Reading circuit structure of microstructure gas detector and microstructure gas detector

Abstract

The utility model discloses a detector reading circuit structure of a microstructure gas detector and the microstructure gas detector. The reading circuit structure of the microstructure gas detector comprises at least three core plates, two metal layers are formed on the two surfaces of each core plate, six metal layers are formed, and the six metal layers are a Pad layer, a U-dimensional wire connecting layer, a first ground layer, a V-dimensional wire connecting layer, a second ground layer and a W-dimensional wire connecting layer in sequence from top to bottom; the Pad layer is provided with a plurality of read-out Pads to form a read-out Pad array, and gaps are reserved between adjacent read-out Pads; a through hole is formed in the center of each read-out Pad, wires of the U-dimensional wire connecting layer, the V-dimensional wire connecting layer and the W-dimensional wire connecting layer are connected with the through holes of the read-out Pads to form Pad read-out strips of the layers where the wires are located, and the wires are located at the positions corresponding to gaps between the read-out Pads. According to the utility model, a reading scheme of two-dimensional positioning and three-dimensional judgment and selection can be realized, multiple case judgment and selection can be realized under a high counting rate, and the quality and the efficiency of data analysis are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of microstructure gas detectors, in particular to a microstructure gas detector readout circuit structure and a microstructure gas detector. Background Art

[0002] Micro-Pattern Gas Detector (MPGD) has the advantages of high counting rate, flexible readout method and good position resolution, and plays a very important role in particle detection in the field of high energy physics.

[0003] Under the existing technology, in order to achieve the result of 100-micron position resolution, combined with the fast pulse electronics readout system and the center of gravity analysis method, the amplification and readout parts of the microstructure gas detector are separated, which makes its readout methods diverse, including surface readout, strip readout and small unit Pad readout, etc. Strip readout can be divided into whole strip readout, Pad connected strip readout and strip pixel readout. Surface readout mainly uses the resistive plane readout method to read data from the four corners of the plane and then locate the position. This readout method is only applicable to low counting rate and low position resolution, and is not applicable to higher counting rate and high-energy particle beam track measurement. The readout structure of the whole strip readout method is a whole strip in one dimension (the strip length is the same as the effective length of the microstructure gas detector, in the order of millimeters), and a pad connection in one dimension (the strip spacing is in the order of microns), so as to achieve the principle that the number of strips covered by the electron beam under the center of gravity readout method is at least three. Since this readout design has an asymmetric distribution, the two-dimensional resolution is slightly different, so people have slightly improved it and adopted a square pad design rotated 45 degrees to achieve a symmetrical distribution of the two-dimensional readout strip structure - pad-connected strip readout. The readout principle of the pad-connected strip readout method is basically the same as the whole strip readout, but it is easier to achieve equal effective areas for two-dimensional readout, so that the two-dimensional resolution tends to be consistent, which makes it easier to make the detector have the same level of performance (signal-to-noise ratio, distributed capacitance). The strip pixel readout method of the gas detector can be used as a sampling type two-dimensional X-ray imaging, and can also be used as a time projection chamber (TPC-Time Projection Chamber). The strip pixel readout design is also in order to meet the principle of at least three readouts under the center of gravity method. In one dimension, it is in the micron level; in the other dimension, it is adapted to the effective length of the detector, which is in the centimeter level. If the length of this dimension is too small, it is easy to cause the induced charge of a single strip to be too small, which makes the signal-to-noise ratio worse. Strip pixel readout can achieve multi-point sampling of the particle's track when it passes through, and at the same time, combine the time and physical information of the process to reconstruct the particle track. Compared with surface readout and strip readout, the advantage of Pad readout is that it can improve the resolution and greatly improve the ability to distinguish multiple hits. However, Pad readout requires a large number of electronic circuits. For the same detector, the strip readout board only needs Circuit electronics, while Pad readout requires Too many electronic circuits are difficult to implement and expensive.

[0004] The current microstructure gas readout structure mainly adopts the two-dimensional strip readout method. However, due to the structural limitations of the two-dimensional strip readout, in the case of multiple hits at high count rates, it is impossible to achieve two or more event selections within the trigger time window of the same data acquisition. As the total count rate increases, the number of multiple hits will increase significantly, but in the current event processing technology, such events can only be discarded. Figure 1As shown, within an electronic read gate width, two events are simultaneously entered as Figure 1 When the position shown in the figure is , and then four sets of paired data can be obtained: , then it will be impossible to determine whether the incident position is A and B, or C and D. For this situation, the current case processing can only be abandoned. Utility Model Content

[0005] The purpose of the utility model is to overcome the defects in the existing above-mentioned technologies and provide a microstructure gas detector readout circuit structure and a microstructure gas detector. The microstructure gas detector readout circuit structure is a three-dimensional readout circuit. The three-dimensional readout circuit combined with the microstructure gas detector can realize the "two-dimensional positioning, three-dimensional selection" readout scheme, and can realize multiple case selection at high counting rate, thereby improving the quality and efficiency of data analysis.

[0006] One purpose of the utility model is to provide a microstructure gas detector readout circuit structure, which is a three-dimensional readout circuit structure, including at least three core boards, two metal layers are formed on the two surfaces of each core board, forming six metal layers, and the six metal layers are, from top to bottom, a Pad layer, a U-dimensional wire connection layer, a first stratum, a V-dimensional wire connection layer, a second stratum, and a W-dimensional wire connection layer; the Pad layer is arranged with multiple readout pads to form a readout pad array and gaps are left between adjacent readout pads; a via is provided in the center of the readout pad, and a layer of wire is arranged on the U-dimensional wire connection layer, the V-dimensional wire connection layer, and the W-dimensional wire connection layer respectively, and the wires of each layer are connected to the vias of the readout pad to form a Pad readout strip of the layer, and the wires are located at positions corresponding to the gaps between the readout pads.

[0007] Optionally, in the top-down state, in the three Pad readout strips in three dimensions in a single case, the angle between adjacent Pad readout strips is .

[0008] Optionally, the number of Pad readout bars corresponding to each dimension in a single case is and arranged parallel to each other.

[0009] Optionally, the readout Pad is in a regular hexagonal shape, and the side length of the regular hexagonal readout Pad is 0.231 mm.

[0010] Optionally, the gap spacing between adjacent readout pads is 0.1 mm, and the line width of the conductive line is set to 0.1 mm.

[0011] Optionally, the via hole in the middle of the readout pad is a circular via hole, and the diameter of the circular via hole is 0.2 mm.

[0012] Optionally, the gap spacing between the via hole and the wire is 0.1 mm.

[0013] Optionally, the center distance between the Pad readout strips in each dimension is 0.75 mm.

[0014] Optionally, the inner wall of the via hole is copper-plated, epoxy resin is filled in the via hole with the copper-plated inner wall, copper is plated on the surface of the epoxy resin again, and the surface of the readout pad is made flush with the surface of the PCB board through grinding.

[0015] Another object of the utility model is to provide a microstructure gas detector, including the microstructure gas detector readout circuit structure.

[0016] The readout circuit structure of the microstructure gas detector of the utility model is a "three-dimensional Pad connecting strip readout" structure, which can realize a "two-dimensional positioning, three-dimensional selection" readout solution, solve the problem that two-dimensional readout cannot simultaneously select multiple hit events, and further improve the counting rate requirements that the microstructure gas detector can meet. By effectively selecting multiple hit events, the event rate can be effectively improved without changing the existing acquisition system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of multiple hit positioning of a readout circuit of a microstructure gas detector under the prior art.

[0018] Figure 2 The utility model is a schematic diagram of the three-dimensional position judgment principle of the readout circuit structure of the microstructure gas detector.

[0019] Figure 3 It is a 3D schematic diagram of the readout circuit structure of the microstructure gas detector of the utility model.

[0020] Figure 4 The utility model is a schematic diagram of the readout circuit structure, readout Pad and wire arrangement of the microstructure gas detector.

[0021] Figure 5 The utility model is a schematic diagram of the wiring arrangement of the readout circuit structure of the microstructure gas detector.

[0022] Figure 6 It is a schematic diagram of the readout circuit structure Pad and wire arrangement dimensions of the utility model microstructure gas detector.

[0023] Figure 7 It is a schematic diagram of a detector composed of a readout circuit structure of a microstructure gas detector of the utility model. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] The readout circuit of the microstructure gas detector of the utility model is based on the two-dimensional Pad connected strip readout and is improved by adding one dimension of position information to perform position judgment, thereby realizing "two-dimensional positioning, three-dimensional judgment". This will neither discard many multiple hit events like the two-dimensional strip readout, nor introduce too many electronic paths like the simple Pad readout, thereby improving the counting rate and position resolution of the detector, thereby improving the detection performance of the microstructure gas detector, and further improving its effective event rate and position resolution.

[0026] To solve Figure 1 In order to solve the problem of position misjudgment in multiple cases, the utility model improves the reading of the two-dimensional Pad connected strips, and adds one dimension on the premise of two dimensions, such as Figure 2 As shown in the figure, the third-dimensional position information is used to judge the particle incident position in the case of multiple hits, thereby realizing "two-dimensional positioning, three-dimensional judgment", as shown in the figure. Figure 2 As shown, within the width of an electronic read gate, two events are simultaneously entered Figure 2 When the position shown in the figure is , and then get two sets of paired data: , at this time, we can determine that the incident positions are A and B.

[0027] Based on this, the microstructure gas detector readout circuit structure designed and provided by the embodiment of the utility model is as follows: Figure 3 As shown, it is a three-dimensional readout circuit structure, including at least three core boards, such as a first core board 70, a second core board 80, and a third core board 90. Two metal layers are formed on the upper and lower surfaces of each core board, forming six metal layers. The six metal layers are, from top to bottom, a Pad layer 10, a U-dimensional wire connection layer 20, a first ground layer 30, a V-dimensional wire connection layer 40, a second ground layer 50, and a W-dimensional wire connection layer 60; wherein, the Pad layer is arranged with a plurality of readout Pads 120 to form a readout Pad array and gaps are left between adjacent readout Pads; a via is provided in the center of the readout Pad, and a layer of wire 130 is arranged on the U-dimensional wire connection layer, the V-dimensional wire connection layer, and the W-dimensional wire connection layer, respectively, and the wire 130 of each layer is connected to the via of the readout Pad 120 to form a Pad readout strip of the layer, and the wire is located at a position corresponding to the gap between the readout Pads, see Figure 4 shown.

[0028] In the present application, since the wires connecting the readout pad are placed on different layers (wires of the same dimension are on the same board layer), the connection between the wires and the readout pad needs to be achieved through the vias. In order to reduce interference, a ground layer (gnd) needs to be placed between every two wire layers to reduce the crosstalk between the wires, i.e., the first ground layer 40 and the second ground layer 50. This requires the use of at least six-layer board structure, i.e., from the first layer to the sixth layer, they are Pad layer, U-dimensional wire connection layer, ground layer, V-dimensional wire connection layer, ground layer, and W-dimensional wire connection layer.

[0029] Furthermore, the first core board and the second core board are combined through the first Prepreg layer 100, and the second core board and the third core board are combined through the second Prepreg layer 110, and finally form the microstructure gas detector readout circuit structure of the utility model, such as Figure 3 shown.

[0030] Optionally, in the top-down state, in the three Pad readout strips in three dimensions in a single case, the angle between adjacent Pad readout strips is ,like Figure 5 As shown, the angle between the U-dimensional wire 131 and the V-dimensional wire 133, and between the V-dimensional wire 133 and the W-dimensional wire 132, and the angle between the U-dimensional wire 131 and the W-dimensional wire 132 is 120 degrees.

[0031] Optionally, the number of Pad readout bars corresponding to each dimension in a single case is Strips are arranged in parallel with each other. More preferably, the number of Pad readout strips corresponding to each dimension in the single case is 3, and the 3 Pad readout strips are arranged in parallel. In this application, the via diameter is selected to be 0.2mm, the pad spacing is 0.1mm, and the safety spacing is 0.1mm. For strip reading, the strip period (pitch) of the single-dimensional readout strip that can be achieved in the processing technology is at least 0.5mm, and because the bottom width of the electron group is generally Therefore, preferably, the number of response readout bars n is within within the scope of article.

[0032] Optionally, in a more preferred embodiment, in the present application, the overall size of the designed microstructure gas detector readout circuit structure is 50mm×50mm, the number of paths in the three dimensions of U, V, and W are 88, 88, and 66 respectively, and the shape of the readout Pad is a regular hexagon, and the side length of the regular hexagonal readout Pad is 0.231mm, such as Figure 6As shown, optionally, the gap spacing between adjacent readout pads is 0.1mm, and the line width of the wire is set to 0.1mm. Optionally, the via hole in the middle of the readout pad is a circular via hole, and the diameter of the circular via hole is 0.2mm; optionally, the gap spacing between the via hole and the wire is 0.1mm. Optionally, the center distance between the Pad readout strips in each dimension (i.e., the strip period pitch) is 0.75mm.

[0033] In the present application, in order to connect readout pads of the same dimension into a strip, a via hole needs to be punched in the middle of each readout pad. The via hole is preferably a circular hole, and the vias are connected by wires through the via holes to form a readout strip in series.

[0034] In one embodiment, the inner wall of the via hole is plated with copper 122, and the via hole after the copper-plated inner wall is filled with epoxy resin 121, and copper is plated on the surface of the epoxy resin again, and the surface of the readout pad is made flush with the surface of the PCB board by grinding. Figure 6 As shown. In the processing technology of the via, a layer of copper is plated on the cylindrical surface of the hole wall of the via by chemical deposition, so that the copper foils that need to be connected in the middle layers can be connected. In this design, the via is used to connect the top pad and the wires of the middle layers, so in order to no longer reduce the effective measurement area of ​​the top pad, the drill hole in the middle of the via needs to be processed to a certain extent. Here, the application adopts the method of "resin plugging, gold plating and flattening" to minimize the adverse factors brought by the via. That is, after the via is processed (after the hole wall of the via is copper-plated), the hole is filled with epoxy resin, and finally copper is plated on the surface of the resin, and the copper-plated PCB board is ground and flattened.

[0035] Since the shrinkage of the resin is small, it has a good bond with the hole wall. The final effect is that the hole is still conductive and there are no dents on the surface, which does not affect the measurement.

[0036] Among them, the microstructure gas detector can be a gas electron multiplier (GEM) or a micromesh gas detector (Micromesh Gaseous Structure, MicromeGAS). Correspondingly, the readout circuit of the microstructure gas detector can be a gas electron multiplier readout circuit or a micromesh gas detector readout circuit.

[0037] Another object of the present utility model is to provide a microstructure gas detector, including the microstructure gas detector readout circuit structure 500 .

[0038] The following takes an electron multiplier as an example to illustrate the structure of a microstructure gas detector using the microstructure gas detector readout circuit structure 500. In the gas electron multiplier, the microstructure gas detector readout circuit structure is arranged below the three-layer cascade GEM film of the gas electron multiplier, and the effective readout surface of the microstructure gas detector readout circuit structure is smaller than the area of ​​the three-layer cascade GEM film.

[0039] Generally, in order to obtain a more uniform electric field strength, in a gas electron multiplier, the effective readout area of ​​the readout board (PCB board) of the readout circuit structure will be slightly smaller than the effective area of ​​the electron multiplier 600. Figure 7 As shown, in the present application, since the effective readout plate area of ​​the microstructure gas detector readout circuit structure 500 is 50 mm×50 mm, a gas electron multiplier with an effective area of ​​60 mm×60 mm is selected for use therewith.

[0040] See also Figure 7 As shown, when in use, in order to obtain electronic signals, the three-dimensional wires of the three-dimensional microstructure gas detector readout circuit structure need to be respectively led out and connected to the preamplifier to amplify the signal and output it. Therefore, a socket 400 is installed on the circuit board to adjust and plan the wires and lead the wires out from the Pad readout part.

[0041] See also Figure 7 As shown, during the measurement process, the three-layer cascade GEM film and the three-dimensional microstructure gas detector readout circuit structure need to be placed in the circular metal cover 300 to shield electromagnetic noise, interference from cosmic rays, etc. Therefore, the multiple sockets 400 that have no direct effect on the detection of electrons are all distributed outside the circular metal cover 300.

[0042] See also Figure 7 As shown, in order to fix the metal cover 300, multiple mounting holes 310 need to be symmetrically arranged, and multiple sockets are symmetrically distributed on the outside of the circular metal cover. Mounting holes 210 are distributed on the four corners of the PCB board 200 of the microstructure gas detector readout circuit structure for fixing the PCB board 200.

[0043] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and the utility model can be implemented in other specific forms without departing from the spirit or basic features of the utility model.

[0044] Therefore, no matter from which point of view, the embodiments should be regarded as illustrative and non-restrictive, and the scope of the present invention is limited by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0045] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A microstructure gas detector readout circuit structure, characterized in that: The invention is a three-dimensional readout circuit structure, comprising at least three core boards, two metal layers are formed on the two surfaces of each core board, and six metal layers are formed. The six metal layers are, from top to bottom, a Pad layer, a U-dimensional wire connection layer, a first ground layer, a V-dimensional wire connection layer, a second ground layer, and a W-dimensional wire connection layer; the Pad layer is provided with a plurality of readout pads to form a readout pad array, and gaps are left between adjacent readout pads; a via is provided in the center of the readout pad, and a layer of wire is arranged on the U-dimensional wire connection layer, the V-dimensional wire connection layer, and the W-dimensional wire connection layer respectively, and the wires of each layer are connected to the vias of the readout pad to form a pad readout strip of the layer, and the wires are located at positions corresponding to the gaps between the readout pads.

2. The microstructure gas detector readout circuit structure according to claim 1, characterized in that: In the top-down state, the angle between adjacent Pad readout strips in three dimensions of a single case is .

3. The readout circuit structure of the microstructure gas detector according to claim 1, characterized in that: The number of Pad readout bars corresponding to each dimension in a single case is and arranged parallel to each other.

4. The microstructure gas detector readout circuit structure according to claim 1, characterized in that: The readout pad is in the shape of a regular hexagon, and the side length of the regular hexagonal readout pad is 0.231 mm.

5. The microstructure gas detector readout circuit structure according to claim 4, characterized in that: The gap spacing between adjacent readout pads is 0.1 mm, and the line width of the conductive line is set to 0.1 mm.

6. The readout circuit structure of the microstructure gas detector according to claim 5, characterized in that: The via hole in the middle of the readout pad is a circular via hole, and the diameter of the circular via hole is 0.2 mm.

7. The readout circuit structure of the microstructure gas detector according to claim 6, characterized in that: The gap between the via hole and the conductor is 0.1 mm.

8. The readout circuit structure of the microstructure gas detector according to claim 7, characterized in that: The center distance between the Pad readout strips in each dimension is 0.75 mm.

9. The microstructure gas detector readout circuit structure according to claim 1, characterized in that: The inner wall of the via hole is copper-plated, and the via hole with the copper-plated inner wall is filled with epoxy resin. Copper is plated on the surface of the epoxy resin again, and the surface of the readout pad is made flush with the surface of the PCB board through grinding.

10. A microstructure gas detector, characterized in that: It comprises the microstructure gas detector readout circuit structure as described in any one of claims 1-9.

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