Under-screen ultrasonic module, bonding structure and electronic device

Abstract

This application provides an under-display ultrasonic module, an adhesive structure, and an electronic device. The under-display ultrasonic module includes an under-display ultrasonic sensor and an adhesive structure. The adhesive structure includes a first adhesive layer, a support layer, and a second adhesive layer, located on opposite sides of the support layer in its thickness direction. The second adhesive layer is bonded to the under-display ultrasonic sensor, and the first adhesive layer is used to bond to the screen, including a glass cover, so that the under-display ultrasonic sensor can be bonded to the underside of the screen via the adhesive structure. The acoustic impedance of the support layer is greater than the acoustic impedance of the first and second adhesive layers, and the total thickness of the adhesive structure ranges from 19µm to 29µm. The technical solution of this application specifically improves the performance and effectiveness of the under-display ultrasonic module in glass cover screens, enabling the large-scale application of under-display ultrasonic detection in electronic devices with glass cover screens.

Description

Technical Field

[0001] This application relates to the field of ultrasonic technology, and in particular to an under-screen ultrasonic module, an adhesive structure, and an electronic device. Background Technology

[0002] Currently, ultrasonic technology is being increasingly applied, for example, through under-display ultrasonic modules for biometric detection. These modules are typically bonded to the underside of the screen. Some types of screens may include a glass cover for protection. Therefore, providing a novel under-display ultrasonic module solution to meet the ultrasonic signal transmission requirements of screens with glass covers (also known as glass cover screens) has become a technical problem that needs to be solved. Utility Model Content

[0003] This application provides an under-screen ultrasonic module, an adhesive structure, and an electronic device.

[0004] According to a first aspect of the embodiments of this application, an under-display ultrasonic module is provided. The under-display ultrasonic module includes: an under-display ultrasonic sensor and an adhesive structure; the adhesive structure includes a first adhesive layer, a support layer, and a second adhesive layer, the first adhesive layer and the second adhesive layer being located on opposite sides of the support layer in the thickness direction, wherein the second adhesive layer is bonded to the under-display ultrasonic sensor, and the first adhesive layer is used to bond to a screen including a glass cover, so that the under-display ultrasonic sensor can be bonded to the underside of the screen through the adhesive structure; wherein the acoustic impedance of the support layer is greater than the acoustic impedance of the first adhesive layer and the acoustic impedance of the second adhesive layer, and the total thickness of the adhesive structure ranges from 19µm to 29µm.

[0005] In some optional embodiments, the adhesive structure satisfies at least one of the following conditions:

[0006] The thickness of the first adhesive layer ranges from 3µm to 10µm;

[0007] The thickness of the support layer ranges from 9µm to 15µm;

[0008] The thickness of the second adhesive layer ranges from 3µm to 10µm.

[0009] In some optional embodiments, the adhesive structure satisfies at least one of the following conditions:

[0010] The thickness of the first adhesive layer ranges from 4µm to 8µm;

[0011] The thickness of the support layer ranges from 9µm to 15µm;

[0012] The thickness of the second adhesive layer ranges from 4µm to 8µm.

[0013] In some optional embodiments, the total thickness of the screen ranges from 550µm to 1000µm, and the thickness of the glass cover ranges from 370µm to 500µm.

[0014] In some optional embodiments, the under-screen ultrasonic module satisfies at least one of the following conditions:

[0015] The first adhesive layer includes one of a PSA adhesive layer, an OCA adhesive layer, and a PMMA adhesive layer, or the first adhesive layer is a multilayer adhesive layer in which at least two of the PSA adhesive layer, OCA adhesive layer, and PMMA adhesive layer are stacked.

[0016] The second adhesive layer includes one of a PSA adhesive layer, an OCA adhesive layer, and a PMMA adhesive layer, or the second adhesive layer is a multilayer adhesive layer in which at least two of the PSA adhesive layer, OCA adhesive layer, and PMMA adhesive layer are stacked.

[0017] The thickness of the first adhesive layer is equal to the thickness of the second adhesive layer;

[0018] The first adhesive layer includes black filler particles;

[0019] The support layer is a metal layer;

[0020] The under-display ultrasonic sensor is an under-display ultrasonic fingerprint sensor, and the under-display ultrasonic module is an under-display ultrasonic fingerprint module.

[0021] In some alternative embodiments, the support layer is a copper foil layer.

[0022] In some optional embodiments, the under-display ultrasonic sensor includes: a substrate, a first electrode, an acoustic layer, and a second electrode;

[0023] The first electrode is located on the substrate, and the acoustic layer is located between the first electrode and the second electrode;

[0024] The second electrode is used to be excited by an excitation signal to induce the acoustic layer to emit ultrasonic signals;

[0025] The first electrode is used to receive the ultrasonic detection signal generated between the second electrode and the first electrode when the returned ultrasonic signal acts on the acoustic layer.

[0026] In some alternative embodiments, the under-display ultrasonic sensor further includes a protective layer that covers at least a portion of the second electrode.

[0027] In some alternative embodiments, the second adhesive layer is bonded to the substrate, or the second adhesive layer is bonded to the protective layer.

[0028] According to a second aspect of the embodiments of this application, an under-display ultrasonic module is provided. The under-display ultrasonic module includes: an under-display ultrasonic sensor and an adhesive structure; the adhesive structure includes a first adhesive layer, a support layer, and a second adhesive layer, the first adhesive layer and the second adhesive layer being located on opposite sides of the support layer in the thickness direction, wherein the second adhesive layer is bonded to the under-display ultrasonic sensor, and the first adhesive layer is used to bond to a screen including a glass cover, so that the under-display ultrasonic sensor can be bonded to the underside of the screen through the adhesive structure; wherein the acoustic impedance of the support layer is greater than the acoustic impedance of the first adhesive layer and the acoustic impedance of the second adhesive layer, the thickness of the first adhesive layer is in the range of 3µm to 10µm, the thickness of the support layer is in the range of 9µm to 15µm, and the thickness of the second adhesive layer is in the range of 3µm to 10µm.

[0029] According to a third aspect of the embodiments of this application, an adhesive structure is provided. The adhesive structure is used to adhere an under-display ultrasonic sensor to the underside of a screen including a glass cover. The adhesive structure includes: a first adhesive layer, a support layer, and a second adhesive layer. The first adhesive layer and the second adhesive layer are respectively located on opposite sides of the support layer in the thickness direction. The second adhesive layer is used to adhere to the under-display ultrasonic sensor, and the first adhesive layer is used to adhere to the screen. The acoustic impedance of the support layer is greater than the acoustic impedance of both the first and second adhesive layers. The total thickness of the adhesive structure ranges from 19 μm to 29 μm.

[0030] According to a fourth aspect of the embodiments of this application, an adhesive structure is provided. The adhesive structure is used to adhere an under-display ultrasonic sensor to the underside of a screen including a glass cover. The adhesive structure includes: a first adhesive layer, a support layer, and a second adhesive layer. The first adhesive layer and the second adhesive layer are respectively located on opposite sides of the support layer in the thickness direction. The second adhesive layer is used to adhere to the under-display ultrasonic sensor, and the first adhesive layer is used to adhere to the screen. The acoustic impedance of the support layer is greater than the acoustic impedance of both the first and second adhesive layers. The thickness of the first adhesive layer ranges from 3µm to 10µm, the thickness of the support layer ranges from 9µm to 15µm, and the thickness of the second adhesive layer ranges from 3µm to 10µm.

[0031] According to a fifth aspect of the embodiments of this application, an electronic device is provided. The electronic device includes a screen, including a glass cover; and an under-screen ultrasonic module as described in any one of the first and second aspects; wherein a first adhesive layer of the under-screen ultrasonic module is bonded to the screen, such that the under-screen ultrasonic module is bonded beneath the screen.

[0032] The under-display ultrasonic module in this embodiment includes an under-display ultrasonic sensor and an adhesive structure with a total thickness ranging from 19µm to 29µm. The adhesive structure comprises a first adhesive layer, a support layer, and a second adhesive layer. The acoustic impedance of the support layer is greater than that of the first and second adhesive layers. The first and second adhesive layers are located on opposite sides of the support layer in its thickness direction. The second adhesive layer is bonded to the under-display ultrasonic sensor, and the first adhesive layer is used to bond to the screen, including the glass cover. This allows the under-display ultrasonic sensor to be bonded to the underside of the screen via the adhesive structure. The thickness of the bonding structure of the under-display ultrasonic module, as well as the difference in acoustic impedance between the support layer and the first and second adhesive layers, can better adapt to the ultrasonic signal transmission requirements of screens including glass covers (also known as glass cover screens). This facilitates acoustic impedance matching between the under-display ultrasonic module and the glass cover screen, reduces ultrasonic signal transmission loss, and thus effectively improves the performance and effectiveness of the under-display ultrasonic module in glass cover screens. It also improves the reliability and performance of under-display ultrasonic testing, making it possible to apply under-display ultrasonic testing on a large scale in electronic devices with glass cover screens. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0034] Figure 1A A schematic diagram of an example under-screen ultrasonic module of this application is shown.

[0035] Figure 1B A schematic diagram of another example of an under-display ultrasonic module in this application is shown.

[0036] Figure 2 A schematic diagram of an example screen's stacked structure is shown.

[0037] Figure 3 A schematic diagram of a multi-media stack is shown.

[0038] Figure 4The equivalent acoustic impedance curve and ultrasonic transmission coefficient curve are shown for a screen including a glass cover with an example thickness.

[0039] Figure 5 The equivalent acoustic impedance curve and ultrasonic transmission coefficient curve are shown for a screen with a glass cover of another example thickness.

[0040] Figure 6 The equivalent acoustic impedance curve and ultrasonic transmission coefficient curve are shown for a screen with a glass cover of another example thickness.

[0041] Figure 7 A schematic diagram of an example adhesive structure of this application is shown.

[0042] Figure 8A A schematic diagram of an example electronic device according to this application is shown.

[0043] Figure 8B A schematic diagram of another example of an electronic device in this application is shown.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1000, Under-display ultrasonic module; 100, Adhesive structure; 110, First adhesive layer; 120, Second adhesive layer; 130, Support layer; 200, Under-display ultrasonic sensor; 210, Substrate; 211, First electrode; 212, Second electrode; 213, Acoustic layer; 214, Protective layer; 300, Screen; 310, Glass cover; 320, Screen body; 3201, BP optical film layer; 3202, First adhesive layer; 3203, Panel layer; 3204, Second adhesive layer; 3205, POL layer; 3206, Third adhesive layer; 400, Electronic device; H1, Thickness of the first adhesive layer; H2, Thickness of the second adhesive layer; H3, Thickness of the support layer; H4, Thickness of the glass cover; Ha, Total thickness of the adhesive structure; Hb, Total thickness of the screen. Detailed Implementation

[0046] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0047] According to a first aspect of the embodiments of this application, referring to... Figure 1A and Figure 1BAs shown, this application provides an under-display ultrasonic module 1000, which includes: an under-display ultrasonic sensor 200 and an adhesive structure 100; the adhesive structure 100 includes a first adhesive layer 110, a support layer 130 and a second adhesive layer 120, the first adhesive layer 110 and the second adhesive layer 120 are respectively located on both sides of the support layer 130 in the thickness direction, wherein the second adhesive layer 120 is bonded to the under-display ultrasonic sensor 200, and the first adhesive layer 110 is used to bond to the screen 300 including a glass cover plate 310, so that the under-display ultrasonic sensor 200 can be bonded to the underside of the screen 300 through the adhesive structure 100; wherein the acoustic impedance of the support layer 130 is greater than the acoustic impedance of the first adhesive layer 110 and the acoustic impedance of the second adhesive layer 120, and the total thickness of the adhesive structure 100 ranges from 19um to 29um.

[0048] Based on this, the under-display ultrasonic module 1000 in this embodiment includes an under-display ultrasonic sensor 200 and an adhesive structure 100 with a total thickness ranging from 19µm to 29µm. The adhesive structure 100 includes a first adhesive layer 110, a support layer 130, and a second adhesive layer 120. The acoustic impedance of the support layer 130 is greater than that of the first adhesive layer 110 and the second adhesive layer 120. The first adhesive layer 110 and the second adhesive layer 120 are located on opposite sides of the support layer 130 in the thickness direction. The second adhesive layer 120 is bonded to the under-display ultrasonic sensor 200. The first adhesive layer 110 is used to bond to the screen 300 including the glass cover plate 310, so that the under-display ultrasonic sensor 200 can pass through the adhesive structure 100. Adhesive to the underside of the screen 300, the under-screen ultrasonic module 1000 in this embodiment of the application, through the thickness of the adhesive structure 100 and the difference in acoustic impedance between the support layer 130 and the first adhesive layer 110 and the second adhesive layer 120, can better adapt to the ultrasonic signal transmission requirements of the screen 300 (also known as the glass cover screen), including the glass cover plate 310. This facilitates acoustic impedance matching between the under-screen ultrasonic module 1000 and the glass cover screen, reduces ultrasonic signal transmission loss, and thus effectively improves the usage effect and performance of the under-screen ultrasonic module 1000 in the glass cover screen, improves the reliability and performance of under-screen ultrasonic detection, and realizes the possibility of large-scale application of under-screen ultrasonic detection in electronic devices with glass cover screens.

[0049] The following provides a detailed description of some optional embodiments of the under-screen ultrasonic module 1000 in this application.

[0050] Optionally, the under-display ultrasonic module 1000 can perform under-display ultrasonic detection, specifically, it can perform ultrasonic biometric detection above the screen 300. The under-display ultrasonic sensor 200 in this application can be any type of ultrasonic sensor, and correspondingly, the under-display ultrasonic module 1000 can be any type of ultrasonic module. For example, in some embodiments, the under-display ultrasonic sensor 200 can be an under-display ultrasonic fingerprint sensor, and the under-display ultrasonic module 1000 can be an under-display ultrasonic fingerprint module, whose detected biometric features may include fingerprint features.

[0051] Therefore, under-display ultrasonic fingerprint detection can be achieved through the under-display ultrasonic module 1000 in this embodiment. Since the under-display ultrasonic module 1000 can better adapt to the ultrasonic signal transmission requirements of the screen including the glass cover (also known as the glass cover screen), and is conducive to achieving acoustic impedance matching between the under-display ultrasonic module and the glass cover screen, reducing the transmission loss of ultrasonic signals, the under-display ultrasonic module 1000 has good stacking performance when used in the glass cover screen, and the under-display ultrasonic module has good performance and effect in the glass cover screen. Therefore, the accuracy and reliability of under-display ultrasonic fingerprint detection are also good.

[0052] In other embodiments, the under-display ultrasonic sensor 200 may also be an under-display ultrasonic touch sensor or other types of sensors for detecting touch. Correspondingly, the under-display ultrasonic module 1000 may be an under-display ultrasonic touch detection module for detecting touch.

[0053] The following text uses the under-display ultrasonic sensor 200 as an example to illustrate the under-display ultrasonic fingerprint sensor.

[0054] The screen 300 in this application embodiment can be any screen with a glass cover. For example, in some optional embodiments, the screen 300 can be, but is not limited to, an OLED (Organic Light-Emitting Diode) screen, an LED (Light-Emitting Diode) screen, etc.

[0055] In this embodiment, the under-display ultrasonic sensor 200 can adopt any structure. For example, in some optional embodiments, refer to... Figure 1A , Figure 1BAs shown, the under-display ultrasonic sensor 200 includes: a substrate 210, a first electrode 211, an acoustic layer 213, and a second electrode 212. The first electrode 211 is located on the substrate 210, and the acoustic layer 213 is located between the first electrode 211 and the second electrode 212. The second electrode 212 is used to be excited by an excitation signal to induce the acoustic layer 213 to emit ultrasonic signals. The first electrode 211 is used to receive the ultrasonic detection signal generated between the second electrode 212 and the first electrode 211 when the returned ultrasonic signal acts on the acoustic layer 213.

[0056] Based on this, the structure of the optional under-display ultrasonic sensor 200 in this application enables the under-display ultrasonic module 1000 to effectively realize the function of under-display ultrasonic feature detection when it is attached to the underside of the screen 300 (glass cover screen).

[0057] Optionally, the substrate 210 can be used to deploy part of the circuit structure of the under-display ultrasonic sensor 200. Optionally, the substrate 210 can be a silicon substrate, a glass substrate, a PET (Polyethylene Terephthalate) layer, or a PI (Polyimide) layer, etc.

[0058] Optionally, one of the first electrode 211 and the second electrode 212 can be a bottom electrode and the other a top electrode. For example, the first electrode 211 can be a bottom electrode and the second electrode 212 can be a top electrode. The first electrode 211 and the second electrode 212 can be made of any material, such as metal, without limitation. For example, the first electrode 211 can be an aluminum electrode or a copper electrode (but is not limited to these), and can include multiple sub-electrodes arranged in an array on the substrate 210, each sub-electrode being considered as a "pixel". For example, the second electrode 212 can be a silver electrode.

[0059] Optionally, the acoustic layer 213 may be a piezoelectric material layer, which generates ultrasonic signal transmission and reception based on the piezoelectric effect (the piezoelectric material layer may include, but is not limited to, at least one of PVDF (polyvinylidene difluoride), lead zirconate titanate, and lithium niobate; the PVDF material may include PVDF, PVDF copolymer, etc.).

[0060] Optionally, the excitation signal applied to the second electrode 212 can be a pulse excitation signal, such as a pulse voltage signal. The excitation signal can be input from an external circuit. By applying the excitation signal to the second electrode 212, an electric field is formed between the second electrode 212 and the first electrode 211, thereby exciting the acoustic layer 213 to emit ultrasonic signals upwards towards the screen 300. The first electrode 211 can receive the ultrasonic detection signal generated between the second electrode 212 and the first electrode 211 when the returned ultrasonic signal acts on the acoustic layer 213. The ultrasonic detection signal can be an electrical signal generated by the returned ultrasonic signal acting on the acoustic layer 213. Optionally, the ultrasonic detection signal received by the first electrode 211 can be used to realize ultrasonic biometric detection (such as ultrasonic fingerprint detection). Optionally, the ultrasonic detection signal can be used to generate an ultrasonic image, and ultrasonic biometric detection can be realized based on the ultrasonic image. For example, taking ultrasonic fingerprint detection as an example, the ultrasonic detection signal can be used to generate an ultrasonic fingerprint image, and fingerprint detection can be performed based on the ultrasonic fingerprint image.

[0061] Optionally, the process of generating an ultrasonic fingerprint image and performing fingerprint detection based on the ultrasonic fingerprint image described above can be implemented by a controller in an electronic device installed in the under-display ultrasonic module 1000 (which can be electrically connected to the under-display ultrasonic sensor 200 of the under-display ultrasonic module 1000); or, in other optional embodiments, the process of generating an ultrasonic fingerprint image can also be implemented by a processing unit in the under-display ultrasonic module 1000, which sends the generated ultrasonic fingerprint image to the controller in the electronic device, and the controller then performs fingerprint detection based on the ultrasonic fingerprint image.

[0062] In some alternative embodiments, refer to Figure 1A , Figure 1B As shown, the under-display ultrasonic sensor 200 may further include a protective layer 214 that covers at least a portion of the second electrode 212. Thus, the protective layer 214 can protect at least a portion of the second electrode 212, for example, preventing water and oxygen corrosion and other adverse environmental factors, thereby improving the lifespan of the under-display ultrasonic sensor 200.

[0063] Optionally, the protective layer 214 can protect the second electrode 212, the acoustic layer 213, and the first electrode 211 to better protect the under-screen ultrasonic sensor 200, avoid water and oxygen corrosion and other adverse environmental factors, and improve the lifespan of the under-screen ultrasonic sensor 200.

[0064] Optionally, the protective layer 214 can be an insulating layer, made of any material. For example, it can be a protective layer made of inorganic insulating materials such as silicon oxide and silicon nitride, or it can be a protective layer made of organic insulating materials such as polyimide and epoxy resin. In some embodiments, the protective layer 214 can be an ink layer. The choice can be made according to actual needs, and no specific limitations are imposed here.

[0065] It should be understood that the principle and optional structure of the under-display ultrasonic sensor 200 (such as an under-display ultrasonic fingerprint sensor) can also be understood according to relevant technologies, and will not be elaborated here. This solution can be implemented using an under-display ultrasonic sensor of any structure.

[0066] In this embodiment, the under-display ultrasonic sensor 200 is bonded to the second adhesive layer 120 of the adhesive structure 100, and the first adhesive layer 110 of the adhesive structure 100 can be bonded to the lower surface of the screen 300 (glass cover screen). Figure 1A , Figure 1B As shown, the lower surface of the screen 300 can be formed by its screen body 320, so that when the under-screen ultrasonic module 1000 is used, it can be adhered to the underside of the screen 300.

[0067] The adhesive structure 100 in this embodiment can be used to fix the under-screen ultrasonic module 1000 and the screen 300, and can also serve as an acoustic impedance matching layer to achieve better ultrasonic energy transmission.

[0068] Optionally, when the under-display ultrasonic module 1000 is bonded to the lower surface of the screen 300 (glass cover screen) and bonded below the screen 300, the bonding structure 100 can serve as an acoustic impedance matching layer between the under-display ultrasonic sensor 200 and the screen 300 (including the glass cover 310). Therefore, its structure is very important. In this embodiment, the lamination performance of the bonding structure 100 is improved by optimizing the thickness of each layer.

[0069] In some alternative embodiments, refer to Figure 1A As shown, the second adhesive layer 120 of the adhesive structure 100 can be bonded to the substrate 210 of the under-display ultrasonic sensor 200. This bonding method, forming such an optional structure, can also be called "back bonding". Optionally, as... Figure 1A As shown, during back bonding, the first electrode 211 can be located on the surface of the substrate 210 away from the bonding structure 100.

[0070] Alternatively, in some other alternative embodiments, refer to Figure 1B As shown, the second adhesive layer 120 of the adhesive structure 100 can be bonded to the protective layer 214 of the under-display ultrasonic sensor 200. This bonding method, forming such an optional structure, can also be called "positive bonding". Optionally, as... Figure 1B As shown, when the substrate is properly bonded, the first electrode 211 can be located on the surface of the substrate 210 near the bonding structure 100.

[0071] It should be understood that the above-mentioned "back-mounted" or "front-mounted" structures can both meet the under-screen bonding requirements of the under-screen ultrasonic sensor 200, and neither will affect the normal use of the under-screen ultrasonic module 1000, effectively ensuring the detection reliability of the under-screen ultrasonic module 1000.

[0072] In this embodiment, the first adhesive layer 110 and the second adhesive layer 120 of the adhesive structure 100 achieve double-sided bonding, and the support layer 130 can provide a certain support for the first adhesive layer 110 and the second adhesive layer 120, thereby improving the structural stability and bonding stability of the adhesive structure 100.

[0073] In this embodiment, the acoustic impedance of the support layer 130 is greater than that of the first adhesive layer 110 and the second adhesive layer 120. The use of a support layer 130 with a higher acoustic impedance than the first adhesive layer 110 and the second adhesive layer 120 in this embodiment facilitates better acoustic impedance matching between the under-display ultrasonic module 1000 and the screen 300 including the glass cover plate 310. This helps reduce the transmission loss of ultrasonic signals, thus more effectively improving the performance and usability of the under-display ultrasonic module 1000 in the glass cover screen, and enhancing the reliability and performance of under-display ultrasonic detection.

[0074] It is understood that the specific acoustic impedance of the first adhesive layer 110, the second adhesive layer 120, and the support layer 130 can be selected as needed, and there is no unique limitation in the embodiments of this application.

[0075] In this embodiment, the total thickness of the adhesive structure 100 ranges from 19µm to 29µm, and the total thickness of the adhesive structure 100 is the sum of the thicknesses of the first adhesive layer 110, the second adhesive layer 120, and the support layer 130. Figure 1A and Figure 1B As shown, Ha represents the total thickness of the adhesive structure 100, where 19um ≤ Ha ≤ 29um. Therefore, the total thickness Ha of the adhesive structure 100 can be selected from, but is not limited to, 19.0um, 19.5um, 20.0um, 20.5um, 21.0um, 21.5um, 22.0um, 22.5um, 23.0um, 23.5um, 24.0um, 24.5um, 25.0um, 25.5um, 26.0um, 26.5um, 27.0um, 27.5um, 28.0um, 28.5um, 29.0um, and so on.

[0076] In this embodiment of the application, the specific thickness of each layer of the adhesive structure 100 is not limited. The specific thickness of the first adhesive layer 110, the second adhesive layer 120 and the support layer 130 can be selected as needed within a specified range.

[0077] For example, in some optional embodiments, the thickness of the first adhesive layer 110 can range from 3µm to 10µm. Figure 1A and Figure 1B As shown, H1 indicates the thickness of the first adhesive layer 110, where 3um ≤ H1 ≤ 10um. Therefore, the thickness H1 of the first adhesive layer 110 can be selected from, but is not limited to, 3.0um, 3.3um, 3.5um, 3.8um, 4.0um, 4.3um, 4.5um, 4.8um, 5.0um, 5.3um, 5.5um, 5.8um, 6.0um, 6.3um, 6.5um, 6.8um, 7.0um, 7.3um, 7.5um, 7.8um, 8.0um, 8.3um, 8.5um, 8.8um, 9.0um, 9.3um, 9.5um, 9.8um, 10.0um, and so on.

[0078] For example, in some optional embodiments, the thickness of the first adhesive layer 110 can be greater than or equal to 4 μm. For schemes where the first adhesive layer 110 includes black filler particles, the addition of these particles increases processing difficulty. If the first adhesive layer 110 is too thin, it will lead to poor stability and high processing difficulty. For schemes where the first adhesive layer 110 is filled with black filler particles, a thickness of 4 μm or greater can significantly improve the reliability of the first adhesive layer 110 and reduce processing requirements. Optionally, the thickness of the first adhesive layer 110 can be between 4 μm and 8 μm.

[0079] For example, in some optional embodiments, the thickness of the second adhesive layer 120 can range from 3µm to 10µm. Figure 1A and Figure 1B As shown, H2 indicates the thickness of the second adhesive layer 120, where 3µm ≤ H2 ≤ 10µm. Therefore, the thickness H2 of the second adhesive layer 120 can be selected from, but is not limited to, 3.0µm, 3.3µm, 3.5µm, 3.8µm, 4.0µm, 4.3µm, 4.5µm, 4.8µm, 5.0µm, 5.3µm, 5.5µm, 5.8µm, 6.0µm, 6.3µm, 6.5µm, 6.8µm, 7.0µm, 7.3µm, 7.5µm, 7.8µm, 8.0µm, 8.3µm, 8.5µm, 8.8µm, 9.0µm, 9.3µm, 9.5µm, 9.8µm, 10.0µm, etc. For example, optionally, the thickness range of the second adhesive layer 120 can be 4µm to 8µm.

[0080] In some alternative embodiments, the thickness of the first adhesive layer 110 may be equal to the thickness of the second adhesive layer 120. Such a structure can reduce the difficulty of manufacturing by eliminating the need to distinguish between the front and back of the adhesive structure 100 during fabrication, for example, when both are made to be identical.

[0081] For example, in some optional embodiments, the thickness of the support layer 130 can range from 9µm to 15µm. Figure 1A and Figure 1B As shown, H3 indicates the thickness of the support layer 130, where 9um ≤ H3 ≤ 15um. Therefore, the thickness H3 of the support layer 130 can be selected from, but is not limited to, 9.0um, 9.5um, 10.0um, 10.5um, 11.0um, 11.5um, 12.0um, 12.5um, 13.0um, 13.5um, 14.0um, 14.5um, 15.0um, and so on.

[0082] In some optional embodiments, when the first adhesive layer 110, the second adhesive layer 120, and the support layer 130 meet their respective thickness ranges, the total thickness also meets the requirement of being between 19 μm and 29 μm.

[0083] It should be understood that, in the embodiments of this application, the thickness range of the first adhesive layer 110 is 3µm to 10µm, the thickness range of the support layer 130 is 9µm to 15µm, and the thickness range of the second adhesive layer 120 is 3µm to 10µm, satisfying at least one of these conditions. This allows the under-display ultrasonic module 1000 to better adapt to the ultrasonic signal transmission requirements of the screen 300 (also referred to as the glass cover screen) including the glass cover plate 310. This facilitates the achievement of acoustic impedance matching between the under-display ultrasonic module and the glass cover screen, reduces the transmission loss of ultrasonic signals, and thus effectively improves the usage effect and performance of the under-display ultrasonic module in the glass cover screen, and improves the reliability and performance of under-display ultrasonic detection.

[0084] For example, in some optional combinations of this application, the thickness of the first adhesive layer 110 is 6 μm, the thickness of the support layer 130 is 12 μm, and the thickness of the second adhesive layer 120 is 6 μm.

[0085] The first adhesive layer 110 in this application embodiment can be made of any material, and is not limited to a single material. For example, in some optional embodiments, the first adhesive layer 110 may include one of PSA (Pressure Sensitive Adhesive), OCA (Optically Clear Adhesive), and PMMA (Poly(methyl methacrylate)) adhesive layers, or the first adhesive layer 110 may be a multilayer adhesive layer in which at least two of PSA, OCA, and PMMA adhesive layers are stacked.

[0086] It should be understood that the optional first adhesive layer 110 can effectively meet the bonding reliability with the screen 300 including the glass cover plate 310. Furthermore, the optional first adhesive layer 110, with a thickness range of 3µm to 10µm, can better adapt to the ultrasonic signal transmission requirements of the screen 300 including the glass cover plate 310 (also referred to as the glass cover screen). This facilitates the acoustic impedance matching between the under-screen ultrasonic module 1000 and the glass cover screen, reduces the transmission loss of ultrasonic signals, and thus effectively improves the performance and effectiveness of the under-screen ultrasonic module in the glass cover screen, thereby improving the reliability and performance of under-screen ultrasonic detection.

[0087] It is understandable that the first adhesive layer 110 can be a single layer of the above-mentioned adhesive layers or a multi-layer stack of adhesive layers, which can be set as needed.

[0088] The second adhesive layer 120 in this embodiment can be made of any material, and is not limited to a single material. For example, in some optional embodiments, the second adhesive layer 120 may include one of a PSA adhesive layer, an OCA adhesive layer, and a PMMA adhesive layer, or the second adhesive layer 120 may be a multilayer adhesive layer in which at least two of the PSA adhesive layer, OCA adhesive layer, and PMMA adhesive layer are stacked.

[0089] It should be understood that the optional second adhesive layer 120 can effectively meet the bonding reliability with the screen 300 including the glass cover plate 310. Furthermore, the optional material of the second adhesive layer 120 adopts the aforementioned thickness range of 3um to 10um, which can better adapt to the ultrasonic signal transmission requirements of the screen 300 including the glass cover plate 310 (also referred to as the glass cover screen). This is beneficial for achieving acoustic impedance matching between the under-screen ultrasonic module 1000 and the glass cover screen, reducing the transmission loss of ultrasonic signals. Therefore, it can effectively and specifically improve the usage effect and performance of the under-screen ultrasonic module in the glass cover screen, and improve the reliability and performance of under-screen ultrasonic detection.

[0090] It is understandable that the second adhesive layer 120 can be a single layer of the above-mentioned adhesive layers or a multi-layer stack of adhesive layers, which can be set as needed.

[0091] The first adhesive layer 110 and the second adhesive layer 120 can be of the same type or different types of adhesive layers; there is no single limitation. For example, in one example, the first adhesive layer 110 can be a PSA adhesive layer, and the second adhesive layer 120 can also be a PSA adhesive layer; in another example, the first adhesive layer 110 can be a PSA adhesive layer, and the second adhesive layer 120 can be an OCA adhesive layer; in yet another example, the first adhesive layer 110 can be a PMMA adhesive layer, and the second adhesive layer 120 can be a stack of PSA and OCA adhesive layers; in yet another example, the first adhesive layer 110 can be an OCA adhesive layer, and the second adhesive layer 120 can be a stack of OCA and PMMA adhesive layers; and in yet another example, the first adhesive layer 110 can be a stack of PSA and OCA adhesive layers, and the second adhesive layer 120 can be a stack of OCA and PMMA adhesive layers. Other cases can be selected as needed, and will not be elaborated here.

[0092] In some optional embodiments, the first adhesive layer 110 may include black filler particles. It should be understood that since the first adhesive layer 110 is used for direct bonding to the screen 300, adding black filler particles to the first adhesive layer 110 in this embodiment can prevent the light transmission of the first adhesive layer 110 from adversely affecting the display of the screen 300, thus better meeting the requirements of under-screen bonding. Furthermore, the black filler particles in the first adhesive layer 110 can effectively improve the elasticity and cushioning capacity of the adhesive layer, increase its toughness and mechanical strength, and further improve the material density and acoustic impedance of the adhesive layer of the bonding structure 100, thereby improving the performance of the under-screen ultrasonic module 1000. For example, when applied to a filterless screen, the first adhesive layer 110 may not be filled with black particles.

[0093] Optionally, the black filler particles may include at least one of carbon powder particles and black pigment particles. By filling the first adhesive layer 110 with these optional black filler particles, the color of the first adhesive layer 110 can be changed to better suit the needs of under-display bonding.

[0094] In some optional embodiments, the second adhesive layer 120 may not need to be filled with black filler particles; a transparent adhesive layer can be used instead. Since the second adhesive layer 120 is directly bonded to the under-display ultrasonic sensor 200, its impact on the light transmittance of the screen 300 is minimal. Using a second adhesive layer 120 without black filler particles results in lower costs and easier manufacturing. Of course, the second adhesive layer 120 may also include filler particles if necessary; these filler particles are not limited to black filler particles, and there is no single limitation.

[0095] The support layer 130 in this embodiment can be made of any material, and there is no single limitation. It can be an organic material support layer or an inorganic material support layer. For example, in some optional embodiments, the support layer 130 can be a metal layer. For example, the metal layer can be at least one of the following metal layers, including but not limited to copper, aluminum, titanium, and iron, or an alloy layer including but not limited to at least two of copper, aluminum, titanium, and iron.

[0096] It should be understood that the adhesive structure 100 made of the metal layer support layer 130 has high structural strength, good adhesive stability, good thermal conductivity and heat resistance. Furthermore, since the metal has a large acoustic impedance, the thickness of the metal layer support layer 130, which is reasonably set in the embodiments of this application, can help to better achieve acoustic impedance matching between the under-screen ultrasonic module 1000 and the screen 300 including the glass cover plate 310.

[0097] Optionally, taking a copper layer as an example, in some embodiments, the support layer 130 can be a copper foil layer. That is, the adhesive structure 100 can be copper foil adhesive. It should be understood that the adhesive structure 100 (i.e., copper foil adhesive) made of a support layer 130 in the form of a copper foil layer has lower cost, higher structural strength, better adhesion stability, and better thermal conductivity and heat resistance, which is beneficial for achieving better acoustic impedance matching between the under-display ultrasonic module 1000 and the screen 300 including the glass cover 310.

[0098] In this embodiment, the screen 300 includes a glass cover, which can adopt any structure. For example, the screen 300 may include a glass cover 310 and a screen body 320. The glass cover 310 is located above the screen body 320 and can serve as a protective structure for the screen body 320. The screen body 320 can be understood as a combination of all the layers in the screen 300 between the first adhesive layer 110 and the glass cover 310. Optionally, the under-screen ultrasonic module 1000 can be bonded to the underside of the screen body 320 via an adhesive structure 100.

[0099] The specific stacked structure of screen 300 is not limited here. For example, in one example embodiment, refer to... Figure 2 An example of a stacked structure of screen 300 is shown, such as Figure 2As shown, the screen 300 includes a glass cover 310 and a screen body 320. The screen body 320 includes a stacked BP optical film layer 3201 (anti-blue light film layer), a first adhesive layer 3202 (e.g., a PSA adhesive layer), a panel layer 3203, a second adhesive layer 3204 (e.g., a PSA adhesive layer), a POL layer 3205 (polarizer layer), and a third adhesive layer 3206 (e.g., an OCA adhesive layer). The glass cover 310 is bonded to the third adhesive layer 3206, and the under-screen ultrasonic module 1000 can be bonded to the BP optical film layer 3201 through the first adhesive layer 110 of the adhesive structure 100. It should be understood that the screen body stacking can be understood with reference to relevant technologies, and will not be elaborated on here.

[0100] The under-display ultrasonic module 1000 in this application has a total thickness of 19µm to 29µm, which can be selected as needed and is applicable to various types of screens 300 including glass cover plates 310. In some optional embodiments, the total thickness of the screen 300 ranges from 550µm to 1000µm, and the thickness of the glass cover plate 310 ranges from 370µm to 500µm.

[0101] As electronic devices (such as smartphones) increasingly demand thinner and lighter screens, the demand for thinner and lighter glass covers is also growing. Using thinner and lighter glass covers requires higher modulus. High-modulus glass covers typically have higher sound velocity and acoustic impedance than ordinary tempered glass, which can affect the ultrasonic detection performance of under-display ultrasonic modules (e.g., ultrasonic fingerprint performance). In this embodiment, a total thickness of 550µm to 1000µm for the screen 300 is considered relatively thin, and a thickness of 370µm to 500µm for the glass cover 310 is also considered relatively thin, thus meeting the thinner and lighter requirements of some electronic devices for both the screen and the glass cover.

[0102] It should be understood that the under-display ultrasonic module 1000 in this embodiment includes an under-display ultrasonic sensor 200 and an adhesive structure 100 with a total thickness ranging from 19µm to 29µm. The adhesive structure 100 includes a first adhesive layer 110, a support layer 130, and a second adhesive layer 120. The acoustic impedance of the support layer 130 is greater than that of the first adhesive layer 110 and the second adhesive layer 120. The first adhesive layer 110 and the second adhesive layer 120 are located on opposite sides of the support layer 130 in the thickness direction. The second adhesive layer 120 is bonded to the under-display ultrasonic sensor 200. The first adhesive layer 110 is used to bond to a relatively thin screen 300 (total thickness ranging from 550µm to 1000µm), which includes a relatively thin glass cover plate 310 (thickness ranging from 370µm to 500µm), so that the under-display ultrasonic sensor can be bonded to the screen. The ultrasonic module 1000 can be bonded to the underside of the screen 300. Through the thickness of the bonding structure 100 of the under-screen ultrasonic module 1000 in this embodiment, and the difference in acoustic impedance between the support layer 130 and the first adhesive layer 110 and the second adhesive layer 120, it can better adapt to the ultrasonic signal transmission requirements of the screen 300 (also known as a relatively thin glass cover screen), including the thin glass cover 310. This is beneficial to achieving acoustic impedance matching between the under-screen ultrasonic module 1000 and the relatively thin glass cover screen, reducing the transmission loss of ultrasonic signals. Therefore, it effectively and specifically improves the usage effect and performance of the under-screen ultrasonic module 1000 in the relatively thin glass cover screen, improves the reliability and performance of under-screen ultrasonic detection, and realizes the possibility of large-scale application of under-screen ultrasonic detection in electronic devices with relatively thin glass cover screens.

[0103] For example, such as Figure 1A and Figure 1B As shown, Hb indicates the total thickness of screen 300, so 550um ≤ Hb ≤ 1000um. Within the above selectable thickness range, the total thickness Hb of screen 300 can be selected from, but is not limited to, 550um, 600um, 650um, 700um, 750um, 800um, 850um, 900um, 950um, 1000um, etc.

[0104] For example, such as Figure 1A and Figure 1B As shown, H4 indicates the thickness of the glass cover 310, where 370 ≤ H4 ≤ 500 μm. Within the above-mentioned selectable thickness range, the thickness H4 of the glass cover 310 can be selected from, but is not limited to, 370 μm, 380 μm, 390 μm, 400 μm, 410 μm, 420 μm, 430 μm, 440 μm, 450 μm, 460 μm, 470 μm, 480 μm, 490 μm, 500 μm, etc.

[0105] In this embodiment, when the under-display ultrasonic module 1000 is an under-display ultrasonic fingerprint module, its operating frequency range can be 10MHz to 14MHz. Within this operating frequency range, the fingerprint detection performance is relatively good.

[0106] The principle of ultrasonic wave transmission in multiple media layers will be explained below, along with some examples, to further demonstrate the beneficial effects of the technical solutions in the embodiments of this application.

[0107] When an ultrasonic wave is transmitted to the interface between two different media, its sound intensity reflection coefficient and transmission coefficient can be obtained by the following formula:

[0108] Sound intensity reflection coefficient:

[0109] Sound intensity transmission coefficient:

[0110] Where z1 and Z2 are the acoustic impedances of the two media, respectively.

[0111] For multi-media stacks (such as...) Figure 3 A schematic diagram of multiple media stacks is shown. As the number of interfaces increases, the reflection paths between different media also increase. For ease of calculation, a transmission line model can be used for equivalent acoustic impedance conversion. Figure 3 As shown, multiple dielectric materials 1-N are stacked, with material 1 as the first input material. The equivalent input acoustic impedance seen at the interface between material N and N+1 is denoted as Z. Ne Then we have the following formula:

[0112]

[0113] Among them, Z N-1 Z represents the acoustic impedance of the (N-1)th layer of material. N-2,e denoted by , w represents the equivalent acoustic impedance from the first layer to the (N-2)th layer, w represents the angular frequency, v represents the sound velocity of the (N-1)th layer, and t represents the thickness of the (N-1)th layer.

[0114] By calculating the equivalent acoustic impedance, the reflection and transmission of ultrasonic waves in multi-layered media can be greatly simplified. Taking ultrasonic fingerprinting as an example, ultrasonic waves are emitted from the under-display ultrasonic fingerprint module, transmitted to the screen surface, and reflected back to the receiver after being reflected by the fingerprint. Since the ridges of a fingerprint are generally filled with air, the acoustic impedance of air is very small, approximately 0 Mrayl, and can be considered to be almost 100% reflected at this interface. Therefore, if the equivalent acoustic impedance of the screen surface can be made close to that of human tissue (approximately 1.5 Mrayl), the ultrasonic waves can have a larger penetration coefficient at the ridges, thereby improving the contrast of the fingerprint image.

[0115] Combining an example of screen 300 stacking, it can be like... Figure 2 As illustrated, the screen 300 includes a glass cover 310 and a screen body 320. The screen body 320 includes a BP optical film layer 3201 (anti-blue light film layer), a first adhesive layer 3202 (e.g., a PSA adhesive layer), a panel layer 3203, a second adhesive layer 3204 (e.g., a PSA adhesive layer), a POL layer 3205 (polarizer layer), and a third adhesive layer 3206. For ease of quantification, the thickness of a set of examples is used for discussion: the thickness of the BP optical film layer 3201 is 75 μm, the thickness of the first adhesive layer 3202 is 13 μm, the thickness of the panel layer 3203 is 40 μm, the thickness of the second adhesive layer 3204 is 15 μm, the thickness of the POL layer 3205 is 44 μm, and the thickness of the third adhesive layer 3206 is 75 μm. The glass cover plate 310 can be considered with a thickness of 370um, 400um, or 450um. The example glass cover plate 310 has a Young's modulus of 107 GPa, a density of 2.5 g / cm3, and a Poisson's ratio of 0.2.

[0116] Currently available commercially available OLED under-display ultrasonic fingerprint solutions use a traditional 15µm thick adhesive. While this adhesive is well-suited for thicker glass cover screens, its ultrasonic penetration performance is poor when the glass cover thickness is between 370µm and 500µm, resulting in suboptimal fingerprint performance. In contrast, the under-display ultrasonic module 1000 provided in this embodiment has an adhesive structure 100 thickness of 19µm to 29µm, offering superior acoustic impedance matching and ultrasonic penetration characteristics.

[0117] For example, such as Figure 4 The equivalent acoustic impedance curve and ultrasonic transmission coefficient curve for a glass cover with an example thickness are shown. Figure 4 The glass cover plate 310 shown has a thickness of 370 μm. For example... Figure 4 The left figure shows curve a1, which represents the equivalent acoustic impedance curve of the bonding structure 100 between the screen 300 and the under-screen ultrasonic module 1000 after the under-screen ultrasonic module 1000 is bonded to the screen 300 (horizontal axis: frequency / MHz, vertical axis: equivalent acoustic impedance / MRayl). In this example, the total thickness of the bonding structure 100 is 24µm, with the first adhesive layer 110 having a thickness of 6µm, the support layer 130 having a thickness of 12µm, and the second adhesive layer 120 having a thickness of 6µm. Curve a2 represents the equivalent acoustic impedance curve of the screen 300 and the 15µm adhesive after the under-screen ultrasonic module using 15µm adhesive is bonded to the screen 300 in related technologies (horizontal axis: frequency / MHz, vertical axis: equivalent acoustic impedance / MRayl). Figure 4As shown in the right figure, curve a3 is the ultrasonic penetration coefficient curve after the under-screen ultrasonic module 1000 in this application is bonded to the screen 300 (the horizontal axis is frequency / MHz, and the vertical axis is the ultrasonic penetration coefficient between the screen surface and the finger interface); curve a4 is the ultrasonic penetration coefficient curve after the under-screen ultrasonic module using 15um screen adhesive is bonded to the screen 300 in the related technology (the horizontal axis is frequency / MHz, and the vertical axis is the ultrasonic penetration coefficient between the screen surface and the finger interface).

[0118] like Figure 4 As shown, when the thickness of the glass cover plate 310 of the screen 300 is 370um, the equivalent acoustic impedance of the bonding structure 100 between the screen 300 and the ultrasonic module 100 under the screen in this solution in the frequency range of 10MHz to 14MHz is closer to the acoustic impedance of human tissue (approximately 1.5MRayl) than that of the screen 300 and the 15um screen adhesive in related technologies (that is, the low point of the a1 curve in the 10MHz to 14MHz range is smaller than the low point of the a2 curve in the 10MHz to 14MHz range). Moreover, in the frequency range of 10MHz to 14MHz, the peak penetration coefficient is increased by nearly double (that is, the peak value of the a3 curve in the 10MHz to 14MHz range is larger than the peak value of the a4 curve in the 10MHz to 14MHz range). Therefore, the acoustic impedance matching performance is better and the ultrasonic penetration characteristics are better.

[0119] For example, such as Figure 5 The equivalent acoustic impedance curve and ultrasonic transmission coefficient curve for a glass cover with another example thickness are shown. Figure 5 The glass cover plate 310 shown has a thickness of 400 μm. For example... Figure 5 The left figure shows curve b1, which represents the equivalent acoustic impedance curve of the bonding structure 100 between the screen 300 and the under-screen ultrasonic module 1000 after the under-screen ultrasonic module 1000 is bonded to the screen 300 (horizontal axis: frequency / MHz, vertical axis: equivalent acoustic impedance / MRayl). In this example, the total thickness of the bonding structure 100 is 24µm, with the first adhesive layer 110 having a thickness of 6µm, the support layer 130 having a thickness of 12µm, and the second adhesive layer 120 having a thickness of 6µm. Curve b2 represents the equivalent acoustic impedance curve of the screen 300 and the 15µm adhesive after the under-screen ultrasonic module using 15µm adhesive is bonded to the screen 300 in related technologies (horizontal axis: frequency / MHz, vertical axis: equivalent acoustic impedance / MRayl). Figure 5As shown in the right figure, curve b3 is the ultrasonic penetration coefficient curve after the under-screen ultrasonic module 1000 in this application is bonded to the screen 300 (the horizontal axis is frequency / MHz, and the vertical axis is the ultrasonic penetration coefficient between the screen surface and the finger interface); curve b4 is the ultrasonic penetration coefficient curve after the under-screen ultrasonic module using 15um screen adhesive is bonded to the screen 300 in the related technology (the horizontal axis is frequency / MHz, and the vertical axis is the ultrasonic penetration coefficient between the screen surface and the finger interface).

[0120] like Figure 5 As shown, when the thickness of the glass cover plate 310 of the screen 300 is 400um, the equivalent acoustic impedance of the bonding structure 100 between the screen 300 and the ultrasonic module 100 under the screen in this solution in the frequency range of 10MHz to 14MHz is closer to the acoustic impedance of human tissue (approximately 1.5MRayl) than that of the screen 300 and the 15um screen adhesive in related technologies (that is, the low point of the b1 curve in the 10MHz to 14MHz range is smaller than the low point of the b2 curve in the 10MHz to 14MHz range). Moreover, in the frequency range of 10MHz to 14MHz, the peak penetration coefficient is increased by nearly double (that is, the peak value of the b3 curve in the 10MHz to 14MHz range is larger than the peak value of the b4 curve in the 10MHz to 14MHz range). Therefore, the acoustic impedance matching performance is better and the ultrasonic penetration characteristics are better.

[0121] For example, such as Figure 6 The equivalent acoustic impedance curve and ultrasonic transmission coefficient curve are shown for a screen with a glass cover of another example thickness. Figure 6 The glass cover plate 310 shown has a thickness of 450 μm. For example... Figure 6 The left figure shows curve c1, which represents the equivalent acoustic impedance curve of the bonding structure 100 between the screen 300 and the under-screen ultrasonic module 1000 after the under-screen ultrasonic module 1000 is bonded to the screen 300 (horizontal axis: frequency / MHz, vertical axis: equivalent acoustic impedance / MRayl). In this example, the total thickness of the bonding structure 100 is 24µm, the thickness of the first adhesive layer 110 is 6µm, the thickness of the support layer 130 is 12µm, and the thickness of the second adhesive layer 120 is 6µm. Curve c2 represents the equivalent acoustic impedance curve of the screen 300 and the 15µm adhesive after the under-screen ultrasonic module using 15µm adhesive is bonded to the screen 300 in related technologies (horizontal axis: frequency / MHz, vertical axis: equivalent acoustic impedance / MRayl). Figure 6As shown in the right figure, curve c3 is the ultrasonic penetration coefficient curve after the under-screen ultrasonic module 1000 in this application is bonded to the screen 300 (the horizontal axis is frequency / MHz, and the vertical axis is the ultrasonic penetration coefficient between the screen surface and the finger interface); curve c4 is the ultrasonic penetration coefficient curve after the under-screen ultrasonic module using 15um screen adhesive is bonded to the screen 300 in the related technology (the horizontal axis is frequency / MHz, and the vertical axis is the ultrasonic penetration coefficient between the screen surface and the finger interface).

[0122] like Figure 6 As shown, when the thickness of the glass cover plate 310 of the screen 300 is 450um, the equivalent acoustic impedance of the bonding structure 100 between the screen 300 and the ultrasonic module 100 under the screen in this solution in the frequency range of 10MHz to 14MHz is closer to the acoustic impedance of human tissue (approximately 1.5MRayl) than that of the screen 300 and the 15um screen adhesive in related technologies (that is, the low point of the c1 curve in the 10MHz to 14MHz range is smaller than the low point of the c2 curve in the 10MHz to 14MHz range). Moreover, in the frequency range of 10MHz to 14MHz, the peak penetration coefficient is increased by nearly double (that is, the peak value of the c3 curve in the 10MHz to 14MHz range is larger than the peak value of the c4 curve in the 10MHz to 14MHz range). Therefore, the acoustic impedance matching performance is better and the ultrasonic penetration characteristics are better.

[0123] Understandably, the above is based on Figures 2-6The illustrative descriptions provided are for illustrative purposes only and are not intended to limit the scope of the embodiments in this application. As can be seen from the above illustrative descriptions, the under-display ultrasonic module 1000 in this application includes an under-display ultrasonic sensor and an adhesive structure with a total thickness ranging from 19µm to 29µm. The adhesive structure includes a first adhesive layer, a support layer, and a second adhesive layer. The acoustic impedance of the support layer is greater than the acoustic impedance of the first and second adhesive layers. The first and second adhesive layers are located on opposite sides of the support layer in the thickness direction. The second adhesive layer is bonded to the under-display ultrasonic sensor, and the first adhesive layer is used to bond to the screen, including the glass cover, so that the under-display ultrasonic sensor can be bonded to the underside of the screen through the adhesive structure. This is achieved through the implementation of this application. The thickness of the bonding structure of the under-display ultrasonic module in the example, as well as the difference in acoustic impedance between the support layer and the first and second adhesive layers, can better adapt to the ultrasonic signal transmission requirements of screens including glass covers (also known as glass cover screens). This facilitates acoustic impedance matching between the under-display ultrasonic module and the glass cover screen, reduces ultrasonic signal transmission loss, and thus effectively improves the performance and effectiveness of the under-display ultrasonic module in glass cover screens. It also improves the reliability and performance of under-display ultrasonic detection, making it possible to apply under-display ultrasonic detection (such as under-display ultrasonic fingerprint detection) on a large scale in electronic devices with glass cover screens.

[0124] According to the second aspect of the embodiments of this application, referring to Figure 1A and Figure 1B As shown, this application provides an under-display ultrasonic module 1000, which includes: an under-display ultrasonic sensor 200 and an adhesive structure 100; the adhesive structure 100 includes a first adhesive layer 110, a support layer 130 and a second adhesive layer 120, the first adhesive layer 110 and the second adhesive layer 120 are respectively located on both sides of the support layer 130 in the thickness direction, wherein the second adhesive layer 120 is bonded to the under-display ultrasonic sensor 200, and the first adhesive layer 110 is used to bond to the screen 300 including a glass cover plate 310, so that the under-display ultrasonic sensor 200 can be bonded to the underside of the screen 300 through the adhesive structure 100; wherein the acoustic impedance of the support layer 130 is greater than the acoustic impedance of the first adhesive layer 110 and the second adhesive layer 120, the thickness range of the first adhesive layer 110 is 3um to 10um, the thickness range of the support layer 130 is 9um to 15um, and the thickness range of the second adhesive layer 120 is 3um to 10um.

[0125] It should be understood that the various optional embodiments of the under-screen ultrasonic module 1000 in the second aspect have been described in detail in the embodiments of the first aspect above, and can be understood by referring to the above, and will not be repeated here.

[0126] According to the third aspect of the embodiments of this application, referring to Figure 1A, Figure 1B as well as Figure 7 As shown, an adhesive structure 100 is provided for bonding an under-display ultrasonic sensor 200 to the underside of a screen 300 including a glass cover plate 310. The adhesive structure 100 includes a first adhesive layer 110, a support layer 130, and a second adhesive layer 120. The first adhesive layer 110 and the second adhesive layer 120 are located on opposite sides of the support layer 130 in the thickness direction. The second adhesive layer 120 is used to bond to the under-display ultrasonic sensor 200, and the first adhesive layer 110 is used to bond to the screen 300. The acoustic impedance of the support layer 130 is greater than that of the first adhesive layer 110 and the second adhesive layer 120. The total thickness of the adhesive structure 100 ranges from 19 μm to 29 μm.

[0127] Based on this, since the total thickness of the bonding structure 100 in this embodiment ranges from 19µm to 29µm, and the bonding structure 100 includes a first adhesive layer 110, a support layer 130, and a second adhesive layer 120, and the acoustic impedance of the support layer 130 is greater than the acoustic impedance of the first adhesive layer 110 and the second adhesive layer 120, the first adhesive layer 110 and the second adhesive layer 120 are respectively located on both sides of the support layer 130 in the thickness direction, the second adhesive layer 120 can be used to bond with the under-display ultrasonic sensor 200, and the first adhesive layer 110 can be used to bond with the screen 300, so that the bonding structure 100 can be used to bond the under-display ultrasonic sensor 200 to the screen 300 including the glass cover plate 310. Below 0, through the thickness of the adhesive structure 100 and the difference in acoustic impedance between the support layer 130 and the first adhesive layer 110 and the second adhesive layer 120, it can better adapt to the ultrasonic signal transmission requirements of the screen 300 (also known as the glass cover screen) including the glass cover 310. This is conducive to achieving acoustic impedance matching between the under-screen ultrasonic module 1000 and the glass cover screen, reducing the transmission loss of ultrasonic signals. Therefore, it effectively and specifically improves the usage effect and performance of the under-screen ultrasonic module 1000 in the glass cover screen, improves the reliability and performance of under-screen ultrasonic detection, and realizes the possibility of large-scale application of under-screen ultrasonic detection in electronic devices with glass cover screens.

[0128] In some optional embodiments, the adhesive structure 100 satisfies at least one of the following conditions:

[0129] The thickness of the first adhesive layer 110 ranges from 3µm to 10µm;

[0130] The thickness of the support layer 130 ranges from 9µm to 15µm;

[0131] The thickness of the second adhesive layer 120 ranges from 3µm to 10µm.

[0132] In some optional embodiments, the adhesive structure 100 satisfies at least one of the following conditions:

[0133] The thickness of the first adhesive layer 110 ranges from 4µm to 8µm;

[0134] The thickness of the support layer 130 ranges from 9µm to 15µm;

[0135] The thickness of the second adhesive layer 120 ranges from 4µm to 8µm.

[0136] In some optional embodiments, the total thickness of the screen 300 ranges from 550µm to 1000µm, and the thickness of the glass cover 310 ranges from 370µm to 500µm.

[0137] In some optional embodiments, the first adhesive layer 110 includes one of a PSA adhesive layer, an OCA adhesive layer, and a PMMA adhesive layer; or, the first adhesive layer 110 is a multilayer adhesive layer in which at least two of a PSA adhesive layer, an OCA adhesive layer, and a PMMA adhesive layer are stacked.

[0138] In some optional embodiments, the second adhesive layer 120 includes one of a PSA adhesive layer, an OCA adhesive layer, and a PMMA adhesive layer; or, the second adhesive layer 120 is a multilayer adhesive layer in which at least two of the PSA adhesive layer, OCA adhesive layer, and PMMA adhesive layer are stacked.

[0139] In some alternative embodiments, the thickness of the first adhesive layer 110 is equal to the thickness of the second adhesive layer 120.

[0140] In some alternative embodiments, the first adhesive layer 110 includes black filler particles.

[0141] In some alternative embodiments, the support layer 130 is a metal layer.

[0142] In some optional embodiments, the under-display ultrasonic sensor 200 is an under-display ultrasonic fingerprint sensor, and the under-display ultrasonic module 1000 is an under-display ultrasonic fingerprint module.

[0143] In some alternative embodiments, the support layer 130 is a copper foil layer.

[0144] In some optional embodiments, the under-display ultrasonic sensor 200 includes: a substrate 210, a first electrode 211, an acoustic layer 213, and a second electrode 212; the first electrode 211 is located on the substrate 210, and the acoustic layer 213 is located between the first electrode 211 and the second electrode 212; the second electrode 212 is used to be excited by an excitation signal to excite the acoustic layer 213 to emit ultrasonic signals; the first electrode 211 is used to receive ultrasonic detection signals generated between the second electrode 212 and the first electrode 211 when the returned ultrasonic signals act on the acoustic layer 213.

[0145] In some alternative embodiments, the under-display ultrasonic sensor 200 further includes a protective layer 214 that covers at least a portion of the second electrode 212.

[0146] In some alternative embodiments, the second adhesive layer 120 is bonded to the substrate 210, or the second adhesive layer 120 is bonded to the protective layer 214.

[0147] It should be noted that the various optional embodiments of the bonding structure 100 in the third aspect have been described in detail in the embodiment of the under-screen ultrasonic module 1000 in the first aspect above, and can be understood by referring to the above text, and will not be repeated here.

[0148] According to the fourth aspect of the embodiments of this application, referring to Figure 1A , Figure 1B as well as Figure 7 As shown, an adhesive structure 100 is provided for bonding an under-display ultrasonic sensor 200 to the underside of a screen 300 including a glass cover plate 310. The adhesive structure 100 includes a first adhesive layer 110, a support layer 130, and a second adhesive layer 120. The first adhesive layer 110 and the second adhesive layer 120 are located on opposite sides of the support layer 130 in the thickness direction. The second adhesive layer 120 is used to bond with the under-display ultrasonic sensor 200, and the first adhesive layer 110 is used to bond with the screen 300. The acoustic impedance of the support layer 130 is greater than that of the first adhesive layer 110 and the second adhesive layer 120. The thickness of the first adhesive layer 110 ranges from 3µm to 10µm, the thickness of the support layer 130 ranges from 9µm to 15µm, and the thickness of the second adhesive layer 120 ranges from 3µm to 10µm.

[0149] It should be understood that the various optional embodiments of the adhesive structure 100 in the fourth aspect have been described in detail in the embodiments of the first aspect above, and can be understood by referring to the above, and will not be repeated here.

[0150] According to the fifth aspect of the embodiments of this application, referring to Figure 8A , Figure 8BAs shown, an electronic device 400 is provided, comprising: a screen 300 including a glass cover 310; and an under-screen ultrasonic module 1000 as described in any one of the first and second aspects; wherein a first adhesive layer 110 of the under-screen ultrasonic module 1000 is bonded to the screen 300 so that the under-screen ultrasonic module 1000 is bonded under the screen 300.

[0151] Optionally, the electronic device 400 can be, but is not limited to, any terminal or non-terminal device, as long as there is a need for under-screen ultrasonic detection. For example, it includes, but is not limited to, mobile phones, tablets, personal computers, etc.

[0152] In this embodiment, the screen 300 can be any screen with a glass cover.

[0153] In some optional embodiments, the under-display ultrasonic sensor 200 can be an under-display ultrasonic fingerprint sensor, the under-display ultrasonic module 1000 can be an under-display ultrasonic fingerprint module, and the detected biometric features can include fingerprint features.

[0154] Optionally, such as Figure 8A As shown, it illustrates... Figure 1A The under-display ultrasonic module 1000 with a "back-mounted" structure is bonded to the underside of the screen body 320 of the screen 300, including the glass cover plate 310, for installation in the electronic device 400. Optionally, as... Figure 8B As shown, it illustrates... Figure 1B The under-display ultrasonic module 1000 with a "positive bonding" structure is bonded to the underside of the screen body 320 of the screen 300, which includes a glass cover plate 310, for installation in the electronic device 400.

[0155] The details regarding the under-display ultrasonic module 1000 and the screen 300 have been described in detail in the embodiments of the first aspect above. Further details will not be elaborated here. For specific optional content and related beneficial effects, please refer to the previous text for understanding.

[0156] It is understood that the above descriptions of various aspects of the embodiments of this application are merely optional exemplary descriptions of the technical solutions of the embodiments of this application, and are not intended to limit the embodiments of this application in any way.

[0157] The optional embodiments of the present application have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present application are not limited thereto. It should be noted that, for the convenience of explaining the embodiments of the present application, the various drawings of the embodiments of the present application are not necessarily drawn to scale, and are only used to facilitate the explanation of the technical solution, and are not intended to limit the embodiments of the present application in any way. Within the scope of the technical concept of the embodiments of the present application, various simple modifications can be made to the technical solutions of the embodiments of the present application. The various technical features included in the different embodiments of the present application can be combined in any suitable manner. In order to avoid unnecessary repetition, the various possible combinations will not be described separately in the embodiments of the present application. However, these simple modifications and combinations should also be regarded as the content disclosed in the embodiments of the present application, and all fall within the protection scope of the embodiments of the present application.

[0158] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". It should be noted that the concepts of "first", "second", etc., mentioned in this application are only used to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies. It should be noted that the modifications "a" and "a plurality" mentioned in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless explicitly indicated in the context, they should be understood as "one or more".

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. An under-screen ultrasonic module, characterized in that, include: Under-display ultrasonic sensor; An adhesive structure includes a first adhesive layer, a support layer, and a second adhesive layer. The first adhesive layer and the second adhesive layer are located on opposite sides of the support layer in the thickness direction. The second adhesive layer is bonded to an under-display ultrasonic sensor, and the first adhesive layer is used to bond to a screen including a glass cover, so that the under-display ultrasonic sensor can be bonded to the underside of the screen through the adhesive structure. The acoustic impedance of the support layer is greater than that of the acoustic impedance of the first adhesive layer and the second adhesive layer, and the total thickness of the adhesive structure ranges from 19µm to 29µm.

2. The under-screen ultrasonic module according to claim 1, characterized in that, The adhesive structure satisfies at least one of the following conditions: The thickness of the first adhesive layer ranges from 3µm to 10µm; The thickness of the support layer ranges from 9µm to 15µm; The thickness of the second adhesive layer ranges from 3µm to 10µm.

3. The under-screen ultrasonic module according to claim 1, characterized in that, The adhesive structure satisfies at least one of the following conditions: The thickness of the first adhesive layer ranges from 4µm to 8µm; The thickness of the support layer ranges from 9µm to 15µm; The thickness of the second adhesive layer ranges from 4µm to 8µm.

4. The under-screen ultrasonic module according to claim 1, characterized in that, The total thickness of the screen ranges from 550um to 1000um, and the thickness of the glass cover ranges from 370um to 500um.

5. The under-screen ultrasonic module according to any one of claims 1-4, characterized in that, The under-screen ultrasonic module satisfies at least one of the following conditions: The first adhesive layer includes one of a PSA adhesive layer, an OCA adhesive layer, and a PMMA adhesive layer, or the first adhesive layer is a multilayer adhesive layer in which at least two of the PSA adhesive layer, OCA adhesive layer, and PMMA adhesive layer are stacked. The second adhesive layer includes one of a PSA adhesive layer, an OCA adhesive layer, and a PMMA adhesive layer, or the second adhesive layer is a multilayer adhesive layer in which at least two of the PSA adhesive layer, OCA adhesive layer, and PMMA adhesive layer are stacked. The thickness of the first adhesive layer is equal to the thickness of the second adhesive layer; The first adhesive layer includes black filler particles; The support layer is a metal layer; The under-display ultrasonic sensor is an under-display ultrasonic fingerprint sensor, and the under-display ultrasonic module is an under-display ultrasonic fingerprint module.

6. The under-screen ultrasonic module according to claim 5, characterized in that, The support layer is a copper foil layer.

7. The under-screen ultrasonic module according to any one of claims 1-4, characterized in that, The under-display ultrasonic sensor includes: a substrate, a first electrode, an acoustic layer, and a second electrode; The first electrode is located on the substrate, and the acoustic layer is located between the first electrode and the second electrode; The second electrode is used to be excited by an excitation signal to induce the acoustic layer to emit ultrasonic signals; The first electrode is used to receive the ultrasonic detection signal generated between the second electrode and the first electrode when the returned ultrasonic signal acts on the acoustic layer.

8. The under-screen ultrasonic module according to claim 7, characterized in that, The under-display ultrasonic sensor also includes a protective layer that covers at least a portion of the second electrode.

9. The under-screen ultrasonic module according to claim 8, characterized in that, The second adhesive layer is bonded to the substrate, or the second adhesive layer is bonded to the protective layer.

10. An under-screen ultrasonic module, characterized in that, include: Under-display ultrasonic sensor; An adhesive structure includes a first adhesive layer, a support layer, and a second adhesive layer. The first adhesive layer and the second adhesive layer are located on opposite sides of the support layer in the thickness direction. The second adhesive layer is bonded to an under-display ultrasonic sensor, and the first adhesive layer is used to bond to a screen including a glass cover, so that the under-display ultrasonic sensor can be bonded to the underside of the screen through the adhesive structure. The acoustic impedance of the support layer is greater than that of the acoustic impedance of the first adhesive layer and the second adhesive layer. The thickness of the first adhesive layer ranges from 3µm to 10µm, the thickness of the support layer ranges from 9µm to 15µm, and the thickness of the second adhesive layer ranges from 3µm to 10µm.

11. An adhesive structure, characterized in that, The adhesive structure is used to attach the under-display ultrasonic sensor to the underside of the screen, including the glass cover. The adhesive structure includes: a first adhesive layer, a support layer, and a second adhesive layer. The first adhesive layer and the second adhesive layer are located on both sides of the support layer in the thickness direction. The second adhesive layer is used to bond with the under-display ultrasonic sensor, and the first adhesive layer is used to bond with the screen. The acoustic impedance of the support layer is greater than that of the acoustic impedance of the first adhesive layer and the second adhesive layer, and the total thickness of the adhesive structure ranges from 19µm to 29µm.

12. An adhesive structure, characterized in that, The adhesive structure is used to attach the under-display ultrasonic sensor to the underside of the screen, including the glass cover. The adhesive structure includes: a first adhesive layer, a support layer, and a second adhesive layer. The first adhesive layer and the second adhesive layer are located on both sides of the support layer in the thickness direction. The second adhesive layer is used to bond with the under-display ultrasonic sensor, and the first adhesive layer is used to bond with the screen. The acoustic impedance of the support layer is greater than that of the acoustic impedance of the first adhesive layer and the second adhesive layer. The thickness of the first adhesive layer ranges from 3µm to 10µm, the thickness of the support layer ranges from 9µm to 15µm, and the thickness of the second adhesive layer ranges from 3µm to 10µm.

13. An electronic device, characterized in that, include: The screen, including the glass cover; and, The under-screen ultrasonic module as described in any one of claims 1-10; The first adhesive layer of the under-screen ultrasonic module is bonded to the screen, so that the under-screen ultrasonic module is bonded to the underside of the screen.

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