X-ray detector employing non-permanent interconnect structure

Abstract

Some embodiments include an X-ray detector comprising: a substrate comprising: a plurality of pixels configured to convert incident X-rays into an electrical signal; a plurality of data lines coupled to the pixels; a printed circuit assembly (PCA) comprising: a circuit configured to convert the electrical signal into digitized data; and an interconnection structure electrically connected between the data line and the circuit, and configured to transmit the electrical signal from the substrate to the PCA.

Description

Cross Reference to Related Applications

[0001] This application claims priority to U.S. Patent Application No. 18 / 335,997, filed June 15, 2023, entitled “X-RAY DETECTOR EMPLOYING NON-PERMANENT INTERCONNECT STRUCTURE,” the entirety of which is incorporated herein by reference. SUMMARY

[0002] An X-ray detector can include an array of pixels disposed on a substrate. Hundreds to thousands of data lines can be coupled to the array, enabling transmission of signals from the pixels. An interconnect structure including readout electronics can be bonded to the substrate with anisotropic conductive film (ACF). The interconnect structure with readout electronics can be electrically connected to a printed circuit assembly (PCA) with other circuitry of the X-ray detector. Failures of the interconnect structure, failures of the connection of the interconnect structure to the substrate, and the like can result in reduced yield and / or increased manufacturing costs. BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

[0003] Figures 1-2 Block diagram of an X-ray detector including an interconnect structure according to some embodiments.

[0004] Figures 3A-3B Block diagram of an X-ray detector including an interconnect structure disposed on one side of a substrate according to some embodiments.

[0005] Figure 4 Block diagram of an X-ray detector including an interconnect structure disposed on multiple sides of a substrate according to some embodiments.

[0006] Figure 5 Block diagram of an X-ray detector including an interconnect structure with a via according to some embodiments.

[0007] Figure 6 Block diagram of an electrical connection between a substrate and a printed circuit assembly according to some embodiments.

[0008] Figure 7 Block diagram of an X-ray detector including an interconnect structure with a compression connection according to some embodiments.

[0009] Figure 8 Block diagram of an X-ray detector including an interconnect structure with a connector according to some embodiments.

[0010] Figures 9-10B Block diagram of an X-ray detector including an interconnect structure with a protrusion according to some embodiments.

[0011] Figure 11 Block diagram of an X-ray detector including an interconnect structure with a PCA flex circuit according to some embodiments.

[0012] Figure 12 Block diagram of an X-ray detector including an interconnect structure with flex circuit, according to some embodiments.

[0013] Figure 13 Block diagram of an X-ray detector including an interconnect structure and multiplexer, according to some embodiments.

[0014] Figure 14 Block diagram of an X-ray detector including an interconnect structure, multiplexer, and common node, according to some embodiments.

[0015] Figure 15 Block diagram of a specific multiplexer, according to some embodiments.

[0016] Figure 16 Block diagram of an X-ray imaging system, according to some embodiments. DETAILED DESCRIPTION

[0017] Embodiments include X-ray detectors that employ non-permanent interconnect structures. Some X-ray detectors include an array substrate having pixels thereon configured to convert X-rays into electrical signals. An interconnect substrate having application specific integrated circuits (ASICs) mounted thereon is attached to the array substrate. The ASICs include readout electronics configured to digitize analog signals from the pixels. The interconnect substrate is attached to the array substrate by anisotropic conductive film (ACF). The interconnect substrate typically employs a flexible substrate so that printed circuit assemblies (PCAs) can be folded under the array substrate, thereby reducing the overall size of the X-ray detector and adapting the detector array and its accompanying circuitry to a particular area or mounting space.

[0018] Mounting the ASICs on the interconnect substrate can increase manufacturing costs. The attachment failure rate of the interconnect substrate to the array substrate can exceed 30%. When the attachment fails, the flexible interconnect structure with the ASICs is discarded, thereby increasing costs. In addition, the attachment process can require skilled technicians for alignment and bonding, specialized training of the technicians, use of specialized equipment, etc. Each of these factors can contribute to increased costs.

[0019] As described herein, embodiments can reduce failure rates, improve connection reliability, reduce scrap rates, simplify manufacturing processes, enable automation, etc.

[0020] Figures 1-2 Block diagram of an X-ray detector including an interconnect structure, according to some embodiments. Referring to Figure 1 In some embodiments, the X-ray detector 100 includes a substrate 102, an interconnect structure 108, and a printed circuit assembly (PCA) 110.

[0021] The substrate 102 includes an array 104 of pixels 103 configured to convert incident X-rays to electrical signals. The substrate 102 can include a rigid substrate, such as glass, ceramic, metal, etc. In other embodiments, the substrate 102 can include a flexible substrate, such as polyimide (PI), polyethylene terephthalate (PET), etc. A plurality of data lines 106 are coupled to the pixels 103.

[0022] The PCA 110 is a device that includes circuitry configured to convert the electrical signals to digitized data. The digitized data can refer to voltage levels derived from the analog electrical signals that represent binary numbers, such as "0" and "1". The ASIC 112 represents the circuitry (or readout electronics). The PCA 110 can include other circuitry 114, such as a processor, FPGA, communication interface, memory, etc. The circuitry configured to convert the electrical signals to digitized data will be referred to as the ASIC 112 in order to distinguish the circuitry from the circuitry 114. Multiple ASICs 112 can be included in the PCA 110 and configured to convert the electrical signals to digitized data. These ASICs can be referred to as the ASIC 112.

[0023] The interconnect structure 108 is electrically connected between the data lines and the ASIC 112 and configured to bi-directionally transfer electrical signals between the substrate 102 and the PCA 110. In some embodiments, the interconnect structure 108 includes a one-to-one correspondence of electrical connections between the circuitry 112 and electrical structures on the substrate 102 for transferring electrical signals. For example, each data line 106 can be electrically connected to a trace on the flexible substrate as part of the interconnect structure 108. Each of these traces can be electrically connected to a corresponding trace on the PCA 110, which in turn is electrically connected to an input of the ASIC 112. The integer N represents the number of data lines 106, electrical signal lines, or traces of the interconnect structure 108.

[0024] In some embodiments, the interconnect structure 108 includes a portion disposed on the substrate 102. In some embodiments, the interconnect structure 108 can include pads, connectors, or the like to connect the data lines 106 to the PCA 110. In some embodiments, the portion of the interconnect structure 108 disposed on the substrate 102 has a thickness greater than the thickness of the data lines 106. For example, the data lines 106 can be metallized with tin, nickel, silver, gold, or other materials in the area outside of the array 104. Thus, the data lines 106 in the area outside of the array 104 can have a thickness greater than the data lines 106 inside of the array 104. This increased thickness can constitute a portion of the interconnect structure 108 to improve connectivity and wear resistance with contacts, connectors, or the like. In some embodiments, the portion of the interconnect structure 108 disposed on the substrate 102 has a thickness that is 5, 10, or 20 times the thickness of the data lines 106 inside of the array 104. Conventionally, the data lines 106 are on the same side of the substrate 102 as the array 104. In some embodiments, the traces of the data lines 106 can extend to both sides of the substrate 102 or provide conductive paths to both sides of the substrate 102. The traces of the data lines 106 on opposite sides of the substrate 102 can use different conductive layers coupled by vias or other similar means.

[0025] Referring to Figure 2 In some embodiments, the X-ray detector 100 can include multiple interconnect structures 108. For clarity, the data lines 106 are not shown. In this example, M interconnect structures 108-1 through 108-M are shown. Each of the M interconnect structures 108 can include N data lines 106, traces, or other electrical connections as described above. The interconnect structures 108 are each electrically connected between the array 104 and the ASIC 112. Each interconnect structure 108 can correspond to a dedicated one of the ASICs 112; however, in other embodiments, each interconnect structure 108 can be electrically connected to the same ASIC 112. Although shown as a layer on the substrate 102 to illustrate that the array 104 is smaller in size than the substrate 102, in some embodiments, the array 104 is integrated with the substrate 102.

[0026] Figures 3A-3B A block diagram of an X-ray detector including an interconnect structure disposed on one side of a substrate according to some embodiments. Referring to Figure 3A In some embodiments, the X-ray detector 100 includes an interconnect structure 108 disposed on one side 102a of the substrate 102. The data lines 106 can extend to a connection location 105 where the data lines 106 can be electrically connected to the interconnect structure 108.

[0027] Referring to Figure 3BIn some embodiments, the interconnect structures 108 can be arranged in multiple rows 109. Two rows 109-1 and 109-2 are used as an example; however, the number of rows 109 can be different in other embodiments. Each row 109 contains one or more interconnect structures 108.

[0028] In some embodiments, the pitch of the connectors, pads, etc. on the substrate 102 can be too large to accommodate each data line 106 in one row 109 of interconnect structures 108, where the pitch is the distance between conductors. The pitch includes the conductors as well as the spacing or insulators between the conductors. Therefore, multiple interconnect structures 108 can be connected to the substrate 102 in sufficient number to connect each data line 106 to the PCA 110. Some data lines 106 can be coupled to the interconnect structures 108 at the connection locations 105 of one row 109, while other data lines 106 can be coupled to the interconnect structures 108 in another row 109. As such, the pitch of the data lines 106 at the connection locations 105 can be large. The larger pitch allows for more types of interconnect structures 108, different connectors, etc. to be used. For example, a connector that matches the pitch of the data lines 106 at the array 104 can not be available. However, if the data lines 106 are divided into two or more rows 105, the pitch of the data lines 106 can be increased by a factor of two or more, allowing for the use of available connectors.

[0029] Figure 4 A block diagram of an X-ray detector including interconnect structures disposed on multiple sides of a substrate according to some embodiments. In some embodiments, the X-ray detector 100 can be similar to other detectors described above; however, the substrate 102 is coupled to interconnect structures 108 on multiple edges 102a-1 through 102a-4. Although a substrate with 4 edges is used as an example, in other embodiments, the substrate 102 can have a different number of edges 102a. At least a portion of the interconnect structures 108 are disposed on these multiple edges 102a.

[0030] Figure 5 A block diagram of an X-ray detector including a via interconnect structure with a bandpass according to some embodiments. In some embodiments, a portion 120 of the interconnect structures 108 is disposed on a side of the substrate 102 opposite the array 104. The portion 120 can include pads, connectors, etc. A plurality of vias 134 can be formed through the substrate 102. In this example, the data lines 106 are coupled to the vias 134. The vias 134 are coupled to the pads 120 that are part of the interconnect structures 108.

[0031] In some embodiments, the substrate 102 is flexible, such as a polyimide (PI), polyethylene terephthalate (PET) substrate, etc. The vias 134 can be formed through the polyimide. However, in other embodiments, the substrate 102 can be rigid and still include the vias 134.

[0032] As described above, the interconnect structures 108 can be disposed at different locations on the substrate 102 along the edges 102a of the substrate 102, on different faces of the substrate 102, in different numbers, etc. The following will refer to the interconnect structures 108 as being disposed on the substrate 102 along the edges 102a of the substrate 102. However, it is understood that the following description applies to the interconnect structures 108 disposed on the substrate 102 in other manners. Figures 6-12 A variety of interconnect structures 108 will be described. Each of the interconnect structures 108 to be described can be disposed in or include various locations, edges 102a, faces, or numbers in the manner described above.

[0033] If an ACF is used to connect the components to the interconnect structures 108, the substrate 102, the ASIC 112, or the PCA 110, it can be difficult to service or replace because the ACF can only be used once (e.g., not reusable). In various embodiments described herein, the use of an ACF can be eliminated. Thus, if it is necessary to disconnect the contacts of the interconnect structures 108, the disconnecting operation does not result in damage to the interconnect structures 108, the ASIC 106, etc. Furthermore, the placement of the ASIC 112 can reduce damage when it is necessary to replace the interconnect structures 108. In some embodiments, the connectors of the interconnect structures 108 can be semi-permanently or detachably coupled to the substrate 102 or the PCA 110.

[0034] In some embodiments, the interconnect structures 108 described herein include only passive electrical connections. Passive electrical connections include dissipative, energy storage, and energy neutral components, such as conductors, resistors, capacitors, and inductors, and do not include active electrical components. Active electrical components include switching, amplifying, or power generating components, such as transistors, integrated circuits, etc.

[0035] Figure 6 A block diagram of electrical connections between a substrate and a printed circuit assembly according to some embodiments. In some embodiments, the electrical connections formed between the substrate 102 and the PCA 110 can include electrical connections for signals other than electrical signals from the pixels 103 of the array 104.

[0036] In this example, the electrical connections include the gate lines 107. Similar to the data lines 106, the gate lines 107 can be coupled to the ASIC 112. However, in other embodiments, the gate lines 107 can be coupled to a separate gate line driver. Although the gate lines 107 are used as an example of connections for other signals, the interconnect structures 108 can also connect power, other control signals, reference voltages, etc. between the PCA 110 and the substrate 102.

[0037] Figure 7A block diagram of an X-ray detector including an interconnect structure with compression connections according to some embodiments. In some embodiments, the substrate 102 includes contact pads 121. In this example, the contact pads 121 are disposed on the side of the substrate opposite the array 104 and the data lines 106; however, in other embodiments, the contact pads 121 can be disposed on the same side as the array 104 and the data lines 106. The contact pads 121 are electrically connected to the data lines 106 through vias 134.

[0038] A plurality of compression contacts 122 are disposed on the PCA 110. Examples of compression contacts 122 include pogo pins, Z-axis interposers, Z-axis interconnect structures, Z-axis flex connectors, etc. The contact pads 121 and the compression contacts 122 are disposed such that when the substrate is aligned with the printed circuit assembly (through alignment structures), the compression contacts 122 are compressed and make contact with the contact pads 121 of the substrate 102. The contact pads 121 and the compression contacts 122 form part of the interconnect structure 108. In some embodiments, the side of the substrate 102 opposite the array 104 can have more area available for the interconnect structure 108.

[0039] In some embodiments, no ACF is used. Contact is made through the interface between the contact pads 121 and the compression contacts 122. Yield can be improved when defective assemblies need to be replaced. If a failure occurs, the compression can be released. The contacts can be re-compressed. In addition, the contact pads 121 can be used to independently test the substrate 102 before the substrate 102 is connected to the PCA 110.

[0040] Figure 8 A block diagram of an X-ray detector including an interconnect structure with connectors according to some embodiments. In some embodiments, the substrate 102 includes a substrate connector 124a. The substrate connector 124a is electrically connected to the data lines 106. The substrate connector 124a includes a sufficient number of contacts to electrically connect the data lines 106 to the ASIC 112.

[0041] The PCA 110 includes a corresponding PCA connector 124b. The PCA connector is electrically connected to the ASIC 106. The PCA connector 124b is configured to engage with the substrate connector 124a. Thus, the substrate connector 124a and the PCA connector 124b can engage to electrically connect the array 104 to the ASIC 106.

[0042] Although an example is provided with a pair of substrate connector 124a and PCA connector 124b, in other embodiments, multiple pairs of substrate connector 124a and PCA connector 124b can electrically connect the substrate 102 to the PCA 110.

[0043] In some embodiments, the substrate connectors 124a allow for easier testing of the array 104. For example, a test system can include connectors similar to the PCA connectors 124b. The connections can be more reliable and repeatable than other types of connections used for testing that are attached to pads on the substrate 102 that are supposed to be connected using ACFs when finally assembled.

[0044] In some embodiments, a single substrate connector 124a can include 256 terminals. As described above, there can be multiple connectors 124a, multiple layers of connectors 124a, etc. to achieve the desired number of connections between the substrate 102 and the PCA 110.

[0045] In some embodiments, the substrate connectors 124a and the PCA connectors 124b can be high-density connectors, each having more than 128 individual electrical contacts. The pitch of the substrate connectors 124a and the PCA connectors 124b can be less than other connectors (pitch of other connectors is greater than 500 micrometers (pm)), but greater than the pitch of the data lines 106. The pitch of the high-density connectors can have a contact pitch of less than 500 pm, 450 pm, 400 pm, 350 pm, 300 pm, 250 pm, or 200 pm. The pitch of the data lines 106 can be about 100 pm, 75 pm, or less. The pitch of the data lines 106 can be less than 150 pm, 120 pm, 110 pm, 100 pm, or 80 pm. In some embodiments, the use of multiple connectors 124a in multiple rows 109 as described above can allow for the use of substrate connectors 124a with a larger pitch to fit within the desired width. For example, the width of the substrate 102 can be limited to 43 cm. About 4000 data lines with a pitch of 100 pm (i.e., about 40 cm) can fit within a width of 43 cm. A substrate connector 124a with a larger pitch can be used in multiple rows 109 to fit within the width. In other embodiments, the substrate connectors 124a can be provided on multiple sides in the manner described above.

[0046] Figures 9-10B A block diagram of an X-ray detector including an interconnect structure with tabs (or ears or tabs) in accordance with some embodiments. In some embodiments, the substrate 102 includes at least one tab 140. This example illustrates two tabs; however, in other embodiments, the substrate 102 can include one or more than two tabs.

[0047] The tabs 140 are integrated with the substrate 102 to extend beyond a norminal side 102a of the substrate 102 or the array 104. The tabs 140 do not extend across the entire side 102a. There can be a gap between at least two tabs.

[0048] PCA connectors 124c and 124d are disposed on the PCA 110. The PCA connectors 124c and 124d can be similar to the PCA connector 124b described above; however, the PCA connectors 124c and 124d are configured to engage with corresponding tabs 140.

[0049] In some embodiments, the substrate 102 and / or the tabs 140 can be flexible. Thus, as shown, the tabs 140 can be bent to engage with the PCA connector 124c. In some embodiments, the substrate 102 and the tabs 140 can be rigid. The PCA connector 124d can be disposed on the PCA 110 such that the tabs 140 can engage with the PCA connector 124d without being bent. Figure 10A

[0050] The data lines 106 are electrically connected with the tabs 140. In some embodiments, the data lines 106 can constitute contacts of the tabs 140 that are electrically connected with terminals of the PCA connector 124c or 124d. In other embodiments, the data lines 106 can be electrically connected to terminals on the tabs 140 that are configured to be electrically connected with terminals of the PCA connector 124c or 124d.

[0051] Referring to FIG. 1, in some embodiments, the tabs 140 extend along an arc of less than 90 degrees when engaged. That is, the tabs can extend parallel to the main plane of the substrate 102 from the substrate 102. However, along the length of the tabs 140, the tabs 140 bend in a direction that is deflected by less than 90 degrees from the initial direction. In this example, the tabs 140 extend along an arc of about 60 degrees. Figure 10A Referring to FIG. 1, in some embodiments, the tabs 140 extend along an arc of more than 90 degrees when engaged. That is, the tabs can extend parallel to the main plane of the substrate 102 from the substrate 102. However, along the length of the tabs 140, the tabs 140 bend in a direction that is deflected by more than 90 degrees from the initial direction. In this example, the tabs 140 extend along an arc of about 180 degrees.

[0052] Figure 10B Referring to FIG. 1, in some embodiments, the tabs 140 are rigid. The tabs 140 can extend parallel to the main plane of the substrate 102. The tabs 140 can be inserted into the PCA connector 124d.

[0053] Figure 11 A block diagram of an X-ray detector including an interconnect structure with a PCA flexible circuit according to some embodiments. In some embodiments, the PCA 110 can include a flexible circuit 150. The flexible circuit 150 can be integrated as a layer of the PCA 110, including traces, circuitry, etc. that extend from other layers of the PCA 110. The substrate 102 includes a substrate connector 124e that is electrically coupled with the data lines 106. The flexible circuit 150 is configured to engage with the substrate connector 124e. The flexible circuit 150 and the substrate connector 124e constitute a portion of the interconnect structure 108. The ASIC 112 is further configured to receive electrical signals through the flexible circuit 150.

[0054] ​​Figure 12 A block diagram of an X-ray detector including an interconnect structure with a flex circuit 152 according to some embodiments. The flex circuit 152 can include only passive components, or no components, or only traces, circuits, etc. In some embodiments, the substrate 102 includes a substrate connector 124f that is electrically coupled to the data lines 106. The PCA 110 includes a PCA connector 124g that is electrically connected to the ASIC 112. The substrate connector 124f and the PCA connector 124g are each configured to engage and electrically connect to the flex circuit 152. The substrate connector 124f, the PCA connector 124g, and the flex circuit 152 make up part of the interconnect structure 108.

[0055] Figure 13 A block diagram of an X-ray detector including an interconnect structure 108 and a multiplexer 1210 according to some embodiments. In some embodiments, the array 104 includes a plurality of pixels 1202. Each pixel 1202 can include circuitry configured to generate a desired signal based on incident radiation (e.g., X-rays). The pixels 1202 can include photodiodes, photodetectors, circuitry including such devices, etc. A scintillator, direct conversion material, or other X-ray conversion material can be part of the array 104 and configured to convert incident X-rays to photons that the pixels 1202 can convert to electrical signals. For example, a scintillator can include a wide variety of materials configured to convert X-ray photons to photons that the pixels 1202 can detect, such as cesium iodide (CsI), cadmium tungstate (CdW04), polyvinyltoluene (PVT), gadolinium oxysulfide (Gd20 2S; GOS; Gadox), terbium-doped gadolinium oxysulfide (Gd20 2S: Tb), etc. Examples of direct conversion materials include cadmium telluride (CdTe), cadmium zinc telluride (CdZnTe or CZT), mercury iodide (Hgl), lead iodide (Pbl), selenium, etc.

[0056] Each pixel is electrically connected to a corresponding line of the data lines 106 and the gate lines 107. The data lines 106 are electrically connected to the multiplexer 1210. The multiplexer 1210 is a circuit configured to select a portion of the data lines 106 to electrically couple to the K conductors 106’ of the interconnect structure 108. In some embodiments, the number of data lines 106, L, can be 4096. The number of conductors 106’ of the interconnect structure 108, K, can be 1024. That is, the multiplexer 1210 can include 1024 independent 4: 1 multiplexers.

[0057] The multiplexer 1210 can be configured to receive a control input 1212. The control input can include J control signals to select a desired output of the multiplexer 1210. Using the multiplexer 1210 example above with multiple independent 4: 1 multiplexers, the number of control signals J can be 2. Other circuitry of the array 104 can be configured to decode these two signals as selection signals for the independent multiplexers. In other embodiments, the number of control signals J can be 4 to directly control the independent multiplexers without decoding. Thus, based on the control input 1212, the multiplexer 1210 can be configured to multiplex electrical signals on selected data lines 106 as a multiplexed electrical signal on a conductor 106' of the interconnect structure 108.

[0058] The PCA 110 can include control logic 1214. The control logic 1214 can include a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a microcontroller, a programmable logic device, discrete gate or transistor logic, combinations of such, or the like. The control logic 1214 can include other circuitry coupled with the ASIC 112, the substrate 102, or the like to enable the control logic 1214 to control operation of such circuitry.

[0059] In some embodiments, the control logic 1214 is configured to control the gate lines 107 and the control input 1212 such that groups of electrical signals on the data lines 106 are sequentially read by the ASIC 112. Using the example above, the multiplexer 1210 can select a first group of 1024 signals from data lines 106-1, 106-5,... 106-1021. Next, the multiplexer 1210 can select a second group of 1024 signals from data lines 106-2, 106-6,... 106-1022, and so on until all of the data lines 106 are selected and read out by the ASIC 112.

[0060] In some embodiments, using multiplexers can reduce the number of ASICs 112. If all of the signals of all of the 106 data lines are to be read synchronously, then one or more ASICs 112 with sufficient processing capability must be employed to process the electrical signals. By multiplexing the electrical signals of the data lines 112, the number of ASICs 112 required can be reduced, for example, by a multiplexing factor. Using the example above, the number of ASICs 112 can be reduced to one quarter. In some embodiments, using multiplexers reduces the number of conductors of the interconnect structure 108. Reliability, yield, and cost can be affected by the number of conductors of the interconnect structure 108 and the number of ASICs 112. Reducing one or more of these can lower cost and increase reliability.

[0061] Figure 14A block diagram of an X-ray detector including an interconnect structure 108, multiplexer 1210, and common node 1218 according to some embodiments. In some embodiments, the substrate 102 includes a common voltage node 1218. A plurality of reset transistors 1220 can be coupled to the data lines 106. The reset transistors 1220 can be configured to selectively connect the data lines 106 to the common voltage node 1218.

[0062] In some embodiments, the reset transistors 1220 can reduce artifacts. The reset transistors can be controlled by the control logic 1214 through the control signals 1216 so that when a certain row of pixels 1202 is deselected, all of the data lines 106 can be coupled to the common voltage node 1218. In some embodiments, all of the inputs 1212 of the multiplexer 1210 can be activated simultaneously.

[0063] In some embodiments, capacitors 1219 are electrically connected between the common voltage node 1221 and at least one of the data lines 106 and / or the output of the multiplexer 1210 at the conductor 106'. These capacitors 1219 can compensate for charge injection during selection of the multiplexer 1210 inputs. The capacitors can be used to compensate for parasitic charge that results from thin film transistor (TFT) switching onto the data lines. This charge can come from parasitic capacitance that results from the pixel 1202 and array 104 trace overlap. Charge compensation capacitors 1219 on the array 104 can provide one of a variety of solutions that can be used for charge compensation.

[0064] Figure 15 A block diagram of a specific multiplexer according to some embodiments. In some embodiments, the multiplexer 1210 includes K independent multiplexers 1210-1 to 1210-K. Each independent multiplexer 1210 includes a select transistor 1211 coupled between a common output 1213 and a corresponding data line 106. The select transistor 1211 is coupled to a corresponding signal in the control signals 1212. Thus, when control signal 1 in the control signals 1212 is activated, every fourth data line 106-1 to 106-4K-3 is coupled to a corresponding common output 1213. The remaining data lines 106 can be coupled to the outputs according to different control signals 1212.

[0065] As described above, in some embodiments, all of the data lines 106 can be coupled to a common node. If each of control signals 1 to 4 in the control signals 1212 are activated simultaneously, the data lines 106 can be collectively coupled to the corresponding outputs 1213.

[0066] In some embodiments, the transistor 1211 can have low resistance and low parasitic capacitance. Examples of such transistors include thin film transistor (TFT) technology, indium gallium zinc oxide (IGZO), polysilicon TFT, etc.

[0067] In some embodiments, the transistor 1211 is formed in the same process as any transistor forming the pixel 1202, integrated with the pixel 1202, or formed in a similar manner. In other embodiments, the multiplexer 1210 can be a discrete integrated circuit mounted to the substrate 102 by flip-chip bonding, wire bonding, etc. In other embodiments, the multiplexer 1210 can be constructed from discrete transistors.

[0068] Figure 16 A block diagram of an X-ray imaging system according to some embodiments. The X-ray imaging system 1600 includes an X-ray source 1602 and a detector 1610. The detector 1610 can include an X-ray detector 100 as described above, among others. In some embodiments, the X-ray source 1602 includes a plurality of field emitters (FE) 1624. Electron beams from the field emitters 1624 can be directed at an anode 1626 to generate X-rays 1620. The X-ray source 1602 is disposed relative to the detector 1610 such that X-rays 1620 can be generated to penetrate a sample 1622 and be detected by the detector 1610. In some embodiments, the detector 1610 is part of a medical imaging system. In other embodiments, the X-ray imaging system 1600 can include a portable vehicle scanning system, as part of a cargo scanning system. The system 1600 can be any system that can include an X-ray detector.

[0069] An X-ray detector, comprising: a substrate 102 including: a plurality of pixels 1202 configured to convert incident X-rays to electrical signals; a plurality of data lines 106 coupled to the pixels 1202; a printed circuit assembly 110 (PCA 110) including: circuitry 112 configured to convert the electrical signals to digitized data; and an interconnect structure 108 electrically connected between the data lines 106 and the circuitry 112 and configured to transmit the electrical signals from the substrate 102 to the PCA 110.

[0070] In some embodiments, at least two of the plurality of data lines 106 have a pitch less than 150 micrometers (pm).

[0071] In some embodiments, the substrate 102 further comprises a plurality of contact pads 121 coupled to the data lines 106 and forming part of the interconnect structure 108; the printed circuit assembly 110 further comprises a plurality of compression contacts 122 forming part of the interconnect structure 108 and disposed on the printed circuit assembly 110 such that, when the substrate 102 is aligned with the printed circuit assembly 110, the compression contacts 122 are compressed and make contact with the contact pads 121 of the substrate 102.

[0072] In some embodiments, the X-ray detector further comprises a plurality of vias 134 through the substrate 102; wherein: the contact pads 121 are disposed on a side of the substrate 102 opposite the data lines 106; the vias 134 electrically connect the contact pads 121 with the data lines 106.

[0073] In some embodiments, the substrate 102 further comprises a substrate connector 124a forming part of the interconnect structure 108 and electrically connected to the data lines 106; the printed circuit assembly 110 further comprises a PCA connector 124a forming part of the interconnect structure 108 and electrically connected to the circuit 112, and configured to engage with the substrate connector 124a.

[0074] In some embodiments, the substrate 102 further comprises at least one tab 140 forming part of the interconnect structure 108, integrated with and extending from the substrate 102, the tab 140 comprising a contact electrically coupled to the data lines 106; the printed circuit assembly 110 further comprises at least one PCA connector 124c, 124d forming part of the interconnect structure 108 and electrically connected to the circuit 112, each of the at least one PCA connector 124c, 124d configured to engage with a corresponding one of the at least one tab 140.

[0075] In some embodiments, when engaged, the at least one tab 140 extends along an arc of more than 90 degrees.

[0076] In some embodiments, the substrate 102 further comprises at least one substrate connector 124e forming part of the interconnect structure 108 and electrically coupled to the data lines 106; the printed circuit assembly 110 further comprises a printed circuit 112 board having integrated a flexible circuit 150, the flexible circuit 150 forming part of the interconnect structure 108 and configured to engage with the at least one substrate 102 connector; wherein the circuit 112 is further configured to receive electrical signals through the flexible circuit 150.

[0077] In some embodiments, the substrate 102 further comprises: at least one substrate connector 124f that forms part of the interconnect structure 108 and is electrically coupled to the data line 106; the printed circuit assembly 110 further comprises: at least one PCA connector 124g that forms part of the interconnect structure 108 and is electrically connected to the circuit 112; the interconnect structure 108 further comprises a flexible circuit 152 electrically connected between the at least one substrate connector 124f and the at least one PCA connector 124g.

[0078] In some embodiments, when engaged, the flexible circuit 112 extends along an arc of more than 90 degrees.

[0079] In some embodiments, the flexible circuits 150, 152 comprise only passive electrical connections.

[0080] In some embodiments, the interconnect structure 108 comprises a high-density connector with a contact pitch of less than 500 micrometers (pm).

[0081] In some embodiments, the substrate 102 further comprises: a multiplexer 1210 electrically connected to the data line 106 and configured to multiplex electrical signals into a multiplexed electrical signal.

[0082] In some embodiments, the multiplexer 1210 comprises a select input; the circuit 112 comprises a select output; and the interconnect structure 108 comprises an electrical connection electrically connected between the select input and the select output.

[0083] In some embodiments, the substrate 102 further comprises: a common voltage node 1218; and a reset transistor 1220 configured to selectively connect the data line 106 to the common voltage node 1218.

[0084] In some embodiments, the multiplexer 1210 comprises at least one discrete integrated circuit.

[0085] In some embodiments, the multiplexer 1210 comprises an assembly integrated with the substrate 102 and formed during a process of forming the pixel 1202.

[0086] In some embodiments, the substrate 102 further comprises: a common voltage node 1221; and a capacitor 1219 electrically connected between the common voltage node 1221 and at least one of the data line 106 and an output of the multiplexer 1210.

[0087] In some embodiments, at least a portion of the interconnect structure 108 is disposed on a plurality of edges of the substrate 102.

[0088] In some embodiments, the interconnect structure 108 comprises a one-to-one correspondence of electrical connections between the circuit 112 and electrical structures on the substrate 102.

[0089] In some embodiments, the interconnect structure 108 further includes a portion disposed on the substrate 102; and the portion of the interconnect structure 108 disposed on the substrate 102 has a thickness that is at least twice a thickness of the data lines 106.

[0090] Some embodiments include a method comprising: generating an electrical signal in response to X-rays incident to a pixel of a substrate; transmitting the electrical signal from the pixel via a plurality of data lines through an interconnect structure; receiving the electrical signal at a circuit on a printed circuit assembly (PCA) through the interconnect structure; and converting the electrical signal to digitized data with the circuit.

[0091] In some embodiments, the method further includes multiplexing the electrical signal prior to transmitting the electrical signal through the interconnect structure.

[0092] An X-ray detector comprising: means for generating an electrical signal in response to X-rays incident to a pixel of a substrate; means for transmitting the electrical signal from the pixel via a plurality of data lines through an interconnect structure; means for receiving the electrical signal at a circuit on a printed circuit assembly (PCA) through the interconnect structure; and means for converting the electrical signal to digitized data with the circuit.

[0093] In some embodiments, the X-ray detector further includes: means for multiplexing the electrical signal prior to transmitting the electrical signal through the interconnect structure.

[0094] While structures, devices, methods, and systems have been described in terms of certain embodiments, the skilled artisan will readily recognize that numerous modifications can be made to the specific embodiment without departing from the spirit and scope of this disclosure. Accordingly, many modifications can be made by one of ordinary skill in the art without departing from the spirit and scope of the claims.

[0095] The claims following the written disclosure are hereby expressly incorporated into this written disclosure, as part of the written disclosure. The present disclosure includes all permutations of the independent claims and their dependent claims. Furthermore, additional embodiments can be derived from the following independent claims and their dependent claims by utilizing their conception in a different manner. These additional embodiments are explicitly incorporated into this written description. These additional embodiments are determined by applying the conception of a given dependent claim to the phrase "any one of the claims starting with claim [x] and ending with the claim immediately preceding this claim" where the term "[x]" in brackets is replaced with the number of the most recently cited independent claim. For example, in a first set of claims starting with independent claim 1, claim 4 can be dependent on any one of claims 1 and 3, these individual dependencies resulting in two different embodiments; claim 5 can be dependent on any one of claims 1, 3 or 4, these individual dependencies resulting in three different embodiments; claim 6 can be dependent on any one of claims 1, 3, 4 or 5, these individual dependencies resulting in four different embodiments; and so on.

[0096] The term "first" with reference to a feature or element in a claim does not necessarily imply that there is a "second" or other such feature or element. Elements recited in means-plus-function format (if any) are intended to functionally be equivalent to the structures, materials, or acts recited in this written description and claims, and are thus equivalent to each other. Embodiments of the exclusive right or exclusive entitlement claimed by the present invention are limited as follows.

Claims

1. An X-ray detector, comprising: a substrate, including: a plurality of pixels configured to convert incident X-rays into electrical signals; a plurality of data lines coupled to the pixels; a printed circuit assembly (PCA), including: circuitry configured to convert the electrical signals into digitized data; and an interconnect structure electrically connected between the data lines and the circuitry and configured to transmit the electrical signals from the substrate to the PCA. At least two of the plurality of data lines have a pitch of less than 150 micrometers (pm).

2. The X-ray detector of claim 1, wherein, 3. The X-ray detector of claim 1, wherein: the substrate further includes: a plurality of contact pads coupled to the data lines and forming part of the interconnect structure; and the printed circuit assembly further includes: a plurality of compression contacts forming part of the interconnect structure and disposed on the printed circuit assembly such that, when the substrate and the printed circuit assembly are aligned, the compression contacts are compressed and make contact with the contact pads of the substrate.

4. The X-ray detector of claim 3, further comprising: a plurality of vias through the substrate; wherein: the contact pads are disposed on an opposite side of the substrate from the data lines; and the vias electrically connect the contact pads with the data lines.

5. The X-ray detector of claim 1, wherein: the substrate further includes: a substrate connector forming part of the interconnect structure and electrically connected with the data lines; and the printed circuit assembly further includes: a PCA connector forming part of the interconnect structure and electrically connected with the circuitry and configured to engage with the substrate connector.

6. The X-ray detector of claim 1, wherein: the substrate further includes: at least one tab forming part of the interconnect structure and integrated with and extending from the substrate, the tab including a contact electrically coupled with the data lines; and the printed circuit assembly further includes: at least one PCA connector forming part of the interconnect structure and electrically connected with the circuitry, each of the at least one PCA connector configured to engage with a corresponding one of the at least one tab.

7. The X-ray detector of claim 1, wherein: the substrate further includes: at least one substrate connector forming part of the interconnect structure and electrically connected with the data lines; and the printed circuit assembly further includes: a printed circuit board having a flexible circuit integrated therewith, the flexible circuit forming part of the interconnect structure and configured to engage with the at least one substrate connector; wherein the circuitry is further configured to receive the electrical signals through the flexible circuit.

8. The X-ray detector of claim 1, wherein: the substrate further includes: at least one substrate connector forming part of the interconnect structure and electrically coupled with the data lines; the printed circuit assembly further includes: at least one PCA connector forming part of the interconnect structure and electrically connected with the circuitry; and ​ The interconnect structure further includes a flexible circuit electrically connected between the at least one substrate connector and the at least one PCA connector.

9. The X-ray detector of claim 8, wherein: The flexible circuit includes only passive electrical connections.

10. The X-ray detector of claim 1, wherein, The interconnect structure includes a high-density connector with a contact pitch less than 500 micrometers (pm).

11. The X-ray detector of claim 1, wherein: The substrate further includes: a multiplexer electrically connected to the data lines and configured to multiplex the electrical signals into a multiplexed electrical signal.

12. The X-ray detector of claim 11, wherein: The multiplexer includes a select input; The circuit includes a select output; and The interconnect structure includes an electrical connection electrically connected between the select input and the select output.

13. The X-ray detector of claim 11, wherein: The substrate further includes: a common voltage node; and a reset transistor configured to selectively connect the data lines to the common voltage node.

14. The X-ray detector of claim 11, wherein: The multiplexer includes a component integrated with the substrate.

15. The X-ray detector of claim 11, wherein: The substrate further includes: a common voltage node; and a capacitor electrically connected between the common voltage node and at least one of the data lines and an output of the multiplexer.

16. The X-ray detector of claim 1, wherein: At least a portion of the interconnect structure is disposed on a plurality of edges of the substrate.

17. The X-ray detector of claim 1, wherein: The interconnect structure includes a one-to-one electrical connection between the circuit and an electrical structure on the substrate.

18. A method comprising: generating an electrical signal in response to an X-ray incident to a pixel of a substrate; transmitting the electrical signal from the pixel via a plurality of data lines through an interconnect structure; receiving the electrical signal at a circuit on a printed circuit assembly (PCA) through the interconnect structure; and converting the electrical signal to digitized data with the circuit.

19. An X-ray detector comprising: means for generating an electrical signal in response to an X-ray incident to a pixel of a substrate; means for transmitting the electrical signal from the pixel via a plurality of data lines through an interconnect structure; means for receiving the electrical signal at a circuit on a printed circuit assembly (PCA) through the interconnect structure; and means for converting the electrical signal to digitized data with the circuit.

20. The X-ray detector of claim 19, further comprising: means for multiplexing the electrical signal prior to transmitting the electrical signal through the interconnect structure. ​ ​

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