Ultrasonic fingerprint module bonding structure, display device and electronic equipment

Abstract

The embodiment of the utility model discloses an ultrasonic fingerprint module bonding structure, a display device and electronic equipment. The thickness of the bonding structure is smaller than or equal to 15 microns, the bonding structure comprises a bonding layer, and the acoustic impedance of the bonding layer is smaller than 5 Mray. According to the invention, the effects of bonding and light blocking can be realized at the same time, the composition of the bonding structure is simplified, and the cost is reduced.

Description

Technical Field

[0001] The present application relates to the field of fingerprint recognition technology, and more specifically, to an ultrasonic fingerprint module bonding structure, a display device, and an electronic device. Background Art

[0002] When the ultrasonic fingerprint module is attached to the under-screen, there are high requirements for the bonding material. First, the bonding material cannot be a porous material, because the ultrasonic wave in the working frequency band of the ultrasonic fingerprint cannot penetrate the air. Second, the microscopic uniformity of the bonding material must be high, and the material must not have defects (generally required to be below the μm level).

[0003] In addition, since the foam layer on the screen corresponding to the position of the ultrasonic fingerprint module has been removed by opening a window, an optical layer needs to be added to ensure a good appearance. Usually, the optical layer is implemented with a layer of metal with high acoustic impedance, such as copper, aluminum, molybdenum, etc. However, in order to ensure good penetration of ultrasound, the metal layer needs to be extremely thin (μm micrometer level), which places high demands on the adhesive layer used for module bonding and is also costly. Utility Model Content

[0004] In view of the deficiencies in the prior art, the present application innovatively provides an ultrasonic fingerprint module bonding structure, a display device and an electronic device, which can solve at least some of the above technical problems.

[0005] In order to achieve the above technical objectives, the first aspect of the present application discloses an ultrasonic fingerprint module bonding structure, wherein the thickness of the bonding structure is less than or equal to 15 μm, and the bonding structure comprises a bonding layer,

[0006] The acoustic impedance of the adhesive layer is less than 5 Mrayl.

[0007] Furthermore, the adhesive layer includes a first layer and a second layer, and the adhesive structure further includes a substrate layer, and the substrate layer is disposed between the first layer and the second layer.

[0008] The acoustic impedance of the substrate layer is less than 5 Mrayl.

[0009] Furthermore, light absorbing material is mixed in the adhesive layer.

[0010] The second aspect of the present application discloses a display device, comprising a display module and a fingerprint recognition module, wherein the fingerprint recognition module is attached to the display module via an adhesive structure, wherein the thickness of the adhesive structure is less than or equal to 15 μm,

[0011] The bonding structure includes a bonding layer, the area of ​​the bonding layer is greater than or equal to the fingerprint recognition module, and the acoustic impedance of the bonding layer is less than 5 Mrayl.

[0012] Furthermore, the bonding layer includes a first layer and a second layer, the bonding structure further includes a substrate layer, the substrate layer is arranged between the first layer and the second layer, the first layer is bonded to the display module, and the second layer is bonded to the fingerprint recognition module.

[0013] The acoustic impedance of the substrate layer is less than 5 Mrayl.

[0014] Furthermore, light absorbing material is mixed in the adhesive layer.

[0015] Furthermore, the display module includes a screen, a copper foil layer is provided on the screen, and the copper foil layer is adhered to the screen by adhesive.

[0016] Windows are opened on the copper foil layer and the adhesive, and the fingerprint recognition module is arranged in the window and adhered to the screen through the adhesive structure.

[0017] Furthermore, the display module comprises a screen, and the screen is provided with a first layer, a substrate layer and a copper foil layer.

[0018] A window is opened on the copper foil layer, and the fingerprint recognition module is arranged in the window and is bonded to the base material layer of the screen through the second layer.

[0019] Furthermore, the display module includes a screen, the screen is a folding screen, a reinforcement layer is provided on the screen, and the bonding structure is bonded to the reinforcement layer.

[0020] Furthermore, a flat layer is provided on the reinforcing layer, and the bonding structure is bonded to the flat layer.

[0021] Furthermore, the fingerprint recognition module further includes: an ultrasonic fingerprint recognition chip.

[0022] A third aspect of the present application discloses an electronic device, comprising the above-mentioned display device.

[0023] The fourth aspect of the present application discloses an electronic device, including a cover plate and a fingerprint recognition module, wherein the fingerprint recognition module is adhered to the cover plate by the above-mentioned ultrasonic fingerprint module bonding structure.

[0024] Furthermore, a flat layer is provided on the cover plate, and the ultrasonic fingerprint module bonding structure is bonded to the flat layer.

[0025] The beneficial effects of this application are:

[0026] The present application adopts a low acoustic impedance bonding structure with a thickness of less than 15 μm and an acoustic impedance of less than 5 Mrayl, so that it does not need to set a metal layer to ensure good ultrasonic fingerprint performance, simplifies the composition of the bonding structure and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A structural schematic diagram showing an ultrasonic fingerprint module bonding structure according to an embodiment of the present application;

[0028] Figure 2 A structural schematic diagram showing an ultrasonic fingerprint module bonding structure according to an embodiment of the present application;

[0029] Figure 3 A partial cross-sectional schematic diagram of a display device according to an embodiment of the present application is shown;

[0030] Figure 4 A partial cross-sectional schematic diagram of a display device according to an embodiment of the present application is shown;

[0031] Figure 5 A partial cross-sectional schematic diagram of a display device according to an embodiment of the present application is shown;

[0032] Figure 6 A partial cross-sectional schematic diagram of a display device according to an embodiment of the present application is shown;

[0033] Figure 7 A partial cross-sectional schematic diagram of a display device according to an embodiment of the present application is shown;

[0034] Figure 8 A partial cross-sectional schematic diagram of a display device according to an embodiment of the present application is shown;

[0035] Fig. 9 A partial cross-sectional schematic diagram of a display device according to an embodiment of the present application is shown;

[0036] Fig.10 A partial cross-sectional schematic diagram of a display device according to an embodiment of the present application is shown;

[0037] Fig.11 A partial cross-sectional schematic diagram of a display device according to an embodiment of the present application is shown;

[0038] Fig.12 A partial cross-sectional schematic diagram of a display device according to an embodiment of the present application is shown;

[0039] Fig.13 A partial cross-sectional schematic diagram of a display device according to an embodiment of the present application is shown;

[0040] Fig.14 A comparison chart of the performance simulation of an OLED screen using the bonding structure of the present application and using copper foil adhesive is shown;

[0041] Fig.15 The graph shows the measured results of the performance of OLED screens using the bonding structure of the present application and using copper foil adhesive.

[0042] In the figure,

[0043] 1. Adhesive layer; 11. First layer; 12. Second layer; 13. Base material layer; 2. Screen; 21. Adhesive; 22. Copper foil layer; 2', Folding screen body; 23. Reinforcement layer; 24. Flat layer; 3. Fingerprint recognition module; 4. Cover plate. DETAILED DESCRIPTION

[0044] The ultrasonic fingerprint module and electronic device provided by the present application are explained and illustrated in detail below in conjunction with the drawings in the specification.

[0045] According to the first aspect of the present application, an ultrasonic fingerprint module bonding structure is provided. In some embodiments, the total thickness of the ultrasonic fingerprint module bonding structure is less than or equal to 15 μm, and the material of each part of the bonding structure is a material with low acoustic impedance, and the acoustic impedance is less than 5 Mrayl. Figure 1 As shown, the bonding structure at least includes a bonding layer 1, and the bonding layer 1 includes but is not limited to a pressure-sensitive adhesive or a thermosetting epoxy resin, and its acoustic impedance is less than 5 Mrayl. In this embodiment, a bonding structure with a small thickness and low acoustic impedance is adopted, so that the ultrasonic fingerprint performance of the bonding structure can be close to that of the bonding structure with a metal layer, which simplifies the composition of the bonding structure and reduces the cost.

[0046] In some embodiments, Figure 2 As shown, the bonding structure further includes a substrate layer 13, the bonding layer 1 includes a first layer 11 and a second layer 12, the substrate layer 13 is disposed between the first layer 11 and the second layer 12, the substrate layer 13 can provide support for the bonding layer 1, making it easier to control the overall thickness of the bonding structure, and prevent glue overflow. Optionally, the substrate layer 13 is a low-impedance polymer material with an acoustic impedance of less than 5 Mrayl, including PET (Polyethylene terephthalate), PE (polyethylene), PI (Polyimide), etc.

[0047] Optionally, a light absorbing material may be mixed in the adhesive layer 1 to improve the light blocking effect, and the light absorbing material includes but is not limited to carbon powder, black ink, etc. Further, a light absorbing material may be mixed in the first layer 11 or the second layer 12, or both of the first layer 11 and the second layer 12.

[0048] According to a second aspect of the present application, a display device is provided, such as Figure 3 , Figure 4As shown, it includes a display module and a fingerprint recognition module 3. Optionally, the fingerprint recognition module 3 includes an ultrasonic fingerprint recognition chip, and the fingerprint recognition module 3 is attached to the display module through an adhesive structure. The adhesive structure includes an adhesive layer 1, the area of ​​the adhesive layer 1 is greater than or equal to the fingerprint recognition module 3, the adhesive layer 1 includes a pressure-sensitive adhesive or epoxy resin, etc., the thickness of the adhesive layer 1 is less than or equal to 15μm, and the acoustic impedance of the adhesive layer 1 is less than 5Mrayl. The adhesive structure is the same structure as the above-mentioned ultrasonic fingerprint module adhesive structure, and the specific composition and parameters are the same, which will not be described in detail here.

[0049] In some embodiments, the display module includes a screen 2, and the screen 2 is optionally an OLED (Organic Light-Emitting Diode) screen. A copper foil layer 22 is provided on the lower side of the screen 2, and the copper foil layer 22 is bonded to the screen 2 by an adhesive 21. Optionally, the adhesive 21 is a double-sided foam adhesive. In the area corresponding to the fingerprint recognition area, a window is opened on the copper foil layer 22 and the adhesive 21 to expose the screen 2, and the fingerprint recognition module 3 is bonded to the screen 2 by an adhesive structure. Optionally, the adhesive structure can be provided with only an adhesive layer 1, or an adhesive layer 1 and a substrate layer 13 can be provided at the same time.

[0050] In some embodiments, the bonding structure includes a bonding layer 1 and a substrate layer 13. The bonding layer 1 includes a first layer 11 and a second layer 12. The substrate layer 13 is disposed between the first layer 11 and the second layer 12. The first layer 11 is bonded to the screen 2, and the second layer 12 is bonded to the fingerprint recognition module 3. The substrate layer 13 can provide support for the bonding layer 1, making it easier to control the overall thickness of the bonding structure and prevent glue overflow. Figure 5 As shown, the area of ​​the first layer 11 and the substrate layer 13 is the same as that of the screen 2, the first layer 11 and the substrate layer 13 are integrated with the screen 2, the copper foil layer 22 is bonded to the substrate layer 13 by the adhesive 21, a window is opened on the copper foil layer 22 corresponding to the position of the fingerprint recognition module 3, and the fingerprint recognition module 3 is bonded to the substrate layer 13 by the second layer 12. In another embodiment, the first layer 11, the substrate layer 13 and the copper foil layer 22 are the laminated structure of the screen 2 itself, and the fingerprint recognition module 3 is directly bonded to the substrate layer 13 of the screen 2 by opening a window in the copper foil layer 22 and by the second layer 12. This solution further reduces the thickness of the ultrasonic fingerprint 3 attached to the screen and simplifies the structure of the attached screen.

[0051] In some embodiments, the display module includes a folding screen, such as Figure 6 , Figure 8 As shown, the folding screen includes a folding screen body 2' and a reinforcement layer 23 arranged on the lower side of the folding screen body 2', and the fingerprint recognition module 3 is bonded to the reinforcement layer 23 through an adhesive structure. Optionally, the reinforcement layer 23 generally has a relatively large roughness, such as Figure 7 , Fig. 9As shown, before attaching the fingerprint recognition module 3, a flat layer 24 is first coated on the reinforcement layer 23, and then the adhesive structure is bonded to the area coated with the flat layer 24. The typical material of the flat layer 24 is Primer glue.

[0052] According to a third aspect of the present application, an electronic device is provided, comprising the above-mentioned display device. In some embodiments, the electronic device comprises a smart phone, a tablet computer, etc.

[0053] In some embodiments, the electronic device includes a smart door lock, an attendance machine, etc., including a cover plate, and the fingerprint recognition module 3 is arranged on the cover plate 4, and the cover plate 4 is made of glass, plastic or metal. Fig.10 , Fig.12 As shown, the fingerprint recognition module 3 is bonded to the cover plate 4 through a bonding structure. The bonding structure may include only the bonding layer 1 or the bonding layer 1 and the substrate layer 13. The first layer 11 of the bonding layer 1 is bonded to the cover plate 4, and the second layer 12 is bonded to the fingerprint recognition module 3. The roughness of the cover plate 4 is generally large, such as Fig.11 , Fig.13 As shown, before bonding the fingerprint recognition module 3 , a flat layer 24 can be coated on the corresponding area of ​​the cover plate 4 , and the bonding structure is bonded to the flat layer 24 , and Primer glue can be used for the flat layer 24 .

[0054] The adhesive structures of the present application with three different thicknesses of 5 μm, 10 μm and 15 μm were respectively selected and set on the OLED screen, and the performance was compared with the OLED screen using copper foil adhesive in the prior art. Fig.14 , Fig.15 As shown, the performance of the adhesive structure of the present application is related to the thickness. When the thickness is larger, the performance is worse than that of the copper foil adhesive. When the thickness is smaller, the performance gap with the copper foil adhesive is smaller, that is, the smaller the thickness, the better the performance. Fig.15 As shown, when the thickness of the bonding structure of the present application reaches 15 μm, the high-frequency lines have become obviously blurred, so it is recommended that the thickness does not exceed 15 μm.

[0055] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0056] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0057] In the description of this specification, the description with reference to the terms "this embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any at least one embodiment or example. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0058] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0059] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and simple improvements made to the essential contents of the present application shall be included in the protection scope of the present application.

Claims

1. An ultrasonic fingerprint module bonding structure, characterized in that: The thickness of the bonding structure is less than or equal to 15 μm. The bonding structure comprises a bonding layer (1), wherein the bonding layer (1) comprises a first layer (11) and a second layer (12). The bonding structure further comprises a substrate layer (13), wherein the substrate layer (13) is arranged between the first layer (11) and the second layer (12). The acoustic impedance of the adhesive layer (1) and the substrate layer (13) are both less than 5 Mrayl.

2. A display device, characterized in that: It comprises a display module and a fingerprint recognition module (3), wherein the fingerprint recognition module (3) is adhered to the display module via an adhesive structure, and the thickness of the adhesive structure is less than or equal to 15 μm. The bonding structure comprises a bonding layer (1), the area of ​​the bonding layer (1) being greater than or equal to the area of ​​the fingerprint recognition module (3), The bonding layer (1) comprises a first layer (11) and a second layer (12), the bonding structure further comprises a substrate layer (13), the substrate layer (13) is arranged between the first layer (11) and the second layer (12), the first layer (11) is bonded to the display module, and the second layer (12) is bonded to the fingerprint recognition module (3), The acoustic impedance of the adhesive layer (1) and the substrate layer (13) are both less than 5 Mrayl.

3. A display device according to claim 2, characterized in that: The display module comprises a screen (2), a copper foil layer (22) is provided on the screen (2), and the copper foil layer (22) is adhered to the screen (2) by means of adhesive (21). A window is formed on the copper foil layer (22) and the adhesive (21); the fingerprint recognition module (3) is arranged in the window and adhered to the screen (2) via the adhesive structure.

4. A display device according to claim 2, characterized in that: The display module comprises a screen (2), on which a first layer (11), a substrate layer (13) and a copper foil layer (22) are arranged. A window is opened on the copper foil layer (22); the fingerprint identification module (3) is arranged in the window and is bonded to the base material layer (13) of the screen (2) through the second layer (12).

5. A display device according to claim 2, characterized in that: The display module comprises a folding screen body (2'), a reinforcing layer (23) is arranged on the folding screen body (2'), and the bonding structure is bonded to the reinforcing layer (23).

6. A display device according to claim 5, characterized in that: A flat layer (24) is provided on the reinforcing layer (23), and the bonding structure is bonded to the flat layer (24).

7. A display device according to claim 2, characterized in that: The fingerprint recognition module (3) further comprises: an ultrasonic fingerprint recognition chip.

8. An electronic device, characterized in that: A display device comprising any one of claims 2 to 7.

9. An electronic device, characterized in that: It comprises a cover plate (4) and a fingerprint recognition module (3), wherein the fingerprint recognition module (3) is adhered to the cover plate (4) by means of the ultrasonic fingerprint module bonding structure according to claim 1.

10. An electronic device according to claim 9, characterized in that: A flat layer (24) is provided on the cover plate (4), and the ultrasonic fingerprint module bonding structure is bonded to the flat layer (24).

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