Thinning method

Abstract

The application relates to the technical field of display, and provides a thinning method. In the thinning method, a polyimide layer and a flat layer are formed before array processing on a first surface of a glass substrate, the polyimide layer is located in a non-pattern area of the first surface, and the flat layer is located in a pattern area of the first surface, so that the area where the sealant can be arranged can be defined by means of the polyimide layer, thus facilitating the control of the form of the sealant and facilitating the assembly of two glass substrates. After thinning, the two glass substrates and the corresponding polyimide layers can be separated through a laser stripping process, and the sealant is also removed, so that the two glass substrates are separated. Therefore, not only can the damage to the surface of the glass substrate caused by the direct contact between the sealant and the glass substrate be improved, but also the problem of the change of the product size and the essential form caused by the cutting process can be improved, so that the subsequent process can be facilitated.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a method for thinning a fingerprint recognition module. Background Technology

[0002] In related technologies, two glass substrates are typically assembled together using sealant, and both substrates are simultaneously thinned before being cut. During this process, the cutting technique is difficult to control, making it challenging to achieve the desired product dimensions and potentially altering the product's fundamental form, thus impacting subsequent manufacturing processes. Summary of the Invention

[0003] Therefore, it is necessary to provide a thinning method to facilitate subsequent processes.

[0004] This application provides a thinning method for a fingerprint recognition module, the thinning method comprising:

[0005] A polyimide layer and a planarization layer are formed on the first surfaces of two glass substrates; the polyimide layer is located in the unpatterned area of ​​the first surface, and the planarization layer is located in the patterned area of ​​the first surface.

[0006] Two glass substrates are fixed together with a sealant such that the first surfaces of the two glass substrates face each other and the sealant forms a sealed space with the two glass substrates; the orthographic projection of the sealant on the first surface is located within the orthographic projection of the polyimide layer on the first surface.

[0007] The two glass substrates are thinned using a thinning process.

[0008] The two glass substrates are separated from their respective polyimide layers by a laser lift-off process.

[0009] In one embodiment, before fixing the two glass substrates together with a sealant such that the first surfaces of the two glass substrates face each other, and before the sealant forms a sealed space with the two glass substrates, the method further includes:

[0010] Circuit patterns and functional membrane structures are sequentially fabricated on the flat layer to form a fingerprint recognition module;

[0011] The orthographic projection of the functional membrane structure onto the first surface lies within the orthographic projection of the planarization layer onto the first surface.

[0012] In one embodiment, before fixing the two glass substrates together with a sealant such that the first surfaces of the two glass substrates face each other, and before the sealant forms a sealed space with the two glass substrates, the method further includes:

[0013] A protective film is disposed on the functional membrane structure;

[0014] The orthographic projection of the protective film on the first surface is located within the orthographic projection range of the planarization layer on the first surface, and covers the orthographic projection of the functional membrane structure on the first surface.

[0015] In one embodiment, prior to forming the polyimide layer and the planarization layer on the first surfaces of the two glass substrates, the method further includes:

[0016] The first surfaces of the two glass plates are treated by a polishing process.

[0017] In one embodiment, prior to the thinning process of the two glass substrates, the method further includes:

[0018] The second surfaces of the two glass plates are treated by a polishing process;

[0019] The second surface is opposite to the first surface.

[0020] In one embodiment, after separating the two glass substrates from the corresponding polyimide layers using a laser lift-off process to separate the two glass substrates, the process further includes:

[0021] The two glass substrates are cut using a cutting process.

[0022] In one embodiment, the cutting process includes a blade cutting process or a laser cutting process.

[0023] In one embodiment, the process for forming the polyimide layer includes a wet transfer process or a vapor deposition transfer process.

[0024] In one embodiment, the wavelength range of the laser in the laser ablation process is 308 nanometers to 351 nanometers.

[0025] In one embodiment, the sealant is configured as a thermosetting acid-resistant adhesive.

[0026] In one embodiment, the thinning process includes an etching process.

[0027] In the aforementioned thinning method, a polyimide layer and a planarization layer are formed on the first surface of the glass substrate before the array process. The polyimide layer is located in the non-patterned area of ​​the first surface, and the planarization layer is located in the patterned area of ​​the first surface. This allows the polyimide layer to define the area where the sealant can be applied, facilitating control over the sealant's shape and simplifying the assembly of the two glass substrates. After thinning, the two glass substrates can be separated from their respective polyimide layers using a laser lift-off process, removing the sealant along with the substrate. This not only mitigates damage to the glass substrate surface caused by direct contact between the sealant and the substrate but also reduces the impact of cutting processes on product dimensions and inherent morphology, thus facilitating subsequent processes.

[0028] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0029] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0030] Figure 1 This is a schematic diagram of a structure in which two substrate pairs are assembled together in an embodiment of a related technology.

[0031] Figure 2 This is a schematic diagram of the structure of a fingerprint recognition module in one embodiment of the related technology;

[0032] Figure 3 This is a schematic diagram of the first state of a double-layer thinning process in an embodiment of the related technology;

[0033] Figure 4 This is a schematic diagram of the second state of a double-layer thinning process in an embodiment of the related technology;

[0034] Figure 5 This is a schematic diagram of the third state of a double-layer thinning process in one embodiment of the related technology;

[0035] Figure 6 This is a schematic diagram of the fourth state of a double-layer thinning process in one embodiment of the related technology;

[0036] Figure 7 This is a schematic diagram of the fifth state of a double-layer thinning process in an embodiment of the related technology;

[0037] Figure 8This is a schematic diagram of the sixth state of a double-layer thinning process in an embodiment of the related technology;

[0038] Figure 9 This is a schematic flowchart of a thinning method in one embodiment of this application;

[0039] Figure 10 This is a schematic diagram of the structure of a glass substrate provided in one embodiment of this application;

[0040] Figure 11 This is a schematic diagram of the structure of a glass substrate after polishing the first surface of the glass substrate provided in one embodiment of this application.

[0041] Figure 12 This is a schematic diagram of a structure in one embodiment of the present application, showing the formation of a planarization layer and a polyimide layer on a first surface of a glass substrate;

[0042] Figure 13 This is a schematic diagram of a structure in one embodiment of the present application, showing that a plurality of patterned areas are provided on the first surface of a glass substrate;

[0043] Figure 14 This is a schematic diagram of a structure in which a circuit pattern is fabricated on a planar layer, according to one embodiment of this application.

[0044] Figure 15 This is a schematic diagram of a structure in which a functional membrane structure is fabricated on a circuit pattern, according to one embodiment of this application.

[0045] Figure 16 This is a schematic diagram of a protective membrane structure provided on a functional membrane structure in one embodiment of this application;

[0046] Figure 17 This is a schematic diagram of a structure in one embodiment of this application where two glass substrates are fixed to each other;

[0047] Figure 18 This is a three-dimensional structural diagram of two glass substrates facing each other in one embodiment of this application;

[0048] Figure 19 This is a schematic diagram of a structure in one embodiment of the present application, showing a sealant applied to a polyimide layer.

[0049] Figure 20 This is a schematic diagram of the structure of two glass substrates after thinning in one embodiment of this application;

[0050] Figure 21 This is a schematic diagram of a structure in one embodiment of the present application, showing that the second surfaces of the two glass substrates have not yet been polished.

[0051] Figure 22 This is a schematic diagram of a structure using laser ablation technology in one embodiment of this application;

[0052] Figure 23 This is a schematic diagram of a glass substrate in one embodiment of this application, in which the polyimide layer and sealant have been removed.

[0053] Brief explanation of component symbols:

[0054] a: First substrate b: Second substrate

[0055] c: Acid-resistant adhesive d: Sealing compound

[0056] 10: TFT substrate m: surface

[0057] 11: Cutting track 20: Adhesive layer

[0058] 30: Membrane structure; 31: Piezoelectric polymer layer

[0059] 32: Conductive layer; 33: First functional layer

[0060] 34: Second functional layer; 35: Organic protective layer

[0061] 40: Protective film

[0062] h1, h2, h3, h4, h5, h6: Thickness

[0063] 100: Glass substrate; 101: First surface

[0064] z1: Patterned area; z2: Non-patterned area

[0065] 102: Second surface; 200: Planarization layer

[0066] 300: Circuit diagram; 400: Functional membrane structure

[0067] p: Polyimide layer; s: Sealant

[0068] f: Protective film x: Laser Detailed Implementation

[0069] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific implementation methods of the embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the embodiments of this application. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application. The embodiments of this application can be implemented in many ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention. Therefore, the embodiments of this application are not limited to the specific embodiments disclosed below.

[0070] It is understood that the terms "first," "second," etc., used in this application may be used to describe various technical terms, but should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. However, unless otherwise stated, these technical terms are not limited to these terms. These terms are only used to distinguish one technical term from another. In the description of embodiments of this application, "a plurality of" or "several" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0071] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0072] In the description of the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the horizontal height of the first feature is higher than the horizontal height of the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0073] It should be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0074] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application and in its specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0075] Currently, the trend towards thinner and lighter electronic devices has become mainstream. This typically involves thinning the display glass substrate to meet the demands for thinner and lighter designs. To ensure production efficiency, a double-layer thinning process is usually used. After the double-layer thinning process, a slitting process is required to obtain the component or product of the corresponding size.

[0076] Figure 1 A schematic diagram of a structure in which two substrate pairs are assembled together is shown in one embodiment of the related art; for ease of explanation, only the parts related to one embodiment of the related art are shown.

[0077] like Figure 1 As shown, during the double-layer thinning process, acid-resistant adhesive c is typically used to bond the first substrate a and the second substrate b together to prevent acid from entering the opposite sides of the first substrate a and the second substrate b during etching and thinning. Simultaneously, to prevent acid erosion of the edges of the first substrate a and the second substrate b during etching and thinning, sealant d is applied at the edges of the first substrate a and the second substrate b to supplement and seal areas where the acid-resistant adhesive c is lacking.

[0078] Figure 2 A schematic diagram of a fingerprint recognition module in one embodiment of the related technology is shown; for ease of explanation, only the parts related to one embodiment of the related technology are shown.

[0079] like Figure 2 As shown, taking a fingerprint recognition module as an example, the fingerprint recognition module includes a TFT (Thin Film Transistor) substrate 10, an adhesive layer 20, and a film structure 30 stacked together. The film structure 30 includes a piezoelectric polymer layer 31, a conductive layer 32, a first functional layer 33, a second functional layer 34, and an organic protective layer 35 sequentially stacked on the TFT substrate 10. The adhesive layer 20 can be a composite organic solvent layer, and the piezoelectric polymer layer 31 can be bonded to the TFT substrate 10 using the adhesive layer 20. The conductive layer 32 can serve as a signal connection layer connecting the first functional layer 33 to the TFT substrate 10. The first functional layer 33 and the second functional layer 34 can be configured to receive and conduct sound waves. The thickness of the first functional layer 33 and the second functional layer 34 can be increased, and the specific configuration can be adjusted according to actual usage.

[0080] For example, with Figure 2For example, the thickness h1 of the TFT substrate 10 can be 70 micrometers to 110 micrometers, the thickness h2 of the piezoelectric polymer layer 31 can be 7 micrometers to 11 micrometers, the thickness h3 of the conductive layer 32 can be 6 micrometers to 8 micrometers, the thickness h4 of the first functional layer 33 can be 5.5 micrometers to 7.5 micrometers, the thickness h5 of the second functional layer 34 can be 5.5 micrometers to 7.5 micrometers, and the thickness h6 of the organic protective layer 35 can be 15 micrometers to 25 micrometers. That is, the thickness of the layer structure disposed on the TFT substrate 10 can be approximately 39 micrometers to 59 micrometers. When two TFT substrates 10 are paired, the interlayer distance between the two TFT substrates 10 is approximately 78 micrometers to 118 micrometers. If other functional film layers are disposed on the TFT substrate 10, or if the thicknesses differ from those shown above, the interlayer distance between the two TFT substrates 10 can be approximately 100 micrometers to 150 micrometers. The interlayer distance is related to the height of the acid-resistant adhesive. Compared to the interlayer distance of less than 5 micrometers between the TFT substrate and the color filter in a liquid crystal display module, the height and width of the acid-resistant adhesive are more difficult to control when it is placed between the two TFT substrates 10 used for fingerprint recognition. At the same time, due to the different structures of the adhesive-coated and non-adhesive-coated areas, the support and stress conditions are different, making it difficult to control the cutting process when cutting the TFT substrate 10.

[0081] Figure 3 This diagram illustrates the first state of a double-layer thinning process in an embodiment of the related technology. Figure 4 This diagram illustrates the second state of a double-layer thinning process in one embodiment of the related technology. Figure 5 A schematic diagram of the third state of a double-layer thinning process in an embodiment of the related technology is shown; Figure 6 A schematic diagram of the fourth state of a double-layer thinning process in an embodiment of the related technology is shown; Figure 7 A schematic diagram of the fifth state of a double-layer thinning process in an embodiment of the related technology is shown; Figure 8 A schematic diagram of the sixth state of a double-layer thinning process in an embodiment of the related art is shown; for ease of explanation, only the parts relevant to an embodiment of the related art are shown. For example, Figure 3 Not shown in the middle Figure 2 The adhesive layer 20 in the middle.

[0082] in, Figures 3 to 8 The first to eighth states in the diagram represent the states of the fingerprint recognition module at different steps in the double-layer thinning process.

[0083] by Figure 2 Taking the illustrated fingerprint recognition module as an example, Figure 3 What is provided in China Figure 2 The diagram illustrates the fingerprint recognition module. Figure 4As shown, a protective film f40 is provided on the membrane structure 30. (As indicated...) Figure 5 As shown, an acid-resistant adhesive c is disposed on the surface m of the TFT substrate 10 where the film structure 30 is provided. Figure 6 As shown, another fingerprint recognition module is aligned so that the two TFT substrates 10 are positioned by means of the acid-resistant adhesive c, and a sealed space is formed between the two TFT substrates 10. Figure 7 As shown, after etching and thinning, two TFT substrates 10 are cut using a dicing process. Figure 8 As shown, the fingerprint recognition module of the required size is obtained, and the protective film 40 can be removed for subsequent processes.

[0084] The inventors of this application have noted that, as mentioned above, for a fingerprint recognition module, the interlayer distance between the two TFT substrates 10 makes it difficult to control the height and width of the anti-acid adhesive c, and consequently, when the anti-acid adhesive c is disposed on the TFT substrate 10, it is also difficult to control its position on the TFT substrate 10. Based on this, in the case of... Figure 7 In the process shown, if mechanical cutting is used, then as follows: Figure 2 As shown, a dicing groove 11 of a certain size is formed on the TFT substrate 10. Therefore, the area that can be cut is limited due to the presence of the dicing groove 11 and the anti-acid adhesive c. Furthermore, the anti-acid adhesive c has a certain height and width, leading to differences in support and stress conditions, making the cutting process difficult to control. Consequently, it is difficult to obtain the desired product size. If laser cutting is used, the aforementioned problems of difficulty in controlling the height and width of the anti-acid adhesive c, the formation of the dicing groove 11, and differences in stress in different areas also exist. Although the dicing groove 11 required by laser cutting is smaller than that of mechanical cutting, since the film structure 30 on the TFT substrate 10 contains organic and inorganic layers, the different coefficients of thermal expansion of the organic and inorganic layers during laser cutting can cause deformation and damage to the film structure 30, potentially altering the product's size and nature. Furthermore, if the anti-acid adhesive c is directly removed or dissociated, there are also issues such as anti-acid adhesive c residue remaining on the TFT substrate 10 and the dissociation process being difficult to control.

[0085] The inventors of this application have discovered that at least some of the aforementioned problems can be avoided by using a removal method that reduces damage. Specifically, the anti-acid adhesive c can be indirectly disposed on the surface m of the TFT substrate 10 via a polyimide layer p, and the anti-acid adhesive c can be removed from the surface m of the TFT substrate 10 by removing the polyimide layer p. The removal of the polyimide layer p from the surface m of the TFT substrate 10 can be achieved using a laser lift-off process. This enables the aforementioned destructive removal method, thereby achieving separation between the two TFT substrates 10.

[0086] Based on this, the embodiments of this application improve the thinning process, thereby reducing damage to the TFT substrate 10 and avoiding some of the aforementioned problems. The thinning method provided by the embodiments of this application will be described below in conjunction with relevant descriptions of some embodiments.

[0087] Figure 9 A schematic flowchart of a thinning method in one embodiment of this application is shown; for ease of explanation, only the parts related to the embodiment of this application are shown.

[0088] Please refer to Figure 9 This application provides a thinning method for a fingerprint recognition module, the method comprising the following steps:

[0089] S110, A polyimide layer p and a planarization layer 200 are formed on the first surface 101 of the two glass substrates 100; the polyimide layer p is located in the unpatterned area z2 of the first surface 101, and the planarization layer 200 is located in the patterned area z1 of the first surface 101.

[0090] Specifically, the glass substrate 100 has a transparent, plate-like structure. The glass substrate 100 can be configured as alkali-free glass. For example... Figure 10 As shown, a glass substrate 100 is provided before the formation of the polyimide layer p and the planarization layer 200. Figure 11 As shown, in some embodiments, the first surface 101 of the glass substrate 100 is treated by a polishing process. This finishing process on the first surface 101 of the glass substrate 100 can result in a smoother surface, facilitating the formation of the polyimide layer p and the planarization layer 200, as illustrated in subsequent figures. That is, Figure 10 The first surface 101 of the glass substrate 100 is the surface before polishing. Figure 11 The first surface 101 of the glass substrate 100 shown in the following schematic diagram is the surface before polishing.

[0091] It is understandable that the first surface 101 is the surface for subsequent array fabrication processes and the setting of related film structures. For example... Figure 12 As shown, the first surface 101 is divided into a patterned area z1 and a non-patterned area z2. The patterned area z1 is used for the aforementioned array fabrication process and for setting related film structures. A portion of the non-patterned area z2 of the first surface 101 needs to be removed according to usage requirements. For example... Figure 13As shown, multiple patterned areas z1 can be formed on the first surface 101, and the area on the first surface 101 excluding the patterned areas z1 is the non-patterned area z2. In subsequent processes, the glass substrate 100 can be cut to the required size to obtain multiple fingerprint recognition modules. Of course, only one patterned area z1 can be formed on the first surface 101, and the area on the first surface 101 excluding the patterned area z1 is the non-patterned area z2. In this way, in subsequent processes, the glass substrate 100 can be cut to the required size to obtain one fingerprint recognition module. The configuration can be set according to actual usage requirements, and this application embodiment does not impose specific limitations on this.

[0092] The first surface 101 of the planarization layer 200 facing away from the glass substrate 100 can be planar to achieve planarization, so as to facilitate the stacking of other film layers. The material of the planarization layer 200 is configured to be a transparent material, such as an organosilicon layer, etc., or other transparent materials can be used.

[0093] A planarization layer 200 can be formed first on the first surface 101 of the two glass substrates 100, followed by the formation of the polyimide layer p. Alternatively, the polyimide layer p can be formed first, followed by the planarization layer 200. As long as the planarization layer 200 is formed in the patterned area z1 and the polyimide layer p is formed in the unpatterned area z2, the choice can be made according to process requirements. This application embodiment does not impose specific limitations on this.

[0094] In some embodiments, the process for forming the polyimide layer p includes a wet transfer process or a vapor deposition transfer process. The choice can be made based on actual application requirements, and this application does not impose specific limitations in this regard.

[0095] In some embodiments, after the planarization layer 200 and the polyimide layer p are formed, as Figure 14 and Figure 15 As shown, a circuit pattern 300 and a functional film structure 400 are sequentially fabricated on the planarization layer 200 to form a fingerprint recognition module. It is understood that the functional film structure 400 can be one of the film layer structures illustrated in the aforementioned related technologies, or it can be a structure including other film layers, as long as it can achieve the fingerprint recognition function. This application embodiment does not impose specific limitations on this. The circuit pattern 300 can be fabricated using an ITO (Indium Tin Oxide) process or a Metal Mesh process, as long as a conductive circuit pattern 300 can be formed on the first surface 101 of the glass substrate 100. This application embodiment does not impose specific limitations on this. It is understood that the orthographic projection of the functional film structure 400 on the first surface 101 lies within the orthographic projection of the planarization layer 200 on the first surface 101.

[0096] In some embodiments, after the circuit pattern 300 and the functional membrane structure 400 are fabricated, such as Figure 16 As shown, a protective film f is provided on the functional film structure 400, thereby protecting the surface of the functional film structure 400 when two glass substrates 100 are subsequently assembled. It is understood that the orthographic projection of the protective film f onto the first surface 101 lies within the orthographic projection range of the planarization layer 200 onto the first surface 101, and covers the orthographic projection of the functional film structure 400 onto the first surface 101. This protects the surface of the functional film structure 400.

[0097] S120. Two glass substrates 100 are fixed together with sealant s so that the first surfaces 101 of the two glass substrates 100 face each other and the sealant s forms a sealed space with the two glass substrates 100; the orthographic projection of the sealant s on the first surface 101 is located within the orthographic projection of the polyimide layer p on the first surface 101.

[0098] Specifically, such as Figure 17 and Figure 18 As shown, Figure 18 This is a three-dimensional structural diagram illustrating a situation where multiple patterned areas z1 are provided on the glass substrate 100. Related film structures are provided on the patterned areas z1. For ease of display, Figure 18 The two glass substrates 100 are in a phase-separated state, and only the functional film structure 400 is shown; the protective film f is not shown. The sealing space formed between the sealant s and the two glass substrates 100 can protect the circuit pattern 300 and the functional film structure 400 on the first surface 101 of the two glass substrates 100. Optionally, the sealant s is configured as an acid-resistant adhesive c to prevent acid from entering the sealed space and corroding the structure within the sealed space.

[0099] In some embodiments, such as Figure 19 As shown, Figure 19 for Figure 17 and Figure 18 The diagram shows different perspectives and partial structural schematics. For ease of explanation, only the relationship between the sealant s, the polyimide layer p, and the patterned area z1 is shown. The edge of the polyimide layer p can have a certain distance from the patterned area z1, which can be set according to usage requirements. The sealant s is disposed in the area where the polyimide layer p is located. Figure 19 This illustrates a situation where the sealant s does not completely cover the polyimide layer p.

[0100] It should be noted that the structures within the patterned areas z1 on the two glass substrates 100 can be the same or different, as long as the sealant s is disposed in the area where the polyimide layer p is located on both glass substrates 100 and can form a sealed space to facilitate subsequent thinning processes. This application embodiment does not impose specific limitations in this regard. The schematic diagram in this application embodiment shows the case where the two glass substrates 100 and the structures within the patterned areas z1 on the two glass substrates 100 are completely identical.

[0101] S130. The two glass substrates 100 are thinned by a thinning process.

[0102] Specifically, thinning processes can include etching processes. For example... Figure 20 As shown, the thickness of the glass substrate 100 can be reduced by etching. In some embodiments, before performing the thinning process, such as... Figure 21 As shown, the second surface 102 of the two glass plates is treated using a polishing process. The second surface 102 is opposite to the first surface 101. That is to say, Figure 20 The second surface 102 of the glass substrate 100 is the surface before polishing. This facilitates the etching process.

[0103] S140. The two glass substrates 100 are separated from the corresponding polyimide layer p by a laser lift-off process, thereby separating the two glass substrates 100.

[0104] Specifically, such as Figure 22 As shown, a laser lift-off process can be performed on one side of the second surface 102 of the two glass substrates 100 using a laser x. Optionally, the wavelength range of the laser x in the laser lift-off process is 308 nm to 351 nm. Correspondingly, the sealant s is configured as an ultraviolet-resistant acid adhesive c. Since the ultraviolet-resistant acid adhesive c cures at a wavelength of 365 nm, this facilitates the laser lift-off process. In some embodiments, to ensure a certain laser transmittance, the glass substrate 100 can be configured to have a transmittance of 70% to 90%.

[0105] During laser lift-off, the molecules within the polyimide layer p receive a light source of a specified wavelength, causing bond breakage. This results in the polyimide layer p losing adhesion to the first surface 101 of the glass substrate 100, and the polyimide layer p separating from the glass substrate 100. Simultaneously, since the sealant s is disposed on the side of the polyimide layer p facing away from the first surface 101 of the glass substrate 100, as... Figure 23 As shown, the sealant s can be removed, and the two glass substrates 100 are separated.

[0106] It should be noted that, in any embodiment of the present invention, the sealant s may also be at least one of thermosetting acid-resistant adhesives or other photocurable adhesives that are not affected by the laser stripping process, or other feasible equivalents, and the present invention is not limited thereto.

[0107] In some embodiments, after the two glass substrates 100 are separated, they can be cut using a cutting process. Optionally, the cutting process includes a blade cutting process or a laser cutting process.

[0108] Therefore, since a polyimide layer p can be disposed in the non-patterned area z2 of the first surface 101 of the glass substrate 100, the area for the sealant s is expanded by the polyimide layer p, facilitating the support and fixation when the two glass substrates 100 are assembled. Simultaneously, since the polyimide layer p is completed before the array process of the glass substrates 100, and the polyimide layer p can be separated from the glass substrate 100 by a laser lift-off process, the problem of difficulty in controlling the cutting process mentioned above is avoided. Furthermore, since the separation of the two glass substrates 100 does not involve a cutting process, the usable space of the non-patterned area z2 can be further expanded, facilitating the placement of the polyimide layer p and the sealant s. Therefore, not only can the damage to the surface of the glass substrate 100 caused by direct contact between the sealant s and the glass substrate 100 be improved, but the problem of changes in product size and intrinsic shape caused by the cutting process can also be mitigated, thereby facilitating subsequent processes.

[0109] It should be understood that the technical solutions described above can be implemented as independent embodiments or combined with each other as combined embodiments in actual implementation. Furthermore, the description of the embodiments of this application is based solely on the convenience of explanation and follows a corresponding order, rather than limiting the execution order between different embodiments. Accordingly, in actual implementation, if multiple embodiments provided by this application need to be implemented, it is not necessary to follow the execution order provided in the description of the embodiments in this application; instead, the execution order between different embodiments can be arranged according to requirements.

[0110] It should be understood that the fingerprint recognition module thinned by the method provided in the above embodiments can be used in display panels and display devices, and can be applied to fields such as mobile terminals, bionic electronics, electronic skin, wearable devices, automotive devices, Internet of Things devices, and artificial intelligence devices. For example, the above electronic devices can be mobile terminals, tablets, PDAs, iPods, smartwatches, laptops, televisions, monitors, etc., and the embodiments of this application do not specifically limit them.

[0111] In summary, referring to the relevant figures provided in the embodiments of this application, the thinning method provided in this application involves forming a polyimide layer p and a planarization layer 200 on the first surface 101 of the glass substrate 100 before performing an array process. The polyimide layer p is located in the non-patterned area z2 of the first surface 101, and the planarization layer 200 is located in the patterned area z1 of the first surface 101. This allows the polyimide layer p to define the area where the sealant s can be applied, thus facilitating the control of the shape of the sealant s and making it easier to assemble the two glass substrates 100 together. After thinning, the two glass substrates 100 can be separated from the corresponding polyimide layer p by a laser lift-off process, thereby removing the sealant s as well, and thus separating the two glass substrates 100. In this process, the use of laser peeling technology not only provides a larger space for setting the sealant s, but also improves the surface of the glass substrate 100 by using the polyimide layer p to prevent damage caused by direct contact between the sealant s and the glass substrate 100. Furthermore, it can improve the problem of changes in product size and essential shape caused by the cutting process, thereby facilitating subsequent processes.

[0112] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0113] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A thinning method for a fingerprint recognition module, characterized in that, The thinning method includes: A polyimide layer and a planarization layer are formed on the first surfaces of two glass substrates; the polyimide layer is located in the unpatterned area of ​​the first surface, and the planarization layer is located in the patterned area of ​​the first surface. A circuit pattern and a functional membrane structure are sequentially fabricated on the planar layer to form a fingerprint recognition module; the orthographic projection of the functional membrane structure on the first surface is located within the orthographic projection of the planar layer on the first surface. Two glass substrates are fixed together with a sealant such that the first surfaces of the two glass substrates face each other and the sealant forms a sealed space with the two glass substrates; the sealant is configured as a thermosetting acid-resistant adhesive or an ultraviolet acid-resistant adhesive, and the orthographic projection of the sealant on the first surface is located within the orthographic projection of the polyimide layer on the first surface. The two glass substrates are thinned using a thinning process. The two glass substrates are separated from their respective polyimide layers by a laser lift-off process, thereby separating the two glass substrates; the wavelength range of the laser in the laser lift-off process is 308 nm to 351 nm.

2. The thinning method according to claim 1, characterized in that, Before fixing the two glass substrates together with sealant so that the first surfaces of the two glass substrates face each other, and before the sealant forms a sealed space with the two glass substrates, the method further includes: A protective film is disposed on the functional membrane structure; The orthographic projection of the protective film on the first surface is located within the orthographic projection range of the planarization layer on the first surface, and covers the orthographic projection of the functional membrane structure on the first surface.

3. The thinning method according to claim 1, characterized in that, Before forming the polyimide layer and the planarization layer on the first surfaces of the two glass substrates, the method further includes: The first surfaces of the two glass substrates are treated by a polishing process.

4. The thinning method according to claim 1, characterized in that, Before the thinning process is performed on the two glass substrates, the method further includes: The second surfaces of the two glass substrates are treated by a polishing process; The second surface is opposite to the first surface.

5. The thinning method according to claim 1, characterized in that, The process of separating the two glass substrates from their respective polyimide layers using a laser lift-off process, after separating the two glass substrates, further includes: The two glass substrates are cut using a cutting process.

6. The thinning method according to claim 5, characterized in that, The cutting process includes a blade wheel cutting process.

7. The thinning method according to claim 5, characterized in that, The cutting process includes laser cutting.

8. The thinning method according to any one of claims 1-7, characterized in that, The process for forming the polyimide layer includes a wet transfer process.

9. The thinning method according to any one of claims 1-7, characterized in that, The process for forming the polyimide layer includes a vapor deposition transfer process.

10. The thinning method according to any one of claims 1-7, characterized in that, The thinning process includes an etching process.

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