JP5379989B2 - Application method, radiation detector manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating method, a coating device, and a method of manufacturing a radiation detector that shorten the coating time in the coating of a solution by inkjet. <P>SOLUTION: In the coating method of coating the solution on the surface of a substrate by the inkjet, droplets are discharged in a columnar shape from the nozzle 609 of an inkjet head 604, also the inkjet head 604 is relatively moved in a main scanning direction to the substrate 601, and the droplets are landed on the substrate while keeping the columnar shape. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a coating method, a coating apparatus, and a method for manufacturing a radiation detector.

  As a technique for forming a circuit pattern or a functional film on a substrate, a technique in which a solution containing conductive fine particles and other functional materials is applied to a substrate by inkjet is known.

  In the application of the solution by inkjet, typically, while moving the inkjet head in the main scanning direction, droplets are ejected from the nozzles of the inkjet head and attached to the substrate. Then, a predetermined pattern or film is formed by leveling (wetting and spreading) droplets on the substrate.

  In addition, a technique has been proposed in which a solution is ejected in a column shape longer than the interval between the inkjet head and the substrate and attached to the substrate (for example, see Patent Documents 1 and 2).

  In the technique disclosed in Patent Document 1, the tip portion of the columnar solution discharged from the head adheres to the substrate surface, and the columnar solution is then drawn into the head, thereby causing dots by the tip portion of the columnar solution. Is formed on the substrate surface. Then, the size of the dots is changed by adjusting the distance between the ink jet head and the substrate, and in particular, fine dots can be formed to achieve high definition.

In the technique disclosed in Patent Document 2, the head and the substrate are relatively moved while the head and the substrate are connected by the columnar solution discharged from the head, so that the solution is linearly formed on the substrate surface. Applied. The line width is controlled with high accuracy by adjusting the relative movement speed between the head and the substrate.
In addition, as a method of applying by ink jet, a technique has been proposed in which the liquid is discharged in a non-uniform discharge state (see Patent Document 3).
JP 2005-131499 A JP 2005-131500 A Japanese Patent Laying-Open No. 2005-040653

In recent years, in application of a solution by ink jet, reduction of the application time is required. However, with the technique disclosed in Patent Document 1, it is difficult to shorten the coating time because the solution is repeatedly ejected and drawn. Further, in the technique disclosed in Patent Document 2, it is necessary to maintain a state in which the head and the substrate are connected by a columnar solution discharged from the head, so that the relative movement speed between the head and the substrate is limited. It is difficult to shorten the application time.
The technique disclosed is specific description has not been made as to whether non-uniform in What specific discharge shape in Patent Document 3, the discharge with heterogeneous shapes After How For this, the landing There is no mention of what can be done.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a coating method, a coating apparatus, and a radiation detector manufacturing method in which the coating time is shortened in coating of a solution by inkjet.

（３）主走査方向のドットピッチＰ１が下記数式（ｉｉ）を満たすことを特徴とする（２）に記載の塗布方法。

（４）副走査方向のドットピッチＰ２が下記数式（ｉｉｉ）を満たすことを特徴とする（２）に記載の塗布方法。

（５）前記溶液がダイラタンシー性を有することを特徴とする（１）〜（４）のいずれかに記載の塗布方法。 The above object is achieved by the following coating method according to the present invention.
(1) A coating method in which a solution is applied to the surface of a substrate by inkjet, and droplets are ejected from the inkjet head in a columnar shape, and the inkjet head is moved relative to the substrate in the main scanning direction to maintain the columnar shape. A coating method characterized by causing the droplets to land on the base material as it is.
(2) The volume of the droplet is V, the length of the droplet is l, the ejection speed of the droplet is V _d , the relative movement speed of the inkjet head in the main scanning direction with respect to the substrate is V _k , The coating method according to (1), wherein the following formula (i) is satisfied, where θ is a contact angle between the droplet and the substrate.

(3) The coating method according to (2), wherein the dot pitch P1 in the main scanning direction satisfies the following mathematical formula (ii).

(4) The coating method according to (2), wherein the dot pitch P2 in the sub-scanning direction satisfies the following mathematical formula (iii).

(5) The coating method according to any one of (1) to (4), wherein the solution has dilatancy.

According to the coating method having the configuration (1), since the solution is ejected as droplets, the restriction on the relative movement speed between the inkjet head and the substrate can be relaxed or eliminated. Then, the droplets are ejected from the inkjet head in a columnar shape, and the inkjet head is relatively moved so that the droplets are landed while maintaining the columnar shape. The height of the droplet can be reduced. Thereby, it is possible to shorten the time required until wetting and spreading to shorten the coating time.
According to the coating method having the configuration (2), the droplet spreads wet without returning to a circular shape. Thereby, it is possible to shorten the time required until wetting and spreading to shorten the coating time.
According to the coating method having the configuration (3), it is possible to unite droplets adjacent in the main scanning direction on the substrate.
According to the coating method having the configuration (4), droplets adjacent in the sub-scanning direction can be united on the substrate.
According to the coating method having the configuration (5), it is possible to discharge droplets in a columnar shape.

（７）主走査方向のドットピッチＰ１が下記数式（ｉｉ）を満たすよう、前記移動手段が前記インクジェットヘッドを主走査方向に相対移動させることを特徴とする（６）に記載の塗布装置。

（８）副走査方向のドットピッチＰ２が下記数式（ｉｉｉ）を満たすよう、前記移動手段が前記インクジェットヘッドを副走査方向に相対移動させることを特徴とする（６）に記載の塗布装置。

Moreover, the said objective is achieved by the following coating device which concerns on this invention.
(6) A coating apparatus for applying a solution to the surface of a substrate by inkjet, an inkjet head having a nozzle for discharging droplets in a columnar shape, and a moving means for moving the inkjet head relative to the substrate; The droplet volume is V, the droplet length is l, the droplet discharge speed is V _d , the relative movement speed of the inkjet head in the main scanning direction with respect to the substrate is V _k , and The coating apparatus characterized by satisfying the following formula (i), where θ is the contact angle between the droplet and the substrate.

(7) The coating apparatus according to (6), wherein the moving unit relatively moves the inkjet head in the main scanning direction so that the dot pitch P1 in the main scanning direction satisfies the following mathematical formula (ii).

(8) The coating apparatus according to (6), wherein the moving unit relatively moves the inkjet head in the sub-scanning direction so that the dot pitch P2 in the sub-scanning direction satisfies the following formula (iii).

According to the coating apparatus having the configuration (6), since the solution is ejected as droplets, the restriction on the relative movement speed between the inkjet head and the substrate can be relaxed or eliminated. Then, the droplets are ejected from the inkjet head in a columnar shape, and the inkjet head is moved relative to each other. At that time, by satisfying the above formula (i), the droplets land while maintaining the columnar shape, and have a circular shape. It spreads in an oval shape without returning. Thereby, it is possible to shorten the time required until wetting and spreading to shorten the coating time.
According to the coating method having the configuration (7), it is possible to unite droplets adjacent in the main scanning direction on the substrate.
According to the coating method having the configuration (8), it is possible to unite droplets adjacent in the sub-scanning direction on the substrate.

Moreover, the said objective is achieved by the manufacturing method of the following radiation detector which concerns on this invention.
(9) a first electrode through which radiation carrying image information is transmitted; a photoconductive layer that is irradiated with the radiation transmitted through the first electrode to generate charges; and the first electrode with respect to the photoconductive layer A second electrode for collecting charges generated by the photoconductive layer, and an organic polymer layer provided between the photoconductive layer and the first electrode. A solution containing a film component of the organic polymer layer on at least the surface of the base material on which the second electrode and the photoconductive layer are laminated (1) to (5) The manufacturing method of the radiation detector characterized by apply | coating by the application | coating method in any one, and forming the said organic polymer layer.

  According to the method of manufacturing the radiation detector having the configuration (9), the time required for forming the organic polymer layer can be shortened. Thereby, a radiation detector can be manufactured efficiently.

  It is possible to provide a coating method, a coating apparatus, and a method for manufacturing a radiation detector which are intended to shorten the coating time in coating a solution by inkjet.

  Hereinafter, preferred embodiments of an inkjet head, a coating apparatus and a coating method, and a method for manufacturing a radiation detector according to the present invention will be described with reference to the drawings.

  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. Image information is recorded by receiving the radiation to be carried, and an image signal representing the recorded image information is output.

  As a radiation detector, a so-called optical reading type radiation detection substrate 500 that reads using a semiconductor material that generates charges by light irradiation, charges generated by radiation irradiation are accumulated, and the accumulated charges are stored in a thin film transistor. There is a radiation detector 400 or the like of a method (hereinafter referred to as TFT method) that reads by turning on and off an electrical switch such as a TFT (Thin Film Transistor).

(Configuration of TFT type radiation detector 400)
First, the configuration of the TFT radiation detector 400 will be described. FIG. 1A is a schematic diagram showing the overall configuration of a TFT type radiation detector 400. FIG. 2 is a diagram showing a main part configuration of the TFT type radiation detector 400 and showing each part laminated on the glass substrate.

  As shown in FIGS. 1A and 2, the TFT radiation detector 400 according to this embodiment is a charge that generates charges when X-rays as an example of radiation carrying image information are incident. As the conversion layer, a photoconductive layer 404 exhibiting electromagnetic wave conductivity is provided. As the photoconductive layer 404, an amorphous material having a high dark resistance, good electromagnetic wave conductivity with respect to X-ray irradiation, and capable of forming a large area film at a low temperature by a vacuum deposition method is preferred.

  For example, an amorphous Se (a-Se) film is used as the amorphous material. A material obtained by doping amorphous Se with As, Sb, or Ge is excellent in thermal stability and is a suitable material for the photoconductive layer 404.

  A bias electrode 401 for applying a bias voltage to the photoconductive layer 404 is formed on the photoconductive layer 404 as a first electrode through which radiation carrying image information is transmitted. The bias electrode 401 is made of, for example, gold (Au). The photoconductive layer 404 is irradiated with radiation that has passed through the bias electrode 401.

  Collecting a plurality of charges as a second electrode for collecting charges generated by the photoconductive layer 404 on the side opposite to the side where the bias electrode 401 is provided with respect to the photoconductive layer 404, that is, below the photoconductive layer 404. An electrode 407a is formed. As shown in FIG. 2, the charge collection electrode 407a is connected to the charge storage capacitor 407c and the switch element 407b, respectively. The charge collection electrode 407 a is provided on the glass substrate 408.

  As shown in FIGS. 1A and 2, a hole injection blocking layer 402 having a hole blocking material is provided as an organic polymer layer between the photoconductive layer 404 and the bias electrode 401. ing. Here, the organic polymer layer may also serve as a charge injection blocking layer having charge selectivity. The charge injection blocking layer has charge selectivity to prevent charge flowing out from the bias electrode 401 with which the charge injection blocking layer is in contact (holes if the bias electrode 401 is positive bias, electrons if it is negative bias). The charge flowing into the bias electrode 401 has a property of passing through.

  That is, as a charge injection blocking layer, a hole injection blocking layer that blocks the injection of holes while being a conductor for electrons, or an electron that blocks the injection of electrons while being a conductor for holes. An injection blocking layer is used. In this embodiment, since the bias electrode 401 is a positive electrode, a hole injection blocking layer 402 is provided as an organic polymer layer.

  As the hole injection blocking layer 402, a film in which a hole blocking material is mixed with an insulating polymer such as polycarbonate, polystyrene, polyimide, polycycloolefin, or the like can be preferably used.

  At least one of the hole blocking materials contained in the hole injection blocking layer 402 is preferably at least one selected from carbon clusters or derivatives thereof. Further, the carbon cluster is preferably at least one selected from fullerene C60, fullerene C70, oxidized fullerene or a derivative thereof.

  In addition, an electron injection blocking layer 406 is provided between the photoconductive layer 404 and the charge collection electrode 407a as shown in FIG.

Further, anti-crystallization layers 403 and 405 are provided between the hole injection blocking layer 402 and the photoconductive layer 404 and between the electron injection blocking layer 406 and the photoconductive layer 404, respectively. The crystallization preventing layer 403, 405 _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.

  Note that an active matrix layer 407 is composed of the charge collection electrode 407a, the switch element 407b, and the charge storage capacitor 407c, and an active matrix substrate 450 is composed of the glass substrate 408 and the active matrix layer 407.

  FIG. 3 is a cross-sectional view showing the structure of one pixel unit of the radiation detector 400, and FIG. 4 is a plan view thereof. The size of one pixel shown in FIGS. 3 and 4 is about 0.1 mm × 0.1 mm to 0.3 mm × 0.3 mm, and this pixel is arranged in a matrix of 500 × 500 to 3000 × for the radiation detector as a whole. About 3000 pixels are arranged.

  As shown in FIG. 3, the active matrix substrate 450 includes a glass substrate 408, a gate electrode 411, a charge storage capacitor electrode (hereinafter referred to as Cs electrode) 418, a gate insulating film 413, a drain electrode 412, a channel layer 415, and a contact electrode. 416, a source electrode 410, an insulating protective film 417, an interlayer insulating film 420, and a charge collection electrode 407a.

  Further, the gate electrode 411, the gate insulating film 413, the source electrode 410, the drain electrode 412, the channel layer 415, the contact electrode 416, and the like constitute a switch element 407b made of a thin film transistor (TFT), and a Cs electrode 418. The gate storage film 413, the drain electrode 412, and the like constitute a charge storage capacitor 407c.

  The glass substrate 408 is a support substrate. As the glass substrate 408, for example, an alkali-free glass substrate (for example, # 1737 manufactured by Corning) can be used. As shown in FIG. 4, the gate electrode 411 and the source electrode 410 are electrode wirings arranged in a lattice pattern, and a switching element 407b made of a thin film transistor is formed at the intersection.

  The source / drain of the switch element 407b is connected to the source electrode 410 and the drain electrode 412, respectively. The source electrode 410 includes a linear portion as a signal line and an extended portion for constituting the switch element 407b, and the drain electrode 412 is provided so as to connect the switch element 407b and the charge storage capacitor 407c. Yes.

  In order to acquire image information, the source electrode 410 is connected to an extraction electrode 470 that extracts the charges collected by the charge collection electrode 407a to the outside. The extraction electrode 470 is provided on the glass substrate 408 and is disposed outside the photoconductive layer 404.

  The gate insulating film 413 is made of SiNx, SiOx, or the like. The gate insulating film 413 is provided so as to cover the gate electrode 411 and the Cs electrode 418, and a part located on the gate electrode 411 functions as a gate insulating film in the switch element 407 b and a part located on the Cs electrode 418. Acts as a dielectric layer in the charge storage capacitor 407c. That is, the charge storage capacitor 407 c is formed by an overlapping region of the Cs electrode 418 and the drain electrode 412 formed in the same layer as the gate electrode 411. Note that the gate insulating film 413 is not limited to SiNx or SiOx, and an anodic oxide film obtained by anodizing the gate electrode 411 and the Cs electrode 418 may be used in combination.

  A channel layer (i layer) 415 is a channel portion of the switch element 407 b and is a current path connecting the source electrode 410 and the drain electrode 412. A contact electrode (n + layer) 416 makes contact between the source electrode 410 and the drain electrode 412.

  The insulating protective film 417 is formed over almost the entire surface (substantially the entire region) on the source electrode 410 and the drain electrode 412, that is, on the glass substrate 408. Thus, the drain electrode 412 and the source electrode 410 are protected, and electrical insulation and separation are achieved. In addition, the insulating protective film 417 has a contact hole 421 at a predetermined position thereof, that is, a portion located on a portion of the drain electrode 412 facing the Cs electrode 418.

  The charge collection electrode 407a is made of an amorphous transparent conductive oxide film. The charge collection electrode 407 a is formed so as to fill the contact hole 421, and is stacked on the source electrode 410 and the drain electrode 412. The charge collection electrode 407a and the photoconductive layer 404 are electrically connected to each other so that charges generated in the photoconductive layer 404 can be collected by the charge collection electrode 407a.

  Next, the charge collection electrode 407a will be described in detail. The charge collection electrode 407a used in the present embodiment is composed of an amorphous transparent conductive oxide film. As an amorphous transparent conductive oxide film material, an oxide of indium and tin (ITO: Indium-Tin-Oxide), an oxide 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.

  As the charge collection electrode 407a, various metal films and conductive oxide films are used, 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 400, 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, X-ray detection characteristics deteriorate during subsequent image detection, and afterimages (virtual images) appear. Therefore, in Japanese Patent Laid-Open No. 9-9153 (corresponding US Pat. No. 5,563,421), when residual charge is generated in the photoconductive layer 404, the residual charge is irradiated by irradiating light from the outside of the photoconductive layer 404. A method of removing by excitation is disclosed. In this case, in order to efficiently irradiate light from the lower side of the photoconductive layer 404 (the charge collection electrode 407a side), the charge collection electrode 407a needs to be transparent to the irradiation light.

  It is desirable to form the charge collection electrode 407a so as to cover the switch element 407b for the purpose of increasing the area filling factor (fill factor) of the charge collection electrode 407a or for shielding the switch element 407b. If the collection electrode 407a is opaque, the switch element 407b cannot be observed after the charge collection electrode 407a is formed.

  For example, when the characteristic inspection of the switch element 407b is performed after forming the charge collection electrode 407a, if the switch element 407b is covered with the opaque charge collection electrode 407a, the cause of the characteristic failure of the switch element 407b is found. Cannot be observed with an optical microscope. Therefore, it is desirable that the charge collection electrode 407a is transparent so that the switch element 407b can be easily observed even after the charge collection electrode 407a is formed.

  The interlayer insulating film 420 is made of a photosensitive acrylic resin, and serves to electrically isolate the switch element 407b. A contact hole 421 passes through the interlayer insulating film 420, and the charge collection electrode 407 a is connected to the drain electrode 412. The contact hole 421 is formed in a reverse taper shape as shown in FIG. A high voltage power supply (not shown) is connected between the bias electrode 401 and the Cs electrode 418.

  Next, a configuration for covering the photoconductive layer 404 will be described. As illustrated in FIG. 1A, a cover glass 440 as an example of a cover member that covers the bias electrode 401 is provided above the bias electrode 401.

  The glass substrate 408 is provided with a protective member 442 to which the cover glass 440 is bonded. The protective member 442 surrounds the periphery of the photoconductive layer 404 and is formed in a box shape with the upper and lower portions opened as a whole.

  The protective member 442 includes a side wall 442a erected on the outer peripheral portion of the glass substrate 408, and a flange portion 442b extending from the upper portion of the side wall 442a to the upper side of the central portion of the glass substrate 408. It is formed in an L shape.

  The cover glass 440 has an upper surface of the outer peripheral portion bonded to the lower surface (inner wall) of the flange portion 442b and is supported by the protective member 442.

  The joint between the protective member 442 and the cover glass 440 is disposed outside the photoconductive layer 404. That is, the protective member 442 and the cover glass 440 are bonded to each other in a region where the photoconductive layer 404 on the glass substrate 408 is not present, but not above the photoconductive layer 404.

  Note that an insulating member having an insulating property is used for the protective member 442. As the insulating member, for example, polycarbonate, polyethylene terephthalate (PET), polymethyl methacrylate (acrylic), or polyvinyl chloride is used.

  Further, the protective member 442 has a lower opening closed with a glass substrate 408 and an upper opening closed with a cover glass 440, and a closed space of a predetermined size is formed in the protective member 442. The photoconductive layer 404 is accommodated in this closed space, and the photoconductive layer 404 is covered with the cover glass 440, the glass substrate 408, and the protective member 442.

  Further, a space surrounded by the cover glass 440, the protection member 442, and the glass substrate 408 is filled with a curable resin 444 as a filling member. As the curable resin 444, for example, a room temperature curable resin such as epoxy or silicon is used.

(Range of formation of hole injection blocking layer 402)
Here, the formation range of the hole injection blocking layer 402 will be described. The hole injection blocking layer 402 as an organic polymer layer has an outer edge, that is, a peripheral edge serving as a boundary with another layer located at a predetermined position, so that the hole injection blocking layer 402 is formed in a predetermined range. The configuration covers the predetermined range.

  In the present embodiment, the outer edge portion of the hole injection blocking layer 402 includes the region end G1 of the image information acquisition region G from which the image information is acquired and the extraction electrode 470 in the region irradiated with the radiation carrying the image information. It is comprised so that it may be located between. A range indicated by an arrow A in FIG. 1A is a range between the region end G1 of the image information acquisition region G and the extraction electrode 470.

  Preferably, the outer edge portion of the hole injection blocking layer 402 according to the present embodiment is outside the image information acquisition region G and has a thickness of 10% or more of the average thickness of the flat portion of the photoconductive layer 404. It is comprised so that it may be located in the area | region which has. The flat portion average film thickness of the photoconductive layer 404 is obtained by measuring the film thicknesses of nine arbitrary points in the image information acquisition region G of the photoconductive layer 404 and averaging the film thicknesses of the nine points. The film thickness was measured by observing the cross section with a microscope at a magnification of 100 times.

  Note that the range indicated by the arrow B in FIG. 1A is the range outside the image information acquisition region G and within the region having a film thickness of 10% or more of the average thickness of the flat portion of the photoconductive layer 404. is there.

  More preferably, the outer edge portion of the hole injection blocking layer 402 according to this embodiment is outside the bias electrode 401 and is in a region having a film thickness of 10% or more of the average thickness of the flat portion of the photoconductive layer 404. Configured to be located in

  Note that a range indicated by an arrow C in FIG. 1A is a range outside the bias electrode 401 and in a region having a thickness of 10% or more of the average thickness of the flat portion of the photoconductive layer 404.

  More preferably, the outer edge portion of the hole injection blocking layer 402 is outside the bias electrode 401 and is located in a region where the slope of the end slope of the photoconductive layer 404 is 50% or less.

  The outer edge portion of the hole injection blocking layer 402 is an end slope where the gradient gradually increases from the flat portion to the outer edge of the photoconductive layer 404, and the gradient is within 50% or less, that is, the gradient is greater than 50%. Is located in a gentle range. A gradient of 50% means that, as shown in FIG. 1B, in a right triangle composed of a side along the film thickness direction of the photoconductive layer 404, a side perpendicular to the side, and a hypotenuse. This is a slope formed by the hypotenuse when the length of the side along the film thickness direction of the conductive layer 404 is 1 and the length of the side perpendicular to the side is 2. The gradient was measured by microscopic observation of the cross section at a magnification of 100 times.

  Note that the range indicated by the arrow D in FIG. 1A is the range outside the bias electrode 401 and within the region where the slope of the end slope of the photoconductive layer 404 is 50% or less.

  The photoconductive layer 404 is formed in a wider area than the bias electrode 401. The charge collection electrode 407a is formed in a region wider than the image information acquisition region G.

  Note that the outer edge portion of the hole injection blocking layer 402 according to the present embodiment may be configured to be located outside the image information acquisition region G and within the region of the photoconductive layer 404.

  Next, an apparatus and a method for forming the above-described hole injection blocking layer 402 will be described. In the present embodiment, the hole injection blocking layer 402 is formed by applying a solution containing a film component to the substrate surface.

  FIG. 13 shows a schematic configuration of a coating apparatus 600 for forming the hole injection blocking layer 402. The coating apparatus 600 uses a substrate 601 in which an active matrix substrate 450, an electron injection blocking layer 406, a crystallization preventing layer 405, and a photoconductive layer 404 are laminated, and the surface of the photoconductive layer 404 that forms the surface layer of the substrate 601. Then, a hole injection blocking layer 402 which is an organic polymer layer is formed. In the case where the anti-crystallization layer 403 is formed between the photoconductive layer 404 and the hole injection blocking layer 402, a substrate in which the anti-crystallization layer 403 is laminated on the photoconductive layer 404 is used as a base material. A hole injection blocking layer 402 is formed on the surface of the crystallization preventing layer 403 that forms the surface layer of the substrate.

  As the film component of the hole injection blocking layer 402, as described above, a mixture of a hole blocking material and an insulating polymer such as polycarbonate, polystyrene, polyimide, polycycloolefin, or the like can be preferably used.

  The coating apparatus 600 includes a substantially sealed coating chamber 602 that coats the above solution onto the surface of the substrate 601, and a holding table 603 that holds the substrate 601 and a holding table 603 that holds the substrate 601 in the coating chamber 602. An inkjet head 604 for applying a solution to the surface of the substrate 601 is provided. According to the inkjet, a mask is not required, the amount of liquid consumption is small, and a film can be accurately formed on the substrate 601 in a non-contact manner.

  In the coating chamber 602, a vibration isolation table 605 and a surface plate 606 supported by the vibration isolation table 605 are provided. On the surface plate 606, a holding table moving mechanism 607 that supports the holding table 603 and a head moving mechanism 608 that supports the inkjet head 604 are provided. The holding table moving mechanism 607 and the head moving mechanism 608 move the inkjet head 604 relative to the holding table 603 in the main scanning direction and the sub-scanning direction so that the surface of the substrate 601 can be scanned by the inkjet head 604. For example, the holding table moving mechanism 607 moves the holding table 603 in the main scanning direction along the first axis of the two horizontal orthogonal axes, and the head moving mechanism 608 moves to the second axis of the two horizontal orthogonal axes. The head 604 is moved in the sub scanning direction along.

  The inkjet head 604 is provided with a nozzle 609 that intermittently discharges a predetermined amount of solution as droplets. As shown in FIG. 14A, droplets are ejected from the nozzle 609 in a substantially columnar shape. In order to increase the length of the droplet by discharging the droplet in a substantially columnar shape, for example, increasing the viscosity of the solution, giving the solution a dilatancy, decreasing the dynamic surface tension of the solution, or discharging the droplet. And a method of significantly increasing the discharge speed (giving very large energy to the actuator for discharging). Dilatancy refers to the property of a liquid whose viscosity increases with increasing shear rate. The dynamic surface tension refers to the surface tension in a flow / stirring situation where the interface is unstable.

Table 1 shows the relationship between the viscosity of the solution and the difficulty of rounding the droplets (ease of maintaining the columnar shape). In Table 1 and Tables 2 to 4 to be described later, “◯” indicates that the droplet is difficult to round, in other words, it is easy to maintain the columnar shape, and “X” indicates that the droplet is easily rounded.

Table 2 shows the relationship between the dilatancy of the solution and the difficulty of rounding the droplets. The viscosity shown in Table 2 is the viscosity at the nozzle 609 where the shear rate increases, and the viscosity at other than the nozzle 609 is 3 [cP].

Table 3 shows the relationship between the surface tension of the solution and the difficulty of rounding the droplets.

Table 4 shows the relationship between the length of the droplet and the difficulty of rounding the droplet.

  As shown in FIG. 14B, the droplets ejected in a columnar shape from the nozzles 609 of the inkjet head 604 are caused to land on the substrate 601 while maintaining the substantially columnar shape by relatively moving the inkjet head 604 in the main scanning direction. . By landing the droplet while maintaining a substantially columnar shape, the height of the droplet immediately after landing can be made smaller than when landing a droplet of the same volume in a spherical shape, and the time required to fully spread out is reduced. Thus, the application time can be shortened.

  In order to land droplets while maintaining a substantially columnar shape, it is desirable that the distance between the nozzle 609 and the base material 601 of the inkjet head 604 is short. For example, the droplet volume V is preferably 30 pl and 1.5 mm or less. Further, it is desirable that the contact angle between the substrate 601 and the solution be as small as possible.

Further, in landing the droplet while maintaining a substantially columnar shape, the droplet volume is V, the droplet length is l, the droplet discharge speed is V _d , and the relative moving speed of the inkjet head 604 with respect to the substrate 601. Is V _k , and the contact angle between the droplet and the substrate 601 is θ, and it is preferable to satisfy the following formula (i).

  The left side in the above formula (i) indicates the length of the droplet in the main scanning direction immediately after landing. The right side in the above formula (i) indicates the diameter D of the droplet when the droplet spreads in a circular shape on the substrate. If the length of the droplet immediately after landing in the main scanning direction is larger than the diameter D of the droplet when it spreads in a circular shape, the droplet spreads without returning to a circular shape. Thereby, it is possible to shorten the time required until wetting and spreading to shorten the coating time.

In order to ensure that the droplets ejected and landed on the substrate 601 as described above are united with the droplets adjacent in the main scanning direction, the dot pitch P1 in the main scanning direction satisfies the following formula (ii). It is preferable to do.

Further, the dot pitch P2 in the sub-scanning direction satisfies the following formula (iii) in order to ensure that the droplets discharged and landed on the substrate 601 as described above are united with the droplets adjacent in the sub-scanning direction. It is preferable to do so.

The mathematical formula (iii) is derived as follows. As shown in FIG. 15, the area S < ^b > 1 in plan view when the liquid droplets have been spread out in a circular shape on the substrate is π · D 2/4. In addition, the liquid droplets landed while maintaining a substantially columnar shape have a substantially elliptical shape in a plan view with some rounding, and the area S2 in the plan view at this time is πb · lV _k / V _d · 1/4. It becomes. Here, LV _k / V _d is the length of the major axis and is the length in the main scanning direction. Further, b is the length of the short axis and is the length in the sub-scanning direction. When S1 = S2, b = D ² · V _d / lV _k is satisfied, but the droplet landed while maintaining a substantially columnar shape spreads wet on the substrate, and the length of the short axis is larger than the above b. . Therefore, by setting P2 ≦ b, that is, the above formula (iii), the droplets adjacent in the sub-scanning direction are surely united.

(Operation principle of TFT radiation detector)
Next, the operation principle of the above-described TFT radiation detector 400 will be described. When the photoconductive layer 404 is irradiated with X-rays, charges (electron-hole pairs) are generated in the photoconductive layer 404. In a state where a voltage is applied between the bias electrode 401 and the Cs electrode 418, that is, in a state where a voltage is applied to the photoconductive layer 404 via the bias electrode 401 and the Cs electrode 418, charge accumulation with the photoconductive layer 404 is performed. Since the capacitor 407c is electrically connected in series, the electrons generated in the photoconductive layer 404 move to the + electrode side and the holes move to the − electrode side. As a result, the charge storage capacitor Charge is accumulated in 407c.

  The charge stored in the charge storage capacitor 407c can be extracted to the outside from the source electrode 410 via the extraction electrode 470 by turning on the switch element 407b by an input signal to the gate electrode 411. Since the electrode wiring composed of the gate electrode 411 and the source electrode 410, the switch element 407b, and the charge storage capacitor 407c are all provided in a matrix, signals input to the gate electrode 411 are sequentially scanned to obtain the source electrode 410. By detecting the signal from each source electrode 410, X-ray image information can be obtained two-dimensionally.

  In Example 1, an electron injection blocking layer 406 made of antimony sulfide having a thickness of 2 μm is formed on the active matrix substrate 450. Next, a Se raw material containing 3% As was formed into a film by vapor deposition to form a crystallization preventing layer 405 having a thickness of 0.15 μm. Subsequently, a Se raw material containing 10 ppm of Na was deposited by vapor deposition to form a photoconductive layer 404 made of amorphous Se having a thickness of 1000 μm.

  Next, a discharge liquid containing at least one kind of hole blocking material selected from carbon clusters or derivatives thereof and containing at least one kind of aromatic solvent represented by the general formulas (1) and (2) is used. Then, a hole injection blocking layer 402 as an organic polymer layer was formed.

（一般式（１）（２）中、Ｒ_1-8は、水素、ハロゲン、またはアルキル基のいずれかを表す。）

(In general formulas (1) and (2), R _1-8 represents hydrogen, halogen, or an alkyl group.)

  In this example, fullerene C60 was used as the carbon cluster. Fullerene C60 used frontier carbon, Inc. property, nanom purple (C60).

  In this example, o-dichlorobenzene as the aromatic solvent was added to 1.05 wt% polycarbonate resin (PCz) (Iupilon PCz-400 manufactured by Mitsubishi Gas Chemical Co., Ltd.), and 30 wt% relative to PCz. % Fullerene C60 was dissolved to prepare a discharge liquid.

The discharged liquid shows dilatancy. Dilatancy refers to the property of a liquid whose viscosity increases with increasing shear rate. The relationship between the shear rate of the discharged liquid and the shear viscosity was measured with a rheometer. The measurement was performed twice in the range of the shear rate of 10 to 1000 [s ⁻¹ ], and the average value is shown in FIG. Since the shear viscosity increases with increasing shear rate, it can be said to be dilatancy.

The exponential approximation in the graph of FIG. 5 is y = 2.331e ^1E-05x . The shear rate applied to the ejected liquid during ejection from the inkjet head is generally said to be about 10 ⁵ [s ⁻¹ ], and the shear viscosity at that time is expected to be 6.07 [mPa · s]. On the other hand, since the shear rate after landing is considered to be 0 [s ⁻¹ ], the shear viscosity at that time is expected to be 2.23 [mPa · s]. Since the viscosity decreases after landing, the liquid easily spreads and is clearly suitable for forming a uniform film.

  In addition, the discharge liquid has a contact angle with the photoconductive layer 404 of 45 ° or less. In this example, a discharge liquid having a contact angle with the photoconductive layer 404 of 5 ° was used.

  The ejected liquid was filled in an inkjet head SE-128 manufactured by FUJIFILM Dimatix, and ejected over a range wider than the image information acquisition region G and not on the extraction electrode 470. The solvent was evaporated with a vacuum dryer to obtain a hole injection blocking layer 402 having a thickness of 0.2 μm. Finally, a bias electrode 401 having a thickness of 0.1 μm was formed by depositing Au by vapor deposition inside the hole injection blocking layer 402 end.

  In the configuration of this example, the outer edge portion of the hole injection blocking layer 402 is located on the 1 mm image information acquisition region G side from the extraction electrode 470, and the region end G1 of the image information acquisition region G from which image information is acquired. And the extraction electrode 470.

  Thereby, the hole injection blocking layer 402 covers the image information acquisition region G of the photoconductive layer 404, and deterioration such as crystallization in the image information acquisition region G of the photoconductive layer 404 can be suppressed. As a result, durability is improved. In addition, since the hole injection blocking layer 402 does not cover the extraction electrode 470, poor conduction of the extraction electrode 470 can be prevented.

  In Example 2, the outer edge portion of the hole injection blocking layer 402 is located 1 mm inside from the end of the bias electrode 401, outside the image information acquisition region G, and in the flat portion average film thickness of the photoconductive layer 404. It is comprised so that it may be located in the area | region which has a film thickness of 10% or more.

  According to the structure of this example, the hole injection blocking layer 402 having charge selectivity has a region having a film thickness of less than 10% of the average thickness of the flat portion of the photoconductive layer 404, that is, a region having a small film thickness. Since it is not covered, creeping discharge that occurs along the hole injection blocking layer 402 hardly occurs.

  In Example 3, the outer edge portion of the hole injection blocking layer 402 is located at a location of 50% of the average thickness of the flat portion of the photoconductive layer 404, outside the bias electrode 401, It is comprised so that it may be located in the area | region which has a film thickness of 10% or more of a flat part average film thickness.

  According to the configuration of this embodiment, since the hole injection blocking layer 402 covers the end portion of the bias electrode 401, discharge breakdown due to electric field concentration on the end portion of the bias electrode 401 can be suppressed.

  In Example 4, the outer edge of the hole injection blocking layer 402 is located 2 mm outside the end of the bias electrode 401, outside the bias electrode 401, and the slope of the end slope of the photoconductive layer 404 is 50%. It is configured to be located in the following area.

  According to the configuration of this example, the hole injection blocking layer 402 is formed in a region where the slope of the end slope of the photoconductive layer 404 is 50% or less, so that the hole injection blocking layer 402 is in a liquid state. Even when it is made of a material, no dripping occurs. If a liquid puddle due to dripping occurs, crystallization of C60 occurs and creeping discharge is liable to occur. However, in this embodiment, dripping does not occur, so creeping discharge can be suppressed.

  Note that the hole injection blocking layer 402 may have a two-layer structure, and antimony sulfide having a thickness of 0.6 μm may be stacked on an organic polymer layer containing fullerene. With this configuration, the hole blocking property can be improved.

(Configuration of optical reading radiation detector)
The present invention can also be applied to an optical reading type radiation detector, and is applied according to the configuration of the hole injection blocking layer 402 in the radiation detector 400 described above. Here, a radiation detection substrate 500 as an optical reading type radiation detector will be described.

  6A and 6B are schematic views of the radiation detection substrate 500. FIG. As shown in FIGS. 6A and 6B, the radiation detection substrate 500 is connected with a TCP 510, a readout device 512 connected thereto, and a high voltage line 514 for applying a high voltage.

  A TCP (Tape Carrier Package) 510 is a flexible wiring board on which a signal detection IC (charge amplifier IC) 511 is mounted. The TCP 510 is connected by thermocompression bonding using an ACF (Anisotropic Conductive Film anisotropic conductive film).

  An extended electrode portion 519 extending from the upper electrode 518 above the detection area 516 is formed, and a high voltage line 514 is connected to the extended electrode portion 519. The detection area 516 for detecting radiation includes a lower electrode 520 for reading signals and applying a high voltage, a radiation detection layer 522 for converting radiation into electric charges, and an upper electrode 518 for applying a high voltage.

  The lower electrode 520 is provided on the glass substrate 536, and the radiation detection lower substrate 524 is configured by the glass substrate 536 provided with the lower electrode 520.

  The production of the radiation detection substrate 500 is roughly divided into the production of a radiation detection lower substrate 524 including the lower electrode 520, the formation of the radiation detection layer 522 and the upper electrode 518, and the connection of the high voltage line 514.

  Hereinafter, the structure of the radiation detection lower substrate 524 will be described. FIG. 7 shows a schematic structure of the radiation detection lower substrate 524. In FIG. 7, TCP 510 is simplified to one channel on the left and one on the left and three channels each for a total of 6 channels. As shown in FIG. 7, the radiation detection lower substrate 524 includes a radiation detection unit 526, a pitch conversion unit 528, and a TCP connection unit 530 as an extraction electrode.

  In the radiation detection unit 526, lower electrodes 520 for extracting signals are arranged in a stripe shape (line shape). In addition, a color filter layer 534 that partially transmits only light of an arbitrary wavelength is formed under the transparent organic insulating layer 532.

  The layers above the color filter layer 534 are referred to as a common B line 520B and a signal S line 520S in a portion without the color filter layer 534. The B line 520B is shared outside the radiation detection unit and has a comb electrode structure. The S line 520S is used as a signal line. The width of the B line 520B is, for example, 20 μm, the width of the S line 520S is, for example, 10 μm, and the interval between the B line 520B and the S line 520S is, for example, 10 μm.

  The width of the color filter layer 534 is, for example, 30 μm. The lower electrode 520 needs to be transparent in order to irradiate light from the back surface, and to be flat in order 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 about 0.2 μm and the flatness is about Ra = 1 nm.

  The color filter layer 534 is a photosensitive resist in which a pigment is dispersed, for example, a red resist used for a color filter of an LCD. In order to eliminate the step of the color filter layer 534, a photosensitive organic transparent insulating layer 532, for example, PMMA is used.

  Further, the glass substrate 536 serving as a support member is preferably transparent and rigid, and more preferably soda lime glass. As an example of the thickness of each layer, the lower electrode 520 is 0.2 μm, the color filter layer 534 is 1.2 μm, the organic transparent insulating layer 532 is 1.8 μm, and the glass substrate 536 is 1.8 mm. The color filter layer 534 and the organic insulating layer 532 are provided only in the radiation detection unit 526, and the boundary is in the radiation detection unit 526 and the pitch conversion unit 528. For this reason, the IZO wiring is formed on the glass substrate 536 in the TCP connection portion 530 through the boundary step portion of the organic insulating layer 532.

  In the radiation detection unit 526, wirings are taken out to the left and right TCPs 510 in units of a certain number. In FIG. 7, it is a unit of 3 lines. An example of the number of lines is 256 lines. The line width in the radiation detection unit 526 is different from the line width in the TCP connection unit 530 and is adjusted, and the line width is adjusted in the pitch conversion unit 528 in order to route the wiring to a predetermined TCP connection position. The B line 520B is made common and similarly drawn out to the TCP connection unit 530.

  In the TCP connection unit 530, a signal S line 520S and a common B line 520B common to the outside of the radiation detection unit are arranged. The common B line 520B is disposed outside the signal S line 520S. As an example of the number, the signal line 256 and the common line are connected to the TCP using five lines above and below. The electrode line / space is 40/40 μm.

  In addition, an alignment mark for TCP is necessary to connect TCP with this TCP connection unit 530. Although it is desirable to form it with a transparent electrode, it is difficult to recognize because it is transparent, and an alignment material is formed using, for example, a color filter layer 534 that is a constituent member of this substrate as an opaque material.

  Next, the radiation detection layer 522 will be described. FIG. 8 is a schematic view schematically showing the configuration of the radiation detection substrate 500. As shown in FIG. 8, the radiation detection layer includes a recording photoconductive layer 542, a charge storage layer 544, a reading photoconductive layer 546, an electrode interface layer 548, an undercoat layer 550, and an overcoat layer 552. ing.

<Photoconductive layer for recording>
The recording photoconductive layer 542 is a photoconductive material that absorbs electromagnetic waves and generates charges, and is an amorphous selenium compound, Bi ₁₂ MO ₂₀ (M: Ti, Si, Ge), Bi ₄ M ₃ O ₁₂ (M: Ti). , Si, Ge), Bi ₂ O ₃ , BiMO ₄ (M: Nb, Ta, V), Bi ₂ WO ₆ , Bi ₂₄ B ₂ O ₃₉ , ZnO, ZnS, ZnSe, ZnTe, MNbO ₃ (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, an alkali metal such as Li, Na, K, Cs, and Rb doped in a small amount between 0.001 ppm and 1 ppm in the layer, LiF, NaF, KF, CsF, RbF A small amount of fluoride such as 10 ppm to 10000 ppm, P, As, Sb, and Ge added between 50 ppm and 0.5%, and As doped from 10 ppm to 0.5% And those doped with a slight amount of Cl, Br, and I 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 an alkali metal of about 0.001 ppm to 1 ppm are contained. Amorphous selenium is preferably used.

Also, Bi1 ₂ MO ₂₀ (M: Ti, Si, Ge), Bi ₄ M ₃ O ₁₂ (M: Ti, Si, Ge), Bi ₂ O ₃ , BiMO ₄ (M: Nb, Ta, V), Bi ₂ WO ₆ , Bi ₂₄ B ₂ O ₃₉ , ZnO, ZnS, ZnSe, ZnTe, MNbO ₃ (M: Li, Na, K), PbO, HgI ₂ , PbI ₂ , CdS, CdSe, CdTe , BiI ₃ , GaAs and other photoconductive substance fine particles can also be used.

  The thickness of the recording photoconductive layer 542 is preferably 100 μm or more and 2000 μm or less in the case of amorphous selenium. In particular, it is particularly preferably in the range of 150 μm to 250 μm for mammography and in the range of 500 μm to 1200 μm for general imaging applications.

<Charge storage layer>
The charge storage layer 544 may be any film that is insulative with respect to the polar charge to be stored, such as an acrylic organic resin, polyimide, BCB, PVA, acrylic, polyethylene, polycarbonate, polyetherimide, or a polymer such as As ₂ S. ₃ , sulfides such as Sb ₂ S ₃ and ZnS, oxides and fluorides. Furthermore, it is more preferable that it is insulative with respect to the charge of the polarity to be accumulated and that it is conductive with respect to the charge of the opposite polarity, and the product of mobility × life is 3 digits or more depending on the polarity of the charge. Substances with differences are preferred.

Preferred compounds include As ₂ Se ₃ , As ₂ Se ₃ doped with Cl, Br, and I from 500 ppm to 20000 ppm, and As ₂ Se ₃ with Se ₂ substituted to about 50% _by Te. _1-x ) ₃ (0.5 <x <1), As ₂ Se ₃ with Se replaced by S to about 50%, As _x Se with As concentration changed by about ± 15% from As ₂ Se ₃ Examples include _y (x + y = 100, 34 ≦ x ≦ 46), an amorphous Se—Te system containing 5-30 wt% Te.

  In the case of using such a substance containing a chalcogenide element, the thickness of the charge storage layer 544 is preferably 0.4 μm or more and 3.0 μm or less, and more preferably 0.5 μm or more and 2 μm or less. Such a charge storage layer 544 may be formed by a single film formation or may be laminated in a plurality of times.

  As a preferable charge storage layer 544 using an organic film, a compound in which a charge transport agent is doped with respect to a polymer such as acrylic organic resin, polyimide, BCB, PVA, acrylic, polyethylene, polycarbonate, and polyetherimide is preferably used. . Preferred charge transfer agents include tris (8-quinolinolato) aluminum (Alq3), N, N-diphenyl-N, N-di (m-tolyl) benzidine (TPD), polyparaphenylene vinylene (PPV), polyalkylthiophene. , Polyvinylcarbazole (PVK), triphenylene (TNF), metal phthalocyanine, 4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran (DCM), liquid crystal molecule, hexapentyloxytriphenylene And a molecule selected from the group consisting of a discotic liquid crystal molecule having a central core containing a π-conjugated condensed ring or a transition metal, a carbon nanotube, and fullerene. The doping amount is 0.1 to 50 wt. Set between%.

<Reading photoconductive layer>
The photoconductive layer for reading 546 is a photoconductive material that absorbs electromagnetic waves, particularly visible light, and generates electric charge. The energy gap of amorphous selenium compound, amorphous Si: H, crystalline Si, GaAs, etc. is 0.7-2. A semiconductor material included in the range of 5 eV can be used. In particular, amorphous selenium is preferable.

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

  The thickness of the photoconductive layer for reading 546 is preferably about 1 μm to 30 μm, as long as it can sufficiently absorb the reading light and can drift the electric charge generated by the electric field accumulated in the charge accumulation layer 544.

<Electrode interface layer>
The electrode interface layer 548 is laid between the recording photoconductive layer 542 and the upper electrode 518 or between the reading photoconductive layer 546 and the lower electrode 520. For the purpose of preventing crystallization, amorphous selenium added with As in the range of i% -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 order to prevent charge injection from the electrode layer, in addition to the above-mentioned additive elements, in particular, in order to prevent hole injection, alkali metals such as Li, Na, K, Rb, Cs, LiF, NaF, KF It is also preferable to dope molecules such as RbF, CsF, LiCl, NaCl, KCl, RbF, CsF, CsCl, and 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 In ₂ O _{3 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 electrode interface layer 548, the reading photoconductive layer 546, the charge storage layer 544, and the recording photoconductive layer 542 have a substrate temperature of 25 ° C. or higher in a vacuum chamber having a degree of vacuum of 10 ⁻³ to 10 ⁻⁷ Torr. The boat or crucible containing each of the above alloys is kept at a temperature of 70 ° C. or lower, and the temperature is raised by resistance heating or electron beam to evaporate or sublimate the alloy or compound, and the layers are laminated on the substrate.

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 is 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. By opening and closing the shutter, a layer in which 5000 ppm of LiF is doped into As10% -doped amorphous selenium can be formed.

<Underlayer>
An undercoat layer 550 can be provided between the reading photoconductive layer 546 and the lower electrode (charge collecting electrode) 520. When there is an electrode interface layer (crystallization prevention layer (A layer)) 548, it is preferably provided between the electrode interface layer 548 and the lower electrode 520. The undercoat layer 550 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 518 and a hole blocking property when a negative bias is applied.

The resistivity of the undercoat layer is preferably 108 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 Sb ₂ S ₃ , SbTe, ZnTe, CdTe, SbS, AsSe, As ₂ S ₃ 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, CeO ₂ , or the like, or an organic polymer layer is preferable. As the organic polymer layer, a film in which an insulating polymer such as polycarbonate, polystyrene, polyimide, or polycycloolefin is mixed with a carbon cluster such as C60 (fullerene) or C70 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.

<Upper layer>
An overcoat layer 552 can be provided between the recording photoconductive layer 542 and the upper electrode (voltage application electrode) 518. When there is an electrode interface layer (crystallization prevention layer (C layer)) 548, it is preferably provided between the electrode interface layer 548 and the upper electrode 518. The overcoat layer 552 preferably has rectification characteristics 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 518, and an electron blocking property when a negative bias is applied. The resistivity of this overcoat layer is preferably 108 Ωcm or more, and the film thickness is preferably 0.01 μm to 10 μm.

  As the layer having electron blocking properties, that is, the electron injection blocking layer, 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 the layer having a hole blocking property, that is, a hole injection blocking layer, an organic polymer layer is preferable. As the organic polymer layer, a film obtained by mixing a hole blocking material with an insulating polymer such as polycarbonate, polystyrene, polyimide, polycycloolefin, or the like can be preferably used.

  At least one of the hole blocking materials contained in the hole injection blocking layer is preferably at least one selected from carbon clusters or derivatives thereof. Further, the carbon cluster is preferably at least one selected from fullerene C60, fullerene C70, oxidized fullerene or a derivative thereof.

  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.

  Next, the upper electrode 518 and the surface protective layer 554 formed on the surface of the upper electrode 518 will be described.

<Upper electrode>
A metal thin film is preferably used as the upper electrode 518 formed on the upper surface of the recording photoconductive layer 542. Materials include Au, Ni, Cr, Au, Pt, Ti, Al, Cu, Pd, Ag, Mg, MgAg 3-20% alloy, Mg-Ag intermetallic compound, MgCu 3-20% 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, and 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, the shutter is opened after the metal lump is melted in the boat by the resistance heating method, vapor deposition is performed for 15 seconds, and cooling is performed. It is formed by repeating a plurality of times until the resistance value becomes sufficiently low.

<Surface protective layer>
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 518. If the upper electrode 518 is open to the atmosphere, creeping discharge will occur, and there is a risk that the subject will get an electric shock. In order to prevent creeping discharge in the upper electrode 518, a surface protective layer 554 is formed on the upper surface of the electrode and an insulation treatment is performed.

  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, high dielectric breakdown strength and high 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 polyparaxylylene 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, it is preferable to perform a moisture-proof treatment to prevent the radiation detection device from aging. Specifically, the structure is covered with a moisture-proof member. As the moisture-proof member, a resin alone such as the insulating polymer is insufficient in function, and a configuration having 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. The X-ray attenuation of this film is about 1%, which is optimal as a member that achieves both a moisture-proof effect and X-ray transmission.

  For example, as shown in FIG. 9, the entire surface of the radiation detection device subjected to insulation treatment with polyparaxylylene 554A is covered with a moisture-proof film 554B, and the periphery of the moisture-proof film 554B is bonded and fixed to the substrate with an adhesive outside the radiation detection device region. To do. Thus, the radiation detection device is sealed with the substrate and the moisture-proof film 554B.

  At the time of this adhesive fixing, polyparaxylylene 554A is chemically very stable, and thus generally has poor adhesion to other members by an adhesive, but light irradiation treatment with ultraviolet light prior to adhesion is performed. The adhesion can be improved by applying. 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 according to the present embodiment uses amorphous selenium, and amorphous selenium may crystallize at a high temperature of 40 ° C. or higher, so that a latent image forming function may not be obtained. Processing is not suitable. 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 554B. The adhesive portion is pressed and fixed uniformly from the upper surface of the moisture-proof film 554B, 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 with 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.

  Although an example of a preferable protective layer / sealing structure is shown in FIG. 9, it is not limited to this. It is preferable to maintain the humidity environment of the device at 30% or less, more preferably 10% or less by forming the protective film.

<Charge extraction amplifier>
In the present embodiment, the electric charge is amplified through an amplifier and then AD converted. FIG. 10 is a block diagram showing the configuration of the charge extraction amplifier and the connection mode between these and the image processing device 150 arranged outside the radiation detection substrate 500.

  The charge amplifier IC 511 serving as a charge extraction amplifier is a multiplexer that multiplexes a number of charge amplifiers 33a and sample hold (S / H) 33b connected to each element 15a of the radiation detection substrate 500, and a signal from each sample hold 33b. 33c.

  The current flowing out from the lower electrode 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 sampled and held element 15a is switched in the arrangement order of the elements 15a. Are sequentially output from the multiplexer 33c (corresponding to a part of main scanning).

  The signal sequentially output from the multiplexer 33c is input to the multiplexer 31c provided on the printed circuit board 31, and 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, thereby completing the main scanning. 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 an external image processing apparatus 150 via a signal cable, and appropriate image processing is performed in the image processing apparatus 150, and the image signal is uploaded to the network 151 together with shooting information. Or it is sent to a printer.

<Image acquisition sequence>
The image forming sequence of this image recording / reading system basically includes the process of irradiating recording light (for example, X-rays) while applying a high voltage and accumulating latent image charges, and irradiating the reading light after completing the application of high voltage. Then, it consists of a process of reading out the latent image charge. As the reading light L, a method of scanning the line light source 301 in the electrode direction (see FIG. 11) is optimal, but other methods are also possible.

  Furthermore, a process of sufficiently erasing the unread latent image charges can be combined as necessary. 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.

  Furthermore, it is known that various charges are accumulated on the electrostatic recording medium before irradiation of recording light 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 recording light and then reading an “afterimage image” 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.

  In the radiation detection substrate 500 as an optical reading type radiation detector, the upper electrode 518 corresponds to the first electrode of the present invention, and the radiation detection layer 522 having the recording photoconductive layer 542 is the photoconductive layer according to the present invention. The lower electrode 520 corresponds to the second electrode according to the present invention, the TCP connection portion 530 corresponds to the extraction electrode of the present invention, and the overcoat layer 552 corresponds to the organic polymer layer of the present invention.

  In the optical reading type radiation detection substrate 500, the overcoat layer 552 can be configured as follows, similarly to the radiation detector 400 described above.

  The overcoating layer 552 as the organic polymer layer has an outer edge portion, that is, a peripheral edge serving as a boundary with another layer is located at a predetermined position, so that the overcoating layer 552 is formed in a predetermined range. It is the structure which covers.

  In the present embodiment, the outer edge portion of the overcoat layer 552 is the region edge G1 of the image information acquisition region G from which the image information is acquired and the TCP connection unit 530 among the regions irradiated with the radiation carrying the image information. It is comprised so that it may be located between. A range indicated by an arrow A in FIG. 12A is a range between the region end G1 of the image information acquisition region G and the TCP connection unit 530.

  Preferably, the outer edge portion of the overcoat layer 552 according to the present embodiment is outside the image information acquisition region G and has a thickness of 10% or more of the average thickness of the flat portion of the radiation detection layer 522. Configured to be located within. The flat part average film thickness of the radiation detection layer 522 is obtained by measuring the film thickness of any nine points in the image information acquisition region G of the radiation detection layer 522 and averaging the film thicknesses of the nine points. The film thickness was measured by observing the cross section with a microscope at a magnification of 100 times.

  Note that the range indicated by the arrow B in FIG. 12A is the range outside the image information acquisition region G and within the region having a thickness of 10% or more of the average thickness of the flat portion of the radiation detection layer 522. is there.

  More preferably, the outer edge portion of the overcoat layer 552 according to the present embodiment is located outside the upper electrode 518 and in a region having a thickness of 10% or more of the average thickness of the flat portion of the radiation detection layer 522. Configured to do.

  Note that a range indicated by an arrow C in FIG. 12A is a range outside the upper electrode 518 and in a region having a thickness of 10% or more of the average thickness of the flat portion of the radiation detection layer 522.

  More preferably, the outer edge portion of the upper coating layer 552 is configured to be located outside the upper electrode 518 and in a region where the slope of the end slope of the radiation detection layer 522 is 50% or less.

  The outer edge portion of the overcoat layer 552 is an end slope where the gradient gradually increases from the flat portion of the radiation detection layer 522 toward the outer edge, and the gradient is less than 50%, that is, the gradient is greater than 50%. Is in a moderate range. A gradient of 50% means that, as shown in FIG. 12B, in a right triangle composed of a side along the film thickness direction of the radiation detection layer 522, a side perpendicular to the side, and a hypotenuse, This is a slope formed by the hypotenuse when the length of the side along the film thickness direction of the detection layer 522 is 1 and the length of the side perpendicular to the side is 2. The gradient was measured by microscopic observation of the cross section at a magnification of 100 times.

  Note that the range indicated by the arrow D in FIG. 12A is the range outside the upper electrode 518 and in the region where the slope of the end slope of the radiation detection layer 522 is 50% or less.

  Note that the radiation detection layer 522 is formed in a wider area than the upper electrode 518. Further, the lower electrode 520 is formed in a region wider than the image information acquisition region G.

  The overcoat layer 552 as an organic polymer layer is formed by laminating a radiation detection lower substrate 524, an undercoat layer 550, a reading photoconductive layer 546, a charge storage layer 544, and a recording photoconductive layer 542. A base material is formed on the surface of the recording photoconductive layer 542. When the electrode interface layer 548 is formed between the recording photoconductive layer 546 and the overcoat layer 552 for the purpose of preventing crystallization, the overcoat layer 552 is connected to the recording photoconductive layer 542 with an electrode. A layer on which the interface layer 548 is laminated is used as a base material, and is formed on the surface of the electrode interface layer 548. Since the apparatus and method for forming the overcoat layer 552 are the same as those of the hole injection blocking layer 402 of the radiation detector 400 described above, description thereof is omitted.

  The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made.

It is the schematic which shows the whole structure of the radiation detector of a TFT system. It is a schematic block diagram which shows the principal part of a TFT type radiation detector. 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. 5 is a graph showing the relationship between the shear rate and the shear viscosity of a discharge liquid used for forming a hole injection blocking layer in a TFT radiation detector. It is a figure which shows schematic structure of the radiation detection board | substrate as a radiation detector of an optical reading system. It is a figure which shows schematic structure of the lower board | substrate for a radiation detection of the radiation detection board | substrate shown in FIG. It is the schematic which showed typically the structure of the radiation detection board | substrate shown in FIG. It is a figure which shows the sealing structure which seals the upper electrode of the radiation detection board | substrate shown in FIG. FIG. 3 is a block diagram showing a configuration of a charge extraction amplifier and a connection mode between the charge extraction amplifier and an image processing apparatus disposed outside the radiation detection substrate. It is the schematic which shows a mode when line light is scanned as reading light. FIG. 7 is a diagram showing an example in which the configuration of the hole injection blocking layer in the TFT radiation detector shown in FIG. 1 is applied to the radiation detection substrate shown in FIG. 6. It is a figure which shows schematic structure of a coating device. It is a figure explaining application | coating of the solution to the base-material surface by the coating device of FIG. It is a figure which shows the shape of a droplet.

Explanation of symbols

400 Radiation detector 401 Bias electrode (first electrode)
402 Hole injection blocking layer (organic polymer layer)
404 Photoconductive layer 407a Charge collection electrode (second electrode)
470 Extraction electrode 500 Radiation detection substrate (radiation detector)
518 Upper electrode (first electrode)
522 Radiation detection layer (photoconductive layer)
520 Lower electrode (second electrode)
530 TCP connection (extraction electrode)
552 Overcoat layer (organic polymer layer)
600 Coating device 601 Base material 602 Coating chamber 604 Inkjet head 607 Holding stand moving mechanism (moving means)
608 Head moving mechanism (moving means)
609 nozzle

Claims (2)

An application method for applying a solution to a substrate surface by inkjet,
Ejected from the inkjet head droplets in a columnar shape is relatively moved in the main scanning direction an inkjet head relative to the substrate, the droplet while maintaining the columnar landed on the substrate, and prior to the substrate A method of coating, wherein the droplets are discharged so that the droplets that have landed on the surface of the droplets are wet and spread together. A first electrode through which radiation carrying image information is transmitted;
A photoconductive layer that generates a charge when irradiated with the radiation transmitted through the first electrode;
A second electrode that is provided on a side opposite to the side on which the first electrode is provided with respect to the photoconductive layer, and collects charges generated by the photoconductive layer;
An organic polymer layer provided between the photoconductive layer and the first electrode;
A method of manufacturing a radiation detector comprising:
The solution containing the film component of the organic polymer layer is applied to the surface of the base material on which at least the second electrode and the photoconductive layer are laminated by the coating method according to claim 1, and the organic polymer layer is applied. A manufacturing method of a radiation detector characterized by forming.

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