JP4765506B2 - Radiation detection panel manufacturing method, radiation detection panel - Google Patents

Description

  The present invention relates to a method for manufacturing a radiation detection panel having a plurality of cells of an anode electrode and a cathode electrode in a two-dimensional arrangement on a substrate and the radiation detection panel, and more particularly to a radiation detection panel suitable for high-density arrangement of cells. The present invention relates to a manufacturing method and a radiation detection panel.

  In order to detect the incident position of radiation such as X-rays or gamma rays, there is a radiation detection device of a type that detects a leakage current generated by exciting gas particles with incident radiation. In such a radiation detection apparatus, a radiation detection panel having a plurality of cells of an anode electrode and a cathode electrode in a two-dimensional arrangement on a substrate is used as a device body for radiation detection. As an example, there is a radiation detector disclosed in Patent Document 1 below.

  As described in this document, the anode electrode is a pattern in which fine circular patterns are arranged in a grid, and a plurality of anode electrode wirings for electrical conduction are arranged for each row. The cathode electrode is a conductor pattern that surrounds each anode electrode at an approximately equal distance from each other, and is a pattern that is electrically connected to each column. Due to such vertical and horizontal electrical arrangement of the anode electrode and the cathode electrode, when a current flows between the anode electrode and the cathode electrode of any cell, this can be detected and the radiation incident position can be specified.

In order to detect a radiation incident position with high resolution, cells of an anode electrode and a cathode electrode need to be arranged on the substrate at a high density. In terms of detection sensitivity, it is necessary to increase the voltage applied between the anode electrode and the cathode electrode in order to detect a smaller current. When the cells are arranged at a high density, the fine shapes of the anode electrode and the cathode electrode become a problem in ensuring normal operation. That is, if the distance between the anode electrode and the surrounding cathode electrode varies depending on the surrounding direction, a discharge occurs at a shorter distance and normal current detection cannot be performed. In order to eliminate the discharge, the applied voltage may be lowered, but the detection sensitivity is deteriorated.
JP 2002-90465 A

  The present invention has been made in view of the above circumstances, and a radiation detection panel manufacturing method and a radiation detection panel capable of arranging cells of an anode electrode and a cathode electrode at high density while avoiding performance deterioration are provided. The purpose is to provide.

To solve the above problems, a manufacturing method of a radiation detection panel according to the present invention includes an anode electrode patterns have a circular a and the first metal and the two-layer structure of the second metal as a pattern, the anode as a pattern and a cathode electrode pattern from the electrode patterns spaced equidistant to have a two-layer structure surrounding and said first metal and said second metal the anode electrode pattern, a layer of outer the second metal respectively Forming on the metal plate, laminating a metal foil on the surface of the metal plate on which the anode electrode pattern and the cathode electrode pattern are formed, and integrating the metal foil, and the insulating plate the metal foil above, before the step of etching to allow circular removal site for the position corresponding to the Kia node electrode pattern, before having the removal site A metal foil processing the insulating plate as a mask, to form a plating layer so as to satisfy the process, the inside before millet via hole to form a via hole so that the reach to the second layer of metal of the anode electrode pattern step And removing the metal plate by etching so that the anode electrode pattern and the cathode electrode pattern are left on the insulating plate side .

  In this manufacturing method, the anode electrode is manufactured by a metal pattern having a two-layer structure. Therefore, for example, if a photolithography technique is used, it can be processed and formed into a fine and accurate shape. In addition, the anode electrode pattern has a structure in which electrical conduction is made to the back side of the insulating plate by a via, but the via hole for forming the via is formed from the back side of the insulating plate, In other words, the anode electrode pattern has a smaller diameter. That is, the anode electrode pattern can be formed smaller. In accordance with this, the pattern of the cathode electrode can be reduced. Therefore, the anode electrode and cathode electrode cells can be arranged at high density while avoiding performance degradation.

The radiation detection panel according to the present invention includes an insulating plate, a circular pattern as a pattern, and a two-layered first metal and second metal , which are located on the insulating plate by sinking in the thickness direction of the insulating plate. an anode electrode patterns have a structure, the position sinks in the thickness direction of the insulating board in the insulating board, spaced equidistant from the anode electrode pattern as a pattern surrounding the anode electrode pattern and the first a cathode electrode patterns have a metal and the two-layer structure of the second metal, to pass through the insulation plate disposed to contact the anode electrode pattern, the diameter closer to the anode electrode pattern and conductive vias smaller shape, provided on the surface of the side opposite to the said anode electrode pattern and the cathode electrode pattern is provided side of the insulating plate , Characterized by comprising an anode wiring pattern electrically conducted to the via.

  In this radiation detection panel, the anode electrode is formed of a metal pattern having a two-layer structure. Therefore, for example, if a photolithography technique is used, it is processed and formed into a fine and accurate shape. The anode electrode pattern is electrically connected to the back side of the insulating plate by a via, but the diameter becomes smaller as the via is closer to the anode electrode pattern. That is, the anode electrode pattern can be made smaller. In accordance with this, the pattern of the cathode electrode can be reduced. Therefore, the anode electrode and cathode electrode cells can be arranged at high density while avoiding performance degradation.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a radiation detection panel and the radiation detection panel which can arrange | position the cell of an anode electrode and a cathode electrode at high density, avoiding performance degradation can be provided.

  As an embodiment of the method for manufacturing a radiation detection panel according to the present invention, the first metal may be nickel, and the second metal may be copper. For example, in addition to this, if the metal plate is copper, in order to form the anode electrode pattern in the laminated state of the metal plate, the first metal, and the second metal, the second metal of the upper layer is first etched. Processing, and then a procedure of etching the first metal can be taken. Further, when the metal plate is finally removed by etching, the nickel layer as the first metal is used as a base and there is no inconvenience.

  As an embodiment, the step of forming the via hole may form the via hole in a shape in which the diameter gradually decreases toward the deep side in the processing direction as the via hole. In order to form in this way, for example, laser processing can be employed. In processing that irradiates the laser beam perpendicular to the insulating plate, the accumulated energy of the light beam striking the processing hole is usually different at the periphery and the center of the hole and is small compared to the periphery. It becomes a processed hole with a gradually decreasing diameter. In processing that irradiates laser light perpendicularly to the insulating plate without intentional consideration so that the diameter gradually decreases toward the deeper side in the processing direction, it is usually on the deeper side in the processing direction. The diameter gradually decreases toward it.

  As an embodiment, the step of forming a plating layer may include a plating layer forming step by electroless plating and a plating layer forming step by electrolytic plating performed after the electroless plating. A conductive layer can be formed on the inner wall of the via hole by electroless plating, and then the plated layer can be formed at a high speed by using this conductive layer as a seed layer for electrolytic plating.

In one embodiment, the step of forming the anode electrode pattern and the cathode electrode pattern on the metal plate includes the step of forming the first metal layer on the metal plate and the second metal layer on the first metal layer. of the layers laminated each metal using an integrated cladding material, wherein to form a et Tchingumasuku the second metal layer on the etching said second metal in the first etchant, the first made by etching the first metal and the first etchant by etching after the etching mask by the etchant at a different second etchant can be a.

  This is an example. In addition, with the formed etching mask, the second metal is etched with the first etchant. After the etching, the etching mask is removed, and the second metal is used as a mask with a second etchant different from the first etchant. A method of etching the first metal can also be adopted.

Further, as an embodiment, after the plating layer is formed so as to fill the via hole, the second metal foil is laminated on the surface of the insulating plate on the side where the metal foil is located via the second insulating plate. And a step of patterning, and a step of patterning the second metal foil on the second insulating plate . An insulating plate and a second metal foil are laminated on the surface of the insulating plate where the metal foil is located, and a build-up process is performed as a multilayer wiring board.

Further, even if the embodiment of the radiation detection panel, a first metal is nickel, the second metal is Ri copper der, outside the layer of the first metal layer and the second metal Ru layer der located, can be.

  As an embodiment, the second insulating plate provided on the surface of the insulating plate on the side where the anode wiring pattern is disposed, and the side of the second insulating plate on which the insulating plate is disposed And a wiring layer provided on the surface on the opposite side. It is the aspect which has a buildup part as a multilayer wiring board.

  Based on the above, embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram schematically showing the structure of a radiation detection panel according to an embodiment of the present invention, in which FIG. 1 (a) is a top view and FIG. 1 (b) is shown in FIG. 1 (a). It is typical sectional drawing of the arrow direction in A-Aa position. As shown in FIG. 1, the radiation detection panel includes an insulating plate 10, a surface conductor pattern (cathode electrode) 11, a surface conductor pattern (anode electrode) 12, a back conductor pattern (anode wiring pattern) 13, and vias 14.

  The surface conductor pattern (anode electrode) 12 is a substantially circular metal pattern that is exposed on one side of the insulating plate 10 and arranged in a grid. The diameter of each is, for example, 60 μm, and is arranged vertically and horizontally, for example, at a pitch of 400 μm. For example, there are about 60,000, for example, in an area of 10 cm × 10 cm as a whole. As shown in FIG. 1B, the surface conductor pattern 12 has a two-layer structure, for example, a nickel layer 121 (thickness, for example, 3 to 5 μm) on the front side and a copper layer 122 (thickness, for example, 5 to 5) on the base side. 18 μm).

  The surface conductor pattern (cathode electrode) 11 is a metal pattern that is formed in a pattern that appears on one surface of the insulating plate 10 and that is spaced from the surface conductor patterns 12 at substantially equal intervals and surrounds the surface conductor patterns 12. The surrounding diameter is, for example, 250 μm, and is a pattern that is continuous in the vertical direction of each row as shown in FIG. Each width thereof is, for example, 350 μm. Moreover, it has a two-layer structure like the anode electrode 12, and the surface side is, for example, a nickel layer 111 (thickness, for example, 3 to 5 μm), and the base side is, for example, a copper layer 112 (thickness, for example, 5 to 18 μm).

  The insulating plate 10 is a plate embedded with a surface conductor pattern (cathode electrode) 11 and a surface conductor pattern (anode electrode) 12 (according to the manufacturing process described later), and the thickness is, for example, 0.07 mm to 0.1 mm. is there. The material is polyimide, for example.

  Each surface conductor pattern (anode electrode) 12 is in contact with a conductive via 14 formed so as to penetrate through the insulating plate 10, whereby the conductor pattern (anode wiring pattern) 13 on the back side of the insulating plate 10 is contacted. Electrical connection. The via 14 is shaped like a truncated cone having a slightly smaller diameter on the surface conductor pattern (anode electrode) 12 side (diameter of, for example, 50 μm on the smaller side, diameter of, for example, 65 μm), and the surface conductor pattern (anode electrode) 12 The electroless copper plating layer 142 (thickness is 0.4 μm to 1.0 μm, for example) including the contact surface with the inner surface is filled with the electrolytic copper plating layer 141.

  Each via 14 is electrically connected by a backside conductor pattern (anode wiring pattern) 13 so that those in the horizontal direction in FIG. 1A are the same electrical node. Each backside conductor pattern (anode wiring pattern) 13 has a width of, for example, 300 μm, and an electroless copper plating layer 132 (thickness, for example, 0.4 μm to 1.0 μm) continuous to the electroless copper plating layer 142 of the via 14. Similarly, it has an electroplating layer 131 (thickness, for example, 10 μm to 16 μm) continuous to the electroplating layer 141. The electroplating layer 131 is on the surface layer side, and the lower side is the electroless plating layer 132. Further, below the electroless plating layer 132, there is a copper layer 133 (thickness, for example, 18 μm).

  The structural feature of the radiation detection panel described above is that the via 14 in contact with the surface conductor pattern (anode electrode) 12 has a truncated cone shape with a slightly smaller diameter on the surface conductor pattern (anode electrode) 12 side. That is. Thereby, the diameter of each surface conductor pattern (anode electrode) 12 can be formed with a smaller size. In addition, the surface conductor pattern (cathode electrode) 11 surrounding each surface conductor pattern 12 can be reduced in accordance with the small diameter of the surface conductor pattern (anode electrode) 12. Therefore, the cells of the anode electrode 12 and the cathode electrode 11 can be arranged at higher density, and high-resolution radiation detection can be performed.

  The surface conductor pattern (anode electrode) 12 is a metal pattern, and can be processed and formed into a fine and accurate shape by using, for example, a photolithography technique. This means that the distance between the surface conductor pattern 12 and the surface conductor pattern 11 does not go in and out extremely due to protrusions or the like depending on the direction, thereby preventing the discharge phenomenon from occurring at a lower applied voltage than intended. it can. In other words, in the case of a cell arrangement with a lower density, a higher voltage can be applied than in the conventional product, and the sensitivity of radiation detection can be increased.

  Next, a method for manufacturing the radiation detection panel shown in FIG. 1 will be described with reference to FIGS. 2 is a process diagram schematically showing a manufacturing process of the radiation detection panel shown in FIG. 1, and FIG. 3 is a continuation diagram of FIG. 2, and is a manufacturing process of the radiation detection panel shown in FIG. FIG. 4 is a continuation diagram of FIG. 3, and is a process diagram schematically showing the manufacturing process of the radiation detection panel shown in FIG. 1 in cross section. In these drawings, the same or equivalent parts as those shown in FIG. In addition, although it is illustrated corresponding to the position A-Aa shown in FIG. 1A, the top and bottom are reversed for convenience of explanation.

  First, as shown in FIG. 2A, a copper plate 20 (metal plate) has a two-layer structure of a first metal (nickel layer 121) and a second metal (copper layer 122) and is substantially circular. The anode electrode 12 has a two-layer structure of a first metal (nickel layer 111) and a second metal (copper layer 112), and is separated from the pattern of the anode electrode 12 at an approximately equal distance. A pattern of the cathode electrode 11 surrounding the pattern of the electrode 12 is formed. The copper plate 20 has a thickness of 100 μm, for example. The thicknesses of the nickel layer 111 and the copper layer 112 are as described above.

  More specifically, in the pattern formation, for example, it is efficient to use a clad material in which a nickel layer is laminated on the copper plate 20 and a copper layer is laminated and integrated on the nickel layer as a material. An etching mask having a predetermined pattern is formed on the surface of the clad material to be patterned using, for example, a well-known photolithography technique, and the copper layer and the nickel layer are etched in this order using the formed mask. If the mask is removed after the etching, the state shown in FIG.

  Here, for example, an aqueous solution containing iron chloride as a component can be used as the copper etchant, and an aqueous solution containing sulfuric acid, nitric acid, or hydrogen peroxide as the component can be used as the nickel etchant. Since the aqueous solution containing sulfuric acid, nitric acid, and hydrogen peroxide solution does not dissolve copper, the etching mask can be removed before the nickel etching process. The metal pattern etching process using photolithography can be performed finely and accurately. The combination of copper and nickel can also be a combination of other metals, provided that such separate etching is possible.

  Next, as shown in FIG. 2B, the insulating plate 10 having a thickness of, for example, 0.1 mm and the thickness of, for example, 18 μm are formed on the copper plate 20 from the patterned nickel layer 112 and 122 side. Copper foil 133A (metal foil) is laminated and integrated. For this purpose, for example, the copper foil 133A is laminated and pressed on the copper plate 20 at a predetermined temperature and pressure through a polyimide prepreg to be the insulating plate 10. The polyimide prepreg is fluidized by heating during the lamination, and as shown in the drawing, the nickel layer 121 and the anode electrode 12 of the copper layer 122, and the nickel layer 111 and the cathode electrode 11 of the copper layer 112 are on the insulating plate 10 side. Sink into the state.

  Next, as shown in FIG. 2C, a circular etching process with a diameter of, for example, 65 μm is performed on the copper foil 133A corresponding to the position of the circular pattern of the anode electrode 12 (primary patterned copper layer 133B). A well-known photolithography technique can be used for this etching process.

  Next, as shown in FIG. 3A, the insulating plate 10 is processed using the primary patterned copper layer 133B obtained by etching as a mask to form a hole (via hole 10a) reaching the copper layer 122. For example, carbon dioxide laser processing can be used for this processing. In the processing of irradiating the insulating plate 10 with laser light substantially perpendicularly, generally, as shown in the figure, the diameter of the hole becomes smaller as it goes deeper into the processing hole. This is because the integrated energy of the light beam striking the machining hole becomes smaller around the hole. In this embodiment, the finished hole having such a shape is used. The diameter of the formed via hole 10a on the copper layer 122 side is, for example, 50 μm.

  Next, as shown in FIG. 3B, the electroless copper plating layers 132B and 142 are formed by electroless plating on the primary patterned copper layer 133B and on the sidewalls and bottom surfaces of the via holes 10a, for example, 0.4 μm. To about 1.0 μm. After electroless plating, electroplating is performed using the formed electroless copper plating layer 132B and 142 as a seed layer, and a thickness of, for example, 15 μm to 40 μm on the inside of the via hole 10a and the electroless copper plating layer 132B on the insulating plate 10 The electrolytic copper plating layer is grown to the extent. In this electrolytic plating, for example, a copper sulfate solution is used as a plating solution, but it is preferable to add a surface active agent so that the plating easily grows even in a fine recess such as the via hole 10a.

  After the electrolytic plating, the electrolytic copper plating layer is etched using, for example, a soft etching agent mainly composed of hydrogen peroxide and sulfuric acid, and electrolysis of, for example, about 10 μm to 16 μm is performed on the electroless copper plating layer 132B on the insulating plate 10. Make sure the copper plating layer remains. As a result, as shown in FIG. 3C, the via 14 and the electrolytic copper plating layer 131B filled with the electrolytic copper plating layer 141 are formed.

  Next, as shown in FIG. 4A, all the copper plate 20 is removed by etching. In this etching, since the nickel layers 111 and 121 serve as a base, the copper layers 112 and 122 are not affected. Subsequently, the primary patterned copper layer 133B, the electroless copper plating layer 132B, and the electrolytic copper plating layer 131B are patterned in a predetermined manner. As shown in FIG. 4B, these are the anode wiring pattern 13 that is the back conductor pattern. (See also FIG. 1). A well-known photolithography technique can be used for this patterning. It should be noted that the procedure shown in FIG. 4A and the procedure shown in FIG.

  Thus, the radiation detection panel shown in FIG. 1 can be obtained. As described above, a particularly difficult process is not required in the manufacturing process, and thus a high-resolution and high-performance radiation detection panel can be obtained without an increase in cost.

  Next, a radiation detection panel according to another embodiment of the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional view schematically showing the structure of a radiation detection panel according to another embodiment of the present invention. In the figure, the same reference numerals are given to the same components as those shown in the already described drawings. A description of this part is omitted.

  The radiation detection panel of this embodiment includes another insulating plate 30 stacked on the side of the insulating plate 10 on which the anode wiring pattern 13 is disposed, and a wiring pattern 31 (wiring layer) stacked thereon. Have The structure in which the insulating plate 30 and the wiring pattern 31 are added to the radiation detection panel manufactured as shown in FIG. 4B is further provided with an insulating plate as shown in FIG. If the copper foil (metal foil) is laminated and integrated, it can be obtained by performing slight processing thereafter.

  In this case, although not shown, it is also a well-known method to provide a vertical conductor so as to penetrate the insulating plate 30 and be sandwiched between the surface of the anode wiring pattern 13 and the surface of the wiring pattern 31. it can. As described above, the side of the insulating plate 10 on which the anode wiring pattern 13 is arranged can have a structure of a build-up multilayer wiring board. If the wiring layer formed by the build-up is used, the signal can be taken out from the panel more freely.

The block diagram which shows typically the structure of the radiation detection panel which concerns on one Embodiment of this invention. Process drawing which shows the manufacturing process of the radiation detection panel shown in FIG. 1 with a typical cross section. FIG. 3 is a continuation diagram of FIG. 2, and is a process diagram schematically showing in cross section the manufacturing process of the radiation detection panel shown in FIG. 1. FIG. 4 is a continuation diagram of FIG. 3, and a process diagram schematically showing a cross-sectional view of the manufacturing process of the radiation detection panel shown in FIG. Sectional drawing which shows typically the structure of the radiation detection panel which concerns on another embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Insulating board, 10a ... Via hole, 11 ... Surface conductor pattern (cathode electrode), 12 ... Surface conductor pattern (anode electrode), 13 ... Back surface conductor pattern (anode wiring pattern), 14 ... Via, 20 ... Copper plate, 30 ... Insulating layer, 31 ... Wiring pattern, 111 ... Nickel layer, 112 ... Copper layer, 121 ... Nickel layer, 122 ... Copper layer, 131 ... Electrolytic copper plating layer, 131B ... Electrolytic copper plating layer on the entire surface, 132 ... Electroless copper plating Layer, 132B ... electroless copper plating layer, 133 ... copper layer, 133A ... copper foil (metal foil), 133B ... primary patterned copper layer, 141 ... electrolytic copper plating layer, 142 ... electroless copper plating layer.

Claims (9)

An anode electrode patterns have a circular a and the first metal and the two-layer structure of the second metal as a pattern, from the anode electrode pattern as a pattern spaced equidistantly surrounds the anode electrode pattern and the first and a cathode electrode patterns have a two-layer structure of metal and said second metal, forming on the metal plate and the second metal as the outer layer, respectively,
Laminating and integrating a metal foil via an insulating plate on the surface of the metal plate on which the anode electrode pattern and the cathode electrode pattern are formed;
A step of etching to allow circular removal site that the said metal foil on the insulating plate, to corresponding pre-positioned and Kia node electrode patterns,
Processing the insulating plate using the metal foil having the removal site as a mask, and forming a via hole so as to reach the second metal layer of the anode electrode pattern;
Forming a plating layer so as to fill the front millet via hole,
And a step of removing the metal plate by etching so that the anode electrode pattern and the cathode electrode pattern are left on the insulating plate side .   The method of manufacturing a radiation detection panel according to claim 1, wherein the first metal is nickel and the second metal is copper.   2. The method of manufacturing a radiation detection panel according to claim 1, wherein the step of forming the via hole forms the via hole in a shape that gradually decreases in diameter toward the deeper side in the processing direction as the via hole.   The radiation detection panel according to claim 1, wherein the step of forming a plating layer includes a plating layer formation step by electroless plating and a plating layer formation step by electrolytic plating performed after the electroless plating. Manufacturing method. The step of forming the anode electrode pattern and the cathode electrode pattern on the metal plate includes the step of forming the first metal layer on the metal plate and the second metal layer on the first metal layer. using the laminated integrated cladding material, wherein the second metal layer on to form a et Tchingumasuku etching the second metal in the first etchant, wherein after etching by the first etchant 2. The method of manufacturing a radiation detection panel according to claim 1, wherein the first metal is etched with a second etchant different from the first etchant by an etching mask. After forming a plating layer so as to fill the via hole, a step of laminating and integrating a second metal foil via a second insulating plate on the surface of the insulating plate on which the metal foil is located; ,
The method of manufacturing a radiation detection panel according to claim 1, further comprising: patterning the second metal foil on the second insulating plate . An insulating plate;
Situated sinks in the thickness direction of the insulating plate on the insulating plate, and an anode electrode patterns have a two-layer structure of a circular a and the first metal and the second metal as a pattern,
The first metal and the second metal are disposed on the insulating plate so as to be located in the thickness direction of the insulating plate and surround the anode electrode pattern as a pattern at an equal distance from the anode electrode pattern . a cathode electrode patterns have a two-layer structure,
Wherein through the insulation plate disposed to contact the anode electrode pattern, and the conductive vias shape diameter closer to the anode electrode pattern is reduced,
Wherein the said anode electrode pattern and the cathode electrode pattern is provided side of the insulating plate provided on the surface of the opposite side, and characterized by including an anode wiring pattern electrically conductive to said via Radiation detection panel. Wherein the first metal is nickel, the second metal is Ri copper der, characterized layers der Rukoto said first metal layer is located outside the layer of the second metal The radiation detection panel according to claim 7. A second insulating plate provided on the surface of the insulating plate on the side where the anode wiring pattern is disposed;
The radiation detection panel according to claim 7, further comprising: a wiring layer provided on a surface of the second insulating plate opposite to the side on which the insulating plate is disposed.

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