Display module and electronic device

Abstract

The application relates to a display module and electronic equipment. The display module comprises a display panel, a functional layer of the display panel away from a light-out side is configured as a metal support layer; a first functional layer is arranged on a side of the metal support layer away from the light-out side, a surface of the first functional layer away from the light-out side has a roughness smaller than that of a surface of the metal support layer away from the light-out side; a glue layer is attached to the first functional layer; and an ultrasonic fingerprint module is arranged on a side of the glue layer away from the first functional layer and is attached to the first functional layer through the glue layer. The display module and the electronic equipment can improve the image uniformity of ultrasonic imaging and improve the accuracy of ultrasonic fingerprint identification.

Description

TECHNICAL FIELD

[0001] The present application relates to the fingerprint identification technical field, in particular to a display module and electronic equipment. BACKGROUND

[0002] Fingerprint identification technology is a common biometric identification technology for verifying identity in modern times. According to the technical principle, the fingerprint identification technology can be mainly divided into optical type, ultrasonic type, capacitive type and the like. The ultrasonic fingerprint identification technology has the advantages of high resolution, long product life, and less influence on fingerprint identification ability by environmental temperature or humidity, so that it is more and more applied to consumer electronic products. However, in the existing electronic products equipped with ultrasonic fingerprint identification modules, the image uniformity of ultrasonic imaging is poor, and the accuracy of ultrasonic fingerprint identification cannot be guaranteed. SUMMARY

[0003] Therefore, it is necessary to provide a display module and electronic equipment, which can improve the image uniformity of ultrasonic imaging and improve the accuracy of ultrasonic fingerprint identification.

[0004] The first aspect of the embodiment of the present application provides a display module, comprising:

[0005] A display panel, a functional layer of the display panel away from the light-out side is constructed as a metal support layer;

[0006] A first functional layer is arranged on a side of the metal support layer away from the light-out side, and the roughness of the surface of the first functional layer away from the light-out side is smaller than the roughness of the surface of the metal support layer away from the light-out side;

[0007] An adhesive layer is attached to the first functional layer;

[0008] An ultrasonic fingerprint module is located on a side of the adhesive layer away from the first functional layer, and is attached to the first functional layer by means of the adhesive layer.

[0009] In the above scheme, the ultrasonic fingerprint module is attached to the first functional layer with small surface roughness through the adhesive layer. Compared with directly attaching the ultrasonic fingerprint module to the metal support layer with large surface roughness, the film thickness uniformity of the adhesive layer is improved, so that the stacking uniformity of each structure layer is good, which is conducive to the conduction of ultrasonic waves. In this way, the image uniformity of ultrasonic imaging can be improved, and the accuracy of ultrasonic fingerprint identification can be improved. On the other hand, since the roughness of the first functional layer is small, the adhesion of the adhesive layer and the first functional layer is more firm, that is, the adhesion is improved, and the risk of subsequent ultrasonic fingerprint module falling off is also avoided, and the reliability of fingerprint identification is improved.

[0010] In one of the embodiments, the surface of the metal support layer facing away from the light-out side is provided with a groove, and the first functional layer is arranged in the groove. In this way, the mutual positioning of the first functional layer and the metal support layer is facilitated.

[0011] In one of the embodiments, the surface of the first functional layer facing away from the light-out side is flush with the edge of the groove. In this way, the size of the display module in the thickness direction can be minimized, so that the display module structure is more compact, and the light weight of the display module is also facilitated.

[0012] In one of the embodiments, the material of the first functional layer is polyimide, polyethylene terephthalate, or polycarbonate. In this way, not only the roughness is low, but also the hardness can meet the use requirements, the cost is low, and the processing is easy.

[0013] In one of the embodiments, the first functional layer is attached to the metal support layer through the adhesive layer. In this way, the first functional layer can be simply arranged on the metal support layer.

[0014] In one of the embodiments, the projection of the first functional layer on the metal support layer covers the projection of the adhesive layer on the metal support layer. In this way, the setting area of the first functional layer is larger than that of the adhesive layer, so that the adhesive layer is entirely arranged on the first functional layer with smaller roughness. The adhesion between the adhesive layer and the first functional layer is more firm, the adhesion is improved, the risk of the subsequent fingerprint module falling off is avoided, and the reliability of the fingerprint identification is improved.

[0015] In one of the embodiments, the adhesive layer includes a first adhesive layer and a second adhesive layer arranged in a stack, the first adhesive layer is attached to the first functional layer, and the second adhesive layer is attached between the first adhesive layer and the fingerprint module. As described above, by arranging the adhesive layer in a two-layer stack structure, compared with arranging only a single-layer adhesive layer, the adhesion between the adhesive layer and the first functional layer can be further improved. In addition, if the adhesive layer is arranged in a two-layer stack structure under the condition that the thickness of the adhesive layer is the same, since the thickness of the single-layer adhesive layer is reduced, the occurrence of air bubbles in the single-layer adhesive layer can be avoided or minimized, and the smooth conduction of ultrasonic waves is facilitated.

[0016] In one of the embodiments, the first adhesive layer is configured as an acrylic adhesive layer or a pressure-sensitive adhesive layer; and the second adhesive layer is configured as a double-sided adhesive.

[0017] In one of the embodiments, the thickness of the first adhesive layer is less than 0.1 μm.

[0018] The second aspect of the embodiments of the present application provides an electronic device including the display module described above. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1A structural schematic diagram of a display module provided by an embodiment of the present application is shown in FIG. 1.

[0020] Figure 2 A schematic diagram of an installation structure of an ultrasonic fingerprint module and a display panel in a display module provided by an embodiment of the present application is shown in FIG. 2.

[0021] Figure 3 A schematic diagram of another installation structure of an ultrasonic fingerprint module and a display panel in a display module provided by an embodiment of the present application is shown in FIG. 3.

[0022] Figure 4 A schematic diagram of still another installation structure of an ultrasonic fingerprint module and a display panel in a display module provided by an embodiment of the present application is shown in FIG. 4.

[0023] Figure 5a A schematic diagram of a test image of an ultrasonic fingerprint module in a display module of the related art is shown in FIG. 5.

[0024] Figure 5b A schematic diagram of another test image of an ultrasonic fingerprint module in a display module of the related art is shown in FIG. 6.

[0025] Figure 6a A schematic diagram of a test image of an ultrasonic fingerprint module in a display module provided by an embodiment of the present application is shown in FIG. 7.

[0026] Figure 6b A schematic diagram of another test image of an ultrasonic fingerprint module in a display module provided by an embodiment of the present application is shown in FIG. 8.

[0027] Explanation of reference numerals:

[0028] 100, display module;

[0029] 10, display panel; 11, metal support layer; 111, groove; 20, first functional layer; 30, adhesive layer; 31, first adhesive layer; 32, second adhesive layer; 50, ultrasonic fingerprint module. DETAILED DESCRIPTION

[0030] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order to not unnecessarily obscure the present application.

[0031] In the description of the application, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the application.

[0032] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0033] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0034] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0035] It is to be noted that when an element is referred to as being "fixed" or "set" on another element, it can be directly on the other element or there can be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there can be an intervening element. The terms "vertical", "horizontal", "upper", "lower", "left", "right", and similar expressions as used herein are for illustrative purposes only and are not intended to be limiting.

[0036] In recent years, foldable-screen mobile phones have gradually entered the market, and are favored by consumers due to their novel design, higher screen operability and other advantages, and the demand of consumers for under-screen fingerprint recognition technology has also increased. There are mainly two kinds of disclosed under-screen fingerprint recognition schemes: the first is an optical scheme, and the second is an ultrasonic scheme. The performance of the optical fingerprint module is greatly affected by the optical transmittance of the screen. With the development of the complexity of internal wiring of the display screen and the flexible screen scheme, the optical transmittance of the screen is reduced, which makes the optical fingerprint scheme unable to meet such application scenarios. The ultrasonic fingerprint module does not depend on the optical transmittance of the screen, and is a better alternative scheme.

[0037] The screen of the foldable-screen mobile phone is a flexible screen body, and the supporting structure adopts a metal supporting layer. The ultrasonic fingerprint module in the related art is generally attached to the back of the metal supporting layer to be carried on the foldable-screen mobile phone. The disadvantage of this scheme is that the ultrasonic fingerprint module has poor adhesion to the metal supporting layer, and the uniformity of the test image of the ultrasonic fingerprint module is poor, which affects the accuracy of the ultrasonic fingerprint recognition.

[0038] The ultrasonic module is attached to the first functional layer, which has a smaller surface roughness. This not only improves the adhesion of the ultrasonic fingerprint module, but also facilitates the conduction of ultrasonic waves, which can improve the image uniformity of ultrasonic imaging and improve the accuracy of ultrasonic fingerprint module recognition.

[0039] The display module and the electronic device of the embodiments of the present application will be described below with reference to the accompanying drawings.

[0040] Figure 1 The structure diagram of the display module provided by the embodiments of the present application is shown in Figure 2 The mounting structure diagram of the ultrasonic fingerprint module and the display panel in the display module provided by the embodiments of the present application is shown in

[0041] Referring to Figure 1 The display module 100 includes a display panel 10, and the display panel 10 has a light-emitting side, i.e., a display side of the display panel 10, Figure 1is a structural schematic diagram viewed from the backlight side (i.e. the side away from the light-emitting side) of the display module 100, the functional layer of the display panel 10 away from the light-emitting side is configured as a metal support layer 11, and the area shown by the dashed box is the attachment area of the ultrasonic fingerprint module 50.

[0042] It can be understood that, in addition to the metal support layer 11, the display panel 10 can also include a display substrate, a cover layer (not shown), and the like, which are stacked on the light-emitting side of the metal support layer 11.

[0043] In the embodiments of the present application, in combination with Figure 1 , Figure 2 , the display module 100 further includes a first functional layer 20, an adhesive layer 30, and an ultrasonic fingerprint module 50. The first functional layer 20 is arranged on the side of the metal support layer 11 away from the light-emitting side, and the roughness of the surface of the first functional layer 20 away from the light-emitting side is less than the roughness of the surface of the metal support layer 11 away from the light-emitting side. The adhesive layer 30 is attached to the first functional layer 20. The ultrasonic fingerprint module 50 is located on the side of the adhesive layer 30 away from the first functional layer 20, and is attached to the first functional layer 20 by means of the adhesive layer 30.

[0044] In the above scheme, the ultrasonic fingerprint module 50 is attached to the first functional layer 20 with smaller surface roughness through the adhesive layer 30. Compared with directly attaching the ultrasonic fingerprint module 50 to the metal support layer 11 with larger surface roughness, the film thickness uniformity of the adhesive layer 30 is improved, the stacking uniformity of each structure layer is good, which is conducive to the conduction of ultrasonic waves, so that the image uniformity of ultrasonic imaging is improved, and the accuracy of ultrasonic fingerprint identification is improved. On the other hand, since the roughness of the first functional layer 20 is smaller, the attachment of the adhesive layer 30 to the first functional layer 20 is more firm, i.e. the adhesion is improved, and the risk of subsequent ultrasonic fingerprint module 50 falling off is also avoided, and the reliability of fingerprint identification is improved.

[0045] In the examples of Figure 1 , Figure 2 , when performing fingerprint identification, the ultrasonic fingerprint module 50 emits ultrasonic signals to the finger (not shown) on the light-emitting side of the display panel 10, the ultrasonic signals pass through the adhesive layer, the first functional layer 20, and the display panel 10 to reach the surface of the finger, and the ultrasonic signals reflected by the surface of the finger are received by the ultrasonic fingerprint module 50 after passing through the display panel 10, the first functional layer 20, and the adhesive layer 30. The ultrasonic fingerprint module 50 converts the received ultrasonic signals into electrical signals, and a fingerprint identification image of the finger can be formed according to the electrical signals.

[0046] It should be noted that the metal support layer 11 can be a titanium alloy support layer, or other types of metal support layers can be selected as needed. The surface roughness of the titanium alloy support layer can be, for example, 3.864 μm.

[0047] Furthermore, to ensure that the surface roughness of the first functional layer 20 facing away from the light-emitting side is less than that of the surface roughness of the metal support layer 11 facing away from the light-emitting side, the first functional layer 20 can be made of non-metallic materials such as polyimide (PI), polyethylene terephthalate (PET), or polycarbonate (PC). When the first functional layer 20 is made of polyimide, polyethylene terephthalate, or polycarbonate, it not only achieves a lower surface roughness but also meets the required hardness, resulting in lower cost and easier processing. When the first functional layer 20 is made of polyimide, its surface roughness can be reduced to 1.34 μm.

[0048] The connection between the first functional layer 20 and the metal support layer 11 can be achieved, for example, by attaching the first functional layer 20 to the metal support layer 11 using an adhesive layer. This simplifies the placement of the first functional layer 20 on the metal support layer 11. The adhesive layer can be applied to the surface of the metal support layer 11 by coating or printing.

[0049] Regarding the arrangement of the first functional layer 20 and the metal support layer 11, combined with Figure 1 , Figure 2 For example, the surface of the metal support layer 11 facing away from the light-emitting side is provided with a groove 111, and the first functional layer 20 is disposed in the groove 111.

[0050] Thus, by setting a groove 111 at a preset position on the surface of the metal support layer 11 and placing the first functional layer 20 in the groove 111, the first functional layer 20 can be placed at a preset position on the metal support layer 11, which facilitates the mutual positioning of the first functional layer 20 and the metal support layer 11.

[0051] The groove 111 here can be formed by milling, which can reduce the roughness of the inner wall of the groove 111, especially the bottom wall, and further improve the bonding between the interface of the first functional layer 20 and the metal support layer 11, which is more conducive to the transmission of ultrasonic waves. It is understood that the groove 111 is not limited to milling, but can also be formed by etching or other methods.

[0052] Furthermore, the surface of the first functional layer 20 facing away from the light-emitting side is flush with the edge of the groove 111.

[0053] The surface of the first functional layer 20 facing away from the light-emitting side is flush with the edge of the groove 111. Specifically, the thickness of the first functional layer 20 is approximately equal to the depth of the groove 111. This can minimize the size of the display module 100 in the thickness direction, making the structure of the display module 100 more compact and also contributing to the lightweighting of the display module 100.

[0054] In a specific implementation, the first functional layer 20 can completely fill the groove 111, which facilitates the installation and positioning of the first functional layer 20.

[0055] In this embodiment, reference is continued. Figure 2 The projection of the first functional layer 20 onto the metal support layer 11 covers the projection of the adhesive layer 30 onto the metal support layer 11.

[0056] Thus, the area of ​​the first functional layer 20 is larger than the area of ​​the adhesive layer 30, so that the entire adhesive layer 30 is disposed on the first functional layer 20. This ensures that the ultrasonic waves emitted by the ultrasonic fingerprint module 50 are transmitted to the finger through the interface between the adhesive layer 30 and the first functional layer 20, resulting in better conductivity. Furthermore, this makes the adhesion between the adhesive layer 30 and the first functional layer 20 more robust, improving adhesion and avoiding the risk of the fingerprint module detaching later, thereby enhancing the reliability of fingerprint recognition.

[0057] Figure 3 This is a schematic diagram of another mounting structure for the ultrasonic fingerprint module and the display panel in the display module provided in the embodiments of this application.

[0058] In this embodiment of the application, in order to further improve the adhesion of the ultrasonic fingerprint module 50, it can be as follows: Figure 3 As shown, the adhesive layer 30 is configured as a double-layer structure. In a specific implementation, the adhesive layer 30 includes a first adhesive layer 31 and a second adhesive layer 32 arranged in a stacked manner. The first adhesive layer 31 is attached to the first functional layer 20, and the second adhesive layer 32 is attached between the first adhesive layer 31 and the ultrasonic fingerprint module 50.

[0059] As described above, by setting the adhesive layer 30 as a two-layer stacked structure, the adhesion between the adhesive layer 30 and the first functional layer 20 can be further improved compared to setting only a single adhesive layer, especially the adhesion at the corners of the adhesive layer 30, which can effectively prevent the ultrasonic fingerprint module 50 from falling off. In addition, with the same adhesive layer thickness, if the adhesive layer 30 is set as a two-layer stacked structure, the thickness of a single adhesive layer is reduced, which can avoid or minimize the formation of air bubbles in a single adhesive layer, thus facilitating the smooth transmission of ultrasonic waves.

[0060] In this embodiment, the adhesive layer 30 can be applied by coating or printing.

[0061] Furthermore, the second adhesive layer 32 can be double-sided tape; the first adhesive layer 31 can be a pure adhesive such as an acrylic adhesive layer or a pressure-sensitive adhesive layer. For example, the first adhesive layer 31 can also be a transparent paste-like room temperature curing adhesive (Primer-C adhesive layer).

[0062] Furthermore, the thickness of the first adhesive layer 32 is less than 0.1 μm, thus achieving good adhesion while preventing excessive thickness from affecting the transmission of ultrasonic waves.

[0063] Figure 4 This is a schematic diagram of another installation structure of the ultrasonic fingerprint module and the display panel in the display module provided in the embodiments of this application.

[0064] Reference Figure 4 ,and Figure 2 The display module 100 shown is different, Figure 4 Instead of a first functional layer 20, the adhesion between the ultrasonic fingerprint module 50 and the metal support layer 11 is improved by setting the adhesive layer 30 as a double-layer structure. In this solution, the ultrasonic fingerprint module 50 is bonded to the metal support layer 11 via the adhesive layer 30.

[0065] Similar to the aforementioned embodiments, the adhesive layer 30 includes a first adhesive layer 31 and a second adhesive layer 32 stacked on top of each other. The first adhesive layer 31 is attached to the metal support layer 11, and the second adhesive layer 32 is attached between the first adhesive layer 31 and the ultrasonic fingerprint module 50.

[0066] As described above, by setting the adhesive layer 30 as a two-layer stacked structure, the adhesion between the adhesive layer 30 and the metal support layer 11 can be further improved compared to setting only a single adhesive layer, especially the adhesion at the corners of the adhesive layer 30, which can effectively prevent the ultrasonic fingerprint module 50 from falling off. In addition, with the same adhesive layer thickness, if the adhesive layer 30 is set as a two-layer stacked structure, the thickness of a single adhesive layer is reduced, which can avoid or minimize the formation of air bubbles in a single adhesive layer, thus facilitating the smooth transmission of ultrasonic waves.

[0067] In this embodiment, the adhesive layer 30 can be applied by coating or printing.

[0068] Furthermore, the second adhesive layer 32 can be double-sided adhesive; the first adhesive layer 31 can be a pure adhesive such as an acrylic adhesive layer or a pressure-sensitive adhesive layer. The double-sided adhesive can include a 6μm copper layer and 3μm adhesive layers (acrylic adhesive or pressure-sensitive adhesive) respectively laminated on opposite sides of the copper layer. When the material of the first adhesive layer 31 is an acrylic adhesive layer or a pressure-sensitive adhesive layer, the thickness of the first adhesive layer 31 can be 10μm. This achieves good adhesion of the ultrasonic fingerprint module 50 while avoiding interference with the transmission of ultrasonic waves. In addition, the adhesive strength of the first adhesive layer 31 can be higher than that of the second adhesive layer 32 to further improve the adhesion between the adhesive layer 30 and the metal support layer 11.

[0069] For example, the first adhesive layer 31 can also be a transparent paste-like room temperature curing adhesive (Primer-C adhesive layer). The Primer-C adhesive layer has good adhesion to both metals and non-metals, making the bond between the metal support layer 11 and the second adhesive layer 32 more secure. When the first adhesive layer 31 is a Primer-C adhesive layer, the thickness of the first adhesive layer 31 is less than 0.1 μm, which can further reduce the thickness of the display module 100 and minimize the impact on ultrasonic wave transmission.

[0070] Figure 5a This is a schematic diagram of a test image of an ultrasonic fingerprint module in a display module of a related technology. Figure 5b This is a schematic diagram of another test image of an ultrasonic fingerprint module in a display module of a related technology; Figure 6a A schematic diagram of a test image of an ultrasonic fingerprint module in a display module provided in an embodiment of this application; Figure 6b This is a schematic diagram of another test image of the ultrasonic fingerprint module in the display module provided in the embodiments of this application.

[0071] Image tests were performed on the ultrasonic fingerprint module in the display module of related technologies and the ultrasonic fingerprint module in the embodiments of this application, and the results are as follows. Figure 5a , Figure 5b , Figure 6a , Figure 6b As shown.

[0072] exist Figure 5a , Figure 5b In the display module of the related technology, the two output images of the ultrasonic fingerprint module are image A1 and image A2, both of which are similar uneven and non-uniform black and white images.

[0073] and Figure 6a , Figure 6b In the display module 100 with the first functional layer 20, the output images of the ultrasonic fingerprint module 50 are image B1 and image B2, respectively. Images B1 and B2 are relatively uniform, without any uneven black and white areas. Therefore, in this embodiment, by bonding the ultrasonic fingerprint module 50 to the first functional layer 20 with low roughness using an adhesive layer 30, the image uniformity of the ultrasonic imaging can be improved, thus enhancing the accuracy of ultrasonic fingerprint recognition.

[0074] An embodiment of the second aspect of this application provides an electronic device including the display module 100 of any of the embodiments of the first aspect described above.

[0075] The display module 100 according to the embodiments of this application is based on the same inventive concept as the display module 100 in the first aspect embodiment described above, and has the same beneficial effects as the display module 100 in the first aspect embodiment described above, which will not be repeated here.

[0076] The electronic devices provided in this application include, but are not limited to, mobile phones, tablets, and laptops.

[0077] Mobile or fixed terminals with circuit boards, such as computers, ultra-mobile personal computers (UMPCs), handheld computers, walkie-talkies, netbooks, POS machines, personal digital assistants (PDAs), dashcams, wearable devices, or virtual reality devices.

[0078] 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.

[0079] The embodiments described above are merely examples of several implementations of the present invention, and their descriptions are relatively specific and detailed.

[0080] However, this should not be construed as a limitation on 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 inventive concept, and these all fall within the scope of protection of this invention. Therefore, the scope of protection of this invention patent should be determined by the appended claims.

Claims

1. A display module, characterized in that, include: The display panel, wherein the functional layer of the display panel opposite to the light-emitting side is constructed as a metal support layer; A first functional layer is disposed on the side of the metal support layer opposite to the light-emitting side, and the roughness of the surface of the first functional layer opposite to the light-emitting side is less than the roughness of the surface of the metal support layer opposite to the light-emitting side. An adhesive layer is attached to the first functional layer; An ultrasonic fingerprint module is located on the side of the adhesive layer opposite to the first functional layer, and is bonded to the first functional layer by means of the adhesive layer. The surface of the metal support layer opposite to the light-emitting side is provided with a groove, and the first functional layer is disposed in the groove; The surface of the first functional layer facing away from the light-emitting side is flush with the edge of the groove opening; The projection of the first functional layer onto the metal support layer covers the projection of the adhesive layer onto the metal support layer.

2. The display module according to claim 1, characterized in that, The first functional layer is made of polyimide, polyethylene terephthalate, or polycarbonate.

3. The display module according to claim 1, characterized in that, The first functional layer is attached to the metal support layer by an adhesive layer.

4. The display module according to any one of claims 1-3, characterized in that, The adhesive layer includes a first adhesive layer and a second adhesive layer stacked on top of each other. The first adhesive layer is attached to the first functional layer, and the second adhesive layer is attached between the first adhesive layer and the fingerprint module.

5. The display module according to claim 4, characterized in that, The first adhesive layer is configured as an acrylic adhesive layer or a pressure-sensitive adhesive layer; the second adhesive layer is configured as double-sided adhesive.

6. The display module according to claim 4, characterized in that, The thickness of the first adhesive layer is less than 0.1 μm.

7. An electronic device, characterized in that, The display module includes any one of claims 1-6.

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