JP2012013483A - Radioactive ray detector using gas amplification and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel pixel type radioactive ray detector having sufficiently high detection sensitivity and a manufacturing method for the same.SOLUTION: A radioactive ray detector comprises a first electrode pattern 212 formed on a first face of an insulating member 211 and having a plurality of circular openings 212A and a second electrode pattern 213 formed on a second face opposite the first face of the insulating member, penetrating the insulating member and having a protrusion 214 of which the tip is exposed substantially in the central part of the openings of the first electrode pattern and the end part is buried in the insulating member, wherein the first electrode pattern and the second electrode pattern have a prescribed difference in potential.

Description

  The present invention relates to a radiation detector using gas amplification by a pixel-type electrode and a method for manufacturing the same.

  Conventionally, a pixel type radiation detector has been used as a radiation detector utilizing gas amplification. In this radiation detector, for example, a strip-like cathode electrode is formed on the surface of a double-sided printed circuit board, an anode strip is formed on the back surface, and openings are formed at regular intervals in the strip-like cathode electrode. A cylindrical anode electrode connected to the anode strip on the back surface, that is, a pixel electrode is formed at the center of the part.

  The radiation detector is disposed, for example, in a mixed gas of Ar and ethane. A voltage of, for example, 600 V is applied between the pixel electrode and the strip-like cathode electrode.

  In the radiation detector, when predetermined radiation is incident on the detector, the gas is ionized to generate electrons, and the electrons are applied between the strip-like cathode electrode and the pixel electrode. Electron avalanche amplification is caused by a high voltage and a strong electric field generated due to the shape (shape anisotropy) of the pixel electrode as a point electrode. On the other hand, positive ions generated by electron avalanche amplification drift toward the surrounding strip-like cathode electrode.

  As a result, the strip-like cathode electrode and the pixel electrode are charged with holes and electrons, respectively. Then, by detecting the positions of the strip-like cathode electrode and the pixel electrode where the charges are generated, the incident position of the radiation on the detector can be specified, and the radiation can be detected (Patent Document 1). .

JP 2002-6047

  In the above-described radiation detector, when the voltage applied to the pixel electrode is increased, the intensity of the generated electric field also increases and the above-described electron avalanche amplification becomes significant. Therefore, the charges charged in the strip-like cathode electrode and the pixel electrode are increased. The amount is increased and the detection sensitivity of radiation is improved. On the other hand, when the voltage applied to the pixel electrode is increased, in particular, a continuous discharge occurs between the pixel electrode and the end of the strip-like cathode electrode exposed at the opening, and the electrodes are damaged. May arise.

  In addition, when a continuous discharge is generated between the pixel electrode and the strip-like cathode electrode, the pixel electrode and the strip-like cathode electrode are almost equipotential, so that the above-mentioned electron avalanche amplification does not occur, and this electron avalanche does not occur. There has been a problem that it becomes impossible to substantially detect radiation due to amplification, and it cannot function as a radiation detector.

  As described above, even if the voltage applied to the pixel electrode is increased for the purpose of improving the detection sensitivity of the radiation detector, as a result, continuous discharge or the like occurs, and the detection sensitivity of the radiation detector is increased. There may be a problem that the radiation detector cannot function.

  On the other hand, when the voltage applied to the pixel electrode is reduced, the above-described continuous discharge is reduced, but the degree of the above-mentioned electronic avalanche amplification is also reduced, and the radiation detection sensitivity is lowered.

  From such a point of view, instead of adjusting the magnitude of the voltage applied to the pixel electrode, attempts have been made to narrow the pixel electrode and improve the strength of the generated electric field. However, since the pixel electrode is formed by via fill plating in the through hole formed in the printed circuit board, it is necessary to narrow the through hole in order to narrow the pixel electrode.

  On the other hand, when the through hole is narrowed, the via fill plating cannot be performed uniformly in the through hole, and the uniform pixel electrode cannot be formed, and problems such as abnormal discharge and dielectric breakdown occur in the pixel electrode. Therefore, the narrowing of the pixel electrode is naturally limited depending on the manufacturing method.

  As a result, at present, the applied voltage to the pixel electrode cannot be sufficiently improved, and the pixel electrode cannot be sufficiently narrowed, and the detection sensitivity of the pixel-type radiation detector can be sufficiently improved. There was a problem that I could not.

  An object of the present invention is to provide a novel pixel-type radiation detector having sufficiently high detection sensitivity and a method for manufacturing the same.

In order to achieve the above object, the present invention provides:
A first electrode pattern formed on the first surface of the insulating member and having a plurality of circular openings;
It is formed on a second surface opposite to the first surface of the insulating member, penetrates the insulating member, and a tip is exposed at a substantially central portion of the opening of the first electrode pattern. A second electrode pattern having a projecting portion in which an end portion is embedded in the insulating member,
The present invention relates to a radiation detector, wherein the first electrode pattern and the second electrode pattern are set to have a predetermined potential difference.

The present invention also provides:
A first step of forming a first electrode layer on the first surface of the insulating member and forming a second electrode layer on a second surface opposite to the first surface of the insulating member. When,
A second step of applying a resist coating, exposure, development, and etching to the first electrode layer to form a plurality of processing openings in the first electrode layer;
Through the plurality of processing openings of the first electrode layer, the insulating member is irradiated with energy rays, or the insulating member is a photosensitive insulating member, and resist coating, exposure, and development are performed. A third step of forming a through hole in the thickness direction of the insulating member;
A fourth step of performing via fill plating in the through hole and forming a metal plating layer so as to bury the through hole;
A mask is disposed in a region excluding the metal plating layer above the first electrode layer, and etching is performed on the first electrode layer and the metal plating layer, thereby the first electrode. Forming a circular opening centered on the metal plating layer in the layer to form a first electrode pattern, comprising the metal plating layer, and substantially the center of the opening of the first electrode pattern A fifth step of forming a second electrode pattern having a tip exposed at the portion and a convex portion having the end embedded in the insulating member and the second electrode layer;
It is related with the manufacturing method of a radiation detector characterized by comprising.

  The inventors of the present invention have intensively studied to achieve the above object. As a result, in the conventional pixel-type radiation detector, for example, 400 V is provided between the pixel electrode constituted by the convex portion in the second electrode pattern and the strip-like cathode electrode constituted by the first electrode pattern. When a voltage of ˜700 V is applied, the electric field concentrates on the rectangular end of the pixel electrode exposed at the opening of the first electrode pattern, resulting in a continuous discharge between the pixel electrode and the strip-like cathode electrode. Has been found to occur.

  Therefore, in this invention, the edge part of the convex part in the 2nd electrode pattern which comprises the above pixel electrodes exists between the 1st electrode pattern and the 2nd electrode pattern, and the inside is convex. It is made to embed in the insulating member which a part penetrates. Accordingly, the convex portion of the second electrode pattern, that is, the end portion of the pixel electrode is not exposed in the opening portion of the first electrode pattern, so that it is possible to suppress the concentration of the electric field at the end portion of the pixel electrode. As a result, it has been found that continuous discharge between the pixel electrode and the strip-like cathode electrode can be suppressed.

  For this reason, even when a high voltage is applied between the convex portions of the first electrode pattern and the second electrode pattern, that is, between the strip-like cathode electrode and the pixel electrode, a continuous discharge therebetween. Therefore, the detection sensitivity of the radiation detector can be improved.

  In the present invention, “the end of the convex portion of the second electrode pattern is embedded in the insulating member” basically means that the end portion of the convex portion is located on the first surface of the insulating member. This means that the position of the end of the convex portion is located below the plane level of the first surface of the insulating member within a maximum range of 35 μm. is there. In either case, the above-described effects of the present invention can be similarly achieved. Note that the latter has an advantage that the manufacturing process can be simplified because the degree of freedom in processing becomes higher.

  Moreover, the convex part of the 2nd electrode pattern which satisfies such requirements can be formed by the etching process in a 5th process so that it may prescribe | regulate with the said manufacturing method. That is, conventionally, when the first electrode pattern (strip-shaped cathode electrode) is formed by forming a circular opening in the first electrode layer, the convex portion is formed later. In order not to etch the metal plating layer, a mask covering the metal plating layer is formed and disposed, and the etching process is performed.

  However, in the present invention, the etching process is performed by exposing the metal plating layer without covering it with a mask. Therefore, by the etching process, the first electrode layer is partially etched away to form a circular opening, and at the same time, the upper portion of the metal plating layer is also etched away. In particular, the end of the convex portion of the electrode pattern 2 is embedded in an insulating member, and the radiation detector can be manufactured.

  The etching process used in the fifth step is preferably a wet etching process. In this case, it is possible to give a selection system when etching the metal material and the insulating material. As described above, only the first electrode layer and the metal plating layer are etched, and the insulating member located below is not etched. Such etching control can be easily performed.

  In general, since the etching rate of the first electrode layer and the metal plating layer is different, using this difference, for example, the tip of the convex portion in the second electrode pattern has a convex continuous curved surface shape. The insulating member can be formed in a planar shape parallel to the first surface of the insulating member. In either case, as long as the end portion is embedded in the insulating member, the above-described effects of the present invention can be achieved.

  In general, the etching rate of the metal plating layer is smaller than the etching rate of the first electrode layer. For example, if the etching time is adjusted to a time for forming an opening with respect to the first electrode layer, the convexity The tip of the shaped part becomes a convex continuous curved surface. In addition, when the etching time is adjusted to such a time that the tip of the convex portion in the second electrode pattern becomes flat, the size of the opening formed in the first electrode layer becomes larger than the design value. There is.

  In this case, by reducing the mask opening corresponding to the opening of the first electrode layer to be formed, the etching rate of the portion located at the edge of the mask opening is reduced, and the first electrode layer is formed. The size of the opening to be formed can be set as designed.

  In addition, in order to make the tip of the convex portion in the second electrode pattern flat, as described above, the convex curved portion having a continuous curved shape is formed without controlling the size of the opening of the mask. When formed, laser irradiation processing can be performed to form a flat shape.

  In the above description, the first electrode pattern is described as a strip-like cathode electrode, the first electrode pattern is described as an anode, and the second electrode pattern having a convex portion constituting a pixel electrode is described as a cathode. This is derived from the description according to the background art. As will be described below, in practice, the first electrode pattern is used as the cathode and the second electrode pattern is used as the cathode according to the use mode. It can also be an anode.

  As described above, according to the present invention, it is possible to provide a novel pixel-type radiation detector having sufficiently high detection sensitivity and a method for manufacturing the same.

It is a top view which shows schematic structure in an example of the radiation detector of this invention. It is a figure which expands and shows the pixel type radiation detector shown in FIG. It is sectional drawing which expands and shows the pixel electrode peripheral part of the pixel-type radiation detector shown in FIG.1 and FIG.2. Similarly, it is sectional drawing which expands and shows the pixel electrode peripheral part of the pixel-type radiation detector shown in FIG.1 and FIG.2. Similarly, it is sectional drawing which expands and shows the pixel electrode peripheral part of the pixel-type radiation detector shown in FIG.1 and FIG.2. Similarly, it is sectional drawing which expands and shows the pixel electrode peripheral part of the pixel-type radiation detector shown in FIG.1 and FIG.2. It is process drawing in an example of the manufacturing method of this invention. Similarly, it is process drawing in an example of the manufacturing method of the present invention. Similarly, it is process drawing in an example of the manufacturing method of the present invention. Similarly, it is process drawing in an example of the manufacturing method of the present invention. Similarly, it is process drawing in an example of the manufacturing method of the present invention. Similarly, it is process drawing in an example of the manufacturing method of the present invention.

  The features and other advantages of the present invention will be described below based on the best mode for carrying out the invention.

  FIG. 1 is a plan view showing a schematic configuration of an example of the radiation detector of the present invention, FIG. 2 is an enlarged view of the pixel-type radiation detector shown in FIG. 1, and FIG. FIG. 3 is an enlarged cross-sectional view of a pixel electrode peripheral portion of the pixel-type radiation detector shown in FIG. 2.

  As shown in FIG. 1, the radiation detector 10 of this example includes a pixel-type radiation detector 20 and a current detection circuit and the like (not shown). As shown in FIG. 2, the pixel-type radiation detector 20 includes a detection panel 21 and an electrode plate 22 provided so as to face each other above the detection panel 21.

  As shown in FIG. 2, the detection panel 21 includes a first electrode pattern 212 having a plurality of circular openings 212 </ b> A formed on the main surface 211 </ b> A of the insulating member 211, and a back surface 211 </ b> B of the insulating member 211. And a second electrode pattern 213 formed on the substrate. The second electrode pattern 213 has a convex portion 214 that penetrates through the insulating member 211 and is exposed at the substantially central portion of the opening 212A of the first electrode pattern 212. The convex portion 214 constitutes a pixel electrode.

  Further, as shown in FIG. 3, the convex portion 214 has a tip 214 </ b> A exposed at a substantially central portion of the opening 212 </ b> A, and an end 214 </ b> B embedded in the insulating member 211. Specifically, in FIG. 3, the position of the end 214 </ b> B of the convex portion 214 is the same as the planar level of the first surface 211 </ b> A of the insulating member 211.

  Note that the end 214B of the convex portion 214 only needs to be embedded in the insulating member 211, and is not necessarily the same as the planar level of the first surface 211A of the insulating member 211. Specifically, the case where the position of the end 214B of the convex portion 214 is positioned below the maximum level of 35 μm from the plane level of the first surface 211A of the insulating member 211 is also included. In either case, the above-described effects of the present invention can be similarly achieved. Note that the latter has an advantage that the manufacturing process can be simplified because the degree of freedom in processing becomes higher.

  Therefore, the convex part 214 of the second electrode pattern 213 may take the form as shown in FIG. 4 with the entire tip 214A of the convex part 214 shown in FIG. 3 lowered. Further, according to the manufacturing method described below (the etching rate of the metal plating layer constituting the convex portion is smaller than the etching rate of the electrode layer constituting the first electrode pattern), as shown in FIG. In addition, the position of the end 214B of the convex portion 214 may be the same as the planar level of the first surface 211A of the insulating member 211, and the tip 214A may be a convex continuous curved surface. Furthermore, the whole convex-shaped part 214 having the tip 214A having such a shape may be lowered to adopt a mode as shown in FIG.

  The thickness t1 of the insulating member 211 can be set to 20 μm to 100 μm, for example. Further, the thickness t2 of the first electrode pattern 212 and the thickness t3 of the second electrode pattern 213 can be set to 5 μm to 18 μm, respectively. Furthermore, the height L1 of the convex portion 214 can be set to be the same as the thickness t1 of the insulating member 211 within the range of the processing error described above. In addition, the diameter D of the opening 212A can be set to 80 μm to 300 μm, for example, and the diameter d of the convex portion 214 can be set to 15 μm to 70 μm.

  The first electrode pattern 212 and the second electrode pattern 213 can be made of a conductive member such as copper, gold, silver, nickel, or aluminum. The insulating member 211 can be made of an insulating resin film or sheet.

  In addition, in the detection panel 21 of the pixel-type radiation detector 20 shown in FIG. 2, a total of eight openings 212A are formed in the first electrode pattern 212 and arranged in two rows by four. The tips of the convex portions 214 are exposed in the openings 212A, so that a total of eight detection electrodes are formed. However, the number and arrangement method of the detection electrodes (the number and arrangement method of the openings 212A and the convex portions 214 in the first electrode pattern 212) can be arbitrarily set as necessary.

  Although not clearly shown in the drawing, the second electrode pattern 213 is also patterned in a strip shape in a direction substantially perpendicular to the arrangement direction of the first electrode patterns 212. However, the second electrode pattern 213 may be patterned in any direction as long as it is not parallel to the first electrode pattern 212.

  A predetermined voltage, for example, a voltage of about 400 V to 700 V is applied between the first electrode pattern 212 and the second electrode pattern 213. In this case, the first electrode pattern 212 can be a cathode and the second electrode pattern 213 can be an anode, or the first electrode pattern 212 can be an anode and the second electrode pattern 213 can be a cathode. it can.

  However, in order to cause the electron avalanche amplification of electrons described below, the shape of the convex portion 214 of the second electrode pattern 213 plays an extremely important role, so the first electrode pattern It is preferable that 212 is a cathode and the second electrode pattern 213 is an anode. Therefore, in the following, a case where the first electrode pattern 212 is a cathode and the second electrode pattern 213 is an anode will be described.

  A space between the detection panel 21 and the electrode plate 22 is filled with a predetermined gas, for example, a mixed gas of Ar and ethane. Furthermore, the electrode plate 22 is biased to a predetermined voltage.

  When radiation is incident on the radiation detector 10 shown in FIG. 1, the radiation collides with the mixed gas, thereby ionizing the mixed gas and generating electrons. The generated electrons receive the bias voltage of the electrode plate 22 in the pixel-type radiation detector 20 and are guided to the detection panel 21, and between the first electrode pattern 212 and the convex portion 214 of the second electrode pattern 213. Due to the large electric field generated due to the voltage applied to, an avalanche is caused and accumulated in the convex portion 214. On the other hand, positive ions generated by the electron avalanche drift toward the surrounding first electrode pattern 212 from the convex portion 214.

  As a result, holes and electrons are charged in the convex portions 214 of the first electrode pattern 212 and the second electrode pattern 213, respectively, so that the positions of the convex portions 214, that is, the pixel electrodes are not shown. By detecting with the detection circuit, the incident position of the radiation in the pixel type radiation detector 20 can be specified, and the radiation can be detected.

  On the other hand, the end portion 214B of the convex portion 214 in the second electrode pattern 213 is embedded in the insulating member 211 as shown in FIG. 3 or FIGS. Accordingly, the end 214B of the convex portion 214 of the second electrode pattern 213 is not exposed in the opening 212A of the first electrode pattern 212, and therefore, between the first electrode pattern 212 and the second electrode pattern 213. Even when a high voltage is applied, it is possible to suppress the concentration of the electric field on the end portion 214B of the convex portion 214.

  As a result, continuous discharge between the end 214B of the convex portion 214 and the end surface of the first electrode pattern 212, particularly the end surface exposed to the opening 212A, can be suppressed, and the detection sensitivity of the radiation detector 10 can be improved. Can do.

  Next, the manufacturing method of the radiation detector of this invention is demonstrated. 7 to 12 are process diagrams showing an example of a method of manufacturing the radiation detector 10 shown in FIGS. 1 to 3, particularly the pixel type radiation detector 20. In addition, in this embodiment, it has shown about the cross section along the PP direction shown in FIG.

  First, as shown in FIG. 7, the first electrode layer 217 made of a conductive member such as copper and the like are formed on the main surface 211A and the back surface 211B of the insulating member 211 made of, for example, a thermosetting resin film or sheet. Two electrode layers 218 are formed.

  Next, as shown in FIG. 8, resist coating, exposure, development, and etching are performed on the first electrode layer 217 to simultaneously form a plurality of processing openings 217 </ b> A in the first electrode layer 217. The electrode layer 218 is strip-shaped.

  Next, as shown in FIG. 9, the insulating member 211 is irradiated with energy rays through the plurality of processing openings 217 </ b> A of the first electrode layer 217, thereby forming a through hole 211 </ b> H in the thickness direction of the insulating member 211. . For example, a laser beam can be used as the energy beam, and a carbon dioxide laser is preferably used. This gas laser processes only the insulating member 211 from its wavelength characteristics, and does not process the electrode layer 218.

  In the case where the insulating member 211 is made of a photosensitive insulating member, the through hole 211H can also be formed by performing resist coating, exposure, and development.

  Next, as shown in FIG. 10, via fill plating such as copper is performed in the through hole 211H, and the metal plating layer 219 is formed so as to bury the through hole 211H.

  Next, as shown in FIG. 11, the mask member 30 is formed on the first electrode layer 217 so as to remove the metal plating layer 219. For example, the mask member 30 is arranged so that the opening 30 </ b> A of the mask member 30 is positioned on the metal plating layer 219. Thereafter, an etching process is performed on the first metal layer 217 and the metal plating layer 219 through the mask member 30, so that a circular opening centered on the metal plating layer 219 is formed as shown in FIG. The first electrode pattern 212 is formed by forming 212A, and the second electrode pattern 213 made of the convex portion 214 made of the metal plating layer 219 and the second electrode layer 218 is made.

  At this time, since the upper portion of the metal plating layer 219 is etched away simultaneously with the formation of the opening 212A, as shown in FIG. 12 (FIG. 3), the convex portion 214 of the second electrode pattern 212 has an end portion thereof. 214B is formed so as to be embedded in the insulating layer 211.

  The etching process used in the process related to FIG. 11 is preferably a wet etching process. In this case, it is possible to provide a selection system when the first metal layer 217 and the metal plating layer 219 and the insulating member 211 are etched, and only the first electrode layer 217 and the metal plating layer 219 are etched downward. Etching control that does not etch the insulating member 211 positioned can be easily performed.

  In addition, the etching rates of the first electrode layer 217 and the metal plating layer 219 are different, and the etching rate of the metal plating layer 219 is generally lower than the etching rate of the first electrode layer 217. Therefore, for example, when the etching time is adjusted to a time for forming the opening 212A with respect to the first electrode layer 217, the tip 214A of the convex portion 214 has a convex shape as shown in FIG. It becomes a continuous curved surface. Further, as shown in FIG. 3 or FIG. 4, when the etching time is adjusted to a time such that the tip 214A of the convex portion 214 in the second electrode pattern 213 becomes flat, it is formed in the first electrode layer 217. The size of the opening 212A may be larger than the design value.

  In this case, by reducing the opening 30A of the mask 30 corresponding to the opening 212A of the first electrode layer 217 to be formed, the portion of the first electrode layer 217 located at the end of the mask opening 30A The etching rate can be reduced, and the size of the opening 212A formed in the first electrode layer 217 can be set as designed.

  Although not particularly shown, in order to flatten the tip 214A of the convex portion 214 in the second electrode pattern 213, the convex shape is not controlled without controlling the size of the opening 30A of the mask 30 as described above. When the continuous curved convex portion 214 is formed, the tip 214A can be processed by being irradiated with a laser to form a flat shape. In this case, the laser spot diameter is set to the size of the tip 214A (about ¼ of the area), and scanning is performed a plurality of times on the tip 214A.

  In addition, as a laser beam for performing such processing, a YAG laser having a high laser beam intensity can be used.

  The present invention has been described in detail based on the above specific examples. However, the present invention is not limited to the above specific examples, and various modifications and changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Radiation detector 20 Pixel type radiation detector 21 Detection panel 22 Electrode plate 211 Insulating member 212 1st electrode pattern 212A Circular opening part of 1st electrode pattern 213 2nd electrode pattern 214 Convex of 2nd electrode pattern Section

Claims (7)

A first electrode pattern formed on the first surface of the insulating member and having a plurality of circular openings;
It is formed on a second surface opposite to the first surface of the insulating member, penetrates the insulating member, and a tip is exposed at a substantially central portion of the opening of the first electrode pattern. A second electrode pattern having a projecting portion in which an end portion is embedded in the insulating member,
A radiation detector using gas amplification, wherein the first electrode pattern and the second electrode pattern are set to have a predetermined potential difference.   The radiation detector using gas amplification according to claim 1, wherein the tip of the convex portion is formed in a convex curved surface shape.   The radiation detector using gas amplification according to claim 1, wherein the tip of the convex portion is formed in a planar shape parallel to the first surface of the insulating member.   The radiation detector using gas amplification according to claim 1, wherein the convex portion is formed by a via fill plating method. A first step of forming a first electrode layer on the first surface of the insulating member and forming a second electrode layer on a second surface opposite to the first surface of the insulating member. When,
A second step of applying a resist coating, exposure, development, and etching to the first electrode layer to form a plurality of processing openings in the first electrode layer;
Through the plurality of processing openings of the first electrode layer, the insulating member is irradiated with energy rays, or the insulating member is a photosensitive insulating member, and resist coating, exposure, and development are performed. A third step of forming a through hole in the thickness direction of the insulating member;
A fourth step of performing via fill plating in the through hole and forming a metal plating layer so as to bury the through hole;
A mask is disposed in a region excluding the metal plating layer above the first electrode layer, and etching is performed on the first electrode layer and the metal plating layer, thereby the first electrode. Forming a circular opening centered on the metal plating layer in the layer to form a first electrode pattern, comprising the metal plating layer, and substantially the center of the opening of the first electrode pattern A fifth step of forming a second electrode pattern having a tip exposed at the portion and a convex portion having the end embedded in the insulating member and the second electrode layer;
A method of manufacturing a radiation detector using gas amplification.   The gas amplification according to claim 5, wherein the tip of the convex portion is formed into a convex curved surface by controlling the time of the etching process in the fifth step. Manufacturing method of used radiation detector.   The etching processing time in the fifth step is controlled to form the tip of the convex portion in a planar shape parallel to the first surface of the insulating member. A method for manufacturing a radiation detector using gas amplification according to claim 5.

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