Preparation method of infrared detection module and infrared detector

Abstract

The embodiment of the invention discloses a preparation method of an infrared detection module and an infrared detector, relates to the technical field of infrared detectors, and is used for solving the problem that a temporary bonding layer is easily influenced by a high-temperature process and is unstable. The preparation method of the infrared detection module comprises the following steps: forming a substrate; connecting a first temporary bonding layer and a first temporary substrate on the first side of the substrate, wherein the first temporary bonding layer is located between the substrate and the first temporary substrate; a first bonding layer is formed on the second side of the substrate under the condition of a first temperature, the second side of the substrate is opposite to the first side of the substrate, and the first temperature is smaller 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 preparation method of the infrared detection module provided by some embodiments of the invention is used for preparing the infrared detection module.

Description

Technical Field

[0001] The present disclosure relates to the technical field of infrared detectors, and particularly to a method for manufacturing an infrared detection module and an infrared detector. Background Art

[0002] A 3D micro-electro-mechanical system (MEMS) infrared detector is a micro-device with infrared detection ability prepared by a wafer-level packaging (WLP) process, and has the advantages of a relatively high density of detection units, a relatively small packaging volume, and a relatively high heat dissipation efficiency.

[0003] In a 3D MEMS infrared detector, the thickness of the device layer is relatively thin, so that during the vertical packaging process of the 3D MEMS infrared detector, the device layer is easily deformed by related processes. Therefore, in related technologies, during the manufacturing process of the 3D MEMS infrared detector, a temporary substrate is connected to one side of the device layer through a temporary bonding layer. The temporary substrate is used to provide a mechanical support function for the device layer, and after the final packaging is completed, the temporary substrate and the temporary bonding layer are removed.

[0004] However, in some cases, the manufacturing process of the 3D MEMS infrared detector includes some high-temperature processes. For example, the process for forming a bonding layer for vertical packaging. In this case, the temporary bonding layer is easily affected by the high-temperature process and becomes unstable, resulting in a reduction in the reliability during the packaging process. Summary of the Invention

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

[0006] In a first aspect, a method for manufacturing an infrared detection module is provided. The method for manufacturing the infrared detection module includes: forming a substrate; connecting a first temporary bonding layer and a first temporary substrate to 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 less 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 greater than the first temperature, the melting point of the first temporary bonding layer can be relatively high. In this way, first, it can ensure that the first temporary bonding layer does not melt or fail under the first temperature condition, thereby avoiding the peeling or damage of the first temporary bonding layer under high-temperature process conditions; second, it can improve the stability of the first temporary bonding layer, enhance the reliability during the encapsulation process, and ensure the stability of the device.

[0008] On the other hand, by setting the melting point of the first temporary bonding layer to be less than the melting point 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, during the heating process of the first temporary bonding layer, the first bonding layer is not likely to melt or fail, and the heating process will not affect the integrity of the encapsulation structure, realizing the controllable removal of the first temporary bonding layer and improving the controllability and repeatability of the encapsulation process.

[0009] Moreover, by setting the melting point of the first temporary bonding layer to be less than the melting point of the first bonding layer, on the basis of ensuring the stability of the first temporary bonding layer, the melting point of the first temporary bonding layer can be relatively low. Thus, the temperature for forming the first temporary bonding layer can be relatively low to avoid the influence of the temperature condition for forming the first temporary bonding layer on other structures; and the first temporary bonding layer can 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, and the first alloy 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.

[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 by a transient liquid-phase bonding process.

[0014] Optionally, forming the 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, with the first metal layer and the second metal layer stacked along the thickness direction of the substrate; the first metal layer includes the first metal; the second metal layer includes the second metal; and, under the first temperature condition, using the transient liquid-phase bonding process to convert the first metal layer and the second metal layer into the first bonding layer, and the first bonding layer includes a first alloy, and the first alloy includes the first metal and the second metal.

[0015] Optionally, the first temporary bonding layer is formed by an eutectic soldering process.

[0016] Optionally, connecting the first temporary bonding layer and the first temporary substrate on the first side of the substrate includes: forming an eutectic alloy layer on the surface of the first side of the substrate and / or 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 connect 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, and 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 connecting the second temporary bonding layer and the second temporary substrate on the second side of the substrate and before connecting the first temporary bonding layer and the first temporary substrate on the first side of the substrate, the preparation method further includes: thinning the substrate from the first side of the substrate; and / or forming a contact structure penetrating the substrate from the first side of the substrate.

[0019] Optionally, before connecting the second temporary bonding layer and the second temporary substrate on the second side of the substrate, the preparation 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, and the protective layer covers the pixel structure; the protective layer is disposed between the pixel structure and the to-be-formed second temporary bonding layer. 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 preparation method further includes: removing the protective layer under a second temperature condition. Wherein, the melting point of the first temporary bonding layer is greater than the second temperature.

[0020] Optionally, the infrared detection module further includes: a spacer 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 spacer layer through the first bonding layer. Before heating the first temporary bonding layer after forming the first bonding layer on the second side of the substrate, the preparation method further includes: connecting a second bonding layer and a light window layer on the side of the spacer layer away from the substrate under a third temperature condition, and the second bonding layer is located between the light window layer and the spacer layer. Wherein, 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.

[0021] Optionally, the range of the third temperature is 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 ranges from 250°C to 300°C; and / or, the range of the first temperature is 180°C to 250°C; and / or, the melting point of the first bonding layer ranges from 400°C to 500°C.

[0023] In a second aspect, an infrared detector is provided. The infrared detector includes a circuit board and an infrared detection module, and the infrared detection module is coupled to the circuit board. The infrared detection module is prepared by using the preparation method of the infrared detection module provided by the above technical solution.

[0024] The beneficial effects achievable by the infrared detector provided by some embodiments of the present disclosure are the same as those achievable by the preparation method of the infrared detection module provided by the above technical solution, and will not be elaborated herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the embodiments of the present disclosure, and constitute a part of the embodiments of the present disclosure. The illustrative embodiments and descriptions thereof of the present disclosure are used to explain the present disclosure and do not constitute an improper limitation of the present disclosure. In the drawings: Figure 1 is a flowchart of a method for preparing an infrared detection module provided by some embodiments of the present disclosure; Figures 2A - 2L is a step diagram of a method for preparing an infrared detection module provided by some embodiments of the present disclosure; Figure 3 is a structural diagram of an infrared detection module provided by some embodiments of the present disclosure; Figure 4 is a structural diagram of an infrared detector provided by some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The technical solutions in some embodiments of the present disclosure will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present disclosure.

[0027] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is to be construed in an open, inclusive sense, i.e., "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples" or "some examples", etc. are intended to indicate that a particular feature, structure, material or characteristic related to the embodiment or example is included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics described above may be included in any one or more embodiments or examples in any appropriate manner.

[0028] In the description of the embodiments of the present disclosure, unless otherwise specified, the meaning of "a plurality" is two or more.

[0029] 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 quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0030] In the related art, the three-dimensional integrated circuit (3D IC) packaging technology is a packaging technology that vertically stacks multiple devices to improve integration and performance. The wafer-level packaging (WLP) process is a packaging process that performs packaging at the wafer level, which can improve packaging density and reduce packaging volume.

[0031] With the continuous progress of microelectromechanical system (MEMS) technology, especially the development of three-dimensional integrated circuit (3D IC) packaging and wafer-level packaging (WLP), the integration of MEMS devices has been continuously improved, and the traditional single-layer packaging structure is difficult to meet the high-performance requirements. The multi-layer stacking package technology can play a relatively important role in improving the device unit density, reducing the packaging volume, and improving the heat dissipation efficiency.

[0032] In some implementation manners, when preparing the 3D MEMS infrared detector 300 by using the multi-layer stacking package technology, in order to reduce the thickness of the stacking structure, the device layer (for example, the substrate of the device layer) is thinned, which will make the device layer become more fragile in subsequent processing and vulnerable to deformation by related processes.

[0033] To this end, in the related art, during the preparation process of a 3D MEMS infrared detector, 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.

[0034] In some implementation manners, the material of the temporary bonding layer includes an organic glue material (for example, epoxy resin or polyurethane) or a water-soluble glue material. These glue materials are prone to decomposition and failure under subsequent high-temperature process conditions, resulting in instability problems of the temporary bonding layer.

[0035] In some other implementation manners, the material of the temporary bonding layer includes a low-melting-point metal (for example, tin-lead alloy or indium-containing alloy). These low-melting-point metal materials are prone to premature melting and failure under subsequent high-temperature process conditions, resulting in instability problems of the temporary bonding layer.

[0036] In some other implementation manners, the process of removing the temporary substrate and the temporary bonding layer (that is, the debonding process of the device layer and the temporary substrate) is a laser radiation process. However, when using this process for debonding, there may be the following two problems: First, the laser radiation depth is relatively limited, making this process suitable for the case of bonding between fewer layers, which is not conducive to improving the packaging density; second, in order to improve the uniformity of laser radiation, this process has certain requirements for the flatness of the sample and / or the refractive index and thermal conductivity of the material of the device layer. For example, it is required that the TTV of the sample is less than 10 μm, resulting in poor adaptability of this process.

[0037] Based on this, some embodiments of the present disclosure provide a preparation method of an infrared detection module 100 (see Figure 2L ), so as to at least solve the problem that the temporary bonding layer is prone to instability due to the influence of high-temperature processes.

[0038] Figure 1 The flowchart of a preparation method of an infrared detection module 100 provided by some embodiments of the present disclosure. Figures 2A - 2L The preparation step diagram of an infrared detection module 100 provided by some embodiments of the present disclosure. The following will be described together Figure 1 and Figures 2A - 2L .

[0039] As Figure 1 shown, the preparation method of the infrared detection module 100 includes S10 to S40.

[0040] S10: As Figure 2A shown, form a substrate 101.

[0041] Exemplarily, the substrate 101 includes a substrate; the substrate can be a silicon substrate, a germanium substrate, a germanium-silicon substrate, a silicon-on-insulator substrate, an indium gallium arsenide substrate, a gallium arsenide substrate, a silicon carbide substrate, or other suitable substrate materials, etc.

[0042] In some examples, the substrate 101 further includes circuit structures formed within or on the substrate.

[0043] S20: As Figure 2F and Figure 2G shown, on the first side 101A of the substrate 101, a first temporary bonding layer 102 is connected to a first temporary substrate 103, and the first temporary bonding layer 102 is located between the substrate 101 and the first temporary substrate 103.

[0044] Exemplarily, the first temporary substrate 103 is a single-crystalline silicon substrate or a glass substrate.

[0045] 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 achieved, enabling the first temporary substrate 103 to provide a mechanical support function for the substrate 101.

[0046] S30: As Figure 2J shown, under a first temperature condition, a first bonding layer 104 is formed on the second side 101B of the substrate 101. The second side 101B of the substrate 101 is opposite to the first side 101A of the substrate 101; the first temperature is lower than the melting point of the first bonding layer 104.

[0047] In some examples, as Figure 2J 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 achieve the connection between the substrate 101 and other functional layers in the infrared detection module 100 except the substrate 101 (such as the spacer layer 110 described in detail below).

[0048] In still other examples, the first bonding layer 104 is spaced from the surface of the second side 101B of the substrate 101; at this time, the first bonding layer 104 can be located between two functional layers provided on the second side 101B of the substrate 101 to achieve the connection between the two functional layers.

[0049] Here, the embodiments of the present disclosure do not limit the functional types of the above functional layers connected to the first bonding layer 104.

[0050] S40: As Figure 2K and Figure 2L shown, the first temporary bonding layer 102 is heated to release the connection between the substrate 101 and the first temporary substrate 103.

[0051] Among them, 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.

[0052] 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 state 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 state to a liquid state. The first temperature can be understood as the formation temperature of the first bonding layer 104.

[0053] Understandably, on the one hand, by setting the melting point of the first temporary bonding layer 102 to be greater than the first temperature, the melting point of the first temporary bonding layer 102 can be relatively high. In this way, firstly, it can ensure that the first temporary bonding layer 102 does not melt or fail under the first temperature condition in S30, thereby avoiding the detachment or damage of the first temporary bonding layer 102 under the high-temperature process conditions in S30. Secondly, compared with some implementation methods where the material of the temporary bonding layer includes low-melting-point metals or glue materials, the first bonding layer 104 can exhibit better structural stability in a high-temperature environment. Thus, the stability of the first temporary bonding layer 102 can be improved, the reliability during the packaging process can be enhanced, and the stability of the device can be ensured.

[0054] On the other hand, by setting the melting point of the first temporary bonding layer 102 to be less than the melting point of the first bonding layer 104, the melting point of the first temporary bonding layer 102 can be relatively lower than that of the first bonding layer 104. In this way, under the heating condition of the first temporary bonding layer 102 in S40, the first bonding layer 104 is not likely to melt or fail, and the high-temperature process in S40 will not affect the integrity of the packaging structure, realizing the controlled removal of the first temporary bonding layer 102. Thus, compared with some implementation methods 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.

[0055] Moreover, by setting the melting point of the first temporary bonding layer 102 to be lower than that of the first bonding layer 104, on the basis of ensuring the stability of the first temporary bonding layer 102, the melting point of the first temporary bonding layer 102 can be relatively low. In this way, the temperature for forming the first temporary bonding layer 102 in S20 can be relatively low, so as to avoid the influence of the temperature condition in S20 on other structures; and the first temporary bonding layer 102 can be removed by heat treatment. Among them, when the first temporary bonding layer 102 is removed by heat treatment, compared with the case of removing the temporary bonding layer by chemical removal or mechanical removal in some implementation manners, first, the accurate and controllable removal of the first temporary bonding layer 102 can be realized, the packaging process of the infrared detection module 100 can be simplified, and the efficiency of the packaging process and the production efficiency of the infrared detection module 200 (see Figure 3 can be improved; second, the safe removal of the first temporary bonding layer 102 can be realized, the damage to other structures in the infrared detection module 200 caused by chemical removal or mechanical removal can be avoided, and the damage risk of other structures in the infrared detection module 200 can be reduced; third, the removal degree of the first temporary bonding layer 102 can be improved, and the problem of incomplete removal affecting the final device performance can be avoided; fourth, the process flexibility of the removal process of the first temporary bonding layer 102 can be improved, and then the adaptability of the preparation method can be improved to meet different packaging requirements.

[0056] The present disclosure embodiment 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, 50°C, etc.

[0057] In some embodiments, in combination 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.

[0058] Exemplarily, 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, 200°C, etc.

[0059] 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, and make the stability of the first temporary bonding layer 102 relatively high during the process of S30. In this way, the reliability during the packaging process can be improved.

[0060] The embodiments of the present disclosure do 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, 150°C, etc.

[0061] In some embodiments, in combination 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.

[0062] Exemplarily, 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, 300°C, etc.

[0063] By setting the difference between the melting point of the first bonding layer 104 and the melting point of the first temporary bonding layer 102 to be greater than or equal to 200°C, the difference between the melting point of the first bonding layer 104 and the melting point of the first temporary bonding layer 102 is relatively large, which can reduce the influence of the heating conditions in S40 on the first bonding layer 104, and make the stability of the first bonding layer 104 relatively high during the process of S40. Thus, the integrity of the packaging structure can be improved.

[0064] In some embodiments, in combination Figure 2H , the melting point range of the first temporary bonding layer 102 is 250°C to 300°C.

[0065] Exemplarily, the melting point of the first temporary bonding layer 102 can be 250°C, 255°C, 260°C, 265°C, 270°C, 275°C, 280°C, 290°C, 300°C, etc.

[0066] Through the above settings, the melting point of the first temporary bonding layer 102 is within a suitable range, which can make 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 described above, the stability of the first temporary bonding layer 102 under high-temperature process conditions can be improved, and 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).

[0067] In some embodiments, the range of the first temperature is 180°C to 250°C.

[0068] Exemplarily, the first temperature can be 180°C, 190°C, 195°C, 200°C, 205°C, 210°C, 220°C, 230°C, 240°C, 250°C, etc.

[0069] With the above settings, the first temperature is within a suitable range, and can make the first temperature lower than the melting point of the first temporary bonding layer 102. As described above, the stability of the first temporary bonding layer 102 under the high-temperature process conditions of S30 can be improved.

[0070] In some embodiments, in combination with Figure 2J , the melting point range of the first bonding layer 104 is 400°C to 500°C.

[0071] Exemplarily, the melting point of the first bonding layer 104 can be 400°C, 420°C, 440°C, 460°C, 480°C, 490°C, 496°C, 500°C, etc.

[0072] With the above settings, the melting point of the first bonding layer 104 is within a suitable range, and can make the melting point of the first bonding layer 104 higher than the melting point of the first temporary bonding layer 102. As described above, under the heating conditions of the first temporary bonding layer 102 in S40, the first bonding layer 104 is not likely to melt or fail, and the high-temperature process in S40 will not affect the integrity of the package structure.

[0073] The embodiments of the present disclosure do not limit the type of the material of the first temporary bonding layer 102.

[0074] In some embodiments, in combination 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 a Group IIIA metal element and / or a Group IVA metal element.

[0075] Compared with metal elements of other groups, Group IIIA metal elements and Group IVA metal elements have the characteristic of relatively low melting points. Therefore, with the above settings, the melting point of the material of the first temporary bonding layer 102 can be relatively low. In this way, firstly, the process difficulty of forming the first temporary bonding layer 102 can be reduced; secondly, the melting point of the first temporary bonding layer 102 can be relatively low. As described above, the first temporary bonding layer 102 can be removed by heat treatment, and the integrity of the package structure will not be affected during the heat removal process (i.e., S40).

[0076] In some embodiments, in combination 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 a Group IIIA metal element and / or a Group IVA metal element.

[0077] Compared with metal elements of other groups, Group IIIA metal elements and Group IVA metal elements have the characteristic of relatively low melting points. Therefore, with the above settings, the melting point of the material of the first bonding layer 104 can be relatively low. In this way, the process difficulty of forming the first bonding layer 104 can be reduced.

[0078] In some embodiments, in combination with Figure 2H , the material of the first temporary bonding layer 102 includes at least one of indium (In) alloy and tin-bismuth (Sn-Bi) alloy.

[0079] Exemplarily, the indium alloy may be a tin-indium-copper (Sn-In-Cu) alloy.

[0080] In a first aspect, through the above settings, the melting point of the first temporary bonding layer 102 can be in the range of 250°C to 300°C, so that 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. As described above, the stability of the first temporary bonding layer 102 under high-temperature process conditions can be improved, and the first temporary bonding layer 102 can be removed by heat treatment, and the integrity of the package structure will not be affected during the heat removal process (i.e., S40). In a second aspect, through the above settings, 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 soldering technology, which is beneficial to realizing the bonding and debonding of the first temporary bonding layer 102. In a third aspect, the above metal materials have good environmental adaptability and environmental protection performance, and compared with traditional packaging materials, environmental pollution can be avoided.

[0081] The embodiments of the present disclosure do not limit the type of the material of the first bonding layer 104.

[0082] In some embodiments, in combination with Figure 2J , the first bonding layer 104 includes a first alloy, and the first alloy 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.

[0083] It can be understood that when the first temperature is greater than the melting point of the second metal and less than the melting point of the first metal, in the process of forming the first bonding layer 104 in S30, the first temperature can reach the melting point of the first metal but not reach the melting point of the second metal, that is, the low-melting-point metal in the first alloy is melted, and the high-melting-point metal in the first alloy is not melted, and the two metals are mixed into the first alloy by 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 further the first temperature can be lower than the melting point of the first bonding layer 104.

[0084] Here, the embodiments of the present disclosure do not limit the difference between the melting point of the first metal and the melting point of the second metal. 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, 95°C, etc.

[0085] In some embodiments, in combination withFigure 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.

[0086] Exemplarily, 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.

[0087] In some examples, when the first bonding layer 104 includes the first alloy, the melting points of the first metal, the second metal, the first temperature, and the first bonding layer 104 are sorted from largest to smallest as the melting point of the first metal, the melting point of the first bonding layer 104, the first temperature, and the melting point of the second metal. That is to say, the melting points of the first bonding layer 104 and the first temperature are both between the melting point of the second metal and the melting point of the first metal. At this time, the difference between the melting point of the first bonding layer 104 and the first temperature is less than the difference between the melting point of the first metal and the melting point of the second metal.

[0088] It can be understood that 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 point of the first metal and the melting point of the second metal is relatively large. In this way, the difference between the melting point of the first bonding layer 104 and the first temperature can be relatively large, which can improve the stability of the first temporary bonding layer 102 under the high-temperature process conditions of S30, and can prevent the first bonding layer 104 from melting or failing 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 package structure.

[0089] In some embodiments, in combination 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.

[0090] Through the above settings, the range of the first temperature can be 180 °C to 250 °C, and the range of the melting point of the first bonding layer 104 can be 400 °C to 500 °C. Furthermore, 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. As described above, it can improve the stability of the first temporary bonding layer 102 under the high-temperature process conditions of S30, and can prevent the first bonding layer 104 from melting or failing 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 package structure.

[0091] In addition, through the above settings, a certain difference can be created between the formation temperature of the first bonding layer 104 (i.e., the first temperature) 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 the temporary bonding of the first temporary substrate 103 and the substrate 101 and improve the process controllability of removing the first temporary bonding layer 102.

[0092] Hereinafter, an exemplary description will be given of the method for forming the first bonding layer 104 (i.e., S30) on the second side 101B of the substrate 101.

[0093] In some embodiments, in combination with Figure 2J , the first bonding layer 104 is formed by a Transient Liquid Phase Bonding (TLP) process.

[0094] In the related art, the transient liquid phase bonding process is a technique for bonding metal layers at a relatively low temperature. During the heating process, some components in the alloy melt and form a stable solid-state connection after cooling. In some examples, the melting point of the bonding layer prepared by the transient liquid phase bonding process can also be referred to as the Second Melting Point, because a new phase is formed in the alloy after undergoing a specific heat treatment, making the melting point of the bonding layer much higher than the initial melting point.

[0095] Based on the above principle, in S32, under the first temperature condition, among the first metal layer and the second metal layer, the simple metal with a lower melting point (e.g., the second metal) is heated to the liquid phase temperature range to melt the simple metal with a lower melting point; during this process, a liquid phase interface of an alloy is formed between the simple metal with a higher melting point (e.g., the first metal) and the simple metal with a lower melting point (e.g., the second metal) in the first metal layer and the second metal layer.

[0096] Understandably, when the first bonding layer 104 is formed by using a transient liquid-phase bonding process, first, during the formation process of the first bonding layer 104, only some components of the alloy need to be melted, so that the formation temperature of the first bonding layer 104 (i.e., the first temperature) is relatively low; second, it can make the melting point of the first bonding layer 104 containing the alloy relatively high, improving the stability of the first bonding layer 104 and being beneficial to enhancing the connection effect of the first bonding layer 104; third, when the melting point of the first bonding layer 104 is relatively high, the melting point of the first bonding layer 104 can be greater than the formation temperature of the first bonding layer 104 (i.e., the first temperature) and greater than the melting point of the first temporary bonding layer 102, so that 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, enabling the temporary bonding of the first temporary substrate 103 and the substrate 101 and improving the process controllability of removing the first temporary bonding layer 102.

[0097] In some embodiments, in combination 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.

[0098] 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.

[0099] Exemplarily, the process of forming the first metal layer can be an evaporation process.

[0100] Exemplarily, the process of forming the second metal layer can be an evaporation process.

[0101] S32: Under the condition of the first temperature, by using a transient liquid-phase bonding process, the first metal layer and the second metal layer are converted into the 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.

[0102] Exemplarily, 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.

[0103] Understandably, when the first bonding layer 104 (i.e., S30) including S31 and S32 is formed on the second side 101B of the substrate 101, the process of forming the first bonding layer 104 is a transient liquid-phase bonding process. As described above, firstly, the forming temperature (i.e., the first temperature) of the first bonding layer 104 can be relatively low; secondly, the melting point of the first bonding layer 104 containing the first alloy can be relatively high, enhancing the stability of the first bonding layer 104; and the melting point of the first bonding layer 104 can be greater than the forming temperature (i.e., the first temperature) of the first bonding layer 104 and greater than the melting point of the first temporary bonding layer 102.

[0104] Hereinafter, a method for 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 will be exemplarily described.

[0105] In some embodiments, in combination with Figure 2F and Figure 2G , the first temporary bonding layer 102 is formed by an eutectic soldering process.

[0106] In the related art, the eutectic soldering process refers to a process of heating multiple (e.g., two) metals to the melting point of the alloy or a temperature close to the melting point of the alloy to form an alloy material.

[0107] Through the above settings, the forming 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 forming temperature and the 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.

[0108] In some embodiments, in combination with Figure 2F and Figure 2G , 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 S21 to S22.

[0109] S21: Form an eutectic alloy layer 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.

[0110] Exemplarily, the process for forming the eutectic alloy layer can be an evaporation process, a sputtering process, or a printing process. With such an arrangement, 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 can be improved, and 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 can be enhanced.

[0111] S22: Adopt a hot pressing process to convert the eutectic alloy layer into the first temporary bonding layer 102, and connect the substrate 101 and the first temporary substrate 103 through the first temporary bonding layer 102.

[0112] Under the action of the hot pressing process, the eutectic alloy layer melts and forms a stable solid-state first temporary bonding layer 102 after cooling. In this way, the connection firmness between the substrate 101 and the temporary substrate 101 can be improved. Moreover, when the first temporary bonding layer 102 is converted from the eutectic alloy layer, the formation temperature of the first temporary bonding layer 102 is 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. In this way, compared with the case where the formation temperature and the 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 made 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 made 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.

[0113] It should be understood that when 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) includes a hot pressing process, the substrate 101 in S20 will bear a certain pressure, which may affect the structure of the substrate 101.

[0114] Therefore, in some embodiments, before 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 preparation method further includes S20F.

[0115] S20F: As Figure 2D shown, connect the second temporary bonding layer 107 and the second temporary substrate 108 on the second side 101B of the substrate 101, and the second temporary bonding layer 107 is closer to the substrate 101 than the second temporary substrate 108.

[0116] Exemplarily, S20F can be performed after S10 and before S20.

[0117] Exemplarily, the second temporary substrate 108 can be a single-crystal silicon substrate 101 or a glass substrate 101.

[0118] After 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, the manufacturing method further includes S20A.

[0119] S20A: As Figure 2G and Figure 2H shown, a debonding process is used to remove the second temporary bonding layer 107 and the second temporary substrate 108. Among them, the melting point of the first temporary bonding layer 102 is greater than the process temperature of the debonding process.

[0120] Exemplarily, S20A can be performed after S20 and before S30.

[0121] It can be understood that through the above settings, during 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, the second side 101B of the substrate 101 is connected with the second temporary bonding layer 107 and the second temporary substrate 108. Thus, the second temporary substrate 108 can provide a mechanical support for the substrate 101 to reduce the influence of S20 on the structure of the substrate 101. Moreover, by setting the melting point of the first temporary bonding layer 102 to be greater than the process temperature of the debonding process, it can be ensured that the first temporary bonding layer 102 does not melt or fail during S20A, thereby avoiding the 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.

[0122] The present disclosure does not limit the type of the 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 less than the melting point of the first temporary bonding layer 102.

[0123] 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 less than that of the first temporary bonding layer 102. At this time, the process temperature of the debonding process of S20A is usually higher than room temperature.

[0124] In some embodiments, in combination with Figure 2G and Figure 2H , the second temporary bonding layer 107 includes a bonding glue layer; the debonding process includes a laser debonding process.

[0125] Exemplarily, when using the laser debonding process, the process temperature for removing the bonding glue layer is room temperature.

[0126] Exemplarily, the material of the bonding glue layer can be epoxy resin or polyurethane.

[0127] With the above settings, compared with 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. Thus, 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, which can improve the stability of the first temporary bonding layer 102 in S20A.

[0128] 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, relevant processing can be performed on the substrate 101 from the second side 101B of the substrate 101. Hereinafter, examples will be given.

[0129] 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.

[0130] T10: As Figure 2E shown, the substrate 101 is thinned from the first side of the substrate 101.

[0131] Exemplarily, the process of thinning the substrate 101 is a mechanical grinding process.

[0132] Exemplarily, the thickness range of the thinned substrate 101 is 50 μm to 150 μm; for example, it is 50 μm, 70 μm, 90 μm, 110 μm, 125 μm, 130 μm or 150 μm, etc.

[0133] By setting like this, the thickness of the substrate 101 can be made thinner, and then the thickness of the infrared detection module 200 can be made thinner, which is beneficial to improving the density of the detection units of the infrared detector 300 and making the packaging volume of the infrared detector 300 relatively small.

[0134] 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.

[0135] T20: As Figure 2F shown, a contact structure 109 penetrating the substrate 101 is formed from the first side of the substrate 101.

[0136] Exemplarily, the contact structure 109 can be coupled to a circuit structure provided in or on the substrate.

[0137] Exemplarily, in the infrared detector 300 (see Figure 4 ), one end of the contact structure 109 away from the first bonding layer 104 can be coupled to the circuit board 310.

[0138] Exemplarily, when the preparation method includes T10, T20 can be carried out after T10.

[0139] Exemplarily, when the substrate 201 includes a silicon substrate, the method for forming the contact structure 109 can include: First, form a through-silicon via K (Through-Silicon Via, TSV) penetrating the silicon substrate; then, fill the through-silicon via K with metal.

[0140] 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, an electroless plating process. The filled metal includes, for example, at least one of copper (Cu), titanium (Ti), and aluminum (Al).

[0141] Exemplarily, the diameter range of the through-silicon via K is 30μm to 100μm; for example, it is 30μm, 40μm, 50μm, 60μm, 70μm, 90μm, or 100μm, etc.

[0142] By setting it like this, the contact structure 109 formed in T20 can be coupled to the circuit structure in the substrate 101. Thus, in the infrared detector 300 (see Figure 4 ), the contact structure 109 can be used to access signals to the infrared detector 300 or lead out the signals of the infrared detector 300. For example, the infrared detection module 200 (see Figure 3 ), can also include an electrode for accessing a power supply signal. The contact structure 109 can stay at the height where the electrode (for example, the front electrode) is located and be coupled to the electrode through the circuit structure to achieve the purpose of accessing a power supply signal to the infrared detector 300.

[0143] It should be understood that before 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, other structures can be formed on 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 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.

[0144] Hereinafter, taking the example where the pixel structure 105 is formed on the second side 101B of the substrate 101 before 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, an example will be given for illustration.

[0145] In some embodiments, before 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, the preparation method further includes R10 to R20.

[0146] R10: As Figure 2B shown, the pixel structure 105 is formed on the second side 101B of the substrate 101.

[0147] Exemplarily, a pixel array is formed in R10, and the pixel array includes a plurality of pixel structures 105 arranged in an array.

[0148] Exemplarily, the pixel structure 105 includes a bridge arm structure and a bridge deck structure, and the bridge deck structure is supported on the substrate 101 through the bridge arm structure. Among them, the bridge deck structure includes, for example, a plurality of functional film layers and is at least configured to absorb optical signals.

[0149] R20: As Figure 2C and Figure 2D 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 to-be-formed second temporary bonding layer 107.

[0150] Exemplarily, in the case where 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 to-be-formed second temporary bonding layer 107.

[0151] Exemplarily, the material of the protective layer 106 can be polyimide (PI) or photoresist.

[0152] Exemplarily, R10 to R20 can be performed after S10 and before S20F.

[0153] 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, the preparation method further includes R30.

[0154] R30: As Figure 2H and Figure 2I 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.

[0155] It should be understood that when the manufacturing method further includes R10 to R20, in S20F, the second temporary bonding layer 107 and the second temporary substrate 108 are connected to the side of the protective layer 106 away from the substrate 101.

[0156] With the above arrangement, in R20, by forming the protective layer 106 on the side of the pixel structure 105 away from the substrate 101, the process of S20F can be prevented from affecting the pixel structure 105. Moreover, by setting the melting point of the first temporary bonding layer 102 to be greater than the second temperature, it is possible to prevent the first temporary bonding layer 102 from melting or failing in R30, thereby avoiding the peeling or damage of the first temporary bonding layer 102 under the process conditions of R30 and improving the stability of the first temporary bonding layer 102.

[0157] As described above, the first bonding layer 104 can be used to realize the connection between the substrate 101 and other functional layers. Hereinafter, the functional layers connected to the substrate 101 will be exemplified.

[0158] In some embodiments, as Figure 2J shown, the infrared detection module 100 further includes: a spacer layer 110 provided 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 spacer layer 110 through the first bonding layer 104.

[0159] Exemplarily, during the process of forming the first bonding layer 104 (i.e., S30) 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 spacer layer 110.

[0160] Exemplarily, the material of the spacer layer 110 includes silicon or glass.

[0161] Exemplarily, the surface of the spacer layer 110 facing away from the substrate 101 is farther away from the substrate 101 than the surface of the pixel structure 105 facing away from the substrate 101.

[0162] Exemplarily, when a pixel array is formed in R10, the spacer layer 110 may include a plurality of spacer patterns, and one spacer pattern surrounds one pixel structure 105; the surface of the spacer layer 110 facing away from the substrate 101 is farther away from the substrate 101 than the surface of the pixel array facing away from the substrate 101.

[0163] It can be understood that the spacer layer 110 is the functional layer connected to the substrate 101. Moreover, with the above arrangement, the spacer layer 110 is higher than the surface height of the pixel array, enabling the spacer layer 110 to enclose and form a sealed space for accommodating the pixel structure 105.

[0164] In some embodiments, after forming the first bonding layer 104 (i.e., S30) on the second side 101B of the substrate 101 and before heating the first temporary bonding layer 102 (i.e., S40), the preparation method further includes S40F.

[0165] S40F: As Figure 2K shown, under a third temperature condition, connect the second bonding layer 111 and the optical window layer 112 on the side of the spacer layer 110 away from the substrate 101, and the second bonding layer 111 is located between the optical window layer 112 and the spacer layer 110. Among them, the melting point of the first temporary bonding layer 102 is greater than the third temperature and less than the melting point of the second bonding layer 111.

[0166] Exemplarily, the material of the optical window layer 112 includes silicon, germanium, or chalcogenide glass.

[0167] Exemplarily, the optical window layer 112 can be configured to: be cut to form the optical window structure 212 of the infrared detection module 200. The optical window structure 212 of the infrared detection module 200 can be used to achieve vacuum encapsulation of the pixel structure 105.

[0168] Here, for the understanding of the formation temperature (i.e., the third temperature) and the melting point of the second bonding layer 111, reference can be made to the description of the formation temperature (i.e., the first temperature) and the melting point of the first bonding layer 104 in the foregoing part, and details are not described herein again.

[0169] Exemplarily, connecting the second bonding layer 111 and the optical window layer 112 on the side of the spacer layer 110 away from the substrate 101 (i.e., S40F) includes S40F.1 to S40F.2.

[0170] S40F.1: Form a third metal layer and a fourth metal layer on the surface of the spacer layer 110 away from the substrate 101, or on the surface of the optical window layer 112 facing the spacer layer 110, and the third metal layer and the fourth metal layer are stacked along the thickness direction of the optical window layer 112.

[0171] S40F.2: Under the third temperature condition, adopt a transient liquid-phase bonding process to convert the third metal layer and the fourth metal layer into the second bonding layer 111.

[0172] Understandably, through the above settings, by using the second bonding layer 111, the connection between the spacer layer 110 and the optical window layer 112 can be achieved. Moreover, similar to the foregoing part, by setting the melting point of the first temporary bonding layer 102 to be greater than the third temperature, it is possible to prevent the first temporary bonding layer 102 from melting or failing under the third temperature condition in S40F, thereby avoiding the detachment or damage of the first temporary bonding layer 102 under the high-temperature process conditions of 40F. By setting the melting point of the first temporary bonding layer 102 to be less than the melting point of the second bonding layer 111, the melting point of the first temporary bonding layer 102 can be made lower than that of the second bonding layer 111. In this way, under the heating condition of the first temporary bonding layer 102 in S40, the second bonding layer 111 is not likely to melt or fail, and the high-temperature process in S40 will not affect the integrity of the packaging structure, realizing the controllable removal of the first temporary bonding layer 102.

[0173] In some embodiments, the range of the third temperature is 180°C to 250°C.

[0174] Exemplarily, the third temperature can be 180°C, 190°C, 195°C, 200°C, 205°C, 210°C, 220°C, 230°C, 245°C, 250°C, etc.

[0175] Through the above settings, within a suitable range of the third temperature, the third temperature can be made less than the melting point of the first temporary bonding layer 102. As described above, this can improve the stability of the first temporary bonding layer 102 under the high-temperature process conditions of S30.

[0176] In some embodiments, combined with Figure 2K , the range of the melting point of the second bonding layer 111 is 400°C to 500°C.

[0177] Exemplarily, 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, 500°C, etc.

[0178] Through the above settings, within a suitable range of the melting point of the second bonding layer 111, the melting point of the second bonding layer 111 can be made greater than the melting point of the first temporary bonding layer 102. As described above, under the heating condition of the first temporary bonding layer 102 in S40, the second bonding layer 111 is not likely to melt or fail, and the high-temperature process in S40 will not affect the integrity of the packaging structure.

[0179] 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 a Group IIIA metal element and / or a Group IVA metal element.

[0180] Compared with metal elements of other groups, metal elements of Group IIIA and Group IVA have relatively low melting points. Therefore, through the above settings, the melting point of the material of the second bonding layer 111 can be relatively low, so that the process difficulty of forming the second bonding layer 111 can be reduced.

[0181] In some embodiments, in combination 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.

[0182] 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.

[0183] Through the above settings, the range of the third temperature can be 180°C to 250°C, and the range of the melting point of the second bonding layer 111 can be 400°C to 500°C. Furthermore, the melting point of the first temporary bonding layer 102 is greater than the third temperature and less than the melting point of the second bonding layer 111. As described above, the stability of the first temporary bonding layer 102 under the high-temperature process conditions of S30 can be improved, and the second bonding layer 111 is not 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 does not affect the integrity of the package structure.

[0184] Some embodiments of the present disclosure further provide an infrared detection module 200, as Figure 3 shown, the infrared detection module 200 is prepared by using the preparation method of the infrared detection module 100 provided by the above technical solution.

[0185] Exemplarily, an infrared detection module 200 is prepared by using the preparation method of the infrared detection module 100 provided by the above technical solution.

[0186] Another exemplarily, a plurality of infrared detection modules 200 are prepared by using the preparation method of the infrared detection module 100 provided by the above technical solution. At this time, the infrared detection module 100 obtained in S40 can be cut to obtain the infrared detection module 200.

[0187] In some examples, as Figure 3 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.

[0188] Exemplarily, 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 provided on the second side 101B of the substrate 201 (see Figure 2I ) forms the first connection pattern 1041.

[0189] Exemplarily, as Figure 3 shown, the infrared detection module 200 further includes a pixel structure 105 and a pad layer 110, and the pad layer 110 is connected to the substrate 201 through the first connection pattern 1041.

[0190] Exemplarily, as Figure 3 shown, the infrared detection module 200 further includes a second connection 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 Figure 2L ) includes one or more second connection patterns 1111.

[0191] Exemplarily, in the case where the optical window layer 112 includes a plurality of optical window structures 212 and the second bonding layer 111 includes a plurality of second connection patterns 1111, the optical window structure 212 is obtained by cutting the optical window layer 112 of the infrared detection module 100 (see Figure 2L ); the second bonding layer 111 provided on the second side 101B of the substrate 201 (see Figure 2L ) forms the second connection pattern 1111.

[0192] Exemplarily, as Figure 3 shown, the infrared detection module 200 further includes a contact structure 109 penetrating the substrate 201.

[0193] The beneficial effects that can be achieved by the infrared detection module 200 provided by some embodiments of the present disclosure are the same as those that can be achieved by the preparation method of the infrared detection module 100 provided by the above technical solution, and will not be elaborated here.

[0194] Some embodiments of the present disclosure further provide an infrared detector 300, as Figure 4 shown, the infrared detector 300 includes a circuit board 310 and the infrared detection module 200 provided by the above technical solution, and the infrared detection module 200 is coupled to the circuit board 310.

[0195] Exemplarily, the infrared detector 300 may further include a third bonding layer 320, and the circuit board 310 is connected to the infrared detection module 200 through the third bonding layer 320.

[0196] Exemplarily, the infrared detector 300 includes a plurality of infrared detection modules 200 arranged in an array. The plurality of infrared detection modules 200 are connected to the circuit board 310 through a third bonding layer 320. In this way, the plurality of infrared detection modules 200 can be mounted on the circuit board 310.

[0197] Exemplarily, a connector for external electrical connection may be provided on the circuit board 310.

[0198] In some examples, the infrared detector 300 further includes an imaging system (not shown in the figure) disposed on the circuit board 310. In this case, the working principle of the infrared detector 300 may be as follows: The infrared radiation emitted by the detected target area and the background environment enters the infrared detector 300 through the light window structure 212. The infrared radiation passes through the pixel structure 105 in the infrared detector 300 and is converted into an electrical signal, and then forms an image on the imaging system.

[0199] The beneficial effects that can be achieved by the infrared detector 300 provided in some embodiments of the present disclosure are the same as those that can be achieved by the infrared detection module 200 provided in the above technical solution, and will not be described in detail here.

[0200] The above is only the specific implementation manner of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present disclosure, and all of them should be covered by the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claimed rights.

Claims

1. A preparation method of an infrared detection module, characterized in that, Comprising: Forming a substrate; Connecting a first temporary bonding layer and 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 is less 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.

2. The preparation method of the infrared detection module according to claim 1, wherein, 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 preparation method of the infrared detection module according to claim 1, characterized in that, The first bonding layer comprises a first alloy, the first alloy comprising 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 preparation method of the infrared detection module according to claim 3, wherein, 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 manufacturing method of the infrared detection module according to claim 1, wherein, The first bonding layer is formed by a transient liquid phase bonding process.

6. The preparation method of the infrared detection module according to claim 1, characterized in that, 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 comprises a first metal; the second metal layer comprises a second metal; and, Under the first temperature condition, using a transient liquid phase bonding process to convert the first metal layer and the second metal layer into the first bonding layer, the first bonding layer comprising a first alloy, the first alloy comprising a first metal and a second metal.

7. The preparation method of the infrared detection module according to claim 1, characterized in that, The first temporary bonding layer is formed by an eutectic soldering process.

8. The preparation method of the infrared detection module according to claim 1, characterized in that Connecting a first temporary bonding layer and a first temporary substrate on a first side of the substrate includes: Forming an 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 connect the substrate and the first temporary substrate through the first temporary bonding layer.

9. The preparation method of the infrared detection module according to any one of claims 1 to 8, characterized in that, 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, the second temporary bonding layer being 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.

10. The preparation method of the infrared detection module according to claim 9, wherein, After connecting the second temporary bonding layer and the second temporary substrate to the second side of the substrate, and before connecting the first temporary bonding layer and the first temporary substrate to the first side of the substrate, the manufacturing method further includes: Thinning the substrate from the first side of the substrate; and / or, Forming a contact structure penetrating the substrate from the first side of the substrate.

11. The preparation method of the infrared detection module according to claim 9, wherein, Before connecting the second temporary bonding layer and the second temporary substrate to the second side of the substrate, the manufacturing 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 to-be-formed second temporary bonding layer; After removing the second temporary bonding layer and the second temporary substrate, and before forming a first bonding layer on the second side of the substrate, the manufacturing method further includes: Removing the protective layer under a second temperature condition; Wherein, the melting point of the first temporary bonding layer is greater than the second temperature.

12. The preparation method of the infrared detection module according to claim 1, characterized in that, The infrared detection module further includes: a spacer layer disposed on the second side of the substrate; The surface of the substrate facing away from the first temporary bonding layer and the spacer layer are connected 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 manufacturing method further includes: Connecting a second bonding layer and an optical window layer to the side of the spacer layer away from the substrate under a third temperature condition, the second bonding layer being located between the optical window layer and the spacer layer; Wherein, 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.

13. The manufacturing method of the infrared detection module according to claim 12, characterized in that, The range of the third temperature is 180°C to 250°C; and / or, The range of the melting point of the second bonding layer is 400°C to 500°C.

14. The preparation method of the infrared detection module according to any one of claims 1 to 8, characterized in that, The range of the melting point of the first temporary bonding layer is 250°C to 300°C; and / or, The range of the first temperature is 180°C to 250°C; and / or, The range of the melting point of the first bonding layer is 400°C to 500°C.

15. An infrared detector, characterized in that, Comprising a circuit board and an infrared detection module, the infrared detection module is coupled to the circuit board; the infrared detection module is prepared by using the manufacturing method of the infrared detection module according to any one of claims 1 to 14.

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