Circuit structure for X-ray detector, manufacturing method of circuit structure and X-ray detector

Abstract

According to the circuit structure for the X-ray detector, the circuit structure is formed on the substrate by adopting the ink through a printing process. The circuit structure comprises a row driving circuit and a column acquisition circuit, wherein each of the row driving circuit and the column acquisition circuit comprises a gate line, a gate insulating layer, a semiconductor layer, a source line, a drain line and a protective layer. The gate insulating layer covers the gate line. The semiconductor layer covers the gate insulating layer. The source line and the drain line are arranged on the upper surface of the semiconductor layer. The protection layer covers the source line and the drain line. The circuit structure is formed by printing ink through a printing technology, in the X-ray imaging process, the circuit structure hardly generates absorptive'development ', fixed-mode noise such as image stripes and shadows caused by internal metal wiring is effectively avoided, and therefore the signal-to-noise ratio and uniformity of imaging are improved.

Description

Technical Field

[0001] This invention belongs to the field of X-ray detectors, specifically relating to a circuit structure for an X-ray detector, a method for manufacturing the same, and an X-ray detector. Background Technology

[0002] In fields such as medical diagnostics, industrial non-destructive testing, and security inspection, digital X-ray imaging technology has become an indispensable core tool. The imaging quality and efficiency of this technology largely depend on the performance of its key component—the X-ray flat panel detector. The detector is responsible for receiving X-rays that penetrate the object being inspected and efficiently and accurately converting them into digital image signals.

[0003] In traditional detector manufacturing processes, readout and control circuits (mainly including row drive lines and column readout lines) are commonly made of metallic materials, such as copper, and fabricated on glass or flexible substrates using microfabrication techniques such as photolithography and etching. While this technology is mature, it increasingly reveals the following inherent drawbacks in the specific application of X-ray imaging. First, metallic materials have a high absorption rate for X-rays. When the detector is operating, after the incident X-rays penetrate the object being measured and the scintillator, some still irradiate the internal metallic circuitry. These metallic lines, like bones or metallic foreign objects, can produce "images" or artifacts in the final image, forming interfering bright and dark stripes or shadows. This inherent structural noise severely reduces image uniformity and signal-to-noise ratio, especially in applications requiring high-sensitivity imaging (such as breast examinations) or low-contrast resolution (such as soft tissue imaging), potentially interfering with accurate diagnosis. Second, the physical properties of metallic materials change under long-term, repeated X-ray irradiation. High-energy photons from X-rays can induce ionization, leading to lattice damage and increased resistivity in metallic conductors, and even degradation of the insulating layer. This radiation damage intensifies over time, causing circuit performance degradation and increased noise, thus shortening the overall reliable lifespan of the detector and increasing maintenance and replacement costs. Finally, the fabrication of microcircuits based on metals such as copper heavily relies on complex, expensive, and energy-intensive semiconductor lithography and etching processes. This process requires vacuum equipment, chemical etching solutions, and precise mask alignment systems, resulting in long production cycles, high costs, and environmentally unfriendly waste liquids. This directly increases the manufacturing cost of high-end detectors, limiting the widespread adoption and application of this technology in broader markets such as primary healthcare and portable devices. Summary of the Invention

[0004] In view of the problems existing in the prior art described above, this application provides a circuit structure for an X-ray detector, a method for manufacturing the same, and an X-ray detector that can produce no imaging artifacts during X-ray imaging.

[0005] To achieve the above and other related objectives, the present invention provides a circuit structure for an X-ray detector, which is formed on a substrate using ink printing technology. The circuit structure includes a row driving circuit and a column acquisition circuit, both of which include:

[0006] Gate line;

[0007] Gate insulating layer, covering the gate line;

[0008] Semiconductor layer, covering the gate insulating layer;

[0009] Source and drain lines are disposed on the upper surface of the semiconductor layer;

[0010] A protective layer covers the source and drain lines.

[0011] Optionally, the printing process is screen printing.

[0012] Optionally, the gate insulating layer and the protective layer are made of insulating ink formed by a printing process.

[0013] Optionally, the gate line, source line, and drain line are made of conductive ink formed by a printing process.

[0014] Optionally, the substrate is a flexible polyimide substrate, a polyethylene terephthalate substrate, or a paper-based flexible substrate.

[0015] Optionally, the thickness of the circuit structure is between 5 μm and 30 μm.

[0016] Another aspect of the present invention provides a method for fabricating a circuit structure for an X-ray detector, comprising the following steps:

[0017] Provide a substrate;

[0018] Gate lines are formed on the substrate using an ink screen printing process;

[0019] On a substrate on which gate lines are formed, a gate insulating layer covering the gate lines is formed by ink screen printing process.

[0020] A semiconductor layer is formed on the gate insulating layer by ink screen printing process;

[0021] Source and drain lines are formed on the semiconductor layer using an ink screen printing process.

[0022] A protective layer is formed on the structure that forms the active and drain lines using an ink screen printing process.

[0023] Optionally, the gate line, source line, and drain line are all formed by printing with conductive ink.

[0024] In another aspect, the present invention provides an X-ray detector, including a circuit structure, the circuit structure comprising the circuit structure described above.

[0025] As described above, the circuit structure for X-ray detectors, the manufacturing method thereof, and the X-ray detector provided by the present invention have at least the following beneficial technical effects:

[0026] This invention discloses a circuit structure for an X-ray detector, which is formed on a substrate using ink printing. The circuit structure includes a row driving circuit and a column acquisition circuit. Both the row driving circuit and the column acquisition circuit include a gate line, a gate insulating layer, a semiconductor layer, a source line, a drain line, and a protective layer. The gate insulating layer covers the gate line. The semiconductor layer covers the gate insulating layer. The source line and drain line are disposed on the upper surface of the semiconductor layer. The protective layer covers the source line and drain line.

[0027] The circuit structure for X-ray detectors in this invention is formed using ink printing. During X-ray imaging, the circuit structure itself produces almost no absorptive "development," effectively avoiding fixed-pattern noise such as image stripes and shadows caused by internal metal wiring. This significantly improves the signal-to-noise ratio and uniformity of the image, providing a clearer image foundation for accurate diagnosis. Furthermore, ink materials (especially carbon-based materials) possess excellent chemical stability and radiation resistance. Under long-term, repeated X-ray irradiation, their electrical performance degradation is far lower than that of metal materials susceptible to ionizing radiation damage. This fundamentally improves the long-term reliability of the detector's core circuitry under irradiation, extends the overall lifespan of the X-ray detector, and reduces maintenance and replacement costs. In addition, the use of additive manufacturing technologies such as screen printing to directly print the circuit completely eliminates the complex mask fabrication, photolithography, development, wet or dry etching, and resist removal steps required in traditional semiconductor processes. This process is simple, requires no expensive photolithography equipment or vacuum systems, has high material utilization, and a short production cycle. Attached Figure Description

[0028] Figure 1 The diagram shown is a schematic diagram of the circuit structure provided in an embodiment of the present invention.

[0029] Figure 2 The diagram shows a schematic representation of the circuit structure, substrate, and TFT structure provided in an embodiment of the present invention.

[0030] Figure 3 The diagram shows a circuit structure and a TFT structure provided in an embodiment of the present invention.

[0031] Figure 4 The flowchart shown is a method for preparing the circuit structure provided in Embodiment 2 of the present invention.

[0032] Figure Labels

[0033] 1. Substrate; 2. Circuit structure; 21. Row driving circuit; 22. Column acquisition circuit; 211. Gate line; 212. Gate insulating layer; 213. Semiconductor layer; 214. Source line; 215. Drain line; 216. Protective layer; 3. TFT structure. Detailed Implementation

[0034] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0035] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Although the illustrations only show components related to the present invention and are not drawn according to the actual number, shape and size of the components, the shape, quantity, positional relationship and proportion of each component can be arbitrarily changed under the premise of realizing the technical solution of this invention, and the layout of the components may also be more complex.

[0036] Example 1

[0037] Reference Figures 1 to 3 This embodiment provides a circuit structure 2 for an X-ray detector. In this embodiment, the circuit structure 2 is formed on a substrate 1 using ink printing. In this embodiment, the substrate 1 is a flexible polyimide substrate, a polyethylene terephthalate substrate, or a paper-based flexible substrate. The thickness of the substrate 1 is between 50 μm and 200 μm. The surface of the substrate 1 is cleaned and plasma activated to enhance the adhesion of subsequent printing inks and ensure printing uniformity.

[0038] In this embodiment, the printing process is screen printing. The screen mesh count is controlled at 300~500 mesh / inch, the squeegee hardness is between 70~90 Shore A, the printing speed is between 50 mm / s and 200 mm / s, and the printing pressure is 0.2~0.5 MPa to ensure the accuracy of the circuit pattern and the consistency of the film thickness.

[0039] Reference Figures 1 to 3 The circuit structure 2 includes a row driving circuit 21 and a column acquisition circuit 22. Both the row driving circuit 21 and the column acquisition circuit 22 include a gate line 211, a gate insulating layer 212, a semiconductor layer 213, a source line 214, a drain line 215, and a protective layer 216. The total thickness of the circuit structure 2 is between 5 μm and 30 μm.

[0040] Reference Figure 1The gate line 211 is made of conductive ink formed by a printing process. This conductive ink is preferably a nano-carbon black or graphene dispersion system, with a solid content between 30% and 50%, a viscosity adjusted to 15 Pa·s to 30 Pa·s, and a surface tension between 2 mN / m and 8 to 35 mN / m. After printing, it is thermo-cured or UV-cured at 80℃ to 150℃ (UV energy between 500 mJ / cm² and 1500 mJ / cm²) to form a stable conductive film with a thickness between 0.5 μm and 2 μm.

[0041] Reference Figure 1 The gate insulating layer 212 covers the gate line 211. The material of the gate insulating layer 212 is insulating ink formed by a printing process. This insulating ink is preferably a polyimide-based or acrylic-based insulating ink with a dielectric constant between 3 and 5 and a volume resistivity ≥ 10⁻⁶. 14 Ω·cm. After printing, it is thermosetting at 120 ℃~180 ℃ to form a dense insulating film with a thickness precisely controlled between 0.2 μm and 1.0 μm, ensuring a dielectric strength ≥200 V / μm, and achieving good interlayer adhesion and interface compatibility to prevent leakage current and breakdown failure.

[0042] Reference Figure 1 The semiconductor layer 213 covers the gate insulating layer 212. A channel pattern is formed in the region corresponding to the gate line 211 using semiconductor ink via screen printing. This semiconductor ink is preferably a metal oxide semiconductor ink (such as an IGZO nanoparticle dispersion) or an organic semiconductor ink (such as a pentane derivative solution), with a carrier mobility ≥ 0.1 cm² / V·s. After printing, a low-temperature curing treatment is performed (curing temperature ≤ 200 ℃, time 30-60 minutes) to form a semiconductor thin film with a thickness between 0.1 μm and 0.5 μm, meeting the electrical performance requirements for detector signal switching.

[0043] Reference Figure 1 Source line 214 and drain line 215 are disposed on the upper surface of semiconductor layer 213. The material of source line 214 and drain line 215 is conductive ink formed by printing process.

[0044] Reference Figure 1 The protective layer 216 covers the source line 214 and the drain line 215. The material of the protective layer 216 is insulating ink formed by a printing process.

[0045] Reference Figures 1 to 3The circuit structure 2 for the X-ray detector of this invention is formed using ink through a printing process. During X-ray imaging, the circuit structure 2 itself produces almost no absorptive "development," effectively avoiding fixed-pattern noise such as image stripes and shadows caused by internal metal wiring. This significantly improves the signal-to-noise ratio and uniformity of the image, providing a clearer image basis for accurate diagnosis. Furthermore, the ink material (especially carbon-based materials) has excellent chemical stability and radiation resistance. Under long-term, repeated X-ray irradiation, its electrical performance degradation is far lower than that of metal materials susceptible to ionizing radiation damage. This fundamentally improves the long-term reliability of the detector's core circuit under irradiation, extends the lifespan of the entire X-ray detector, and reduces maintenance and replacement costs. In addition, the use of additive manufacturing technologies such as screen printing to directly print the circuit completely eliminates the complex mask fabrication, photolithography, development, wet or dry etching, and resist removal steps required in traditional semiconductor processes. This process is simple, requires no expensive photolithography equipment and vacuum systems, has high material utilization, and a short production cycle.

[0046] Example 2

[0047] This embodiment provides a method for fabricating circuit structure 2 for an X-ray detector, referring to... Figures 1 to 4 This includes the following steps:

[0048] S100: Provides a substrate;

[0049] Reference Figure 2 and Figure 4 A substrate 1 is provided, which serves as the physical carrier and mechanical support for the circuit structure 2 of this invention. In this embodiment, the substrate 1 is preferably a flexible polyimide (PI) substrate, a polyethylene terephthalate (PET) substrate, or a paper-based flexible substrate, with its thickness precisely controlled within the range of 50 μm to 200 μm to ensure a good balance between flexibility and mechanical strength. Before printing, the surface of the substrate 1 needs to undergo systematic pretreatment: firstly, ultrasonic cleaning with anhydrous ethanol or isopropanol for 10 to 15 minutes is performed to remove surface oil and particulate contaminants; subsequently, oxygen plasma treatment is performed in a vacuum plasma cleaner with a power setting of 100 W to 300 W, a treatment time of 2 to 5 minutes, and a gas flow rate of 20 sccm to 50 sccm. This treatment can significantly increase the surface energy of the substrate (contact angle ≤30°), enhance the wettability and adhesion of subsequent inks, and improve the edge sharpness and thickness uniformity of the printed pattern (thickness deviation ≤±5%). The treated substrate needs to be printed within 30 minutes in a clean environment to prevent surface activity degradation.

[0050] S200: Gate lines are formed on the substrate by ink screen printing process;

[0051] Reference Figure 1 and Figure 4 Carbon-based conductive inks (such as nano-carbon black, graphene, or carbon nanotube dispersion systems) are used. The ink has a solid content of 30%–50%, a viscosity adjusted to 15 Pa·s–30 Pa·s, a surface tension of 28 mN / m–35 mN / m, and a thixotropic index of 3–6, ensuring good flowability and shape retention during printing. Gate lines 211 with a pre-defined gate pattern are formed on the substrate using a high-precision screen printing machine. The screen is made of stainless steel with a mesh count of 300 mesh / inch–500 mesh / inch, a film thickness of 15 μm–25 μm, and a latex thickness of 5 μm–10 μm. The pattern opening size accuracy is controlled within ±2 μm. The printing process parameters are as follows: squeegee hardness 70 Shore A ~ 90 Shore A, printing speed 50 mm / s ~ 200 mm / s, printing pressure 0.2 MPa ~ 0.5 MPa, squeegee angle 75° ~ 85°, and ink return blade pressure 0.1 MPa ~ 0.2 MPa. The wet film thickness of the printed gate line 211 is between 10 μm and 20 μm, and the linewidth / spacing (L / S) accuracy can reach 20 μm ~ 50 μm. The printed substrate is then transferred to an oven or UV curing equipment for curing: the thermal curing temperature is between 80 ℃ and 150 ℃, the heating rate is ≤ 5 ℃ / min, and the holding time is 30 minutes to 60 minutes; or UV curing is used, with a UV energy density of 500 mJ / cm² ~ 1500 mJ / cm² and a wavelength between 365 nm and 405 nm. After curing, the dry film thickness of the gate line 211 is between 0.5 μm and 2 μm, and the resistivity stability deviation is ≤ ±10%, forming a stable conductive film layer.

[0052] S300: On a substrate on which the gate lines are formed, a gate insulating layer covering the gate lines is formed by an ink screen printing process.

[0053] Reference Figure 1 and Figure 4 Insulating inks (such as polyimide, acrylic, or epoxy resin insulating inks) are used. These inks have a solid content of 20%–40%, a viscosity of 10 Pa·s–25 Pa·s, a dielectric constant of 3–5, and a volume resistivity ≥10¹. 4The breakdown field strength is ≥200 V / μm, with an Ω·cm Ω·cm. The gate line 211 is fully covered by screen printing, with printing parameters similar to the S200 process, but the squeegee pressure is appropriately reduced to 0.15 MPa ~ 0.3 MPa to prevent excessive printing pressure from deforming the underlying gate line 211. The wet film thickness after printing is 15 μm ~ 30 μm, which is then subjected to a stepped thermosetting process at 120 ℃ ~ 180 ℃: first, pre-baking at 80 ℃ for 10 minutes, then curing at 120 ℃ for 20 minutes, and finally main curing at 150 ℃ ~ 180 ℃ for 30 ~ 60 minutes, allowing the solvent to fully evaporate and form a dense cross-linked network structure. After curing, the dry film thickness of the gate insulating layer 212 is precisely controlled within the range of 0.2 μm to 1.0 μm, with a thickness uniformity deviation of ≤ ±8%, dielectric strength ≥ 200 V / μm, and interlayer adhesion (100-cross test) ≥ 4B grade, ensuring no pinholes or cracks, and possessing good dielectric properties and interlayer adhesion.

[0054] S400: A semiconductor layer is formed on the gate insulating layer by an ink screen printing process;

[0055] Reference Figure 1 and Figure 4 Semiconductor patterns are formed in the region corresponding to gate line 211 by screen printing using semiconductor ink (such as metal oxide semiconductor ink or organic semiconductor ink). After printing, the semiconductor layer 213 is cured at a low temperature (usually ≤200℃) to form a semiconductor layer 213, whose carrier mobility must meet the requirements of detector signal switching.

[0056] S500: Source lines and drain lines are formed on the semiconductor layer by ink screen printing process;

[0057] Reference Figure 1 and Figure 4 Source lines 214 and drain lines 215 are formed on semiconductor layer 213 by screen printing using carbon-based conductive ink.

[0058] S600: A protective layer is formed on the structure in which the source line and drain line are formed by an ink screen printing process.

[0059] Reference Figure 1 and Figure 4 Finally, insulating ink is used to print and cover the entire circuit structure 2, forming a protective layer 216. After curing, the protective layer 216 provides mechanical protection, environmental isolation, and insulation protection, completing the preparation of the circuit structure 2.

[0060] The fabrication method for the circuit structure 2 of the X-ray detector in this embodiment utilizes layer-by-layer additive printing, avoiding the complex processes of mask fabrication, resist coating, exposure, development, etching, and resist removal found in traditional photolithography. The process is simplified from over ten steps to six core printing steps. The all-carbon-based ink material system exhibits a low X-ray absorption coefficient and a high radiation damage threshold, fundamentally solving the problems of development artifacts and radiation aging of metal circuits under X-rays. Furthermore, ink-based screen printing technology is characterized by low cost and simple process, significantly reducing manufacturing complexity and overall cost. This provides a feasible process path for the mass production of high-performance, low-cost, and long-life flexible X-ray detectors.

[0061] Example 3

[0062] This embodiment provides an X-ray detector, which includes a circuit structure. The circuit structure includes the circuit structure described in Embodiment 1 and also has the above-mentioned technical effects.

[0063] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A circuit structure for an X-ray detector, characterized in that, The circuit structure is formed on a substrate using ink printing technology. The circuit structure includes a row driving circuit and a column acquisition circuit, and both the row driving circuit and the column acquisition circuit include: Gate line; A gate insulating layer covers the gate line; A semiconductor layer covering the gate insulating layer; Source and drain lines are disposed on the upper surface of the semiconductor layer; A protective layer covers the source line and the drain line.

2. The circuit structure for an X-ray detector according to claim 1, characterized in that, The printing process is screen printing.

3. The circuit structure for an X-ray detector according to claim 1, characterized in that, The gate insulating layer and the protective layer are made of insulating ink formed by a printing process.

4. The circuit structure for an X-ray detector according to claim 1, characterized in that, The gate line, the source line, and the drain line are made of conductive ink formed by a printing process.

5. The circuit structure for an X-ray detector according to claim 1, characterized in that, The substrate is a flexible polyimide substrate, a polyethylene terephthalate substrate, or a paper-based flexible substrate.

6. The circuit structure for an X-ray detector according to claim 1, characterized in that, The thickness of the circuit structure is between 5 μm and 30 μm.

7. A method for fabricating a circuit structure for an X-ray detector, characterized in that, Includes the following steps: Provide a substrate; Gate lines are formed on the substrate by ink screen printing process; On a substrate on which the gate lines are formed, a gate insulating layer covering the gate lines is formed by an ink screen printing process. A semiconductor layer is formed on the gate insulating layer by an ink screen printing process; Source and drain lines are formed on the semiconductor layer using an ink screen printing process; A protective layer is formed on the structure in which the source and drain lines are formed by an ink screen printing process.

8. The method for fabricating the circuit structure for an X-ray detector according to claim 7, characterized in that, The gate line, the source line, and the drain line are all formed by printing with conductive ink.

9. An X-ray detector, characterized in that, It includes a circuit structure, which includes the circuit structure described in any one of claims 1 to 6.

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