JP2022092707A - Method for manufacturing radiation detector - Google Patents

Abstract

To provide a method for manufacturing a radiation detector that can stably manufacture a flexible matrix panel with an area sensor on a flexible insulating layer, while reducing the cost.SOLUTION: A flexible insulting layer is provided on a first substrate, and has a pixel array and a wiring material electrically connected to an electric circuit which takes out an electric signal from the pixel array. A roller is connected to the insulating layer so that the insulating layer is rotated, whereby the insulating layer is separated from the first substrate. Further, the roller is rotated in a direction reverse to the direction during the separation so that a second substrate is attached to the flexible insulating layer.SELECTED DRAWING: Figure 6

Description

The present invention relates to a method for manufacturing a radiation detection device.

The manufacturing technique of a matrix panel for a display device such as a liquid crystal display using a thin film transistor (TFT) has been improved, and the size of the panel has been increased and the screen of the display unit has been increased. This manufacturing technique is applied to a matrix panel as a large area area sensor having a photoelectric conversion element composed of a switch element such as a TFT and a semiconductor.

This matrix panel is used in the field of radiation detection devices such as medical X-ray imaging devices in combination with a scintillator that converts radiation such as X-rays into light such as visible light. This matrix panel was generally formed on a glass substrate, but in recent years, the development of flexible matrix panels using resin substrates and the like has progressed, and the weight of the device has been reduced and high reliability to withstand impact and deformation. It is also being used for radiation detectors because it can be expected to have sex.

As a method for forming a flexible matrix panel, it is common to place a resin material or the like in a thin film on a rigid substrate such as a glass substrate and form an area sensor on the thin film. Such a flexible matrix panel is used by being peeled off from an unnecessary glass substrate as in Patent Document 1, for example.

In Patent Document 1, a matrix panel is prepared in which a flexible insulating layer made of a resin material such as polyimide is formed on a substrate such as glass, and a plurality of photoelectric conversion elements made of TFTs or semiconductors are formed on the flexible insulating layer. .. Then, Patent Document 1 shows a step of arranging a scintillator and a protective member for protecting the scintillator on a matrix panel and peeling the scintillator from a substrate such as glass in that state.

Japanese Unexamined Patent Publication No. 2009-133837

Although the peeling from the substrate in Patent Document 1 is performed by irradiation with a laser beam, the apparatus itself can be large and expensive in order to efficiently irradiate the matrix panel with the laser beam. Therefore, when manufacturing a flexible matrix panel, there is a problem in terms of manufacturing cost.

Therefore, an object of the present invention is to provide a method for manufacturing a radiation detection device capable of manufacturing a flexible matrix panel having an area sensor and a scintillator on a flexible insulating layer at a reduced cost. Is.

The above-mentioned problem is caused by the pixel array on a flexible insulating layer provided on a first surface in which a pixel array having a plurality of pixels, each having a photoelectric conversion element, is provided on a first surface. The connection step of connecting an electric circuit for extracting an electric signal to the outside and an electrically connected wiring member, and the flexibility of contacting the first substrate on a second surface facing the first surface. In order to peel off the property insulating layer from the first substrate, the flexible insulating layer is removed from the first substrate by rotating a roller connected to the first surface in the first rotation direction. It is a method of manufacturing a radiation detection device that performs a peeling step of peeling, and is separated from the first substrate by rotating the roller in a second rotation direction that is opposite to the first rotation direction. The problem is solved by a method for manufacturing a radiation detection device, which comprises a bonding step of bonding the second surface to a second substrate constituting the radiation detection device.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for manufacturing a radiation detection device capable of stably manufacturing a flexible matrix panel having an area sensor and a scintillator on a flexible insulating layer while reducing the cost thereof.

Schematic diagram of a radiographic imaging system using a flexible matrix panel according to the first embodiment of the present invention. Sectional drawing of the flexible matrix panel which concerns on 1st Embodiment of this invention Manufacturing flow of flexible matrix panel according to the first embodiment of the present invention Schematic diagram of the peeling and pasting unit according to the first embodiment of the present invention. Cross-sectional view of the flexible matrix panel according to the first embodiment of the present invention at the end of the peeling step from the first substrate. Cross-sectional view at the start of the process of bonding the second substrate to the flexible matrix panel according to the first embodiment of the present invention.

(First Embodiment)
Hereinafter, the present invention will be described through an exemplary embodiment with reference to the accompanying drawings. The following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiment, not all of the plurality of features are essential for the invention, and the plurality of features may be arbitrarily combined. Further, in the attached drawings, the same or similar configurations are given the same reference numbers, and duplicate explanations are omitted. Further, the term radiation may include, for example, X-rays, α-rays, β-rays, γ-rays, particle beams, and cosmic rays.

FIG. 1 is a schematic diagram of a radiation imaging system using a radiation detection device to which the matrix panel of the present invention is applied. The radiation detection device 12 and the radiation generator 13 are connected to the processing unit 14. Radiation is emitted from the radiation generator 13 according to the control by the processing unit 14, and the radiation detection device 12 detects the radiation transmitted through the subject. The radiation detection device 12 transmits information on the detected radiation as a signal to the processing unit 14, and the processing unit 14 performs desired arithmetic processing and generates a radiation image for diagnosis.

FIG. 2 is a schematic diagram of a radiation detection panel 100 incorporated in the radiation detection device 12. Hereinafter, the radiation detection panel 100 incorporated in the radiation detection device 12 will be described with reference to FIGS. 2 (a) to 2 (c). 2 (a) is a plan view of the radiation incident surface of the radiation detection panel 100, and FIGS. 2 (b) and 2 (c) show two patterns of different manufacturing methods between A and A'in FIG. 2 (a). It is a sectional view.

The matrix panel 110 is circuit-connected to a pixel array 112 in which a plurality of pixels having a photoelectric conversion element that converts incident radiation or light into an electric signal and a TFT that is a switch element are arranged on a flexible insulating layer 111. The unit 132 is arranged. In this embodiment, the switch element and the conversion element are an amorphous silicon thin film transistor (a-Si TFT) and a MIS type pixel, respectively. The switch element and the conversion element are not limited to the above combination, and known techniques such as a polysilicon TFT, an oxide TFT, and a PIN type pixel can be used.

The back surface of the surface of the flexible insulating layer 111 on which the matrix panel is formed is in contact with the first substrate 114. The first substrate 114 may be made of a material having high rigidity and capable of withstanding the formation temperature of the photoelectric conversion element or the TFT. Specifically, as the first substrate 114, an insulating substrate made of glass or ceramics is suitable.

As the flexible insulating layer 111, a material that can withstand the formation temperature of the photoelectric conversion element or the TFT and a material with high workability can be used. Specifically, as the flexible insulating layer 111, an organic insulating layer such as polyimide or polyamide is used.

The matrix panel 110 is formed by applying and curing a liquid flexible insulating layer 111 to the first substrate 114, or by crimping the sheet-shaped flexible insulating layer 111 to the first substrate 114. The flexible insulating layer 111 is formed on the first substrate 114 by the above method. At this time, an adhesive layer may be used between the first substrate 114 and the flexible insulating layer 111.

Next, the pixel array 112 and the circuit connection portion 132 are formed on the surface of the flexible insulating layer 111 facing the surface in contact with the substrate 114, that is, on the flexible insulating layer 111. The pixel array 112 is connected to a plurality of pixels (not shown), a drive line that is a wiring for controlling the TFT, a bias line that is a wiring for supplying a bias to the photoelectric conversion element, and one of the source and drain electrodes of the TFT. It is composed of signal lines and the like.

The sensor protection layer 113 is formed for the purpose of protecting the pixel array 112. The material of the sensor protection layer 113 is preferably a material that withstands heat when forming the scintillator 120 and improves the adhesion of the scintillator 120. Specifically, as the sensor protective layer 113, various resins such as urethane resin, acrylic resin, phenol resin, epoxy resin, unsaturated polyester resin, polyimide resin, silicone resin and diallyl phthalate resin are used.

The scintillator 120 refers to a member having a function of converting radiation such as X-rays into visible light. The scintillator 120 includes a scintillator layer 121, a protective layer adhesive layer 122, and a scintillator protective layer 123. As the scintillator layer 121, a mixture of scintillator particles such as gadolinium acid sulfide (GOS) with a binder, or cesium iodide (CsI) activated with thallium or sodium is suitable. In the scintillator layer 121 using GOS, a method of applying GOS on the pixel array 112 or a method of laminating sheets formed by using GOS is adopted.

In the scintillator layer 121 using CsI, a vapor deposition method under vacuum is generally used, and a plurality of columnar crystals having a diameter of about 1 to several tens of microns are grown on the pixel array 112 to a desired thickness. To form. As a feature of CsI, there are voids between the columns of the crystal, and due to the difference in the refractive index between the crystal and air, the light is repeatedly totally reflected in the crystal, and the effectively emitted light is transmitted to the photoelectric conversion element. Can be done. This makes it possible to obtain a high MTF (Modulation Transfer Function).

FIG. 2B is a cross-sectional view when the scintillator 120 is formed on the pixel array 112 by coating or vapor deposition. 2 (c) is a cross-sectional view of a scintillator layer 121 formed on a separately prepared scintillator base 124 and bonded onto the pixel array 112 via the scintillator adhesive layer 125.

In either method, in order to protect the scintillator layer 121, the scintillator protection layer 123 covering the scintillator layer 121 can be formed. The scintillator protective layer 123 includes metals such as aluminum, copper and stainless steel, resins such as polyparaxylylene, epoxy resin, acrylic resin and polyester resin, and composite materials composed of resin and ceramics such as alumina and titanium oxide. It can be used.

The radiation detection panel 100 is a laminated body including a matrix panel 110 and a scintillator 120. A wiring member 131 such as a flexible wiring board may be connected to the pixel array 112 of the radiation detection panel 100 via a circuit connection portion 132. Further, the radiation detection panel 100 may be provided with a second substrate 133 via a substrate adhesive layer 150 (not shown in FIG. 2).

The required functions of the second substrate 133 differ depending on the required characteristics of the radiation detection panel 100, and the rigidity of the flexible insulating layer 111 is improved, the moisture resistance is improved, the radiation detection panel 100 is shielded from light, and the resistance to external noise is improved. , And it is desirable to have a function of buffering vibration and external stress.

For example, the second substrate 133 is made of a material that absorbs a component of radiation that has passed through the flexible insulating layer 111. Further, it is desirable that the rigidity of the second substrate 133 is higher than the rigidity of the flexible insulating layer. Specifically, a material such as lead, tungsten, or iron is suitable for the second substrate 133. When the reflection of radiation from the rear of the second substrate 133 is small, the material of the second substrate 133 can be a resin having a light-shielding property, and the weight of the radiation detection device 12 can be reduced by using the resin. can.

FIG. 3 shows a manufacturing flow of a flexible matrix panel according to the first embodiment of the present invention.

In S201, the first substrate 114 is placed on the stage 160 in preparation for performing the subsequent steps.

In S202, the flexible insulating layer 111 is formed on the first substrate 114. The flexible insulating layer 111 may be formed by applying a material to the first substrate 114 and curing it, or by crimping the flexible insulating layer on a sheet.

In S203, a pixel array 112 in which a switch element and a conversion element are arranged in a two-dimensional matrix is formed on the flexible insulating layer 111.

In S204, a scintillator forming step of forming the scintillator 120 on the pixel array 112 is performed. As the scintillator layer 121, the above-mentioned GOS or cesium iodide (CsI) activated with thallium (Tl) or sodium (Na) is suitable.

In S205, a protective layer forming step of forming the scintillator protective layer 123 that protects the scintillator 120 together with the protective layer adhesive layer 122 is performed.

In S206, a connection step is performed in which an electric circuit for extracting an electric signal that has become image information in the pixel array 112 is connected to the circuit connection portion 132 by using a wiring member 131.

In S207, the peeling step of peeling the flexible insulating layer 111 from the first substrate 114 used for forming the flexible insulating layer 111, and subsequently the second substrate 133 is peeled off from the flexible insulating layer 111. The bonding process of bonding to is performed. The first substrate 114 and the flexible insulating layer 111 are peeled off, and the first substrate 114 is removed from the stage 160. After that, the second substrate 133 is set on the stage, and the peeled surface of the flexible insulating layer 111 is bonded onto the second substrate 133 via the substrate adhesive layer 150 by the method described later in the description of FIG.
By going through the steps of S201 to 207 as described above, the radiation detection device 12 can be manufactured.

Consider a case where the step of peeling the flexible insulating layer 111 from the first substrate 114 and the step of attaching the second substrate 133 to the flexible insulating layer 111 in S207 are separated from each other. In this case, the peeled flexible insulating layer 111 is placed on the transport table, the flexible insulating layer 111 is removed from the transfer table in the next step, and the flexible insulating layer 111 is attached to the second substrate 133. In this way, dedicated devices are required for the peeling step and the step of attaching to the second substrate 133, and the problem of device cost becomes an issue. Further, as the number of times the flexible insulating layer is conveyed increases, the frequency of troubles caused by the flexibility also increases.

Specifically, when the load from the electric circuit mounted in S206 is applied to the flexible insulating layer 111, the flexible insulating layer 111 is stretched, and the pixel array 112 and the pixel array 112 and the external circuit connection portion 132 are formed. There is a risk of damage to the wiring that connects the two. In view of the above, the present invention proposes a method in which two steps, a peeling step and a pasting step, are performed by one device. As a result, a manufacturing method with low equipment cost and less trouble is realized.

Next, the peeling and attachment of the support substrate in step 207, which are the features of the manufacturing method of the present invention, will be described in detail with reference to FIGS. 4 to 6.

FIG. 4 is a schematic diagram for explaining the peeling and pasting unit according to the present embodiment. Hereinafter, the peeling and pasting unit 140 will be described with reference to FIG. 4 (a) which is a perspective view and FIG. 4 (b) which is a side view.

As shown in FIGS. 4A and 4B, the peeling and pasting unit 140 includes a roller 141 and a clamp 142 for connecting the peeling object. The rotation direction of the roller 141 at the time of peeling is the A direction in the drawing, and by advancing in the B direction while rotating, the peeling object is peeled along the roller 141.

At this time, the roller 141 may not be moved in the B direction, and the stage 160 (not shown in FIG. 4) on which the peeling object is mounted may be moved in the direction opposite to the B direction. That is, the roller 141 may be moved in the B direction relative to the stage 160 on which the object to be peeled is mounted. Similarly, in the bonding step described later, the roller 141 may be moved or the stage 160 may be moved.

The method of connecting the object to be peeled off may be a method of providing a mechanism for sandwiching the clamp 142 and fixing the object, or a method of fixing the object to be peeled off so as to be sandwiched between the roller 141 and the clamp 142. Further, the object to be peeled off may be adhesively fixed to the roller 141 with an adhesive sheet or tape (not shown). Further, it is desirable that the clamp film 143, which is a fixing member, is installed at the end of the peeling object and the clamp film 143 is peeled off together with the peeling object, rather than being fixed to the peeling target unit 140 as it is.

The roller width of the roller 141 is preferably at least larger than the width of the scintillator 120 in order to prevent the scintillator 120 from being destroyed. Further, the movement of the roller 141 is set so that the wiring member 131 is not stepped on, so that the wiring member 131 can be prevented from being destroyed or electrically short-circuited. Other external sizes and surface hardness can be selected according to the size, height, and material of the work (object to be peeled off).

FIG. 5 is a cross-sectional view showing how the flexible insulating layer 111 has been peeled off from the first substrate 114. Since the first substrate 114 is unnecessary for the radiation detection device 12 of the present invention, it is removed from the stage 160 and discarded.

FIG. 6 is a cross-sectional view of a bonding step of bonding the second substrate to the flexible matrix panel according to the present embodiment. FIG. 6 shows the start state of the step of attaching the flexible insulating layer 111 to the second substrate 133 via the substrate adhesive layer 150.

On the stage 160 from which the first substrate 114 has been removed, the second substrate 133 having the substrate adhesive layer 150 arranged on the surface is arranged. The flexible insulating layer 111 is attached to the second substrate 133 by rotating the roller 141 in the direction of arrow A', which is the reverse rotation of the rotation of the roller 141, and advancing the roller 141 in the direction of B'. It is preferable that the peeling and pasting unit 140 is configured to be displaceable in the height direction (C direction in the drawing) of the rotation center of the roller 141 according to the thickness of the second substrate 133 at the time of bonding.

The work fixing tape 161 shown in FIG. 6 has one end fixed to the stage 160 and the other end fixed to the end of the flexible insulating layer 111, and the flexible insulating layer 111 is fixed to the second substrate. This is intended to prevent misalignment when bonding to 133.

In the peeling and supporting substrate pasting performed in S207 in the flow of the present embodiment, the portion where the scintillator 120 is formed has high rigidity, and a step is generated between the portion where the scintillator 120 is formed and the portion where the scintillator 120 is not formed. At this step, stress is likely to be applied to the flexible insulating layer 111 at the time of peeling. Therefore, if a cushioning material is arranged so as to eliminate the step and peeling and attaching the support substrate, damage to the flexible insulating layer 111 can be reduced.

According to the above embodiment, the flexible matrix panel is peeled off by using the rotation of the roller 141, and then bonded by using the same device by using the rotation opposite to that at the time of peeling. , Equipment cost can be reduced. Further, since the transfer between the devices is reduced, troubles such as disconnection due to the flexibility of the matrix panel can be reduced.

12 Radiation detection device 100 Radiation detection panel 110 Matrix panel 111 Flexible insulating layer 112 Pixel array 114 First board 120 Scintillator 133 Second board 141 Roller

Claims (8)

A pixel array having a plurality of pixels, each having a photoelectric conversion element, provided on a first substrate is provided on a flexible insulating layer provided on the first surface, and an electric signal obtained by the pixel array is sent to the outside. The connection process that connects the electrical circuit for taking out and the wiring member that is electrically connected,
In order to peel off the flexible insulating layer in contact with the first substrate on the second surface facing the first surface from the first substrate, a roller connected to the first surface is used. , A peeling step of peeling the flexible insulating layer from the first substrate by rotating in the first rotation direction.
It is a manufacturing method of a radiation detection device that performs
The second surface is formed on a second substrate constituting the radiation detection device different from the first substrate by rotating the roller in a second rotation direction which is opposite to the first rotation direction. A method for manufacturing a radiation detection device, which comprises performing a bonding process. The manufacturing method according to claim 1, further comprising a scintillator forming step of forming a scintillator that converts radiation into light on the pixel array. The manufacturing method according to claim 2, further comprising a protective layer forming step of forming a protective layer for protecting the scintillator on the scintillator. The manufacturing method according to any one of claims 1 to 3, wherein the roller is configured so that the position of the center of rotation can be displaced in the direction of the thickness of the flexible insulating layer. The manufacturing method according to any one of claims 1 to 4, wherein the rigidity of the second substrate is larger than the rigidity of the flexible insulating layer. The manufacturing method according to any one of claims 1 to 5, wherein the second substrate is a resin having a light-shielding property. The manufacturing method according to any one of claims 1 to 6, wherein the second substrate is a metal that absorbs radiation. The production method according to claim 7, wherein the metal that absorbs radiation contains any one of lead, tungsten, and iron.

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