Photon counting detector

Abstract

The present disclosure relates to a photon counting detector comprising a plurality of detector tiles. Each detector tile comprises a sensor material layer (20), an integrated circuit (30), an input / output connection or flexure (50), a high voltage electrode or foil (60), and an anti-scatter grid (10). The input / output connection or flexure is connected to the integrated circuit. The integrated circuit is configured to read out a signal from the sensor material layer. The anti-scatter grid is positioned adjacent to a surface of the sensor material layer. The high voltage electrode or foil extends across the surface of the sensor material layer and is configured to provide a bias voltage to the surface of the sensor material layer. The high voltage electrode or foil comprises at least one tail portion (70). With respect to the photon counting detector and the plurality of detector tiles, the high voltage electrode or foil of a first detector tile is configured to electrically connect with a high voltage electrode or foil of an adjacent detector tile via one or more of the at least one tail portion of the first detector tile and / or via one or more of the at least one tail portion of the adjacent detector tile.

Description

Technical Field

[0001] The present invention relates to a photon counting detector and a detector block for a photon counting detector. Background Art

[0002] Energy-resolving photon counting detectors for X-ray spectral computed tomography (CT) utilize direct conversion sensor materials such as CdTe, CZT, silicon, GaAs, Ge, and perovskites. These sensor materials are semiconductor compounds that require high voltage bias (e.g., 300 V / mm) to ensure a uniform electric field within the body. As in conventional X-ray CT, spectral CT detectors will also need to be able to provide a large detection area. It has been proposed to use detectors composed of tiles or detector modules to expand the detection area. US2010 / 0327173A1 describes a detector module that includes a direct conversion crystal for converting incident photons into electrical signals, the direct conversion crystal having an anode layer deposited on a first surface and a cathode layer deposited on a second surface. The module also includes a redistribution layer deposited on the anode layer, the redistribution layer being configured to adapt the pad array layout of the direct conversion crystal to a predetermined conductor pattern, and an integrated circuit in electrical communication with the direct conversion crystal. Multiple input / output electrical paths are connected to the redistribution layer to provide connections between the imaging module and another interconnect level.

[0003] US 2013 / 049151 A1 describes an interconnect structure suitable for connecting an anode illuminated detector module to downstream circuitry. In certain embodiments, the interconnect structure is based on or includes low atomic number or polymer features and / or is formed at a density or thickness to minimize or reduce radiation attenuation of the interconnect structure.

[0004] US 2004 / 217293 A1 describes a gamma camera in which multiple radiation detector elements have a rod-shaped first electrode. A semiconductor device surrounds the first electrode to contact it for radiation reception. Second electrodes, provided on the sides of the semiconductor device, are removably attached to a retaining member. The retaining member has a first electrode contact portion that contacts the first electrode and a second electrode contact portion that contacts the second electrode. A collimator is arranged on the radiation entrance side of the multiple radiation detector elements, forming multiple radiation paths corresponding to the multiple radiation detector elements. Gamma ray detection signals output from the first electrode contact portion are transmitted to a signal processing integrated circuit. A high voltage is applied to the second electrode via the second electrode contact portion.

[0005] WO 2017 / 093500A1 relates to a radiation detector, in particular a direct conversion radiation detector. To provide a simple distribution of the supplied high voltage, the radiation detector comprises a plurality of detector modules arranged adjacent to one another. Each detector module comprises a sensor layer for converting incident radiation into electrical charge, a first electrode deposited on a first surface of the sensor layer facing the incident radiation, a second electrode deposited on a second surface of the sensor layer opposite the first surface, readout electronics in electrical contact with the second electrode, and a carrier for carrying the sensor layer and the readout electronics. The radiation detector further comprises an electrically conductive conducting layer and an anti-scatter device, which are arranged on top of one another and cover the plurality of detector modules on the side facing the incident radiation.

[0006] However, it is extremely difficult to make a large area detector from such tiles or modules. In contrast to the case of conventional X-ray detectors, the top of the energy-resolving photon counting detector also needs to be biased, i.e. a bias voltage must be applied to each tile. For limited coverage detectors, the HV (high voltage) is connected to the cathode by a small cable through a decoupling capacitor. However, for large detectors, the HV cannot be distributed using cables because it requires welding (i.e. affects maintainability) and will interfere with the impinging X-ray spectrum (from the wires distributing the HV over the detection area). Routing the HV along the side of the detector will also have an adverse effect on sensor performance.

[0007] These issues need to be addressed. Summary of the Invention

[0008] It would be advantageous to have an improved way of providing large-area photon counting detectors. The objects of the invention are solved by the subject matter of the independent claims, wherein further embodiments are incorporated into the dependent claims. It should be noted that the aspects and examples of the invention described below also apply to photon counting detectors and detector tiles for photon counting detectors.

[0009] In a first aspect, there is provided:

[0010] A photon counting detector includes a plurality of detector segments. Each detector segment includes:

[0011] sensor material layer;

[0012] integrated circuit;

[0013] Input / output connections or flexible bodies;

[0014] High voltage electrodes or foils; and

[0015] Anti-scatter grid.

[0016] The input / output connection or flexible body is connected to the integrated circuit. The integrated circuit is configured to read out signals from the sensor material layer. The anti-scatter grid is positioned adjacent to a surface of the sensor material layer. The high voltage electrode or foil extends across the surface of the sensor material layer and is configured to provide a bias voltage to the surface of the sensor material layer, and wherein the high voltage electrode or foil includes at least one tail portion.

[0017] For the photon counting detector, the high voltage electrode or foil of a first detector tile is configured to be electrically connected to the high voltage electrode or foil of an adjacent detector tile via one or more of the at least one tail portion of the first detector tile and / or via one or more of the at least one tail portion of an adjacent detector tile.

[0018] In other words, the photon-counting detector is provided in a modular form, enabling the configuration of detectors of varying sizes. This is achieved by each tile, or detector module, of the photon-counting detector having its own HV flexible foil, enabling the HV connection between the tiles to be mechanically established in a daisy-chain style when placed adjacent to one another. Thus, the bias voltage that must be applied to each tile propagates to each tile via adjacent tiles. This connection is operational for one-dimensional detectors and can also be used in two-dimensional arrangements.

[0019] In this way, the new photon counting detector may find utility in photon counting spectroscopic computed tomography detection with direct conversion sensor materials and for photon counting detectors targeting a large coverage of applications utilizing direct conversion sensor materials.

[0020] In other words, a new technique is provided to distribute the high-voltage bias of direct-conversion sensors in photon-counting CT, compatible with large coverage areas. This is achieved by spreading the high-voltage bias across the detector tiles so that it does not interfere with the sensor's performance and impact spectrum. Daisy-chain-like interconnections are established across the tiles using contact pressure. This can be achieved during assembly or when a detector tile needs to be replaced. The technique is compatible with complete tile assemblies that include their own anti-scatter grids (ASGs).

[0021] Thus, a new modular photon counting detector arrangement made of individual tiles that propagate bias voltages to adjacent tiles and in which each tile has its own anti-scatter grid allows for convenient replacement of individual tiles when necessary. Furthermore, by having each tile have its own anti-scatter grid, the stringent alignment requirements associated with the anti-scatter grid are alleviated.

[0022] A high-voltage electrode or foil, where a first detector tile can be electrically connected to a high-voltage electrode or foil of an adjacent detector tile using one or more tail portions of the electrode or foil of the first detector tile and / or the electrode or foil of an adjacent detector tile, does not necessarily mean that the tail portions must be in direct contact with each other. For example, a high-voltage electrode or foil of one detector tile can be in electrical contact with its ASG, and the tail portion of the high-voltage foil of an adjacent detector tile can then contact the ASG of the first detector tile. Alternatively, the tail portions can contact each other from adjacent detector tiles, or the tail portions of the high-voltage foils of the detector tiles can contact a separate electrode or flexible body that is itself connected to a high-voltage power supply. In this way, the high-voltage foils are electrically connected to each other, with the tail portions of these foils used to distribute the high-voltage bias required for the sensor material layer.

[0023] In examples, the high voltage electrode or foil of the first detector tile is configured to be electrically connected to the high voltage electrode or foil of a second adjacent detector tile via one or more of the at least one tail portion of the first detector tile and / or via one or more of the at least one tail portion of a second adjacent detector tile.

[0024] In examples, the high voltage electrode or foil of the first detector tile is configured to be electrically connected to the high voltage electrode or foil of the third adjacent detector tile via one or more of the at least one tail portion of the first detector tile and / or via one or more of the at least one tail portion of the third adjacent detector tile.

[0025] In examples, the high voltage electrode or foil of the first detector tile is configured to be electrically connected to the high voltage electrode or foil of the fourth adjacent detector tile via one or more of the at least one tail portion of the first detector tile and / or via one or more of the at least one tail portion of the fourth adjacent detector tile.

[0026] In an example, one or more of the at least one tail portion of the first detector tile are configured to make electrical connections with one or more of the at least one tail portion of the adjacent detector tile.

[0027] In an example, for each detector tile, the anti-scatter grid is not electrically connected to the high voltage electrode or foil.

[0028] In this way, the high voltage electrode or foil can be provided with the bias voltage required for the sensor material layer without the ASG itself then being at a high potential, which may aid maintenance or reinstallation in some cases.

[0029] In an example, for each detector tile, a surface of the high voltage electrode or foil facing away from the layer of sensor material comprises an insulating layer.

[0030] In an example, the anti-scatter grid is electrically connected to the high-voltage electrode or foil for each detector tile. The anti-scatter grid of the first detector tile is configured to be electrically connected to the anti-scatter grid of an adjacent detector tile via the one or more of the at least one tail portion of the first detector tile and / or via the one or more of the at least one tail portion of an adjacent detector tile.

[0031] In an example, the tail portion in contact with the anti-scatter grid of an adjacent detector tile extends in a direction away from the sensor material layer and / or the tail portion in contact with the tail portion of an adjacent detector tile extends in said direction away from the sensor material layer.

[0032] In an example, for each detector tile, one or more of the at least one tail portion are fixedly attached to one or more respective sides of the anti-scatter grid.

[0033] In an example, the photon counting detector includes at least one high voltage connection or flexible body, and wherein each detector tile of the plurality of detector tiles adjacent to a high voltage connection or flexible body of the at least one high voltage connection or flexible body is configured to be electrically connected to the high voltage connection or flexible body through a tail portion.

[0034] Thus, the high voltage electrode or foil of one detector tile is connected to the high voltage electrode or foil of an adjacent detector tile via the tail portions of both being connected to a common high voltage flexible body.

[0035] Obviously, there can be two rows of detector tiles on either side of a common high voltage flexible body.

[0036] In examples, each detector tile has a high voltage electrode or foil comprising one, or two, or three, or four tail portions.

[0037] Different detector tiles in a photon counting detector may have high voltage electrodes or foils with different numbers of tail sections.

[0038] In an example, each detector tile is configured to be removed from a photon counting detector.

[0039] In a second aspect, a detector tile for a photon counting detector comprising a plurality of detector tiles is provided. The detector tile comprises:

[0040] sensor material layer;

[0041] integrated circuit;

[0042] Input / output connections or flexible bodies;

[0043] High voltage electrodes or foils; and

[0044] Anti-scatter grid.

[0045] An input / output connection or flex is connected to an integrated circuit. The integrated circuit is configured to read signals from a plurality of pixels of the sensor material layer. An anti-scatter grid is positioned adjacent to a surface of the sensor material layer. A high voltage electrode or foil extends across the surface of the sensor material layer and is configured to provide a bias voltage to the surface of the sensor material layer, and the high voltage electrode or foil includes at least one tail portion.

[0046] In examples, when connected into the photon counting detector, the high voltage electrode or foil of the detector tile is configured to be electrically connected to the high voltage electrode or foil of an adjacent detector tile via one or more of the at least one tail portion of the detector tile and / or via one or more of at least one tail portion of an adjacent detector tile.

[0047] Advantageously, the benefits provided by any of the above aspects apply equally to all other aspects, and vice versa.

[0048] The above aspects and examples will be apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Exemplary embodiments will be described below with reference to the following drawings:

[0050] Figure 1 An example of an assembled stack of tile detectors is shown, including high voltage (HV) foil extensions for daisy-chain connection;

[0051] Figure 2 An example of interconnection of HV foils across adjacent tile detectors in one dimension is shown;

[0052] Figure 3 An example of an isolated backscatter grid (ASG) for a patch detector is shown;

[0053] Figure 4 An example of a detector tile including two HV tails for spreading the HV potential is shown;

[0054] Figure 5 An example of four detector tiles is shown, where the HV bias potential propagates from one detector tile to the next via the HV tail;

[0055] Figure 6 An example of an HV foil and HV tail as seen from the top is shown, wherein no ASG is shown, and sensor material layers such as CZT, ASIC, input / output connections, and base are not shown and would be hidden underneath;

[0056] Figure 7 shows examples of different HV distributions within a module consisting of two rows of four detector tiles; and

[0057] Figure 8 An example of HV distribution is shown, where a double-sided HV tree contacts the HV tail from each tile. DETAILED DESCRIPTION

[0058] Figure 1-8 The invention relates to a photon counting detector and a detector block used for the photon counting detector.

[0059] In an example, a photon counting detector is provided that includes multiple detector tiles. Each detector tile includes a sensor material layer 20, an integrated circuit 30, an input / output connection or flexible body 50, a high-voltage electrode or foil 60, and an anti-scatter grid 10. The input / output connection or flexible body connects to the integrated circuit (e.g., an application-specific integrated circuit (ASIC)). The input / output connection may consist of one or more components. For example, a rigid or flexible interposer may be used to interface the sensor with the ASIC pixels. The flexible body may also be used to provide power and control signals to the ASIC while also distributing digital readout signals to a data management system. Alternatively, the input / output connection or flexible body 50 may be a single component (e.g., a rigid / flexible body or a flexible body) that performs both pixel interconnection and ASIC control / power / readout. The integrated circuit is configured to read signals from the sensor material layer. This may be from multiple pixels in the sensor material layer. The anti-scatter grid is located near the surface of the sensor material layer. The high-voltage electrode or foil 60 extends across the surface of the sensor material layer and is configured to provide a bias voltage to the surface of the sensor material layer. The high-voltage electrode or foil includes at least one tail portion 70. With respect to the photon counting detector and the plurality of detector tiles, a high voltage electrode or foil of a first detector tile is configured to be electrically connected to a high voltage electrode or foil of an adjacent detector tile via one or more of the at least one tail portion of the first detector tile and / or via one or more of the at least one tail portion of an adjacent detector tile.

[0060] It is important to note that the I / O connections or flexible body can actually be in the form of multiple components and have separate functions. For example, there may be a rigid interposer for pixel-to-pixel connections, while the "flexible body" can be considered to have the purpose of communication with the external "world" and power for the ASIC. However, here, the I / O connections or flexible body can serve both purposes simultaneously.

[0061] In an example, the high voltage electrode or foil of each subsequent or adjacent detector tile is connected to a high voltage power supply via the tail portion(s) of the previous tile or the ASG itself.

[0062] In an example, the tail portion of at least one high voltage electrode or foil is directly connected to the high voltage power supply 100 or directly connected to a connection or flexible body 110 leading to the high voltage power supply.

[0063] Thus, for example, the end detector tiles of a photon counting detector can be directly connected to a voltage source, and the other detector tiles are provided with the required high voltage via connections to adjacent detector tiles in a daisy-chain manner.

[0064] According to an example, the high voltage electrode or foil of a first detector tile is configured to be electrically connected to the high voltage electrode or foil of a second adjacent detector tile via one or more tail portions of the at least one tail portion of the first detector tile and / or via one or more tail portions of the at least one tail portion of a second adjacent detector tile.

[0065] According to an example, the high voltage electrode or foil of a first detector tile is configured to be electrically connected to the high voltage electrode or foil of a third adjacent detector tile via one or more tail portions of the at least one tail portion of the first detector tile and / or via one or more tail portions of the at least one tail portion of a third adjacent detector tile.

[0066] According to an example, the high voltage electrode or foil of a first detector tile is configured to be electrically connected to the high voltage electrode or foil of a fourth adjacent detector tile via one or more tail portions of the at least one tail portion of the first detector tile and / or via one or more tail portions of the at least one tail portion of a fourth adjacent detector tile.

[0067] According to an example, one or more tail portions of the at least one tail portion of a first detector tile are configured to be electrically connected to one or more tail portions of the at least one tail portion of an adjacent detector tile.

[0068] According to an example, for each detector tile, the anti-scatter grid is not electrically connected to the high voltage electrode or foil.

[0069] According to an example, for each detector tile, the surface of the high voltage electrode or foil facing away from the layer of sensor material comprises an insulating layer.

[0070] According to an example, for each detector tile, the anti-scatter grid is electrically connected to the high voltage electrode or foil. The anti-scatter grid of a first detector tile is configured to be electrically connected to the anti-scatter grid of an adjacent detector tile via one or more of the at least one tail portion of the first detector tile and / or via one or more of the at least one tail portion of an adjacent detector tile.

[0071] According to an example, the tail portion of the anti-scatter grid contacting an adjacent detector tile extends in a direction away from the sensor material layer. Additionally or alternatively, the tail portion of the tail portion contacting an adjacent detector tile extends in a direction away from the sensor material layer.

[0072] According to an example, for each detector tile, one or more of the at least one tail portion is fixedly attached to one or more respective sides of the anti-scatter grid.

[0073] According to an example, the photon counting detector includes at least one high voltage connection or flexible body 110. Each of the plurality of detector tiles adjacent to the at least one high voltage connection or flexible body is configured to be electrically connected to the high voltage connection or flexible body through a tail portion.

[0074] One or more high voltage connections or flexible bodies 110 can be placed at different locations relative to the detector tile of the photon counting detector, such as centered or offset to one side, or at the end of the photon counting detector, or all of these for multiple high voltage connections or flexible bodies.

[0075] According to an example, each detector tile has a high voltage electrode or foil comprising one, or two, or three or four tail portions.

[0076] According to an example, each detector tile is configured to be removed from a photon counting detector.

[0077] In an example, a photon counting detector is provided that includes a plurality of detector tiles. Each detector tile includes a sensor material layer 20, an integrated circuit 30, an input / output connection or flexible body 50, a high-voltage electrode or foil 60, and an anti-scatter grid 10. The input / output connection or flexible body is connected to the integrated circuit. The integrated circuit is configured to read out signals from the sensor material layer. This signal can come from a plurality of pixels in the sensor material layer. The anti-scatter grid is located near a surface of the sensor material layer. The high-voltage electrode or foil extends across the surface of the sensor material layer and is configured to provide a bias voltage to the surface of the sensor material layer. The high-voltage electrode or foil includes at least one tail portion 70. With respect to the photon counting detector and the plurality of detector tiles, the high-voltage electrode or foil of a first detector tile is configured to be electrically connected to a high-voltage power supply 80 via one or more of the at least one tail portion of the first detector tile and / or via one or more of the at least one tail portion of an adjacent detector tile.

[0078] In an example, a detector tile for a photon counting detector is provided, comprising a plurality of detector tiles. The detector tile includes a sensor material layer 20, an integrated circuit 30, an input / output connection or flexible body 50, a high-voltage electrode or foil 60, and an anti-scatter grid 10. The input / output connection or flexible body is connected to the integrated circuit. The integrated circuit is configured to read out a signal from the sensor material layer. This signal can be from multiple pixels in the sensor material layer. The anti-scatter grid is located near the surface of the sensor material layer. The high-voltage electrode or foil extends across the surface of the sensor material layer and is configured to provide a bias voltage to the surface of the sensor material layer. The high-voltage electrode or foil includes at least one tail portion 70.

[0079] According to an example, when connected in a photon counting detector, the high voltage electrode or foil of a detector tile is configured to be electrically connected to the high voltage electrode or foil of an adjacent detector tile via one or more of the at least one tail portion of the detector tile and / or via one or more of the at least one tail portion of an adjacent detector tile.

[0080] In examples, when connected into a photon counting detector, a high voltage electrode or foil of a detector tile is configured to be electrically connected to a high voltage electrode or foil of a second adjacent detector tile via one or more of the at least one tail portion of the detector tile and / or via one or more of the at least one tail portion of a second adjacent detector tile.

[0081] In examples, when connected in a photon counting detector, the high voltage electrode or foil of a detector tile is configured to be electrically connected to the high voltage electrode or foil of a third adjacent detector tile via one or more of the at least one tail portion of the detector tile and / or via one or more of the at least one tail portion of a third adjacent detector tile.

[0082] In examples, when connected into a photon counting detector, the high voltage electrode or foil of a detector tile is configured to be electrically connected to the high voltage electrode or foil of a fourth adjacent detector tile via one or more of the at least one tail portion of the detector tile and / or via one or more of the at least one tail portion of a fourth adjacent detector tile.

[0083] In an example, when connected to a photon counting detector, one or more of the at least one tail portion of a detector tile are configured to make electrical connection with one or more of the at least one tail portion of an adjacent detector tile.

[0084] In an example, the anti-scatter grid is not electrically connected to the high voltage electrode or foil.

[0085] In an example, a surface of the high voltage electrode or foil facing away from the sensor material layer comprises an insulating layer.

[0086] In an example, the anti-scatter grid is electrically connected to a high voltage electrode or foil, and wherein, when connected in a photon counting detector, the anti-scatter grid of a detector tile is configured to be electrically connected to the anti-scatter grid of an adjacent detector tile via one or more of the at least one tail portion of the detector tile and / or via one or more of the at least one tail portion of an adjacent detector tile.

[0087] In examples, when connected into a photon counting detector, one or more tail portions that contact the anti-scatter grid of an adjacent detector tile extend in a direction away from the sensor material layer, and / or wherein one or more tail portions that contact the tail portion of an adjacent detector tile extend in a direction away from the sensor material layer.

[0088] In an example, one or more of the at least one tail sections are fixedly attached to respective sides of the anti-scatter grid.

[0089] In an example, the high voltage electrode or foil comprises one, or two, or three or four tail portions.

[0090] In an example, the detector tile is configured to be inserted into and removed from the photon counting detector.

[0091] Continuing with these figures, these show detector tiles that can be formed into a photon counting detector. Each detector tile consists of multiple elements in a stack. The detector tile has an anti-scatter grid (ASG) 10, a direct conversion sensor material layer 20 and an interposer, also known as an input / output connection or flexure. The detector tile also has a photon counting ASIC 30 and a mechanical base 40. The ASG is a pixelated arrangement of X-ray attenuating walls that absorb most of the X-ray photons rather than striking them in the normal (perpendicular) direction of the direct conversion material (e.g. CZT, CdTe, Si, GaAs, Ge, Se, perovskite, etc.). An ASG pixel comprises one or more CZT equivalent pixels. The CZT material layer has a top common electrode (cathode) on its top surface. The HV potential needs to be brought to this top side of the CZT. Typically, a polyimide or polyamide foil with a conductive plane is in contact with the CZT cathode, and this provision of the HV potential is referred to here as being provided by the HV electrode or foil 60. Because it carries hardly any current (a few μA), the HV foil is very thin and covers the entire area of ​​the CZT (uniform X-ray absorption). A plurality of pixelated electrodes (anodes) are also provided on the bottom side of the CZT material layer. The pixels are defined by the geometric arrangement of the anodes on the bottom side and the electric field generated by biasing the detector to a high voltage (negative HV on the cathode) relative to the anode (close to ground). The interaction of X-rays within the CZT body generates electron-hole pairs (clouds) separated by the electric field. The electrons drift towards the anode, thereby causing a charge signal for the pixel (3D volume) where the interaction occurs. The ASIC captures the signal and generates a pulse height voltage internally, whose amplitude is proportional to the charge (energy) of the incident photon. A set of energy discriminators within the ASIC allows the number of photons of a certain energy to be classified. In a first embodiment, each ASG pixel comprises an equivalent CZT pixel. Other arrangements are not limited, for example 1 to 2x2. The CZT pixels are connected to the same number of ASIC channels by means of an interposer. An interposer may not be absolutely necessary and the ASIC (especially if equipped with through silicon vias) can have direct contact (1:1) with the CZT. The interposer acts as a redistribution layer (if necessary) to bridge the possible pixel pitch gap between the CZT and the ASIC. ASIC power and digital readout are routed through input / output connections or flexible bodies 50 which may also be referred to as flexible cables. This can be considered part of the interposer assembly. Routing is provided to the second interconnect level (data management system). The ASIC is attached to a mechanical base 40 for stability, cooling and mechanical fixation to the data management system and rack. The above is not limited to other arrangements. For example, the ASG can be a 1D arrangement (slit), which may be suitable for CT scanners with limited coverage. Due to strict alignment requirements and maintainability, it is preferred that each detector tile has its own ASG, and the new HV distribution technology described here is compatible with complete tile assemblies, where each detector tile includes its own ASG.

[0092] Figure 1 An assembled stack of tile detectors is shown, including an HV foil 60 having an extension or tail portion 70 that can be used for "daisy-chain" HV bias connections. The HV electrode or foil has a tail portion 70 that extends in one direction (preferably in z). That is, the HV foil electrode or foil 60 is larger than the area of ​​the CZT sensor, wherein the HV electrode or foil 60 has the tail portion 70. This is in Figure 1 The HV foil 60 with the extension or tail 70 also contains the metal plane that carries the HV potential. It is assumed that the HV foil is flexible and can be bent easily. The extension or tail 70 can span the entire width of the piece, or just a small "finger" like limb, such as Figure 6 As shown in more detail in . Figure 1 The configuration assumes that the HV tail 70 and I / O connection or flexure 50 emerge from the detector tile along the z-dimension. This is for illustrative purposes only. In practice, the preferred orientation of the I / O connection flexure 50 is along the y-axis, exiting the tile. However, the I / O flexure and one or more tail sections can be aligned in a different orientation as desired.

[0093] Figure 2 The interconnection of the HV electrodes or foils 60 across multiple detector tiles is shown, here along the z-direction. Thus, as the detector tiles are placed adjacent to one another, with the sensor material layers 20 (e.g., CZT) aligned, the HV tail portion 70 of one detector tile is forced into pressure contact with the preceding detector tile. In this particular embodiment, the ASG 10 is in electrical contact with the underlying HV electrode or foil 60. The HV tail portion 70 of the adjacent tile only needs to make contact with the ASG 10 of the preceding detector tile. Figure 2 An example of 4 cm equivalent isocenter coverage is shown (assuming 1 cm coverage per tile), however other sizes and coverages are clearly possible. Figure 1 ,exist Figure 2 In FIG. 5 , the I / O connections or flexible bodies 50 for each tile are depicted on the z-axis for illustration purposes only and could, for example, be in another direction.

[0094] Figure 3 An example of an isolated anti-scatter grid (ASG) for a patch detector is shown. Figure 2 As discussed, the ASG can be electrically connected to the HV. Typically, maintenance on the photon counting detector requires disconnecting the HV to ensure the safety of the maintenance personnel, and thus leaving the ASG connected to the HV does not necessarily pose an immediate risk. However, there can be situations where electrical isolation of the ASG from the HV is useful, and this is in Figure 3 , where the ASG is isolated while still allowing daisy-chain distribution of the HV bias. Figure 3 As shown, the detector tile has an ASG with a partially wrapped base. Thus, the high voltage electrode or foil 60 and its tail portion 70 (wherein Figure 3 The embodiment (with two tail portions at either end of the high voltage foil 60) is in the form of a conductive layer 80 with an insulating layer 90 between the conductive layer and the ASG 10. In other words, the conductive layer acts as a daisy-chain connection for the HV potential while not making contact with the ASG. It is worth noting that these layers can essentially be a single layer of polyimide deposited on a single-sided metal plane.

[0095] Figure 4 An example of a detector tile including two HV tails 70 for spreading the HV potential is shown. The HV electrode or foil 60 has extensions or tail portions 70a and 70b on both sides of the tile (along Z). One tail portion 70a is aligned with the reference Figure 1-2 The ASG 10 is used in the same manner as described. However, the second tail portion 70b is lifted and bonded to the side of the ASG 10. In this case, the HV electrode or foil 60 is completely isolated on its top side, i.e., the ASG is not exposed to the HV. By lifting the second tail and bonding it to one side of the ASG, the metal plane is exposed and available for use by adjacent tiles. Figure 4 In one image is shown such a further extension or tail portion of the HV foil and the position of the second HV tail portion after assembly has been completed.It should be noted that the HV electrode or foil 60 does not need to be isolated on its top side, in which case the ASG would be exposed to the HV.

[0096] Figure 5 An example of four detector tiles is shown, where the HV bias potential is propagated from one detector tile to the next via the HV tail portion 70. The module components and HV contacts are clearly shown. The HV electrodes or foils 60 with associated tail portions 70 are identical, but are Figure 5 are drawn differently in order to make the arrangement easier to visualize.

[0097] The above-described embodiments rely on pressure contact to propagate the HV potential. The HV tail portion 70, whether on one or more than one side of the detector tile, can be equipped with a metal spring to actually make the contact. In this way, the overall structure can better accommodate the small movements required for proper alignment of each tile without losing the HV contact. Alternatively, the HV contact can utilize compressible conductive foam (and / or in combination with polyamide foil) to accommodate assembly tolerances.

[0098] In the above embodiments, in particular Figure 2 and Figure 5In the illustrated embodiment, only one "daisy chain" connection is shown. This means that if the first detector tile (designated as the leftmost detector tile in this case) needs to be replaced, all detector tiles must first be removed. However, in another embodiment, the daisy chain is split down the middle. That is, there are two daisy chain connections (the tail portion 70 of the high-voltage electrode or foil 60), one from either side of the module along z. In this case, in a worst-case maintenance repair scenario, only the failed detector tile needs to be removed. Other configurations are possible.

[0099] Note that all of the above embodiments prevent the HV connections from having to pass through the sides of the detector tile, which mitigates adverse effects on sensor performance due to distortion of the electric field on the sides when the HV connections are via the sides of the detector tile.

[0100] As mentioned above, the HV tail portion(s) 70 may have different forms. Figure 6 Several examples are shown as viewed from the top (ASG not shown for clarity). For all figures, the high voltage electrode foil 60 is shown extending in the y-axis (60y) and the y-axis (60z). A) and B) are with Figure 2 In A) there is a single HV tail portion 70 extending across the high voltage electrode or foil 60, whereas in B) the HV tail portion is in the form of a finger. The version shown at C) is compatible with Figure 4 and Figure 5 The embodiments shown are compatible. In this case, there are two tail sections 70a and 70b, and the HV occupies the entire width of the tile (along y). However, it is possible to have one or more smaller tail sections, as shown in case B). Case D) shows a combination of C), in which the HV tail sections are in the form of fingers, with tail sections 70a and 70b located on opposite sides of the detector tile, and a third HV tail section 70c oriented vertically. This provides the ability to extend the tile in two dimensions. For example, it is possible to spread the HV further on the detector tiles in y, either within a module (which might, for example, consist of two rows of detector tiles along z) or across modules. Although not preferred, it is theoretically possible to bring the HV connection to a single tile and let the HV spread throughout the detector. Then, Figure 6 Figure E) shows another example that is particularly well-suited for distributing HV potentials across detector tiles within a module while also providing redundancy. Here, tail sections 70a and 70b extend from opposite sides of the detector tile in one axial direction, while tail sections 70c and 70d extend from opposite sides of the detector tile in an orthogonal axial direction. Thus, if one of the HV potentials fails to make proper contact, three points of redundancy are still provided.

[0101] Figure 7Two potential module configurations are shown. In this case (seen from the top), the I / O connections or flexures 50 are detached along y and the HV tail portions 70a, 70b are oriented along z, as is preferred in practical implementations. For these examples, it is assumed that each module consists of 2 rows of tiles along z. These show the case with 2 HV power supplies 100 (or one with two connections). HV is propagated along z from detector tile to detector tile using HV electrodes or foils to have, for example, Figure 7 The left-hand side example Figure 6 The tail portion shown in C, although with Figure 6 C shows those narrower HV tail portions 70a and 70b. Figure 7 The modules shown in the right-hand side example are Figure 6 D uses a HV electrode or foil 60 with tail portions 70a, 70b, 70c and 70d in a similar manner. In this case, the initial detector patch receives the HV potential and is further distributed across the patch in both the z and y directions. In this case, a higher level of redundancy is achieved with respect to failure of a single connection via a single HV tail portion. It should also be noted that in Figure 7 In the right-hand side example of FIG, only one power supply is required, but two are shown for redundancy reasons.

[0102] Figure 8 Yet another embodiment is shown in which a single double-sided flexible body 110 is placed between two rows of tiles along z. In this case, the HV electrodes or foils 60 for the four detector tiles on the left hand side have tail portions 70, such as Figure 6 As shown in B, for the four detector tiles on the right, a level of redundancy is provided and the HV electrodes or foils 60 have Figure 6 D shows tail portions 70a, 70b and 70c, and in practice tail portion 70b could be omitted. However, here, one HV tail portion 70 of each detector tile goes to the side and contacts an additional flexible component 110 coupled to an HV power supply 100.

[0103] It should be noted that in all of the above embodiments, the HV electrode or foil 60 need not cover the entire area of ​​the detector tile where it extends over its sensor material layer 20. It may be patterned for alignment purposes, and it may be made of a variety of materials, and it may be partially transparent, etc.

[0104] It should be noted that embodiments of the present invention are described with reference to different subject matters. In particular, some embodiments are described with reference to method-type claims, while other embodiments are described with reference to apparatus-type claims. However, those skilled in the art will appreciate from the foregoing and following descriptions that, unless otherwise indicated, any combination of features relating to different subject matters, in addition to any combination of features belonging to one subject matter, is also considered to be disclosed with this application. However, all features may be combined to provide synergistic effects that exceed the simple sum of the features.

[0105] Although the present invention has been described and illustrated in detail in the drawings and the foregoing description, such description and illustration should be considered illustrative or exemplary rather than restrictive. The present invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention from a study of the drawings, the disclosure, and the appended claims.

[0106] In the claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. A single processor or other unit may perform the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A detector tile for a photon counting detector comprising a plurality of detector tiles, wherein: The detector block includes: a sensor material layer (20); integrated circuits (30); Input / output connections (50); a high voltage electrode (60); and anti-scatter grid (10); wherein the input / output connection is connected to the integrated circuit; wherein the integrated circuit is configured to read out a signal from the sensor material layer; wherein the anti-scatter grid is positioned adjacent to a surface of the sensor material layer; and wherein the high voltage electrode extends across the surface of the sensor material layer and is configured to provide a bias voltage to the surface of the sensor material layer, and wherein the high voltage electrode includes at least one tail portion (70), It is characterized by: The high voltage electrode is configured to make an electrical connection with the high voltage electrode of an adjacent detector tile via one or more of the at least one tail portion of a first detector tile.

2. The detector piece according to claim 1, wherein: The input / output connection is a flexible body.

3. The detector piece according to claim 1, wherein: The high voltage electrode is a high voltage foil.

4. A photon counting detector comprising: A plurality of detector tiles according to claim 1.

5. The photon counting detector according to claim 4, wherein The high voltage electrode of the first detector tile is configured to be electrically connected to the high voltage electrode of a second adjacent detector tile via one or more of the at least one tail portion of the first detector tile and / or via one or more of the at least one tail portion of a second adjacent detector tile.

6. The photon counting detector according to claim 5, wherein The high voltage electrode of the first detector tile is configured to be electrically connected to the high voltage electrode of the third adjacent detector tile via one or more of the at least one tail portion of the first detector tile and / or via one or more of the at least one tail portion of a third adjacent detector tile.

7. The photon counting detector according to claim 6, wherein The high voltage electrode of the first detector tile is configured to be electrically connected to the high voltage electrode of the fourth adjacent detector tile via one or more of the at least one tail portion of the first detector tile and / or via one or more of the at least one tail portion of a fourth adjacent detector tile.

8. The photon counting detector according to any one of claims 4 to 7, wherein: One or more of the at least one tail portion of the first detector tile are configured to make electrical connections with one or more of the at least one tail portion of an adjacent detector tile.

9. The photon counting detector according to any one of claims 4 to 7, wherein: For each detector tile, the anti-scatter grid is not electrically connected to the high voltage electrode.

10. The photon counting detector according to claim 9, wherein For each detector tile, a surface of the high voltage electrode facing away from the sensor material layer comprises an insulating layer.

11. The photon counting detector according to any one of claims 4 to 7, wherein: For each detector tile, the anti-scatter grid is electrically connected to the high-voltage electrode, and wherein the anti-scatter grid of the first detector tile is configured to be electrically connected to the anti-scatter grid of the adjacent detector tile via the one or more tail portions of the at least one tail portion of the first detector tile and / or via the one or more tail portions of the at least one tail portion of the adjacent detector tile.

12. The photon counting detector according to any one of claims 4 to 7, wherein: The tail portion in contact with the anti-scatter grid of the adjacent detector tile extends in a direction away from the sensor material layer, and / or wherein, A tail portion that contacts a tail portion of an adjacent detector tile extends in the direction away from the sensor material layer.

13. The photon counting detector according to any one of claims 4 to 7, wherein: For each detector tile, one or more of the at least one tail portion are fixedly attached to one or more respective sides of the anti-scatter grid.

14. The photon counting detector according to any one of claims 4 to 7, comprising at least one high voltage connection (110) being a flexible body, and wherein, Each detector tile of the plurality of detector tiles adjacent to a high voltage connection of the at least one high voltage connection is configured to be electrically connected to the high voltage connection through a tail portion.

15. The photon counting detector according to any one of claims 4 to 7, wherein: Each detector tile has a high voltage electrode including one tail portion, two tail portions, three tail portions, or four tail portions.

16. The photon counting detector according to any one of claims 4 to 7, wherein: Each detector tile is configured to be removed from the photon counting detector.

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