplexer 33c is provided. The current flowing out of the image detector 10 is converted into a voltage by each charge amplifier 33a, the voltage is sampled and held at a predetermined timing by the sample hold 33b, and the voltage corresponding to each element 15a sampled and held is in the order of arrangement of the elements 15a. The signals are sequentially output from the multiplexer 33c so as to be switched (corresponding to a part of main scanning). The signals sequentially output from the multiplexer 33c are input to the multiplexer 31c provided on the printed circuit board 31. Further, the voltage corresponding to each element 15a is sequentially output from the multiplexer 31c so as to be switched in the arrangement order of the elements 15a, and the main scanning is completed. To do. The signals sequentially output from the multiplexer 31c are converted into digital signals by the A / D converter 31a, and the digital signals are stored in the memory 31b. The image signal once stored in the memory 31b is sent to the external image processing device 150 via the signal cable 90, and is subjected to appropriate image processing in the image processing device 150, uploaded to the network 151 together with the photographing information, Sent to server or printer.

<Image acquisition sequence>
The image forming sequence of the image recording / reading system basically includes the process of irradiating recording light (for example, X-rays) while applying a high voltage to accumulate latent image charges, and irradiating the reading light after completing the application of high voltage. And the process of reading out the latent image charge. As the reading light, a method of scanning line light in the electrode direction (see FIG. 14) is optimal, but other methods are also possible. Furthermore, if necessary, it is possible to combine the process of sufficiently erasing the unread latent image charges. This erasing process is performed by irradiating the entire surface of the panel with erasing light. The entire surface may be irradiated at once, or line light or spot light may be scanned over the entire surface, after the reading process, and / or This is performed before the latent image accumulation process. When irradiating the erasing light, erasing efficiency can be increased by combining high voltage application. Further, by performing “pre-exposure” after applying a high voltage and before irradiating the recording light, it is possible to erase a charge (dark current charge) due to a dark current generated when a high voltage is applied.

Further, it is known that various charges are accumulated on the electrostatic recording medium before the recording light irradiation due to causes other than these. Since these residual signals affect the image information signal to be output next as an afterimage phenomenon, it is desirable to reduce them by correction.
As a method of correcting the afterimage signal, a method of adding an afterimage reading process to the above-described image recording and reading process is effective. This afterimage recording process is performed by applying a high voltage without irradiating the recording light and then reading the “afterimage” with the reading light. The afterimage signal can be corrected by subtracting it from the signal. The afterimage reading process is performed before or after the image recording reading process. Further, an appropriate erasing process can be combined before or after the afterimage reading process.

[Detailed structure of TFT radiation detector]
FIG. 15 shows a schematic configuration of a TFT type radiation detector 1400. As shown in FIG. 15, the radiation detector 1400 includes a photoconductive layer 1404 exhibiting electromagnetic wave conductivity as a charge conversion layer that generates charges when X-rays as radiation are incident. The photoconductive layer 1404 is an amorphous material that has a high dark resistance in a state where a bias voltage is applied, exhibits good electromagnetic wave conductivity with respect to X-ray irradiation, and can form a large-area film at a low temperature by a vacuum evaporation method. Quality (amorphous) materials are preferred, and amorphous Se (a-Se) films are used. A material obtained by doping amorphous Se with As, Sb, and Ge is excellent in thermal stability and is a suitable material.

  A single bias electrode 1401 is stacked on the photoconductive layer 1404 as an upper electrode for applying a bias voltage to the photoconductive layer 1404. For example, gold (Au) is used for the bias electrode 1401.

  Under the photoconductive layer 1404, a plurality of charge collection electrodes 1407a are formed as lower electrode portions. As shown in FIG. 15, each charge collection electrode 1407a is connected to a charge storage capacitor 1407c and a switch element 1407b, respectively.

Further, an intermediate layer is provided between the photoconductive layer 1404 and the bias electrode 1401. The intermediate layer is a layer existing between the upper electrode and the charge conversion layer, and may also serve as a charge injection blocking layer (including charge accumulation and diode formation). Although a resistance layer or an insulating layer may be used as the charge injection blocking layer, it is preferably a hole injection blocking layer that blocks hole injection while being a conductor for electrons, or for holes. For example, an electron injection blocking layer that blocks the injection of electrons while being a conductor is used. As the hole injection blocking layer, it may be used CeO2, ZnS, and Sb ₂ S _3. Of these, ZnS is desirable because it can be formed at a low temperature. Examples of the electron injection blocking layer include Sb ₂ S ₃ , CdS, Te doped Se, CdTe, organic compounds, and the like. Note that Sb ₂ S ₃ becomes both a hole injection blocking layer and an electron injection blocking layer depending on the position where it is provided. In this embodiment, since the bias electrode is a positive electrode, a hole injection blocking layer 1402 is provided as an intermediate layer. Further, an electron injection blocking layer 1406 is provided between the photoconductive layer 1404 and the charge collection electrode 1407a, although it is not an intermediate layer of the present invention.

Further, anti-crystallization layers 1403 and 1405 are provided between the hole injection blocking layer 1402 and the photoconductive layer 1404 and between the electron injection blocking layer 1406 and the photoconductive layer 1404, respectively. The crystallization preventing layer 1403 and 1405 GeSe, can be used and _{GeSe 2, Sb 2 Se 3,} a-As 2 Se 3, Se-As, Se-Ge, a Se-Sb-based compounds.

  In this embodiment, the hole injection blocking layer 1402, the crystallization prevention layer 1403, the photoconductive layer 1404, the crystallization prevention layer 1405, and the electron injection blocking layer 1406 are combined with the radiation detection layer 1430 (the radiation detection layer in the above embodiment). 106). Further, a charge detection layer 1407 is formed from the charge collection electrode 1407a, the switch element 1407b, and the charge storage capacitor 1407c, and the active matrix substrate 1450 is formed from the glass substrate 408 (corresponding to the glass substrate 104 of the above embodiment) and the charge detection layer 1407. Is configured.

  FIG. 16 is a sectional view showing the structure of one pixel unit of the radiation detector 1400, and FIG. 17 is a plan view thereof. The size of one pixel shown in FIGS. 16 and 17 is about 0.1 mm × 0.1 mm to 0.3 mm × 0.3 mm, and this pixel is about 500 × 500 to 3000 × 3000 pixels in a matrix for the radiation detector 1400 as a whole. It is arranged.

  As shown in FIG. 16, the active matrix substrate 1450 includes a glass substrate 1408, a gate electrode 1411, a charge storage capacitor electrode (hereinafter referred to as Cs electrode) 1418, a gate insulating film 1413, a drain electrode 1412, a channel layer 1415, and a contact electrode. 1416, a source electrode 1410, an insulating protective film 1417, an interlayer insulating film 1420, and a charge collection electrode 1407a.

  The gate electrode 1411, the gate insulating film 1413, the source electrode 1410, the drain electrode 1412, the channel layer 1415, the contact electrode 1416, and the like constitute a switch element 1407b made of a thin film transistor (TFT), and a Cs electrode 1418. In addition, a charge storage capacitor 1407c is configured by the gate insulating film 1413, the drain electrode 1412, and the like.

  The glass substrate 1408 is a support substrate. As the glass substrate 1408, for example, a non-alkali glass substrate (for example, # 1737 manufactured by Corning) can be used. As shown in FIG. 17, the gate electrode 1411 and the source electrode 1410 are electrode wirings arranged in a lattice pattern, and a switching element 1407b made of a thin film transistor (hereinafter referred to as TFT) is formed at the intersection.

  The source and drain of the switch element 1407b are connected to the source electrode 1410 and the drain electrode 1412, respectively. The source electrode 1410 includes a linear portion as a signal line and an extended portion for constituting the switch element 1407b, and the drain electrode 1412 is provided so as to connect the switch element 1407b and the charge storage capacitor 1407c. Yes.

  The gate insulating film 1413 is made of SiNx, SiOx, or the like. The gate insulating film 1413 is provided so as to cover the gate electrode 1411 and the Cs electrode 1418, and a part located on the gate electrode 1411 acts as a gate insulating film in the switch element 1407 b and a part located on the Cs electrode 1418. Acts as a dielectric layer in the charge storage capacitor 1407c. In other words, the charge storage capacitor 1407 c is formed by an overlapping region of the Cs electrode 1418 and the drain electrode 1412 formed in the same layer as the gate electrode 1411. Note that the gate insulating film 1413 is not limited to SiNx or SiOx, and an anodic oxide film obtained by anodizing the gate electrode 1411 and the Cs electrode 1418 may be used in combination.

  A channel layer (i layer) 1415 is a channel portion of the switch element 1407 b and is a current path connecting the source electrode 1410 and the drain electrode 1412. A contact electrode (n + layer) 1416 makes contact between the source electrode 1410 and the drain electrode 1412.

  The insulating protective film 1417 (corresponding to the insulating protective film 200 in the above embodiment) is formed over substantially the entire surface (substantially the entire region) on the source electrode 1410 and the drain electrode 1412, that is, on the glass substrate 1408. Thus, the drain electrode 1412 and the source electrode 1410 are protected, and electrical insulation and separation are achieved. Further, the insulating protective film 1417 has a contact hole 1421 at a predetermined position thereof, that is, a portion located on a portion of the drain electrode 1412 facing the Cs electrode 1418.

  The charge collection electrode 1407a is made of an amorphous transparent conductive oxide film. The charge collection electrode 1407 a is formed so as to fill the contact hole 1421, and is stacked on the source electrode 1410 and the drain electrode 1412. The charge collection electrode 1407a and the photoconductive layer 1404 are electrically connected to each other so that charges generated in the photoconductive layer 1404 can be collected by the charge collection electrode 1407a.

  The interlayer insulating film 1420 is made of a photosensitive acrylic resin, and serves to electrically isolate the switch element 1407b. A contact hole 1421 passes through the interlayer insulating film 1420, and the charge collection electrode 1407 a is connected to the drain electrode 1412. The contact hole 1421 is formed in a reverse taper shape as shown in FIG.

  A high voltage power supply (not shown) is connected between the bias electrode 1401 and the Cs electrode 1418. A voltage is applied between the bias electrode 1401 and the Cs electrode 1418 by the high voltage power source. As a result, an electric field can be generated between the bias electrode 1401 and the charge collection electrode 1407a via the charge storage capacitor 1407c.

  At this time, since the photoconductive layer 1404 and the charge storage capacitor 1407c are electrically connected in series, if a bias voltage is applied to the bias electrode 1401, charges are generated in the photoconductive layer 1404. (Electron-hole pairs) are generated. Electrons generated in the photoconductive layer 1404 move to the positive electrode side, and holes move to the negative electrode side. As a result, charges are stored in the charge storage capacitor 1407c.

  In the radiation detector as a whole, a plurality of charge collection electrodes 1407a are arranged one-dimensionally or two-dimensionally, and charge storage capacitors 1407c individually connected to the charge collection electrodes 1407a are connected individually to the charge storage capacitors 1407c. A plurality of switch elements 1407b are provided. Accordingly, one-dimensional or two-dimensional electromagnetic wave information is temporarily stored in the charge storage capacitor 1407c, and the switch element 1407b is sequentially scanned, whereby the one-dimensional or two-dimensional charge information can be easily read out.

  Next, the operation principle of the TFT radiation detector 1400 will be described.

  When the photoconductive layer 1404 is irradiated with X-rays, charges (electron-hole pairs) are generated in the photoconductive layer 1404. In a state where a voltage is applied between the bias electrode 1401 and the Cs electrode 1418, that is, in a state where a voltage is applied to the photoconductive layer 1404 via the bias electrode 1401 and the Cs electrode 1418, the photoconductive layer 1404 and the charge accumulation are performed. Since the capacitor 1407c is electrically connected in series, electrons generated in the photoconductive layer 1404 move to the positive electrode side and holes move to the negative electrode side. As a result, the charge storage capacitance Charge is accumulated in 1407c.

  The charge stored in the charge storage capacitor 1407c can be extracted to the outside through the source electrode 1410 by turning on the switch element 1407b by an input signal to the gate electrode 1411. Since the electrode wiring composed of the gate electrode 1411 and the source electrode 1410, the switch element 1407b, and the charge storage capacitor 1407c are all provided in a matrix, signals input to the gate electrode 1411 are sequentially scanned to obtain the source electrode 1410. By detecting the signal from each of the source electrodes 1410, it becomes possible to obtain X-ray image information two-dimensionally.

  Next, the charge collection electrode 1407a will be described in detail.

  The charge collection electrode 1407a is composed of an amorphous transparent conductive oxide film. Examples of amorphous transparent conductive oxide film materials include oxides of indium and tin (ITO: Indium-Tin-Oxide), oxides of indium and zinc (IZO: Indium-Zinc-Oxide), indium and germanium. An oxide (IGO: Indium-Germanium-Oxide) or the like having a basic composition can be used.

In addition, various metal films and conductive oxide films are used as the charge collection electrode, and transparent conductive oxide films such as ITO (Indium-Tin-Oxide) are often used for the following reasons. When the incident X-ray dose is large in the radiation detector, unnecessary charges may be trapped in the semiconductor film (or in the vicinity of the interface between the semiconductor film and an adjacent layer). Since such residual charges are stored for a long time or move while taking time, the X-ray detection characteristics are deteriorated during the subsequent image detection, and an afterimage (virtual image) appears. Japanese Patent Application Laid-Open No. 9-9153 (corresponding US Pat. No. 5,563,421) discloses that when residual charges are generated in the photoconductive layer, the residual charges are excited by irradiating light from the outside of the photoconductive layer. A method for removing the image is disclosed. In this case, in order to irradiate light efficiently from the lower side (charge collecting electrode side) of the photoconductive layer, the charge collecting electrode needs to be transparent to the irradiation light. In addition, for the purpose of increasing the area filling factor (fill factor) of the charge collection electrode or for shielding the switch element, it is desired to form the charge collection electrode so as to cover the switch element, but the charge collection electrode is opaque. In this case, the switch element cannot be observed after the charge collecting electrode is formed.
For example, when the characteristics of the switch element are inspected after the charge collection electrode is formed, if the switch element is covered with an opaque charge collection electrode, when a defective characteristic of the switch element is found, to clarify the cause It cannot be observed with an optical microscope or the like. Therefore, it is desirable that the charge collection electrode is transparent so that the switch element can be easily observed even after the charge collection electrode is formed.

(A) is a figure which shows typically a mode that X-ray imaging is carried out with the radiation detector for mammography concerning embodiment of this invention, (B) is a schematic whole figure of a radiation detector. (A) of the sheet | seat concerning embodiment of this invention is sectional drawing, (B) is a top view. It is explanatory drawing which shows the outline | summary of the whole process which affixes a sheet | seat on a radiation detection device to (A)-(D). It is explanatory drawing which shows typically the process (A)-(D) which affixes a sheet | seat on a radiation detection device. It is explanatory drawing which shows typically the process (E)-(H) which affixes a sheet | seat on a radiation detection device. It is explanatory drawing which shows the process (A) and (B) which affix a sheet | seat on a radiation detection device. It is explanatory drawing which shows the process (C) and (D) which affix a sheet | seat on a radiation detection device. It is explanatory drawing which shows the process (E) and (F) which affix a sheet | seat on a radiation detection device. It is explanatory drawing which looked at the process (A) and (B) which affixes a sheet | seat on a radiation detection device from the side. It is a table | surface which shows the specification of a sheet | seat. It is a figure which shows typically the state by which two protective films were laminated | stacked. (A) which shows typically the radiation detection device in the detailed structure of an optical reading type radiation detector is a top view, (B) is BB sectional drawing of (A). (A) is a plan view schematically showing a lower substrate for radiation detection in a detailed structure of an optical reading type radiation detector, (B) is a sectional view taken on line BB in (A), and (C) is (A). It is CC sectional drawing of). It is sectional drawing which modeled the structural example of the preferable layer structure in the detailed structure of an optical reading type radiation detector. It is a perspective view which shows the example of the preferable surface protective layer and sealing structure in the detailed structure of a radiation detector of an optical reading system. FIG. 4 is a block diagram showing details of the current detection means and the high voltage power supply unit, and how to connect the image detector, the current detection means, and an image processing apparatus arranged outside the apparatus. It is explanatory drawing explaining the optimal scanning direction. It is the schematic which shows the structure of the radiation detector of a TFT system. It is sectional drawing which shows the structure of 1 pixel unit of a TFT type radiation detector. It is a top view which shows the structure of 1 pixel unit of a TFT type radiation detector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Radiation detector 102 Radiation detection device 102B Chest wall side surface (1st side surface)
102C Back surface 102D Side surface (second side surface)
104 Glass substrate (substrate)
106 radiation detection layer 106B surface 200 protective film 300 sheet 300C first end surface 300D second end surface 306 reinforcing film 306A notch

Claims (11)

A sheet that is bent from the side of a radiation detection device on which a radiation detection layer for converting radiation into electric charges is formed and is attached to the surface of the radiation detection layer, and is adhered to the radiation detection device. Protective film,
A reinforcing film that is bonded to the protective film and has a notch formed in the bent portion;
A sheet characterized by comprising:   The sheet according to claim 1, wherein the reinforcing film is peeled off after being attached to the radiation detection device.   The sheet according to claim 2, wherein an adhesive force between the reinforcing film and the protective film is weaker than an adhesive force between the protective film and the radiation detection device.   4. The separator sheet according to claim 1, wherein a separator sheet that is peeled off before being attached to the radiation detection device is attached to the adhesive surface of the protective film. 5. Sheet.   The sheet according to claim 4, wherein an adhesive force between the separator sheet and the protective film is weaker than an adhesive force between the reinforcing film and the protective film.   The sheet according to any one of claims 1 to 5 is attached to a surface of the radiation detection layer from a side surface of a radiation detection device in which a radiation detection layer for converting radiation into electric charge is formed on a substrate. A radiation detector characterized by being attached. A sheet affixing method for affixing a sheet across the surface of the radiation detection layer from the first side surface of the radiation detection device in which a radiation detection layer for converting radiation into electric charge is formed on a substrate,
The sheet is
A protective film adhered to the radiation detection device;
A reinforcing film that is bonded to the protective film and has a notch formed in the bent portion;
Have
The first end surface of the sheet is positioned with respect to the back surface of the radiation detection device opposite to the surface on which the radiation detection layer is formed, and the second end surface of the sheet orthogonal to the first end surface is detected by the radiation. Positioning for positioning against a second side of the radiation detection device orthogonal to the first side of the device;
After the positioning step, the sheet is attached to the first side surface of the radiation detection device, the attaching step of bending at the cut portion and attaching to the surface of the radiation detection layer;
A sheet sticking method comprising:   The sheet sticking method according to claim 7, further comprising a peeling step for peeling the reinforcing film after the sticking step.   The sheet sticking method according to claim 8, wherein an adhesive force between the reinforcing film and the protective film is weaker than an adhesive force between the protective film and the radiation detection device. A separator sheet is attached to the adhesive surface of the protective film of the sheet,
The sheet sticking method according to any one of claims 7 to 9, further comprising a pre-peeling step for peeling the separator before the sticking step.   The sheet sticking method according to claim 10, wherein an adhesive force between the separator sheet and the protective film is weaker than an adhesive force between the reinforcing film and the protective film.

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