Preparation method of resistive micro-groove type detector and detector

Abstract

The invention provides a preparation method of a resistive micro-groove type detector and a detector, and the preparation method comprises the steps: S1, plating a resistive DLC film on the lower surface of a polyimide film of which the upper surface is coated with a metal layer, and carrying out the patterning of the resistive DLC film, and obtaining an amplification structure unit substrate; s2, preparing a read-out electrode plate, and laminating the amplification structure unit base material and the read-out electrode plate; s3, manufacturing a metalized via hole outside the sensitive region; s4, preparing a first groove array on the amplification structure unit base material, and preparing a charge discharge line in the first groove; s5, preparing a second groove array on the amplification structure unit base material as an amplification structure; and S6, manufacturing a peripheral circuit, integrating a drift electrode and setting an air gap layer as a drift region to complete the preparation of the resistive microgroove type detector.

Description

Technical Field

[0001] The present disclosure relates to the technical field of gas detectors, and in particular to a preparation method of a resistive microgroove detector and the detector. Background Art

[0002] Gas detectors, with their low cost, play an important role in the field of large-area particle detection. Collision experiments are one of the most effective means of studying the fundamental properties of nuclear and particle physics. The main development directions of the new generation of colliders are high brightness and high energy, which pose great challenges to the response capability, spatial resolution, and radiation resistance of traditional gas detectors. Microstructured gas detectors are a new type of gas detector developed based on PCB and etching processes. Compared with traditional gas ionization chambers and filament chambers, microstructured gas detectors have advantages such as fast response, high counting rate capability, and high position resolution. However, current microstructured gas detectors still have problems such as poor readout performance, low sensitivity, and poor productivity or maintainability due to complex or unreasonable structures. Summary of the Invention

[0003] In view of this, in order to at least partially solve at least one of the above-mentioned technical problems, the present disclosure provides a method for preparing a resistive microgroove detector and a detector.

[0004] In order to achieve the above objectives, the technical solutions disclosed in this disclosure are as follows:

[0005] According to an embodiment of one aspect of the present disclosure, a method for preparing a resistive microgroove detector is provided, comprising operations S1 to S6:

[0006] S1: coating a resistive DLC film on the lower surface of a polyimide film having a metal layer on the upper surface and patterning the resistive DLC film to obtain an amplified structural unit substrate;

[0007] S2: preparing a readout electrode plate and pressing the amplification structure unit substrate and the readout electrode plate together;

[0008] S3: Make metalized vias outside the sensitive area;

[0009] S4: preparing a first groove array on the amplification structure unit substrate, and preparing a charge discharge line in the first groove;

[0010] S5: preparing a second groove array as an amplification structure on the amplification structure unit substrate; and

[0011] S6: Make peripheral circuits, integrate drift electrodes, and set an air gap layer as a drift region to complete the preparation of the resistive microgroove detector.

[0012] According to the embodiment of the present disclosure, the thickness of the polyimide film is d, which is in the range of 50 μm≤d≤125 μm.

[0013] According to an embodiment of the present disclosure, the charge discharge line is prepared by depositing a conductive material in the first groove, so that the charge discharge line contacts the resistive DLC film at the bottom of the first groove, thereby achieving rapid discharge of the charge accumulated on the DLC film.

[0014] According to an embodiment of the present disclosure, the DLC film is patterned by using a photoresist film with a pattern for protection and removing the DLC film not protected by the photoresist film using a sandblasting process.

[0015] According to an embodiment of the present disclosure, operation S2 includes: pressing the amplifying structure unit substrate onto the surface of the readout electrode plate using prepreg and polyimide material, with a pressure value of 7 bar to 20 bar during pressing.

[0016] According to the embodiment of the present disclosure, the metal layer is a Cu / Cr composite metal layer. After the metallized via is completed, the thickness of Cu in the metal layer is 10 μm to 15 μm.

[0017] According to an embodiment of another aspect of the present disclosure, a resistive microgroove detector prepared based on the preparation method described in any one of the above items is provided, which includes, from top to bottom, a drift electrode, an air gap layer, an amplifying structure unit, and a bottom readout electrode unit, wherein: the air gap layer between the drift electrode and the amplifying structure unit serves as a drift region, and the drift region obtains primary electrons under the action of the particles to be measured and drifts to the amplifying structure unit; the amplifying structure unit includes a plurality of first grooves and a plurality of second grooves, wherein the first grooves are provided with charge discharge lines, and the second grooves serve as amplifying structures; the first grooves and the second grooves divide the metal layer on the surface of the substrate of the amplifying structure unit into a plurality of strip-type first readout strips, and the bottom readout electrode unit includes a plurality of second readout strips, and the first readout strips and the second readout strips constitute a two-dimensional grid readout electrode.

[0018] According to an embodiment of the present disclosure, the first groove is an elongated groove, and the cross section of the first groove is wide at the top and narrow at the bottom. Assuming the thickness of the polyimide film is d, 50 μm ≤ d ≤ 125 μm, the width of the upper notch of the first groove is 2d, and the width of the bottom of the first groove is between 70 μm and 2d. The second groove is an elongated groove, and the cross section of the second groove is wide at the top and narrow at the bottom. Assuming the thickness of the polyimide film is d, 50 μm ≤ d ≤ 125 μm, the width of the upper notch of the second groove is between d and d + 20 μm, and the width of the bottom of the second groove is between 20 μm and d.

[0019] According to the embodiment of the present disclosure, the thickness of the resistive DLC film is between 20 nm and 200 nm, and the surface resistivity is between 10 MΩ / □ and 200 MΩ / □. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0021] Figure 1 Schematic diagram of the three-dimensional amplified structure of the resistive micro-well detector.

[0022] Figure 2 Schematic diagram of a resistive microgroove detector according to an embodiment of the present disclosure.

[0023] Figure 3 Flowchart of a method for preparing a resistive microgroove detector according to an embodiment of the present disclosure.

[0024] Figure 4a This is a schematic diagram of the process flow corresponding to operation S1 in the preparation method of the resistive microgroove detector.

[0025] Figure 4b Schematic diagram of the process flow corresponding to operation S2 in the preparation method of the resistive microgroove detector.

[0026] Figure 4c This is a schematic diagram of the process flow corresponding to operation S3 in the preparation method of the resistive microgroove detector.

[0027] Figure 4d This is a schematic diagram of the process flow corresponding to operation S4 in the preparation method of the resistive microgroove detector.

[0028] Figure 4e This is a schematic diagram of the process flow corresponding to operation S5 in the preparation method of the resistive microgroove detector.

[0029] Figure 4f This is a schematic diagram of the process flow corresponding to operation S6 in the preparation method of the resistive microgroove detector. DETAILED DESCRIPTION

[0030] The present disclosure provides a preparation method and detector of a resistive micro-groove detector, which uses a long groove as the amplifying structure of the detector. The metal layer on the top of the long groove is in the form of a long strip, which can itself serve as a one-dimensional readout strip, which can effectively solve the charge sharing effect caused by the two-dimensional readout strips being located on the same side of the amplifying structure, and significantly improve the amplitude of the sensing signal; and because the groove structure can allow the etching liquid to flow effectively in the groove during etching, the rate of exchange between the etching liquid in the groove and the outside world is faster, so that for a polyimide substrate of the same thickness, the time required to etch the groove structure is much less than the time required to etch the blind hole structure, which greatly reduces the lateral etching of polyimide, so the difficulty of making a groove-type amplifying structure on a thick polyimide substrate is much less than the difficulty of making a blind hole-type amplifying structure; in addition, the design is very suitable for adding a charge discharge line in the middle of the amplifying structure to improve the counting rate capability, so it can adapt to more application occasions.

[0031] Currently, in large-scale collision experiments, microstructured gas detectors are gradually taking on the tasks of track detection and large-area triggering in specific high-count regions. Examples include the three-layer GEM (gaselectron multiplier) detector used for small-angle track detection in the COMPASS experiment and the large-area MicroMegas detector used for muon triggering in the forward region of the ATLAS NSW (new small wheel) experiment. Three-layer GEM detectors employ cascade multiplication, with a complete detector consisting of three independent layers of GEM membranes. This results in a complex structure and high mass. Furthermore, each GEM membrane requires strong tension, which requires additional gluing or mechanical tensioning, making installation very complex. MicroMegas detectors use stainless steel mesh to focus the electric field, achieving high gain with a monopole structure. However, the mesh still requires strong tension to maintain air gap uniformity, thus still bearing the process complexity associated with the tension maintenance system. In recent years, a type of tension-free monopole MPGD based on etching technology has been invented. The monopole multiplication structure and the avoidance of tension maintenance system make this type of detector simple in structure and very easy to install, and it has begun to be used in various accelerator experiments.

[0032] An existing technical solution is the resistive micro-well gas detector (μRWELL), whose three-dimensional structure is as follows Figure 1As shown in Figure 1 , the amplification structure is a blind hole, with copper on the top, APICAL in the middle, and DLC at the bottom. To achieve two-dimensional position sensitivity, a two-dimensional strip readout is often used, with the readout strip made of copper. The μRWELL multiplication structure is created by chemically etching the insulating dielectric. The detection sensitive unit is bonded to the PCB readout board via a vacuum thermocompression process, eliminating the need for tension and simplifying the installation process. Furthermore, due to the introduction of the DLC resistive electrode, the μRWELL can achieve high gain through unipolar amplification. The unipolar multiplication structure significantly reduces the detector's structural complexity, facilitating mass reduction and further reducing installation complexity. However, this two-dimensional readout detector has the following disadvantages: 1. The two-dimensional readout strips are located on the same side of the amplification structure, sharing the generated charge during signal generation. This significantly reduces the signal amplitude of the unidimensional readout strip. Furthermore, due to the different distances between the two-dimensional readout strips and the amplification structure, the readout strip width must be adjusted to achieve equivalent signals on the two-dimensional strips. Improper optimization can easily affect the signal amplitude and, consequently, position resolution performance. 2. The well-type blind hole multiplication structure is an inverted truncated cone with a wide top and narrow bottom. The geometry is relatively closed. If sparks occur during actual operation, cleaning is very difficult, often requiring high-pressure water jet flushing accompanied by ultrasonic cleaning. 3. Etching blind hole structures on polyimide substrates thicker than 50μm takes a long time. The polyimide substrate is subject to significant lateral etching, which can easily cause copper to fall off. When the polyimide substrate thickness exceeds 75μm, well-type blind holes can no longer be produced by purely chemical etching, which also limits the application of μRWELL detectors.

[0033] Therefore, in order to solve the problems existing in the two-dimensional readout of the existing μRWELL solution, it is necessary to invent a position-sensitive gas detector suitable for large-area applications. It should adopt an easily scalable strip readout solution, and it is necessary to significantly improve the amplitude of the single-dimensional readout signal by solving the charge sharing effect. At the same time, it should also have a matching charge discharge structure to improve the counting ability of the large-area detector and adapt to large-area position-sensitive applications. In addition, the preparation method of this detector should be applicable to a variety of polyimide substrates of different thicknesses, so as to effectively expand the application range of the detector. In order to achieve the above purpose, the present disclosure proposes a preparation method and detector of a resistive microgroove detector. The detector uses long strip grooves as the amplification structure of the detector. The top metal layer between the grooves is long strip-shaped and can itself serve as a one-dimensional readout strip, which can effectively solve the charge sharing effect caused by the two-dimensional readout strips being located on the same side of the amplification structure, and significantly improve the amplitude of the sensing signal; and because the groove structure can allow the etching liquid to flow effectively in the groove during etching, the rate of exchange between the etching liquid in the groove and the outside world is faster, which makes the time required to etch the groove structure for the same thickness of polyimide much less than the time required to etch the blind hole structure, which greatly reduces the lateral etching of polyimide. Therefore, the difficulty of making a groove-type amplification structure on thick polyimide is much less than the difficulty of making a blind hole-type amplification structure; in addition, the design is very suitable for adding a charge discharge line in the middle of the amplification structure to improve the counting rate capability, so it can adapt to more applications.

[0034] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0035] In the embodiment of the present disclosure, Figure 3 and Figure 4a-4f As shown, a method for preparing a resistive microgroove detector with a charge discharge structure is provided, including operations S1 to S6.

[0036] S1: coating a resistive DLC film on the lower surface of a polyimide film having a metal layer on the upper surface and patterning the resistive DLC film to obtain an amplified structural unit substrate;

[0037] S2: preparing a readout electrode plate and pressing the amplification structure unit substrate and the readout electrode plate together;

[0038] S3: Make metalized vias outside the sensitive area;

[0039] S4: preparing a first groove array on the amplification structure unit substrate, and preparing a charge discharge line in the first groove;

[0040] S5: preparing a second groove array as an amplification structure on the amplification structure unit substrate; and

[0041] S6: Make peripheral circuits, integrate drift electrodes, and set an air gap layer as a drift region to complete the preparation of the resistive microgroove detector.

[0042] According to the embodiment of the present disclosure, Figure 4a As shown, operation S1 includes:

[0043] First, if Figure 4a As shown in section (1), a polyimide substrate (using Apical as an example) with a metal layer (using a Cu / Cr layer as an example) on one side is used, where the polyimide thickness is 50-125 μm. The surface of the polyimide film without copper is roughened to increase the bonding strength during the coating process.

[0044] Furthermore, if Figure 4a As shown in part (2), a resistive DLC film is prepared on the roughened surface of a polyimide film using a magnetron sputtering method. The thickness of the DLC film is between 20 nm and 200 nm, and the surface resistivity is between 10 MΩ / □ and 200 MΩ / □.

[0045] Furthermore, if Figure 4a As shown in part (3), according to the size of the detector to be processed, a polyimide substrate coated with resistive DLC is cut to a suitable size, positioning holes are processed on the substrate, and a photoresist film is applied to the side coated with DLC and exposed and developed according to the positioning holes, so that the DLC in the sensitive area of the detector is protected by the photoresist film, while the DLC outside the sensitive area is completely exposed. Then, sandblasting is performed. The purpose is to remove the DLC film outside the sensitive area of the detector. After sandblasting, the photoresist film is removed, and the resulting amplification structure unit substrate is cleaned.

[0046] According to the embodiment of the present disclosure, Figure 4b As shown, operation S2 includes:

[0047] First, if Figure 4b As shown in part (1), the readout electrode plate and readout structure (second readout strip) of the detector are prepared by standard PCB process, and positioning holes are processed.

[0048] Furthermore, if Figure 4bAs shown in part (2), vacuum lamination technology is used to press the DLC-coated polyimide substrate onto the readout electrode board using Pre-preg film (Pre-impregnated, prepreg) and a polyimide film (such as Kapton) with a thickness of (12±0.5) μm. The pressure used for pressing is 7 bar~20 bar. After pressing, the structure from bottom to top is the readout electrode PCB, Pre-preg, Kapton, Pre-preg, and the amplification structure unit substrate coated with DLC at the bottom, wherein the copper-clad side of the amplification structure unit substrate is at the top.

[0049] According to the embodiment of the present disclosure, Figure 4c As shown, operation S3 includes:

[0050] Holes are drilled in areas outside the sensitive area where there is no DLC and metalized by electroplating, so that the readout circuit on the Cu layer of the amplification structure unit substrate can be interconnected with the circuit on the readout electrode board PCB for signal readout; after the vias are metallized, the thickness of the Cu layer in the Cu / Cr layer on the polyimide increases to 10μm~15μm.

[0051] According to the embodiment of the present disclosure, Figure 4d As shown in , operation S4 includes:

[0052] First, if Figure 4d As shown in part (1), a photoresist film is applied to the surface of the amplified structural unit substrate and exposed and developed to produce an etching pattern for the charge discharge line. The developed photoresist film is then used as a mask to etch the Cu layer in the metal layer, and then the Cu layer is etched using Cu as a mask.

[0053] Furthermore, if Figure 4d As shown in part (2), the remaining Cu / Cr layer is used as a mask to etch the polyimide substrate. After sufficient etching, the DLC at the bottom of the groove will be exposed. The first groove is a long strip groove. The cross section of the first groove is wide at the top and narrow at the bottom. The width of the first groove where the charge discharge line is located is 2d, where d is the thickness of the polyimide substrate, 50μm≤d≤125μm, and the width of the bottom of the first groove is between 70μm and 2d.

[0054] Furthermore, if Figure 4d As shown in part (3), the conductive silver paste is applied to the first groove by screen printing or scraping, and then the residual silver paste on the surface of the Cu layer is cleaned as much as possible with a clean cloth soaked in alcohol. After the conductive silver paste in the first groove is completely solidified, the surface of the Cu layer is cleaned and polished using the deburring process used in PCB processing to ensure that there is no conductive silver paste residue on the surface of the Cu layer.

[0055] Furthermore, if Figure 4d As shown in part (4), the groove array portion coated with silver paste is patterned and electroplated to ensure that the silver paste has a good electrical connection with the Cu layer. Since the bottom of the silver paste is connected to the DLC and the top is connected to the Cu layer, the DLC can have a good electrical connection with the copper on the top layer of the polyimide. The result after pattern plating the first groove array is shown in Figure 4d As shown in part (4), the thickness of the Cu layer produced by pattern electroplating is 5μm~10μm.

[0056] According to the embodiment of the present disclosure, Figure 4e As shown, S5 includes:

[0057] First, if Figure 4e As shown in part (1), a photoresist film is applied to the surface of the amplifying structure unit substrate after operation S4 and then exposed and developed to produce a mask pattern for etching the amplifying structure. The developed photoresist film is then used as a mask to etch the Cu layer. After the Cu layer is etched, the Cr layer is etched using the Cu layer as a mask. The groove width etched on the metal layer is d~(d+20μm), where d is the thickness of the polyimide used, 50μm≤d≤125μm.

[0058] Furthermore, if Figure 4e As shown in part (3), the polyimide substrate is etched using the remaining Cu / Cr layer as a mask until the DLC layer is reached, resulting in an array of multiple second grooves. The second grooves serve as the groove-type amplification structure, completing the preparation of the groove-type amplification structure unit. The minimum width of the bottom of the second groove etched on the polyimide is 20μm, and the maximum width is d, where d is the thickness of the polyimide substrate used.

[0059] According to the embodiment of the present disclosure, Figure 4f As shown, in operation S6, peripheral circuits are produced on the Cu / Cr layer of the slot-type amplifying structure unit and the Cu layer on the bottom surface of the readout electrode PCB, and the outer shape of the board is processed to obtain a composite PCB structure consisting of the amplifying structure unit and the bottom readout electrode unit. This step mainly produces circuits for high-voltage supply, charge discharge line connection and signal output on the surface of the polyimide substrate and the readout electrode board PCB, and processes the outer shape of the composite PCB structure according to the detector design. Then, the drift electrode is integrated and the air gap layer is set as the drift region, and finally the preparation of the resistive micro-groove detector with a charge discharge structure is completed.

[0060] Example 1: Combination Figure 3 and Figure 4a-4fAs shown in the figure, a resistive microgroove detector with an effective area of 10cm×10cm is used as an example to illustrate the detector preparation method proposed in the present invention: First, a polyimide (Apical) substrate with a thickness of 50μm and a length and width of 30cm and coated with a Cu / Cr layer on one side is cut, wherein the Cu thickness is 5μm and the Cr thickness is 10nm. The substrate is pasted on a standard copper substrate, and the exposed surface of the polyimide substrate is treated using the surface roughening process used in PCB processing to increase the surface roughness of the polyimide substrate. Furthermore, the polyimide substrate is clamped on a rotating rack in the chamber of a magnetron sputtering coating device; the vacuum degree of the chamber is controlled to 5×10 -5The power applied to the graphite target is 2-5kW, preferably 4kW; the sputtering time is 20-40min, preferably 35min. The resulting resistive DLC electrode has a surface resistivity of approximately 60-70MΩ / □. Furthermore, positioning holes are machined on the DLC-coated polyimide substrate. A photoresist film is then applied to one side of the DLC and exposed and developed, protecting a 13cm×13cm area of DLC as the sensitive region. The DLC outside the sensitive region is exposed. This 13cm×13cm sensitive region includes not only the 10cm×10cm effective detector operating area, but also the additional processing area required to process this 10cm×10cm effective region. The DLC outside the sensitive region not protected by the photoresist film is then sandblasted away. After sandblasting, the photoresist film is removed using a film stripping process. Finally, the film is cleaned and dried to obtain a substrate suitable for subsequent lamination and etching. Furthermore, the detector readout electrode plate is fabricated using standard PCB processes. The readout structure consists of a one-dimensional readout strip, referred to as the second readout strip. The second readout strip has a thickness of 5μm-15μm, preferably 5μm. The thickness of the second readout strip influences the thickness of the subsequent prepreg film (e.g., Pre-Preg). Vacuum lamination is then used to press a 12.5μm-50μm thick polyimide material (e.g., Kapton) between the amplification structure unit substrate and the readout electrode plate PCB using a 25μm-50μm thick Pre-Preg. The preferred thickness for Pre-Preg is 25μm, and the preferred thickness for Kapton is 12.5μm. The pressure is 7-20 bar, preferably 10 bar. For example, a 25μm thick pure adhesive Pre-Preg and a 12.5μm thick Kapton are used. The amplification structure unit substrate, coated with a resistive DLC film on the bottom, is pressed onto the readout electrode plate at a pressure of 10 bar to produce a composite PCB substrate. Furthermore, drilling and metallization are performed on the laminated composite PCB board to complete the production of metallized vias. The metallized vias located outside the sensitive area are used for circuit connection, including connection between the readout strip and the readout connector. After the metallization is completed, the thickness of the Cu layer on the upper surface of the amplifying structure unit substrate is 10~15μm, and the preferred value is 15μm. Furthermore, a photoresist film is affixed to the surface of the Cu layer and exposed and developed to produce the first groove pattern required for the charge discharge circuit. The slot width of the first groove where the charge discharge line is located is twice the thickness of the polyimide substrate, preferably 100μm here. The period length of the charge discharge line needs to be determined according to the counting rate requirement of the detector, which is 51.2mm here. In this way, the entire detector plane can be partitioned and the charge discharged in combination with the subsequent steps; thereafter, the developed photoresist film is used as a mask, and the Cu layer is etched using a copper etching solution, and then the Cr layer is etched using the Cu layer as a mask. Furthermore, the polyimide substrate is etched using the Cu / Cr layer as a mask to expose the bottom resistive DLC. The bottom width of the first groove is about 80 μm.Furthermore, screen printing is used to coat the charge discharge line slots with conductive silver paste, and then a clean cloth with alcohol is used to clean the residual silver paste on the copper surface as much as possible. After the conductive silver paste in the slots is completely solidified, the surface of the Cu layer is cleaned and polished using the deburring process in the PCB processing technology to ensure that there is no conductive silver paste residue on the surface of the Cu layer. Furthermore, the first groove array portion coated with silver paste is subjected to graphic electroplating to achieve metallization of the first groove, and the thickness of the deposited metal Cu is 5-10μm, with an optimal value of 5μm. The metallic copper deposited in this process will be connected to the bottom DLC through the conductive silver paste, ultimately achieving rapid discharge of the accumulated charge on the DLC. Furthermore, a photoresist film is affixed to the surface of the amplifying structure unit substrate and exposed and developed to produce a mask pattern for etching the second groove of the amplifying structure. The amplification structure period is 200μm, the Cu / Cr etched in one period is 70μm wide, and the remaining Cu / Cr is 130μm wide; then the Cu layer is etched using the developed photoresist film as a mask, and then the Cr is etched using Cu as a mask. Further, the polyimide substrate is etched using the remaining Cu / Cr layer as a mask to obtain multiple second grooves as groove-type amplification structures. Due to the anisotropic etching characteristics of polyimide, the etched second groove groove structure is wide at the top and narrow at the bottom, presenting an inverted trapezoidal structure. The width of the upper groove of the second groove is 70μm obtained by graphical preparation, and the width of the lower groove bottom is determined according to the etching time of the polyimide substrate. The minimum width is 20μm, and the maximum width is the same as the thickness of the polyimide substrate, preferably 50μm. Further, circuit production and shape processing are performed on the Cu / Cr layer on the surface of the polyimide substrate and the Cu layer on the bottom surface of the readout electrode. The connecting lines are fabricated using standard PCB processes and connected to the peripheral circuits through the previously completed metallized vias. Finally, the detector's outer shape is machined using a milling machine. Drift electrodes are then integrated and an air gap layer is set as the drift region, completing the fabrication of a resistive microgroove detector with a charge discharge structure.

[0061] Another embodiment of the present disclosure further provides a resistive microgroove detector prepared by the above-mentioned preparation method, Figure 2 and Figure 4a-4f As shown, the detector includes a drift electrode, an air gap layer, an amplification structure unit, and a bottom readout electrode unit from top to bottom, wherein:

[0062] The air gap layer between the drift electrode and the amplifying structure unit serves as a drift region. The drift region obtains primary electrons under the action of the particles to be measured and drifts to the amplifying structure unit.

[0063] The amplifying structure unit includes a plurality of first grooves and a plurality of second grooves, wherein the first grooves are provided with charge discharge lines and the second grooves serve as amplifying structures; and;

[0064] The first groove and the second groove divide the metal layer on the surface of the amplifying structure unit into a plurality of strip-shaped first readout strips. The bottom readout electrode unit includes a plurality of second readout strips. The first readout strips and the second readout strips constitute a two-dimensional grid readout electrode.

[0065] The first groove is an elongated groove with a cross-section that is wider at the top and narrower at the bottom. Assuming the thickness of the polyimide film is d, and 50μm≤d≤125μm, the width of the upper opening of the first groove is 2d, and the width of the bottom of the first groove is between 70μm and 2d. The second groove is an elongated groove with a cross-section that is wider at the top and narrower at the bottom. Assuming the thickness of the polyimide film is d, and 50μm≤d≤125μm, the width of the upper opening of the second groove is between d and d+20μm, and the width of the bottom of the second groove is between 20μm and d. The thickness of the resistive DLC film is between 20nm and 200nm, and the surface resistivity is between 10MΩ / □ and 200MΩ / □.

[0066] This invention proposes a method for preparing a resistive microslot detector and a detector that inherits most of the advantages of the μRWELL detector. Furthermore, the detector boasts a range of advantages, including low material mass, minimal processing difficulty, low manufacturing cost, and ease of fabrication into various shapes. Therefore, it holds great promise for application in large-area track measurement. In particular, compared to the μRWELL detector, the present invention offers the following significant advantages:

[0067] (1) It solves the problem of too small induced signals on each dimension due to charge distribution when using a two-dimensional readout strip, and can make the two-dimensional signal amplitudes equivalent, reducing the cost of optimizing the readout settings. Most of the two-dimensional readout designs of MPGD detectors are located on one side of the amplification region. This method can only collect induced charges from one side. The two-dimensional readout strips will share the induced charge, which will inevitably cause the induced signal amplitude to become smaller. The two-dimensional readout strips adopted by the resistive microgroove detector provided by the present invention are on both sides of the multiplication region. Both two-dimensional readout electrodes can collect all the induced charges. Therefore, under the condition of the same gas gain, the output signal of the resistive microgroove detector is much larger than that of the μRWELL detector, so the signal-to-noise ratio of the detector system is greatly improved. In addition, because charge distribution is also avoided, similar two-dimensional signal amplitudes can be obtained by simply setting the two-dimensional readout strips to the same effective width, reducing the time and production cost of optimizing the two-dimensional readout settings.

[0068] (2) The cleaning process is simple, which not only reduces the maintenance cost of the detector and increases its operating life, but also expands the application of microstructure gas detectors. Due to the openness of the groove structure of the long groove, the detector can be simply cleaned by rollers, air guns, and ultrasonic cleaning, without the need for a composite cleaning method such as a high-pressure water gun plus ultrasonic cleaning like the μRWELL detector. This makes the maintenance difficulty and cost of the resistive microgroove detector very low, and can also effectively increase the service life of the detector. In addition, in applications requiring low mass, such as the inner diameter track detector application of the collision experiment spectrometer, the supporting structure of the detector is usually honeycomb paper and foam with very low mass. If the detector needs to be cleaned with a high-pressure water gun, the supporting structure will undergo irreversible deformation, thereby completely destroying the entire detector. The resistive microgroove detector does not need to be rinsed with a high-pressure water gun, so this problem does not exist when used as an inner diameter track detector, which also effectively expands the application of MPGD in track measurement in collider experiments.

[0069] (3) Adapting to the etching process of thick polyimide materials (thickness > 50μm), thicker groove-type amplification structures can be produced, which is beneficial to improving signal amplitude and reducing parasitic capacitance. Due to the openness of the groove structure, the polyimide and etching solution exchange more fully during the chemical etching process, thus reducing the etching time. This can reduce the lateral etching of the polyimide, ensure the integrity of the Cu layer at the top of the groove, and thus achieve the etching of thick polyimide. The thicker groove-type amplification structure can further improve gas multiplication to increase signal amplitude, and can also reduce the readout strip capacitance to adapt to larger area applications.

[0070] In addition, the present invention also proposes a manufacturing process for a matching charge discharge line structure, which can ensure that high counting capacity is maintained in large-area applications and can further adapt to large-area applications.

[0071] The embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It should be noted that any implementations not depicted or described in the drawings or the main text of the specification are known to those skilled in the art and are not described in detail. Furthermore, the above definitions of the various elements and methods are not limited to the various specific structures, shapes, or methods described in the embodiments, and can be easily modified or replaced by those skilled in the art.

[0072] Furthermore, unless otherwise specified, ordinal numbers such as "first" and "second" are used herein solely to distinguish multiple components with the same name and do not imply a hierarchy, level, execution order, or process sequence between them. A "first" component and a "second" component may appear together in the same component or in different components. The presence of a component with a higher ordinal number does not necessarily imply the presence of the other component with a lower ordinal number.

[0073] In this document, unless otherwise specified, the so-called feature A "or" or "and / or" feature B means that A exists alone, B exists alone, or A and B exist at the same time; the so-called feature A "and" or "and" or "and" feature B means that A and B exist at the same time; the so-called "include", "comprise", "have" and "contain" mean including but not limited to these.

[0074] Furthermore, in this document, terms such as "upper," "lower," "left," "right," "front," "back," or "between" are used solely to describe the relative positions of multiple elements and can be interpreted to include translation, rotation, or mirroring. Furthermore, in this document, unless otherwise specified, "an element is on another element" or similar descriptions do not necessarily mean that the element contacts the other element.

[0075] Furthermore, unless specifically described or required to occur sequentially, the order of the steps is not limited to the order listed above and may be varied or rearranged based on desired design requirements. Furthermore, the above embodiments may be mixed and matched with each other or with other embodiments based on design and reliability considerations. That is, the technical features of different embodiments may be freely combined to form more embodiments.

[0076] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A method for preparing a resistive microgroove detector, comprising: S1: coating a resistive DLC film on the lower surface of a polyimide film having a metal layer on the upper surface and patterning the resistive DLC film to obtain an amplified structural unit substrate; S2: preparing a readout electrode plate and pressing the amplification structure unit substrate and the readout electrode plate together; S3: Make metalized vias outside the sensitive area; S4: preparing a first groove array on the amplification structure unit substrate, and preparing a charge discharge line in the first groove; S5: preparing a second groove array as an amplification structure on the amplification structure unit substrate; and S6: Make peripheral circuits, integrate drift electrodes, and set an air gap layer as a drift region to complete the preparation of the resistive microgroove detector. 2 . The method for preparing a resistive microgroove detector according to claim 1 , wherein the thickness of the polyimide film is d, and the range of the thickness of the polyimide film is 50 μm ≤ d ≤ 125 μm.

3. According to the preparation method of the resistive micro-groove detector according to claim 1, the charge discharge line is prepared by depositing a conductive material in the first groove, so that the charge discharge line contacts the resistive DLC film at the bottom of the first groove, thereby realizing rapid discharge of the accumulated charge on the DLC film.

4. The method for preparing a resistive microgroove detector according to claim 1, wherein the DLC film is patterned by using a patterned photoresist film for protection and removing the DLC film not protected by the photoresist film using a sandblasting process.

5. The method for preparing the resistive microgroove detector according to claim 1, wherein operation S2 comprises: The amplification structure unit substrate is pressed onto the surface of the readout electrode plate through prepreg and polyimide material, and the pressure value during pressing is 7 bar to 20 bar. 6 . The method for preparing a resistive microgroove detector according to claim 1 , wherein the metal layer is a Cu / Cr composite metal layer, and after the metallized vias are formed, the thickness of Cu in the metal layer is 10 μm to 15 μm.

7. A resistive microgroove detector prepared by the preparation method according to any one of claims 1 to 6, comprising, from top to bottom, a drift electrode, an air gap layer, an amplification structure unit, and a bottom readout electrode unit, wherein: The air gap layer between the drift electrode and the amplifying structure unit serves as a drift region. The drift region obtains primary electrons under the action of the particles to be measured and drifts to the amplifying structure unit. The amplifying structure unit includes a plurality of first grooves and a plurality of second grooves, wherein the first grooves are provided with charge discharge lines and the second grooves serve as amplifying structures; The first groove and the second groove divide the metal layer on the surface of the amplifying structure unit substrate into a plurality of strip-shaped first readout strips. The bottom readout electrode unit includes a plurality of second readout strips. The first readout strips and the second readout strips constitute a two-dimensional grid readout electrode.

8. The resistive microgroove detector according to claim 7, wherein the first groove is a long strip-shaped groove, and the cross-section of the first groove is wide at the top and narrow at the bottom. Assuming that the thickness of the polyimide film is d, 50μm≤d≤125μm, the width of the upper groove of the first groove is 2d, and the width of the bottom of the first groove is between 70μm and 2d.

9. The resistive microgroove detector according to claim 7, wherein the second groove is a long strip groove, and the cross section of the groove is wide at the top and narrow at the bottom. Assuming that the thickness of the polyimide film is d, 50μm≤d≤125μm, the width of the upper groove of the second groove is between d and d+20μm, and the width of the bottom of the second groove is between 20μm and d.

10. The resistive microgroove detector according to claim 7, wherein the thickness of the resistive DLC film is between 20 nm and 200 nm, and the surface resistivity is between 10 MΩ / □ and 200 MΩ / □.

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