Fabrication method of infrared detection module, infrared detector

Abstract

This disclosure provides a method for fabricating an infrared detection module and an infrared detector, relating to the field of infrared detector technology, and addresses the problem of instability caused by the susceptibility of temporary bonding layers to high-temperature processes. The method for fabricating the infrared detection module includes: forming a substrate; connecting a first temporary bonding layer to a first temporary substrate on a first side of the substrate, the first temporary bonding layer being located between the substrate and the first temporary substrate; forming a first bonding layer on a second side of the substrate under a first temperature condition, the second side of the substrate being opposite to the first side of the substrate, the first temperature being lower than the melting point of the first bonding layer; and heating the first temporary bonding layer to release the connection between the substrate and the first temporary substrate; wherein the melting point of the first temporary bonding layer is greater than the first temperature and less than the melting point of the first bonding layer. The method for fabricating an infrared detection module provided by this disclosure is used to fabricate an infrared detection module.

Description

Technical Field

[0001] This disclosure relates to the field of infrared detector technology, and in particular to a method for preparing an infrared detection module and an infrared detector. Background Technology

[0002] 3D micro-electro-mechanical system (MEMS) infrared detectors are miniature devices with infrared detection capabilities fabricated using wafer-level packaging (WLP) technology. They have advantages such as high detection unit density, small package size, and high heat dissipation efficiency.

[0003] In 3D MEMS infrared detectors, the device layer is relatively thin, making it susceptible to deformation during the vertical packaging process. To address this, a temporary bonding layer is used during the fabrication of 3D MEMS infrared detectors to connect a temporary substrate to one side of the device layer. This temporary substrate provides mechanical support for the device layer, and both the temporary substrate and the temporary bonding layer are removed after final packaging.

[0004] However, in some cases, the fabrication process of 3D MEMS infrared detectors involves high-temperature processes, such as the formation process of bonding layers for vertical packaging. In these cases, the temporary bonding layers are susceptible to instability due to the high-temperature process, which leads to a reduction in reliability during the packaging process. Summary of the Invention

[0005] Some embodiments of this disclosure provide a method for fabricating an infrared detection module and an infrared detector, which are used to solve the problem that temporary bonding layers are easily affected by high-temperature processes and become unstable.

[0006] In a first aspect, a method for fabricating an infrared detection module is provided. The method includes: forming a substrate; connecting a first temporary bonding layer to a first temporary substrate on a first side of the substrate, the first temporary bonding layer being located between the substrate and the first temporary substrate; forming a first bonding layer on a second side of the substrate under a first temperature condition, the second side of the substrate being opposite to the first side of the substrate, the first temperature being lower than the melting point of the first bonding layer; and heating the first temporary bonding layer to release the connection between the substrate and the first temporary substrate. Wherein, the melting point of the first temporary bonding layer is greater than the first temperature and less than the melting point of the first bonding layer.

[0007] Understandably, on the one hand, by setting the melting point of the first temporary bonding layer to be higher than the first temperature, the melting point of the first temporary bonding layer can be relatively high. This has two advantages: first, it can prevent the first temporary bonding layer from melting or failing under the first temperature condition, thereby avoiding the first temporary bonding layer from falling off or being damaged under high temperature process conditions; second, it can improve the stability of the first temporary bonding layer, thereby improving the reliability of the packaging process and ensuring the stability of the equipment.

[0008] On the other hand, by setting the melting point of the first temporary bonding layer to be lower than that of the first bonding layer, the melting point of the first temporary bonding layer can be lower than that of the first bonding layer. In this way, the first bonding layer is less likely to melt or fail during the heating process, so that the heating process will not affect the integrity of the packaging structure. This achieves the controllable removal of the first temporary bonding layer and improves the controllability and repeatability of the packaging process.

[0009] Furthermore, by setting the melting point of the first temporary bonding layer to be lower than that of the first bond layer, the melting point of the first temporary bonding layer can be made relatively low while ensuring its stability. This allows the temperature at which the first temporary bonding layer is formed to be relatively low, thus avoiding the influence of the temperature conditions at which the first temporary bonding layer is formed on other structures. It also allows the first temporary bonding layer to be removed by heat treatment.

[0010] Optionally, the difference between the melting point of the first temporary bonding layer and the first temperature is greater than or equal to 60°C; and / or, the difference between the melting point of the first bonding layer and the melting point of the first temporary bonding layer is greater than or equal to 200°C.

[0011] Optionally, the first bonding layer includes a first alloy, which includes a first metal and a second metal; the melting point of the first metal is greater than the melting point of the second metal; and the first temperature is greater than the melting point of the second metal and less than the melting point of the first metal.

[0012] Optionally, the difference between the melting point of the first metal and the melting point of the second metal is greater than or equal to 100°C.

[0013] Optionally, the first bonding layer is formed using a transient liquid phase bonding process.

[0014] Optionally, forming a first bonding layer on the second side of the substrate includes: forming a first metal layer and a second metal layer on the second side of the substrate, the first metal layer and the second metal layer being stacked along the thickness direction of the substrate; the first metal layer comprising a first metal; the second metal layer comprising a second metal; and, under a first temperature condition, employing a transient liquid phase bonding process to transform the first metal layer and the second metal layer into a first bonding layer, the first bonding layer comprising a first alloy, the first alloy comprising a first metal and a second metal.

[0015] Optionally, the first temporary bonding layer is formed using a eutectic bonding process.

[0016] Optionally, connecting the first temporary bonding layer and the first temporary substrate on the first side of the substrate includes: forming a eutectic alloy layer on the surface of the first side of the substrate, and / or on the surface of the first temporary substrate facing the substrate; and using a hot pressing process to convert the eutectic alloy layer into the first temporary bonding layer, and connecting the substrate and the first temporary substrate through the first temporary bonding layer.

[0017] Optionally, before connecting the first temporary bonding layer and the first temporary substrate on the first side of the substrate, the preparation method further includes: connecting a second temporary bonding layer and a second temporary substrate on the second side of the substrate, wherein the second temporary bonding layer is closer to the substrate than the second temporary substrate. After connecting the first temporary bonding layer and the first temporary substrate on the first side of the substrate, the preparation method further includes: using a debonding process to remove the second temporary bonding layer and the second temporary substrate; wherein the melting point of the first temporary bonding layer is greater than the process temperature of the debonding process.

[0018] Optionally, after the second temporary bonding layer and the second temporary substrate are connected on the second side of the substrate, and before the first temporary bonding layer and the first temporary substrate are connected on the first side of the substrate, the fabrication method further includes: thinning the substrate from the first side of the substrate; and / or forming a contact structure through the substrate from the first side of the substrate.

[0019] Optionally, before attaching the second temporary bonding layer and the second temporary substrate to the second side of the substrate, the fabrication method further includes: forming a pixel structure on the second side of the substrate; and forming a protective layer on the side of the pixel structure away from the substrate, the protective layer covering the pixel structure; the protective layer is disposed between the pixel structure and the second temporary bonding layer to be formed. After removing the second temporary bonding layer and the second temporary substrate, and before forming the first bonding layer on the second side of the substrate, the fabrication method further includes: removing the protective layer under a second temperature condition. Wherein, the melting point of the first temporary bonding layer is higher than the second temperature.

[0020] Optionally, the infrared detection module further includes a pad layer disposed on the second side of the substrate. The surface of the substrate facing away from the first temporary bonding layer is connected to the pad layer through the first bonding layer. After the first bonding layer is formed on the second side of the substrate, and before heating the first temporary bonding layer, the fabrication method further includes: under a third temperature condition, connecting a second bonding layer and an optical window layer on the side of the pad layer away from the substrate, with the second bonding layer located between the optical window layer and the pad layer. The melting point of the first temporary bonding layer is greater than the third temperature but less than the melting point of the second bonding layer.

[0021] Optionally, the third temperature ranges from 180°C to 250°C; and / or, the melting point of the second bonding layer ranges from 400°C to 500°C.

[0022] Optionally, the melting point of the first temporary bonding layer is in the range of 250°C to 300°C; and / or, the first temperature is in the range of 180°C to 250°C; and / or, the melting point of the first bonding layer is in the range of 400°C to 500°C.

[0023] Secondly, an infrared detector is provided. The infrared detector includes a circuit board and an infrared detection module, with the infrared detection module coupled to the circuit board. The infrared detection module is fabricated using the method described above.

[0024] The beneficial effects that the infrared detectors provided in some embodiments of this disclosure can achieve are the same as the beneficial effects that the infrared detection module preparation method provided in the above technical solutions can achieve, and will not be repeated here. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of embodiments of this disclosure and form part of the embodiments of this disclosure, illustrate exemplary embodiments of this disclosure and are used to explain this disclosure, but do not constitute an undue limitation of this disclosure. In the drawings:

[0026] Figure 1 A flowchart illustrating a method for fabricating an infrared detection module, provided for some embodiments of this disclosure;

[0027] Figures 2A to 2L A step diagram illustrating the fabrication process of an infrared detection module provided for some embodiments of this disclosure;

[0028] Figure 3 A structural diagram of an infrared detection module provided for some embodiments of this disclosure;

[0029] Figure 4 This is a structural diagram of an infrared detector provided for some embodiments of the present disclosure. Detailed Implementation

[0030] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0031] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0032] In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0033] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0034] Among related technologies, three-dimensional integrated circuit (3D IC) packaging technology is a packaging technology that vertically stacks multiple devices to improve integration and performance. Wafer-level packaging (WLP) is a packaging process that performs packaging at the wafer level, which can increase packaging density and reduce packaging volume.

[0035] With the continuous advancement of microelectromechanical systems (MEMS) technology, especially the development of 3D integrated circuit (3D IC) packaging and wafer-level packaging (WLP), the integration density of MEMS devices is constantly increasing, making it difficult for traditional single-layer packaging structures to meet high-performance requirements. Multi-layer stacking package technology plays a significant role in improving device unit density, reducing package size, and enhancing heat dissipation efficiency.

[0036] In some implementations, when a 3D MEMS infrared detector 300 is fabricated using multilayer stacking packaging technology, the device layer (e.g., the substrate of the device layer) is thinned in order to reduce the thickness of the stacked structure. This makes the device layer more fragile in subsequent processing and susceptible to deformation due to the influence of related processes.

[0037] Therefore, in the fabrication process of 3D MEMS infrared detectors, a temporary bonding layer and a temporary substrate are connected to one side of the device layer to support the device layer; and after the final packaging is completed, the temporary substrate and the temporary bonding layer are removed.

[0038] In some implementations, the temporary bonding layer is made of organic adhesive materials (e.g., epoxy resin or polyurethane) or water-soluble adhesive materials. These adhesive materials are prone to decomposition and failure under subsequent high-temperature processing conditions, causing instability in the temporary bonding layer.

[0039] In some other implementations, the temporary bonding layer is made of low-melting-point metals (e.g., tin-lead alloys or indium-containing alloys). These low-melting-point metals are prone to premature melting and failure under subsequent high-temperature processing conditions, causing instability in the temporary bonding layer.

[0040] In some implementations, the process of removing the temporary substrate and temporary bonding layer (i.e., the process of debonding the device layer from the temporary substrate) is a laser irradiation process. However, using this process for debonding may have the following two problems: First, the laser irradiation depth is relatively limited, making this process suitable for cases with fewer layers bonded together, which is not conducive to improving packaging density; second, in order to improve the uniformity of laser irradiation, this process has certain requirements on the flatness of the sample and / or the refractive index and thermal conductivity of the device layer material, for example, requiring the sample's TTV to be less than 10 μm, making the adaptability of this process poor.

[0041] Based on this, some embodiments of this disclosure provide an infrared detection module 100 (see also...). Figure 2L The preparation method of the temporary bonding layer is proposed to at least solve the problem that the temporary bonding layer is easily affected by high temperature process and is unstable.

[0042] Figure 1 A flowchart illustrating a method for fabricating an infrared detection module 100, provided for some embodiments of this disclosure. Figures 2A to 2L This diagram illustrates the fabrication steps of an infrared detection module 100 provided for some embodiments of this disclosure. These steps will be described together below. Figure 1 and Figures 2A to 2L .

[0043] like Figure 1 As shown, the method for preparing the infrared detection module 100 includes steps S10 to S40.

[0044] S10: As Figure 2A As shown, substrate 101 is formed.

[0045] For example, the substrate 101 includes a substrate; the substrate may be a silicon substrate, germanium substrate, germanium silicon substrate, silicon-on-insulator substrate, indium gallium arsenide substrate, gallium arsenide substrate, silicon carbide substrate, or other suitable substrate materials.

[0046] In some examples, substrate 101 also includes circuit structures formed within or on the substrate.

[0047] S20: As Figure 2F and Figure 2G As shown, a first temporary bonding layer 102 and a first temporary substrate 103 are connected on the first side 101A of the substrate 101, and the first temporary bonding layer 102 is located between the substrate 101 and the first temporary substrate 103.

[0048] For example, the first temporary substrate 103 is a single-element silicon substrate or a glass substrate.

[0049] It should be understood that by using the first temporary bonding layer 102, the connection between the substrate 101 and the first temporary substrate 103 can be realized, so that the first temporary substrate 103 can provide mechanical support for the substrate 101.

[0050] S30: As Figure 2J As shown, under a first temperature condition, a first bonding layer 104 is formed on the second side 101B of the substrate 101, with the second side 101B of the substrate 101 opposite to the first side 101A of the substrate 101; the first temperature is less than the melting point of the first bonding layer 104.

[0051] In some examples, such as Figure 2J As shown, the first bonding layer 104 is connected to the surface of the second side 101B of the substrate 101. At this time, the first bonding layer 104 can be used to realize the connection between the substrate 101 and other functional layers in the infrared detection module 100 other than the substrate 101 (e.g., the padding layer 110 described in detail below).

[0052] In some other examples, the first bonding layer 104 is spaced apart from the surface of the second side 101B of the substrate 101; in this case, the first bonding layer 104 may be located between two functional layers disposed on the second side 101B of the substrate 101 to achieve the connection of the two functional layers.

[0053] Here, this embodiment of the disclosure does not limit the functional type of the functional layer connected to the first bonding layer 104.

[0054] S40: As Figure 2K and Figure 2L As shown, the first temporary bonding layer 102 is heated to disconnect the substrate 101 and the first temporary substrate 103.

[0055] The melting point of the first temporary bonding layer 102 is greater than the first temperature and less than the melting point of the first bonding layer 104.

[0056] Here, the melting point of the first temporary bonding layer 102 refers to the temperature at which the first temporary bonding layer 102 changes from a solid to a liquid state. The melting point of the first bonding layer 104 refers to the temperature at which the first bonding layer 104 changes from a solid to a liquid state. The first temperature can be understood as the formation temperature of the first bonding layer 104.

[0057] Understandably, on the one hand, by setting the melting point of the first temporary bonding layer 102 to be higher than the first temperature, the melting point of the first temporary bonding layer 102 can be relatively high. This has two advantages: first, it prevents the first temporary bonding layer 102 from melting or failing under the first temperature condition in S30, thereby avoiding the first temporary bonding layer 102 from falling off or being damaged under the high-temperature process conditions in S30; second, compared with some implementations where the temporary bonding layer material includes low-melting-point metals or adhesive materials, the first bonding layer 104 can exhibit better structural stability in high-temperature environments. Thus, the stability of the first temporary bonding layer 102 can be improved, the reliability of the packaging process can be enhanced, and the stability of the device can be ensured.

[0058] On the other hand, by setting the melting point of the first temporary bonding layer 102 to be lower than that of the first bonding layer 104, the melting point of the first temporary bonding layer 102 can be lower than that of the first bonding layer 104. In this way, under the heating conditions of the first temporary bonding layer 102 in S40, the first bonding layer 104 is less likely to melt or fail, and the high-temperature process in S40 will not affect the integrity of the packaging structure. This achieves controlled removal of the first temporary bonding layer 102. Thus, compared with some implementations where the temporary bonding layer process poses a potential risk of damage to the device layer structure, the controllability and repeatability of the packaging process can be improved.

[0059] Furthermore, by setting the melting point of the first temporary bonding layer 102 to be lower than that of the first bonding layer 104, the stability of the first temporary bonding layer 102 can be ensured while maintaining a relatively low melting point. This allows for a relatively low temperature at which the first temporary bonding layer 102 is formed in S20, thus avoiding the influence of the temperature conditions in S20 on other structures. It also allows the first temporary bonding layer 102 to be removed by heat treatment. Compared to some implementations that use chemical or mechanical removal methods to remove the temporary bonding layer, heat treatment allows for precise and controllable removal of the first temporary bonding layer 102, simplifying the packaging process of the infrared detection module 100 and improving the efficiency of the packaging process and the infrared detection module 200 (see [reference]). Figure 3 The advantages of this method are: 1) Improved production efficiency; 2) Safe removal of the first temporary bonding layer 102, avoiding damage to other structures in the infrared detection module 200 caused by chemical or mechanical removal methods, thus reducing the risk of damage to other structures in the infrared detection module 200; 3) Increased removal degree of the first temporary bonding layer 102, avoiding the problem of incomplete removal affecting the performance of the final device; 4) Enhanced process flexibility of the removal process of the first temporary bonding layer 102, thereby improving the adaptability of the preparation method to meet different packaging requirements.

[0060] This disclosure does not limit the range of the difference between the melting point of the first temporary bonding layer 102 and the first temperature. For example, the difference between the melting point of the first temporary bonding layer 102 and the first temperature can be 20°C, 30°C, 40°C, or 50°C, etc.

[0061] In some embodiments, combined with Figure 2H The difference between the melting point of the first temporary bonding layer 102 and the first temperature is greater than or equal to 60°C.

[0062] For example, the difference between the melting point of the first temporary bonding layer 102 and the first temperature can be 60°C, 70°C, 80°C, 94°C, 100°C, 120°C, 150°C or 200°C, etc.

[0063] By setting the difference between the melting point of the first temporary bonding layer 102 and the first temperature to be greater than or equal to 60°C, the difference between the melting point of the first temporary bonding layer 102 and the first temperature is relatively large, which can reduce the influence of the first temperature condition in S30 on the first temporary bonding layer 102, making the stability of the first temporary bonding layer 102 higher during the process of S30. In this way, the reliability of the packaging process can be improved.

[0064] This disclosure does not limit the range of the difference between the melting point of the first bonding layer 104 and the melting point of the first temporary bonding layer 102. For example, the difference between the melting point of the first bonding layer 104 and the melting point of the first temporary bonding layer 102 can be 50°C, 80°C, 100°C, or 150°C, etc.

[0065] In some embodiments, combined with Figure 2J The difference between the melting point of the first bonding layer 104 and the melting point of the first temporary bonding layer 102 is greater than or equal to 200°C.

[0066] For example, the difference between the melting point of the first bonding layer 104 and the melting point of the first temporary bonding layer 102 can be 200°C, 210°C, 225°C, 230°C, 240°C, 250°C, 280°C or 300°C, etc.

[0067] By setting the melting point difference between the first bonding layer 104 and the first temporary bonding layer 102 to be greater than or equal to 200°C, the relatively large difference between the melting points of the first bonding layer 104 and the first temporary bonding layer 102 can reduce the influence of the heating conditions in S40 on the first bonding layer 104, making the stability of the first bonding layer 104 higher during the S40 process. In this way, the integrity of the packaging structure can be improved.

[0068] In some embodiments, combined with Figure 2H The melting point of the first temporary bonding layer 102 is in the range of 250℃~300℃.

[0069] For example, the melting point of the first temporary bonding layer 102 may be 250°C, 255°C, 260°C, 265°C, 270°C, 275°C, 280°C, 290°C or 300°C, etc.

[0070] With the above settings, the melting point of the first temporary bonding layer 102 is within a suitable range, which makes the melting point of the first temporary bonding layer 102 greater than the first temperature and less than the melting point of the first bonding layer 104. As mentioned above, this can improve the stability of the first temporary bonding layer 102 under high temperature process conditions, and enable the first temporary bonding layer 102 to be removed by heat treatment, and the integrity of the packaging structure will not be affected during the heat removal process (i.e., S40).

[0071] In some embodiments, the first temperature ranges from 180°C to 250°C.

[0072] For example, the first temperature can be 180°C, 190°C, 195°C, 200°C, 205°C, 210°C, 220°C, 230°C, 240°C, or 250°C, etc.

[0073] With the above settings, the first temperature is within a suitable range, which can make the first temperature lower than the melting point of the first temporary bonding layer 102. As mentioned above, this can improve the stability of the first temporary bonding layer 102 under the high-temperature process conditions of S30.

[0074] In some embodiments, combined with Figure 2J The melting point of the first bonding layer 104 is in the range of 400℃~500℃.

[0075] For example, the melting point of the first bonding layer 104 may be 400°C, 420°C, 440°C, 460°C, 480°C, 490°C, 496°C or 500°C, etc.

[0076] With the above settings, the melting point of the first bonding layer 104 is within a suitable range, which makes the melting point of the first bonding layer 104 greater than the melting point of the first temporary bonding layer 102. As mentioned above, this makes it possible for the first bonding layer 104 to not easily melt or fail under the heating conditions of the first temporary bonding layer 102 in S40, so that the high-temperature process in S40 will not affect the integrity of the packaging structure.

[0077] The present disclosure does not limit the type of material of the first temporary bonding layer 102.

[0078] In some embodiments, combined with Figure 2H The material of the first temporary bonding layer 102 includes an alloy material, and the alloy material included in the first temporary bonding layer 102 includes Group IIIA metal elements and / or Group IVA metal elements.

[0079] Compared to other groups of metals, Group IIIA and Group IVA metals have relatively low melting points. Therefore, through the above settings, the melting point of the material of the first temporary bonding layer 102 can be relatively low. This has two advantages: first, it reduces the difficulty of forming the first temporary bonding layer 102; second, it allows the first temporary bonding layer 102 to have a relatively low melting point, as mentioned above, so that the first temporary bonding layer 102 can be removed by heat treatment, and the integrity of the packaging structure will not be affected during the heat removal process (i.e., S40).

[0080] In some embodiments, combined with Figure 2J The material of the first bonding layer 104 includes an alloy material, and the alloy material included in the first bonding layer 104 includes Group IIIA metal elements and / or Group IVA metal elements.

[0081] Compared to metals from other groups, Group IIIA and IVA metals have relatively low melting points. Therefore, by adopting the above-mentioned configuration, the melting point of the material of the first bonding layer 104 can be relatively low, thereby reducing the difficulty of forming the first bonding layer 104.

[0082] In some embodiments, combined with Figure 2H The material of the first temporary bonding layer 102 includes at least one of an indium (In) alloy and a tin-bismuth (Sn-Bi) alloy.

[0083] For example, the indium alloy described above can be a tin-indium-copper (Sn-In-Cu) alloy.

[0084] Firstly, through the above-mentioned configuration, the melting point of the first temporary bonding layer 102 can be in the range of 250℃~300℃, thereby making the melting point of the first temporary bonding layer 102 higher than the first temperature and lower than the melting point of the first bonding layer 104. As mentioned above, this improves the stability of the first temporary bonding layer 102 under high-temperature process conditions and allows the first temporary bonding layer 102 to be removed by heat treatment, without affecting the integrity of the packaging structure during the heat removal process (i.e., S40). Secondly, through the above-mentioned configuration, the material of the first temporary bonding layer 102 is a eutectic alloy, enabling the first temporary bonding layer 102 to be formed by eutectic bonding technology, which is beneficial for achieving the bonding and debonding of the first temporary bonding layer 102. Thirdly, the above-mentioned metal material has good environmental adaptability and environmental protection performance, and compared with traditional packaging materials, it can avoid pollution to the environment.

[0085] The present disclosure does not limit the type of material of the first bonding layer 104.

[0086] In some embodiments, combined with Figure 2J The first bonding layer 104 includes a first alloy, which includes a first metal and a second metal; the melting point of the first metal is greater than the melting point of the second metal; the first temperature is greater than the melting point of the second metal and less than the melting point of the first metal.

[0087] Understandably, when the first temperature is greater than the melting point of the second metal but less than the melting point of the first metal, during the formation of the first bonding layer 104 in S30, the first temperature can reach the melting point of the first metal but not the melting point of the second metal. That is, the low-melting-point metal in the first alloy melts while the high-melting-point metal in the first alloy does not melt, and the two metals are mixed into a first alloy by utilizing the diffusion effect between the two metals. In this way, the first temperature can be lower than the melting point of the first alloy, and thus the first temperature can be lower than the melting point of the first bonding layer 104.

[0088] In this embodiment, the difference between the melting point of the first metal and the melting point of the second metal is not limited. For example, the difference between the melting point of the first metal and the melting point of the second metal can be 80°C, 85°C, 90°C, or 95°C, etc.

[0089] In some embodiments, combined with Figure 2J The difference between the melting point of the first metal and the melting point of the second metal is greater than or equal to 100°C.

[0090] For example, the difference between the melting point of the first metal and the melting point of the second metal can be 100°C, 150°C, 200°C, 240°C, 300°C, 350°C, 400°C, 460°C, 500°C, 600°C, 700°C, or 800°C, etc.

[0091] In some examples, when the first bonding layer 104 comprises a first alloy, the melting point of the first metal, the melting point of the second metal, the first temperature, and the melting point of the first bonding layer 104 are ordered from largest to smallest as follows: melting point of the first metal, melting point of the first bonding layer 104, first temperature, and melting point of the second metal. That is, the melting point and the first temperature of the first bonding layer 104 are both between the melting point of the second metal and the melting point of the first metal. In this case, the difference between the melting point of the first bonding layer 104 and the first temperature is less than the difference between the melting points of the first metal and the second metal.

[0092] Understandably, when the difference between the melting point of the first metal and the melting point of the second metal is greater than or equal to 100°C, the difference between the melting points of the first metal and the second metal is relatively large. This can make the difference between the melting point of the first bonding layer 104 and the first temperature relatively large, which can improve the stability of the first temporary bonding layer 102 under the high temperature process conditions of S30, and make the first bonding layer 104 less likely to melt or fail under the heating conditions of the first temporary bonding layer 102 in S40, so that the high temperature process in S40 will not affect the integrity of the packaging structure.

[0093] In some embodiments, combined with Figure 2J The material of the first bonding layer 104 includes at least one of gold-indium (Au-In) alloy, gold-tin (Au-Sn) alloy, copper-tin (Cu-Sn) alloy and copper-indium (Cu-In) alloy.

[0094] With the above settings, the range of the first temperature can be 180℃~250℃, and the range of the melting point of the first bonding layer 104 can be 400℃~500℃. This makes the melting point of the first temporary bonding layer 102 greater than the first temperature and less than the melting point of the first bonding layer 104. As mentioned above, this can improve the stability of the first temporary bonding layer 102 under the high-temperature process conditions of S30, and make the first bonding layer 104 less likely to melt or fail under the heating conditions of the first temporary bonding layer 102 in S40, so that the high-temperature process in S40 will not affect the integrity of the packaging structure.

[0095] Furthermore, through the above settings, there can be a certain difference between the formation temperature (i.e., the first temperature) of the first bonding layer 104 and the melting point of the first bonding layer 104. In this way, the melting point of the first temporary bonding layer 102 can be selected as a temperature between the formation temperature of the first bonding layer 104 and the melting point of the first bonding layer 104, so as to achieve temporary bonding between the first temporary substrate 103 and the substrate 101 and improve the process controllability of removing the first temporary bonding layer 102.

[0096] The method of forming a first bonding layer 104 (i.e., S30) on the second side 101B of the substrate 101 will be described exemplarily below.

[0097] In some embodiments, combined with Figure 2J The first bonding layer 104 is formed using a transient liquid phase bonding (TLP) process.

[0098] In related technologies, transient liquid phase bonding is a technique for bonding metal layers at relatively low temperatures. During heating, some components of the alloy melt and form a stable solid-state bond upon cooling. In some examples, the melting point of the bonded layer prepared using transient liquid phase bonding can also be called the second melting point. This is because a new phase is formed after the alloy undergoes specific heat treatment, making the melting point of the bonded layer much higher than the initial melting point.

[0099] Based on the above principle, in S32, under the first temperature condition, in the first metal layer and the second metal layer, the elemental metal with a lower melting point (e.g., the second metal) is heated to the liquid phase temperature range, causing the elemental metal with a lower melting point to melt; during this process, in the first metal layer and the second metal layer, the elemental metal with a higher melting point (e.g., the first metal) and the elemental metal with a lower melting point (e.g., the second metal) form an alloy liquid phase interface.

[0100] Understandably, when the first bonding layer 104 is formed using a transient liquid phase bonding process, firstly, during the formation of the first bonding layer 104, only a portion of the alloy components need to be melted, resulting in a lower formation temperature (i.e., the first temperature) for the first bonding layer 104; secondly, the melting point of the first bonding layer 104 containing the alloy can be higher, thereby improving the stability of the first bonding layer 104 and enhancing its bonding effect; thirdly, with a higher melting point, the melting point of the first bonding layer 104 can be greater than the formation temperature (i.e., the first temperature) and also greater than the melting point of the first temporary bonding layer 102. This allows the melting point of the first temporary bonding layer 102 to be selected as a temperature between the formation temperature and the melting point of the first bonding layer 104, enabling temporary bonding between the first temporary substrate 103 and the substrate 101, and improving the controllability of the process for removing the first temporary bonding layer 102.

[0101] In some embodiments, combined with Figure 2J A first bonding layer 104 (i.e., S30) is formed on the second side 101B of the substrate 101, including S31 and S32.

[0102] S31: A first metal layer and a second metal layer are formed on the second side 101B of the substrate 101. The first metal layer and the second metal layer are stacked along the thickness direction of the substrate 101. The first metal layer includes a first metal; the second metal layer includes a second metal.

[0103] For example, the process for forming the first metal layer can be an evaporation process.

[0104] For example, the process for forming the second metal layer can be an evaporation process.

[0105] S32: Under the first temperature condition, a transient liquid phase bonding process is used to transform the first metal layer and the second metal layer into a first bonding layer 104. The first bonding layer 104 includes a first alloy, and the first alloy includes a first metal and a second metal.

[0106] For example, the first metal layer and the second metal layer formed in S31 can be patterned film layers; the first bonding layer 104 formed in S32 can be a patterned film layer; thus, the first bonding layer 104 can be used to connect patterned functional structures, such as the pad layer 110 described in detail below.

[0107] Understandably, when the formation of the first bonding layer 104 (i.e., S30) on the second side 101B of the substrate 101 includes S31 and S32, the process for forming the first bonding layer 104 is a transient liquid phase bonding process. As mentioned above, firstly, the formation temperature (i.e., the first temperature) of the first bonding layer 104 can be lower; secondly, the melting point of the first bonding layer 104 containing the first alloy can be higher, thereby improving the stability of the first bonding layer 104; and the melting point of the first bonding layer 104 can be greater than the formation temperature (i.e., the first temperature) and greater than the melting point of the first temporary bonding layer 102.

[0108] The following will exemplarily describe a method for connecting a first temporary bonding layer 102 to a first temporary substrate 103 (i.e., S20) on a first side 101A of a substrate 101.

[0109] In some embodiments, combined with Figure 2F and Figure 2G The first temporary bonding layer 102 is formed by eutectic bonding process.

[0110] In related technologies, eutectic bonding refers to a process of heating multiple (e.g., two) metals to a temperature close to or at the melting point of an alloy to form an alloy material.

[0111] With the above settings, the formation temperature of the first temporary bonding layer 102 is the same as or approximately the same as the debonding temperature, and is the same as or approximately the same as the melting point of the first temporary bonding layer 102. Thus, compared with the case where the formation temperature and debonding temperature of the first temporary bonding layer 102 are not the same, the difference between the melting point of the first temporary bonding layer 102 and the first temperature can be larger, and the difference between the melting point of the first bonding layer 104 and the melting point of the first temporary bonding layer 102 can be larger, which can improve the stability of the first temporary bonding layer 102 and reduce the influence of the heating conditions in S40 on the first bonding layer 104.

[0112] In some embodiments, combined with Figure 2F and Figure 2G A first temporary bonding layer 102 is connected to a first temporary substrate 103 on the first side 101A of the substrate 101 (i.e., S20), including S21~S22.

[0113] S21: A eutectic alloy layer is formed on the surface of the first side 101A of the substrate 101 and / or on the surface of the first temporary substrate 103 facing the substrate 101.

[0114] For example, the process for forming the eutectic alloy layer can be an evaporation process, a sputtering process, or a printing process. This configuration can improve the uniformity of the eutectic alloy layer on the surface of the first side 101A of the substrate 101 and / or the surface of the first temporary substrate 103 facing the substrate 101, and enhance the adhesion of the eutectic alloy layer on the surface of the first side 101A of the substrate 101 and / or the surface of the first temporary substrate 103 facing the substrate 101.

[0115] S22: Using a hot pressing process, the eutectic alloy layer is transformed into a first temporary bonding layer 102, and the substrate 101 and the first temporary substrate 103 are connected through the first temporary bonding layer 102.

[0116] Under the action of hot pressing, the eutectic alloy layer melts and forms a stable solid first temporary bonding layer 102 after cooling. This improves the bonding strength between the substrate 101 and the temporary substrate 101. Moreover, when the first temporary bonding layer 102 is obtained by transforming the eutectic alloy layer, the formation temperature and debonding temperature of the first temporary bonding layer 102 are the same, and the melting point of the first temporary bonding layer 102 is the same or approximately the same. Thus, compared with the case where the formation temperature and debonding temperature of the first temporary bonding layer 102 are different, the difference between the melting point of the first temporary bonding layer 102 and the first temperature can be larger, and the difference between the melting point of the first bonding layer 104 and the melting point of the first temporary bonding layer 102 can be larger, which can improve the stability of the first temporary bonding layer 102 and reduce the influence of the heating conditions in S40 on the first bonding layer 104.

[0117] It should be understood that when the process of connecting the first temporary bonding layer 102 and the first temporary substrate 103 (i.e., S20) on the first side 101A of the substrate 101 includes a hot pressing process, the substrate 101 in S20 will be subjected to a certain pressure, which may affect the structure of the substrate 101.

[0118] Therefore, in some embodiments, the preparation method further includes S20F before the first temporary bonding layer 102 and the first temporary substrate 103 are connected on the first side 101A of the substrate 101 (i.e., S20).

[0119] S20F: As Figure 2D As shown, a second temporary bonding layer 107 and a second temporary substrate 108 are connected on the second side 101B of the substrate 101, with the second temporary bonding layer 107 being closer to the substrate 101 than the second temporary substrate 108.

[0120] For example, S20F can be performed after S10 and before S20.

[0121] For example, the second temporary substrate 108 may be a single-element silicon substrate 101 or a glass substrate 101.

[0122] After the first temporary bonding layer 102 and the first temporary substrate 103 are connected on the first side 101A of the substrate 101 (i.e., S20), the preparation method further includes S20A.

[0123] S20A: such as Figure 2G and Figure 2H As shown, a debonding process is used to remove the second temporary bonding layer 107 and the second temporary substrate 108. The melting point of the first temporary bonding layer 102 is higher than the process temperature of the debonding process.

[0124] For example, S20A can be performed after S20 and before S30.

[0125] Understandably, through the above configuration, during the process of connecting the first temporary bonding layer 102 and the first temporary substrate 103 on the first side 101A of the substrate 101 (i.e., S20), the second side 101B of the substrate 101 is connected to the second temporary bonding layer 107 and the second temporary substrate 108. Thus, the second temporary substrate 108 can provide mechanical support to the substrate 101, reducing the impact of S20 on the structure of the substrate 101. Furthermore, by setting the melting point of the first temporary bonding layer 102 to be higher than the process temperature of the debonding process, the first temporary bonding layer 102 can be prevented from melting or failing in S20A, thereby avoiding detachment or damage of the first temporary bonding layer 102 under the process conditions of S20A, and improving the stability of the first temporary bonding layer 102.

[0126] This disclosure does not limit the type of material of the second temporary bonding layer 107, as long as it can meet the requirement that the process temperature of the debonding process is lower than the melting point of the first temporary bonding layer 102.

[0127] In some examples, the material of the second temporary bonding layer 107 includes a low-melting-point metal, and the melting point of the low-melting-point metal is lower than that of the first temporary bonding layer 102. In this case, the process temperature of the debonding process of S20A is usually higher than room temperature.

[0128] In some embodiments, combined with Figure 2G and Figure 2H The second temporary bonding layer 107 includes a bonding adhesive layer; the debonding process includes a laser debonding process.

[0129] For example, a laser debonding process is used to remove the bonding adhesive layer at room temperature.

[0130] For example, the material of the bonding adhesive layer can be epoxy resin or polyurethane.

[0131] With the above settings, compared to the case where the second temporary bonding layer 107 includes a low-melting-point metal, the process temperature of the debonding process in S20A can be relatively low. In this way, the difference between the melting point of the first temporary bonding layer 102 and the process temperature of the debonding process can be relatively large, thereby improving the stability of the first temporary bonding layer 102 in S20A.

[0132] It should be understood that when the second temporary bonding layer 107 and the second temporary substrate 108 are connected to the second side 101B of the substrate 101, the first side 101A of the substrate 101 is well supported. In this case, the substrate 101 can be processed from the second side 101B of the substrate 101. The following will provide an example.

[0133] In some embodiments, after the second temporary bonding layer 107 and the second temporary substrate 108 are connected to the second side 101B of the substrate 101 (i.e., S20F), and before the first temporary bonding layer 102 and the first temporary substrate 103 are connected to the first side 101A of the substrate 101 (i.e., S20), the preparation method further includes T10.

[0134] T10: As Figure 2E As shown, the substrate 101 is thinned from the first side of the substrate 101.

[0135] For example, the process for thinning the substrate 101 is a mechanical polishing process.

[0136] For example, the thickness of the thinned substrate 101 ranges from 50 μm to 150 μm; for example, 50 μm, 70 μm, 90 μm, 110 μm, 125 μm, 130 μm or 150 μm.

[0137] This configuration allows for a thinner substrate 101, which in turn makes the infrared detection module 200 thinner. This helps to increase the density of the detection units in the infrared detector 300 and makes the package size of the infrared detector 300 relatively small.

[0138] In some embodiments, after the second temporary bonding layer 107 and the second temporary substrate 108 are connected to the second side 101B of the substrate 101 (i.e., S20F), and before the first temporary bonding layer 102 and the first temporary substrate 103 are connected to the first side 101A of the substrate 101 (i.e., S20), the preparation method further includes T20.

[0139] T20: such as Figure 2F As shown, a contact structure 109 is formed from the first side of the substrate 101, penetrating the substrate 101.

[0140] For example, the contact structure 109 may be coupled to a circuit structure disposed in or on a substrate.

[0141] For example, infrared detector 300 (see Figure 4 In the circuit, the end of the contact structure 109 that is away from the first bonding layer 104 can be coupled to the circuit board 310.

[0142] For example, if the preparation method includes T10, T20 can be performed after T10.

[0143] For example, when the substrate 201 includes a silicon substrate, the method of forming the contact structure 109 may include: first, forming a through-silicon via (TSV) through the silicon substrate; and then filling the through-silicon via K with metal.

[0144] Here, the process for forming the through-silicon via K is, for example, a dry etching process. The process for filling the metal is, for example, a chemical electroplating process. The filling metal includes, for example, at least one of copper (Cu), titanium (Ti), and aluminum (Al).

[0145] For example, the diameter of the through-silicon via K ranges from 30 μm to 100 μm; for example, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 90 μm or 100 μm.

[0146] With this configuration, the contact structure 109 formed in T20 can be coupled to the circuit structure in the substrate 101, thus enabling the infrared detector 300 (see also...) Figure 4 In this configuration, the contact structure 109 can be used to input signals to the infrared detector 300 or to extract signals from the infrared detector 300. For example, the infrared detection module 200 (see...) Figure 3 It may also include electrodes for accessing power signals. The contact structure 109 may remain at the height of the electrodes (e.g., the front electrodes) and be coupled to the electrodes through a circuit structure to enable access to power signals for the infrared detector 300.

[0147] It should be understood that other structures may be formed on the second side 101B of the substrate 101 before the second temporary bonding layer 107 and the second temporary substrate 108 (i.e., S20F) are connected to the second side 101B of the substrate 101; in this case, the process of connecting the second temporary bonding layer 107 and the second temporary substrate 108 (i.e., S20F) to the second side 101B of the substrate 101 may affect these structures. Therefore, these structures can be protected before the second temporary bonding layer 107 and the second temporary substrate 108 (i.e., S20F) are connected to the second side 101B of the substrate 101.

[0148] Hereinafter, we will take the example of a pixel structure 105 being formed on the second side 101B of the substrate 101 before the second temporary bonding layer 107 and the second temporary substrate 108 (i.e., S20F) are connected to the second side 101B of the substrate 101, as an example.

[0149] In some embodiments, the preparation method further includes R10 to R20 before the second temporary bonding layer 107 and the second temporary substrate 108 (i.e., S20F) are connected to the second side 101B of the substrate 101.

[0150] R10: such as Figure 2B As shown, a pixel structure 105 is formed on the second side 101B of the substrate 101.

[0151] For example, a pixel array is formed in R10, which includes a plurality of pixel structures 105 arranged in an array.

[0152] For example, the pixel structure 105 includes a bridge arm structure and a bridge deck structure, with the bridge deck structure supported on the substrate 101 by the bridge arm structure. The bridge deck structure, for example, includes multiple functional film layers and is at least configured to absorb light signals.

[0153] R20: such as Figure 2C and Figure 2D As shown, a protective layer 106 is formed on the side of the pixel structure 105 away from the substrate 101, and the protective layer 106 covers the pixel structure 105; the protective layer 106 is disposed between the pixel structure 105 and the second temporary bonding layer 107 to be formed.

[0154] For example, if a pixel array is formed in R10, the protective layer 106 can cover the pixel array; the protective layer 106 is disposed between the pixel array and the second temporary bonding layer 107 to be formed.

[0155] For example, the material of the protective layer 106 may be polyimide (PI) or photoresist.

[0156] For example, R10~R20 can be performed after S10 and before S20F.

[0157] The preparation method further includes R30 after removing the second temporary bonding layer 107 and the second temporary substrate 108 (i.e., S20A) and before forming the first bonding layer 104 (i.e., S30) on the second side 101B of the substrate 101.

[0158] R30: such as Figure 2H and Figure 2I As shown, under the second temperature condition, the protective layer 106 is removed; wherein, the melting point of the first temporary bonding layer 102 is greater than the second temperature.

[0159] It should be understood that, in the case where the preparation method further includes R10 to R20, the second temporary bonding layer 107 and the second temporary substrate 108 in S20F are connected to the side of the protective layer 106 away from the substrate 101.

[0160] With the above settings, in R20, by forming a protective layer 106 on the side of the pixel structure 105 away from the substrate 101, the influence of the S20F process on the pixel structure 105 can be avoided. Moreover, by setting the melting point of the first temporary bonding layer 102 to be higher than the second temperature, the first temporary bonding layer 102 in R30 can be prevented from melting or failing, thereby preventing the first temporary bonding layer 102 from falling off or being damaged under the process conditions of R30, and improving the stability of the first temporary bonding layer 102.

[0161] As mentioned above, the first bonding layer 104 can be used to realize the connection between the substrate 101 and other functional layers. The functional layers connected to the substrate 101 will be illustrated below.

[0162] In some embodiments, such as Figure 2J As shown, the infrared detection module 100 further includes a padding layer 110 disposed on the second side 101B of the substrate 101. The surface of the substrate 101 facing away from the first temporary bonding layer 102 is connected to the padding layer 110 through the first bonding layer 104.

[0163] For example, during the formation of the first bonding layer 104 on the second side 101B of the substrate 101 (i.e., S30), the surface of the substrate 101 facing away from the first temporary bonding layer 102 is connected to the pad layer 110.

[0164] For example, the material of the pad layer 110 includes silicon or glass.

[0165] For example, the surface of the pad layer 110 that is away from the substrate 101 is further away from the substrate 101 than the surface of the pixel structure 105 that is away from the substrate 101.

[0166] For example, in the case where a cell array is formed in R10, the padding layer 110 may include a plurality of padding patterns, one padding pattern surrounding a cell structure 105; the surface of the padding layer 110 facing away from the substrate 101 is further away from the substrate 101 than the surface of the cell array facing away from the substrate 101.

[0167] Understandably, the padding layer 110 is a functional layer connected to the substrate 101. Moreover, through the above arrangement, the padding layer 110 is higher than the surface height of the pixel array, so that the padding layer 110 can enclose and form a sealed space for accommodating the pixel structure 105.

[0168] In some embodiments, the preparation method further includes S40F after the first bonding layer 104 is formed on the second side 101B of the substrate 101 (i.e., S30) and before the first temporary bonding layer 102 is heated (i.e., S40).

[0169] S40F: As Figure 2K As shown, under the third temperature condition, a second bonding layer 111 and a light window layer 112 are connected on the side of the pad layer 110 away from the substrate 101, with the second bonding layer 111 located between the light window layer 112 and the pad layer 110. The melting point of the first temporary bonding layer 102 is greater than the third temperature but less than the melting point of the second bonding layer 111.

[0170] For example, the material of the light window layer 112 includes silicon, germanium, or chalcogenide glass.

[0171] For example, the light window layer 112 can be configured as a light window structure 212 formed by cutting to create the infrared detection module 200. The light window structure 212 of the infrared detection module 200 can be used to achieve vacuum encapsulation of the pixel structure 105.

[0172] For an understanding of the formation temperature (i.e., the third temperature) and melting point of the second bonding layer 111, please refer to the description of the formation temperature (i.e., the first temperature) and melting point of the first bonding layer 104 in the preceding section, which will not be repeated here.

[0173] For example, a second bonding layer 111 and a light window layer 112 (i.e., S40F) are connected on the side of the pad layer 110 away from the substrate 101, including S40F.1 to S40F.2.

[0174] S40F.1: A third metal layer and a fourth metal layer are formed on the surface of the pad layer 110 away from the substrate 101, or on the surface of the light window layer 112 facing the pad layer 110, and the third metal layer and the fourth metal layer are stacked along the thickness direction of the light window layer 112.

[0175] S40F.2: Under the third temperature condition, a transient liquid phase bonding process is used to transform the third metal layer and the fourth metal layer into the second bonding layer 111.

[0176] Understandably, through the above configuration, the connection between the pad layer 110 and the optical window layer 112 can be achieved using the second bonding layer 111. Furthermore, similarly to the aforementioned part, by setting the melting point of the first temporary bonding layer 102 to be higher than the third temperature, the first temporary bonding layer 102 can be prevented from melting or failing under the third temperature condition in S40F, thereby avoiding the first temporary bonding layer 102 from detaching or being damaged under the high-temperature process conditions of 40F. By setting the melting point of the first temporary bonding layer 102 to be lower than the melting point of the second bonding layer 111, the melting point of the first temporary bonding layer 102 is lower than that of the second bonding layer 111. This ensures that under the heating conditions of the first temporary bonding layer 102 in S40, the second bonding layer 111 is less likely to melt or fail, preventing the high-temperature process in S40 from affecting the integrity of the packaging structure, and achieving controllable removal of the first temporary bonding layer 102.

[0177] In some embodiments, the third temperature ranges from 180°C to 250°C.

[0178] For example, the third temperature can be 180°C, 190°C, 195°C, 200°C, 205°C, 210°C, 220°C, 230°C, 245°C, or 250°C, etc.

[0179] With the above settings, the third temperature is within a suitable range, which can make the third temperature lower than the melting point of the first temporary bonding layer 102. As mentioned above, this can improve the stability of the first temporary bonding layer 102 under the high-temperature process conditions of S30.

[0180] In some embodiments, combined with Figure 2K The melting point of the second bonding layer 111 is in the range of 400℃~500℃.

[0181] For example, the melting point of the second bonding layer 111 can be 400°C, 415°C, 440°C, 460°C, 480°C, 490°C, 496°C or 500°C, etc.

[0182] With the above settings, the melting point of the second bonding layer 111 is within a suitable range, which makes the melting point of the second bonding layer 111 greater than that of the first temporary bonding layer 102. As mentioned above, this makes it possible for the second bonding layer 111 to not easily melt or fail under the heating conditions of the first temporary bonding layer 102 in S40, so that the high-temperature process in S40 will not affect the integrity of the packaging structure.

[0183] In some embodiments, combined with Figure 2K The material of the second bonding layer 111 includes an alloy material, and the alloy material included in the second bonding layer 111 includes Group IIIA metal elements and / or Group IVA metal elements.

[0184] Compared to metals from other groups, Group IIIA and IVA metals have relatively low melting points. Therefore, by adopting the above-mentioned configuration, the melting point of the material of the second bonding layer 111 can be relatively low, thereby reducing the difficulty of forming the second bonding layer 111.

[0185] In some embodiments, combined with Figure 2K The material of the second bonding layer 111 includes at least one of gold-indium (Au-In) alloy, gold-tin (Au-Sn) alloy, copper-tin (Cu-Sn) alloy and copper-indium (Cu-In) alloy.

[0186] It should be understood that the material of the first bonding layer 104 and the material of the second bonding layer 111 may be the same or different.

[0187] With the above settings, the range of the third temperature can be 180℃~250℃, and the range of the melting point of the second bonding layer 111 can be 400℃~500℃. This makes the melting point of the first temporary bonding layer 102 greater than the third temperature and less than the melting point of the second bonding layer 111. As mentioned above, this can improve the stability of the first temporary bonding layer 102 under the high-temperature process conditions of S30, and make the second bonding layer 111 less likely to melt or fail under the heating conditions of the first temporary bonding layer 102 in S40, so that the high-temperature process in S40 will not affect the integrity of the packaging structure.

[0188] Some embodiments of this disclosure also provide an infrared detection module 200, such as Figure 3 As shown, the infrared detection module 200 is prepared using the preparation method of the infrared detection module 100 provided by the above technical solution.

[0189] For example, the method for preparing the infrared detection module 100 provided by the above technical solution produces an infrared detection module 200.

[0190] As another example, the method for fabricating the infrared detection module 100 provided by the above technical solution produces multiple infrared detection modules 200. In this case, the infrared detection module 200 can be obtained by cutting the infrared detection module 100 obtained in S40.

[0191] In some examples, such as Figure 3 As shown, the infrared detection module 200 includes a substrate 201 and a first connection pattern 1041; the substrate 101 includes one or more substrates 201, and the first bonding layer 104 includes one or more first connection patterns 1041.

[0192] For example, in the case where the substrate 101 includes a plurality of substrates 201 and the first bonding layer 104 includes a plurality of first connection patterns 1041, the substrate 201 is obtained by cutting the substrate 101 of the infrared detection module 100; the first bonding layer 104 disposed on the second side 101B of the substrate 201 (see [reference]). Figure 2I This forms the first connecting pattern 1041.

[0193] For example, such as Figure 3 As shown, the infrared detection module 200 also includes a pixel structure 105 and a padding layer 110, which is connected to the substrate 201 via a first connection pattern 1041.

[0194] For example, such as Figure 3 As shown, the infrared detection module 200 also includes a second bonding pattern 1111 of the optical window structure 212; the optical window layer 112 includes one or more optical window structures 212, and the second bonding layer 111 (see [reference]). Figure 2L It includes one or more second connection patterns 1111.

[0195] For example, when the optical window layer 112 includes multiple optical window structures 212 and the second bonding layer 111 includes multiple second connection patterns 1111, the optical window structure 212 is cut by cutting the optical window layer 112 of the infrared detection module 100 (see [reference]). Figure 2L The second bonding layer 111 is obtained by means of the second side 101B of the substrate 201 (see also...). Figure 2L This forms the second connecting pattern 1111.

[0196] For example, such as Figure 3 As shown, the infrared detection module 200 also includes a contact structure 109 that penetrates the substrate 201.

[0197] The beneficial effects that the infrared detection module 200 provided in some embodiments of this disclosure can achieve are the same as the beneficial effects that the preparation method of the infrared detection module 100 provided in the above technical solution can achieve, and will not be repeated here.

[0198] Some embodiments of this disclosure also provide an infrared detector 300, such as Figure 4 As shown, the infrared detector 300 includes a circuit board 310 and an infrared detection module 200 provided by the above technical solution, and the infrared detection module 200 is coupled to the circuit board 310.

[0199] For example, the infrared detector 300 may also include a third bonding layer 320, through which the circuit board 310 and the infrared detection module 200 are connected.

[0200] For example, the infrared detector 300 includes multiple infrared detection modules 200 arranged in an array. The multiple infrared detection modules 200 are connected to the circuit board 310 through a third bonding layer 320, so that the multiple infrared detection modules 200 can be mounted on the circuit board 310.

[0201] For example, the circuit board 310 may be provided with a connector for external electrical connection.

[0202] In some examples, the infrared detector 300 also includes an imaging system (not shown) disposed on the circuit board 310. In this case, the infrared detector 300 can operate as follows: infrared radiation emitted by the target area and the background environment enters the infrared detector 300 through the light window structure 212, and the infrared radiation is converted into an electrical signal by the pixel structure 105 in the infrared detector 300 and then imaged on the imaging system.

[0203] The beneficial effects that the infrared detector 300 provided in some embodiments of this disclosure can achieve are the same as the beneficial effects that the infrared detection module 200 provided in the above technical solutions can achieve, and will not be repeated here.

[0204] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A method for manufacturing an infrared detection module, characterized in that, include: Forming a base; A first temporary bonding layer is connected to a first temporary substrate on a first side of the substrate, wherein the first temporary bonding layer is located between the substrate and the first temporary substrate; Under a first temperature condition, a first bonding layer is formed on a second side of the substrate, the second side of the substrate being opposite to the first side of the substrate; The first temperature is lower than the melting point of the first bonding layer; and, The first temporary bonding layer is heated to disconnect the substrate from the first temporary substrate; Wherein, the melting point of the first temporary bonding layer is greater than the first temperature and less than the melting point of the first bonding layer; Connecting a first temporary bonding layer to a first temporary substrate on a first side of the substrate includes: A eutectic alloy layer is formed on the surface of the first side of the substrate, and / or on the surface of the first temporary substrate facing the substrate; and, A hot-pressing process is used to transform the eutectic alloy layer into the first temporary bonding layer, and to connect the substrate to the first temporary substrate through the first temporary bonding layer.

2. The method for preparing the infrared detection module according to claim 1, characterized in that, The difference between the melting point of the first temporary bonding layer and the first temperature is greater than or equal to 60°C; and / or, The difference between the melting point of the first bonding layer and the melting point of the first temporary bonding layer is greater than or equal to 200°C.

3. The method for preparing the infrared detection module according to claim 1, characterized in that, The first bonding layer includes a first alloy, which includes a first metal and a second metal; the melting point of the first metal is greater than the melting point of the second metal; the first temperature is greater than the melting point of the second metal and less than the melting point of the first metal.

4. The method for preparing the infrared detection module according to claim 3, characterized in that, The difference between the melting point of the first metal and the melting point of the second metal is greater than or equal to 100°C.

5. The method for preparing the infrared detection module according to claim 1, characterized in that, The first bonding layer is formed using a transient liquid phase bonding process.

6. The method for preparing the infrared detection module according to claim 1, characterized in that, A first bonding layer is formed on the second side of the substrate, comprising: A first metal layer and a second metal layer are formed on the second side of the substrate, the first metal layer and the second metal layer being stacked along the thickness direction of the substrate; the first metal layer comprises a first metal; the second metal layer comprises a second metal; and, Under the first temperature condition, a transient liquid phase bonding process is used to transform the first metal layer and the second metal layer into the first bonding layer. The first bonding layer includes a first alloy, and the first alloy includes a first metal and a second metal.

7. The method for preparing the infrared detection module according to claim 1, characterized in that, The first temporary bonding layer is formed using a eutectic bonding process.

8. The method for preparing the infrared detection module according to any one of claims 1 to 7, characterized in that, Before connecting the first temporary bonding layer to the first temporary substrate on the first side of the substrate, the fabrication method further includes: A second temporary bonding layer and a second temporary substrate are connected on the second side of the substrate, wherein the second temporary bonding layer is closer to the substrate than the second temporary substrate; After connecting the first temporary bonding layer and the first temporary substrate to the first side of the substrate, the fabrication method further includes: The second temporary bonding layer and the second temporary substrate are removed using a debonding process. The melting point of the first temporary bonding layer is greater than the process temperature of the debonding process.

9. The method for preparing the infrared detection module according to claim 8, characterized in that, After the second temporary bonding layer and the second temporary substrate are connected to the second side of the substrate, and before the first temporary bonding layer and the first temporary substrate are connected to the first side of the substrate, the fabrication method further includes: Thin the substrate from a first side; and / or, A contact structure is formed from the first side of the substrate, extending through the substrate.

10. The method for preparing the infrared detection module according to claim 8, characterized in that, Before attaching the second temporary bonding layer and the second temporary substrate to the second side of the substrate, the fabrication method further includes: A pixel structure is formed on the second side of the substrate; and, A protective layer is formed on the side of the pixel structure away from the substrate, the protective layer covering the pixel structure; the protective layer is disposed between the pixel structure and the second temporary bonding layer to be formed; After removing the second temporary bonding layer and the second temporary substrate, and before forming the first bonding layer on the second side of the substrate, the fabrication method further includes: Under a second temperature condition, the protective layer is removed; The melting point of the first temporary bonding layer is greater than the second temperature.

11. The method for preparing the infrared detection module according to claim 1, characterized in that, The infrared detection module further includes: a padding layer disposed on the second side of the substrate; The surface of the substrate facing away from the first temporary bonding layer is connected to the pad layer through the first bonding layer; After forming the first bonding layer on the second side of the substrate and before heating the first temporary bonding layer, the preparation method further includes: Under a third temperature condition, a second bonding layer and a light window layer are connected on the side of the pad layer away from the substrate, with the second bonding layer located between the light window layer and the pad layer; The melting point of the first temporary bonding layer is greater than the third temperature and less than the melting point of the second bonding layer.

12. The method for preparing the infrared detection module according to claim 11, characterized in that, The third temperature range is 180℃~250℃; and / or, The melting point of the second bonding layer is in the range of 400℃~500℃.

13. The method for preparing the infrared detection module according to any one of claims 1 to 7, characterized in that, The melting point of the first temporary bonding layer is in the range of 250°C to 300°C; and / or, The first temperature range is 180℃~250℃; and / or, The melting point of the first bonding layer is in the range of 400℃~500℃.

14. An infrared detector, characterized in that, The device includes a circuit board and an infrared detection module, wherein the infrared detection module is coupled to the circuit board; the infrared detection module is prepared by the method for preparing an infrared detection module as described in any one of claims 1 to 13.

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