Fingerprint sensor and electronic device

Abstract

The application discloses a kind of fingerprint sensor and electronic device, belong to sensing technical field.Fingerprint sensor, including: substrate, photosensitive device, light emitting module and protective cover plate.Due to the multiple conductive structures in protective cover plate are electrically connected with light emitting module, and the orthographic projection of each conductive structure on substrate and the orthographic projection of corresponding photosensitive device on substrate at least partially overlap.Therefore, under the premise that light emitting module can be protected by protective cover plate, it is guaranteed that the fingerprint ridge in the user's finger can be electrically connected with light emitting module through conductive structure, so that fingerprint sensor can normally detect the fingerprint of user's finger.So, it can effectively reduce the probability that the side of light emitting module away from substrate is easily scratched, and then make the sensing effect of fingerprint sensor better.

Description

Technical Field

[0001] This application relates to the field of sensing technology, and in particular to a fingerprint sensor and electronic device. Background Technology

[0002] With the continuous development of science and technology, fingerprint sensors have gradually been applied to people's daily lives. Fingerprint sensors can examine human fingerprints, which are innate biological characteristics, consisting of a series of fingerprint ridges and valleys on the surface of the skin at the fingertips.

[0003] Currently, fingerprint sensors typically include: a substrate, multiple photosensitive devices on the substrate, and a light-emitting module located on the side of the multiple photosensitive devices facing away from the substrate. When a user presses their finger against the fingerprint sensor, the fingerprint ridges on the user's finger come into contact with the light-emitting module, causing light to be emitted from the points of contact with the fingerprint ridges. The light emitted by the light-emitting module can be sensed by the multiple photosensitive devices on the substrate and transmitted as electrical signals to a control component electrically connected to the fingerprint sensor. This allows the control component to generate a fingerprint image of the user based on the received electrical signals.

[0004] However, the hardness of the side of the light-emitting module facing away from the substrate in a fingerprint sensor is usually low, making it very easy to scratch, which in turn leads to poor sensing performance of the fingerprint sensor. Summary of the Invention

[0005] This application provides a fingerprint sensor and electronic device. It solves the problem of poor sensing performance in existing fingerprint sensors. The technical solution is as follows:

[0006] On the one hand, a fingerprint sensor is provided, including:

[0007] Substrate;

[0008] Multiple photosensitive devices located on the substrate;

[0009] A light-emitting module located on the side of the plurality of photosensitive devices facing away from the substrate;

[0010] Additionally, a protective cover plate is located on the side of the light-emitting module facing away from the substrate. The protective cover plate has multiple conductive structures, which are electrically connected to the light-emitting module. Each of the multiple conductive structures corresponds to one of the multiple photosensitive devices. The orthographic projection of the conductive structure on the substrate at least partially overlaps with the orthographic projection of the corresponding photosensitive device on the substrate.

[0011] Optionally, the orthographic projection of the conductive structure on the substrate lies within the orthographic projection of the corresponding photosensitive device on the substrate.

[0012] Optionally, the area of ​​the conductive structure projected onto the substrate is less than or equal to the area of ​​the corresponding photosensitive device projected onto the substrate.

[0013] Optionally, the width of the orthographic projection of the conductive structure onto the substrate in the target direction is equal to the width of the orthographic projection of the corresponding photosensitive device onto the substrate in the target direction.

[0014] Alternatively, the width of the orthographic projection of the conductive structure onto the substrate in the target direction is equal to half the width of the orthographic projection of the corresponding photosensitive device onto the substrate in the target direction.

[0015] The target direction is the row or column arrangement direction of the plurality of photosensitive devices.

[0016] Optionally, the protective cover includes: an insulating protective layer and the plurality of conductive structures, wherein the insulating protective layer has a plurality of through holes corresponding one-to-one with the plurality of conductive structures, and the conductive structures are located in the corresponding through holes.

[0017] Optionally, the conductive structure is a columnar structure distributed within the corresponding through-hole, and the thickness of the insulating protective layer is the same as the height of the conductive structure.

[0018] Optionally, the orthographic projection of the via on the substrate is circular, and the distance between any two adjacent vias in the insulating protective layer is greater than or equal to the diameter of the via.

[0019] Optionally, the insulating protective layer is a sheet structure made of at least one of glass, ceramic and polycarbonate materials.

[0020] Optionally, the conductive structure is a columnar structure made of at least one of copper, silver, aluminum and iron.

[0021] Optionally, the thickness of the insulating protective layer ranges from 0.1 mm to 0.5 mm.

[0022] Optionally, the fingerprint sensor further includes an adhesive layer located between the protective cover and the light-emitting module, wherein the orthographic projection of the adhesive layer on the substrate does not coincide with the orthographic projection of the conductive structure on the substrate.

[0023] Optionally, the light-emitting module includes: a first light-transmitting electrode, a light-emitting layer, and a dielectric layer stacked along a direction perpendicular to and away from the substrate, wherein the dielectric layer is electrically connected to the conductive structure;

[0024] The photosensitive device includes: a first light-shielding electrode, a photoelectric conversion layer, and a second light-transmitting electrode stacked along a direction perpendicular to and away from the substrate;

[0025] The fingerprint sensor further includes a light-transmitting shielding electrode located between the first light-transmitting electrode and the second light-transmitting electrode, wherein the light-transmitting shielding electrode is insulated from the first light-transmitting electrode and from the second light-transmitting electrode.

[0026] Optionally, the dielectric layer is a light-shielding dielectric layer.

[0027] Optionally, the dielectric layer includes a protective dielectric layer and a light-shielding dielectric layer stacked together, wherein the protective dielectric layer is closer to the protective cover plate than the light-shielding dielectric layer.

[0028] Optionally, the fingerprint sensor further includes a driving circuit on the substrate and electrically connected to a first light-shielding electrode in the photosensitive device.

[0029] Optionally, the driving circuit has at least one thin-film transistor, and the photosensitive device further includes: a second light-shielding electrode located on the side of the second light-transmitting electrode opposite to the substrate, wherein the orthographic projection of the second light-shielding electrode on the substrate does not coincide with the orthographic projection of the photoelectric conversion layer on the substrate, and the orthographic projection of the active layer in the thin-film transistor on the substrate is located within the orthographic projection of the second light-shielding electrode on the substrate.

[0030] On the other hand, an electronic device is provided, the electronic device comprising: a control component, and a fingerprint sensor as described above, electrically connected to the control component.

[0031] Optionally, the electronic device further includes: a housing connected to the edge region of the fingerprint sensor, and a metal sheet located on the housing;

[0032] The control component has an AC drive unit, the power line of which is electrically connected to the first light-transmitting electrode in the light-emitting module, and the ground line of which is electrically connected to the metal sheet.

[0033] The beneficial effects of the technical solutions provided in this application include at least the following:

[0034] A fingerprint sensor includes a substrate, a photosensitive device, a light-emitting module, and a protective cover. The protective cover has multiple conductive structures electrically connected to the light-emitting module, and the orthographic projection of each conductive structure onto the substrate at least partially overlaps with the orthographic projection of the corresponding photosensitive device onto the substrate. Therefore, while protecting the light-emitting module, the protective cover ensures that the fingerprint ridges of the user's finger can be electrically connected to the light-emitting module through the conductive structures, allowing the fingerprint sensor to detect the user's fingerprint normally. This effectively reduces the probability of the side of the light-emitting module facing away from the substrate being easily scratched, thus improving the sensing performance of the fingerprint sensor. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of a fingerprint sensor provided by related technologies;

[0037] Figure 2 This is a schematic diagram of the light-emitting principle of a light-emitting module provided by related technologies;

[0038] Figure 3 This is a schematic diagram of the structure of a fingerprint sensor provided in an embodiment of this application;

[0039] Figure 4 This is a schematic diagram of another fingerprint sensor provided in an embodiment of this application;

[0040] Figure 5 This is a schematic diagram showing the positional relationship between a conductive structure and a photosensitive device provided in an embodiment of this application;

[0041] Figure 6 This is a top view of a protective cover provided in an embodiment of this application;

[0042] Figure 7 This is a schematic diagram of another fingerprint sensor provided in an embodiment of this application;

[0043] Figure 8 This is a schematic diagram of light emission from a light-emitting module provided in an embodiment of this application;

[0044] Figure 9 This is a schematic diagram of the film structure of a light-emitting module provided in an embodiment of this application;

[0045] Figure 10This is a schematic diagram of the film structure of a fingerprint sensor provided in an embodiment of this application;

[0046] Figure 11 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application;

[0047] Figure 12 This is a top view of an electronic device provided in an embodiment of this application. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0049] Please refer to the relevant technologies. Figure 1 , Figure 1 This is a schematic diagram of a fingerprint sensor provided by related technology. The fingerprint sensor 00 may include: a substrate 01, a plurality of photosensitive devices 02 located on the substrate 01, and a light-emitting module 03 located on the side of the plurality of photosensitive devices 02 facing away from the substrate 01. In this way, after the light-emitting module 03 emits light, at least some of the plurality of photosensitive devices 02 can sense the light emitted by the light-emitting module 03.

[0050] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the light-emitting principle of a light-emitting module provided by related technologies. The light-emitting module 03 may include: a first electrode layer 031, a light-emitting layer 032, and a dielectric layer 033 stacked together. The first electrode layer 031 is closer to the photosensitive device 02 than the light-emitting layer 032. Typically, an AC driving module is used to apply a certain amount of AC current to the first electrode layer 031 in the light-emitting module 03, and the human body needs to be in contact with the ground terminal of the AC driving module. Thus, when a human finger touches the dielectric layer 033 in the light-emitting module 03, an electric field is formed between the fingerprint ridge V in the finger and the first electrode layer 031, causing the light-emitting layer 033 to emit light under the action of this electric field.

[0051] In this scenario, after a user presses their finger against the fingerprint sensor, the fingerprint ridge V in the user's finger comes into contact with the dielectric layer 033 in the light-emitting module 03. This allows the fingerprint ridge V in contact with the dielectric layer 033 to form an electric field with the first electrode layer 031. Under the influence of this electric field, the portion of the light-emitting layer 032 corresponding to the fingerprint ridge V emits light. This light emitted from the portion of the light-emitting layer 032 corresponding to the fingerprint ridge V is then sensed by the corresponding photosensitive device 02. The photosensitive device 02 converts the light signal into an electrical signal and transmits it as an electrical signal to the control component electrically connected to the fingerprint sensor 00. The control component then generates the user's fingerprint image based on the received electrical signal.

[0052] However, since the dielectric layer 033 in the light-emitting module 03 typically has low hardness, and this dielectric layer 033 comes into direct contact with the user's finger, the side of the dielectric layer 033 facing away from the substrate 01 in the fingerprint sensor 00 is easily scratched, resulting in poor sensing performance of the fingerprint sensor 00.

[0053] Furthermore, in related technologies, if a protective layer is provided on the side of the dielectric layer 033 in the light-emitting module 03 facing away from the substrate 01, the dielectric layer 033 in the light-emitting module 03 can be protected, reducing the probability of the side of the light-emitting module 03 facing away from the substrate 01 being scratched. However, after a user's finger presses the fingerprint sensor 00, the fingerprint ridge V in the user's finger is separated from the dielectric layer 033 by the protective layer provided on the side of the light-emitting module 03 facing away from the substrate 01, thereby causing the fingerprint sensor 00 to malfunction. Therefore, this application proposes the following inventive steps.

[0054] In the embodiments of this application, please refer to Figure 3 , Figure 3 This is a schematic diagram of the structure of a fingerprint sensor provided in an embodiment of this application. The fingerprint sensor 000 may include: a substrate 100, a plurality of photosensitive devices 200 located on the substrate 100, a light-emitting module 300 located on the side of the plurality of photosensitive devices 200 facing away from the substrate 100, and a protective cover plate 400 located on the side of the light-emitting module 300 facing away from the substrate 100. Here, the plurality of photosensitive devices 200 may be arranged in an array on the substrate 100, and the light-emitting module 300 may be disposed as a whole layer on the side of the plurality of photosensitive devices 200 facing away from the substrate 100.

[0055] The protective cover plate 400 has multiple conductive structures 401, which are electrically connected to the light-emitting module 300. Each conductive structure 401 corresponds to a multiple photosensitive device 200. The orthographic projection of the conductive structure 401 on the substrate 100 at least partially overlaps with the orthographic projection of the corresponding photosensitive device 200 on the substrate 100.

[0056] In this configuration, when a user presses their finger against the fingerprint sensor, the fingerprint ridge of the user's finger comes into contact with a portion of the conductive structure 401 in the protective cover 400. This conductive structure 401 then establishes an electrical connection between the fingerprint ridge and the light-emitting module 300, allowing the portion of the light-emitting module 300 connected to this conductive structure 401 to emit light. Furthermore, since the orthographic projections of each conductive structure 401 onto the substrate 100 at least partially overlap with the orthographic projections of the corresponding photosensitive device 200 onto the substrate 100, the light emitted by the light-emitting module 300 can be sensed by the corresponding photosensitive device 200. The photosensitive device 200 then converts the light signal into an electrical signal and transmits it as an electrical signal to the control component electrically connected to the fingerprint sensor 000. This allows the control component to generate a fingerprint image of the user based on the received electrical signal, thereby detecting the user's fingerprint. Here, the side of the user's finger that contacts the fingerprint sensor 000 is the front of the fingerprint sensor 000.

[0057] In this embodiment, the protective cover 400 is provided with multiple conductive structures 401 electrically connected to the light-emitting module 300, and the orthographic projection of each conductive structure 401 on the substrate 100 at least partially overlaps with the orthographic projection of the corresponding photosensitive device 200 on the substrate 100. Therefore, while protecting the light-emitting module 300, the protective cover 400 ensures that the fingerprint ridge of the user's finger can be electrically connected to the light-emitting module 300 through the conductive structures 401, enabling the fingerprint sensor 000 to normally detect the user's fingerprint.

[0058] In summary, the fingerprint sensor provided in this application includes: a substrate, a photosensitive device, a light-emitting module, and a protective cover. Because the protective cover has multiple conductive structures electrically connected to the light-emitting module, and the orthographic projection of each conductive structure on the substrate at least partially overlaps with the orthographic projection of the corresponding photosensitive device on the substrate, the protective cover protects the light-emitting module while ensuring that the fingerprint ridge of the user's finger can be electrically connected to the light-emitting module through the conductive structures, allowing the fingerprint sensor to normally detect the user's fingerprint. This effectively reduces the probability of the side of the light-emitting module facing away from the substrate being easily scratched, thereby improving the sensing performance of the fingerprint sensor.

[0059] In this embodiment, for a clearer view of the fingerprint sensor's structural diagram, please refer to... Figure 4 , Figure 4This is a schematic diagram of another fingerprint sensor provided in this application embodiment. The orthographic projection of the conductive structure 401 in the protective cover 400 onto the substrate 100 lies within the orthographic projection of the corresponding photosensitive device 200 onto the substrate 100. Thus, after the conductive structure 401 contacts the fingerprint ridge in the user's finger, the portion of the light-emitting module 300 electrically connected to this conductive structure 401 can emit light, and all of this light can be directed towards the photosensitive device 200 corresponding to this conductive structure 401, resulting in a higher intensity of light sensed by the photosensitive device 200. Consequently, the photosensitive device 200 converts the sensed light signal into an electrical signal with greater intensity, resulting in a better fingerprint image generated subsequently based on the electrical signal output by the photosensitive device 200.

[0060] Please refer to the following in this application: Figure 5 , Figure 5 This is a schematic diagram illustrating the positional relationship between a conductive structure and a photosensitive device according to an embodiment of this application. The area of ​​the orthographic projection of the conductive structure 401 in the protective cover 400 onto the substrate 100 is less than or equal to the area of ​​the orthographic projection of the corresponding photosensitive device 200 onto the substrate 100. For example, when the orthographic projection of the conductive structure 401 onto the substrate 100 is circular and the orthographic projection of the corresponding photosensitive device 200 onto the substrate 100 is square, the circular shape of the orthographic projection of the conductive structure 401 onto the substrate 100 can be the inscribed circle of the square of the corresponding photosensitive device 200 onto the substrate 100. In other possible implementations, the shape of the orthographic projection of the conductive structure 401 onto the substrate 100 can be the same as the shape of the orthographic projection of the corresponding photosensitive device 200 onto the substrate 100, and this embodiment of the application does not limit this.

[0061] In this embodiment, the width of the orthographic projection of the conductive structure 401 in the protective cover 400 onto the substrate 100 in the target direction is equal to half the width of the orthographic projection of the corresponding photosensitive device 200 onto the substrate 100 in the target direction. Alternatively, the width of the orthographic projection of the conductive structure 401 in the protective cover 400 onto the substrate 100 in the target direction is equal to the width of the orthographic projection of the corresponding photosensitive device 200 onto the substrate 100 in the target direction. Here, the target direction is the row arrangement direction Y or column arrangement direction X of the plurality of photosensitive devices 200. It should be noted that the width of the orthographic projection of the photosensitive device 200 onto the substrate 100 in the target direction can range from 25 micrometers to 100 micrometers.

[0062] In this scenario, when the width of the orthogonal projection of the conductive structure 401 onto the substrate 100 in the target direction is equal to half the width of the orthogonal projection of the corresponding photosensitive device 200 onto the substrate 100 in the target direction, if the width of the orthogonal projection of the photosensitive device 200 onto the substrate 100 in the target direction is 50.8 micrometers, then the width of the orthogonal projection of the conductive structure 401 onto the substrate 100 in the target direction can be 25.4 micrometers. Similarly, when the width of the orthogonal projection of the conductive structure 401 onto the substrate 100 in the target direction is equal to the width of the orthogonal projection of the corresponding photosensitive device 200 onto the substrate 100 in the target direction, if the width of the orthogonal projection of the photosensitive device 200 onto the substrate 100 in the target direction is 50.8 micrometers, then the width of the orthogonal projection of the conductive structure 401 onto the substrate 100 in the target direction can be 50.8 micrometers. Thus, each photosensitive device 200 in the fingerprint sensor 000 has a corresponding conductive structure 401. In this way, after the fingerprint ridge on the user's finger comes into contact with the conductive structure 401, the portion of the light-emitting module 300 electrically connected to the conductive structure 401 can emit light, and this light can be directed towards the photosensitive device 200 corresponding to the conductive structure 401. Thus, each photosensitive device 200 in the fingerprint sensor 000 can sense the light directed towards it, thereby improving the sensing accuracy of the fingerprint sensor 000.

[0063] It should be noted that, Figure 5 The following is an illustrative example: the width Rx of the orthographic projection of the conductive structure 401 on the substrate 100 in the column arrangement direction X is equal to the width Hx of the orthographic projection of the corresponding photosensitive device 200 on the substrate 100 in the column arrangement direction X, and the width Ry of the orthographic projection of the conductive structure 401 on the substrate 100 in the row arrangement direction Y is equal to the width Hy of the orthographic projection of the corresponding photosensitive device 200 on the substrate 100 in the row arrangement direction Y.

[0064] In this application, as Figure 4 As shown, the protective cover 400 may include an insulating protective layer 402 and the aforementioned plurality of conductive structures 401. The insulating protective layer 402 has a plurality of through holes V corresponding one-to-one with the plurality of conductive structures 401, and the conductive structures 401 are located within the corresponding through holes V. Here, an insulating protective layer 402 exists between any two adjacent conductive structures 401 to prevent electrical connections between the conductive structures 401. In this way, the fingerprint image sensed by the fingerprint sensor 000 provided in this embodiment will not have any adhesion, thereby effectively improving the quality of the fingerprint image sensed by the fingerprint sensor 000.

[0065] In this embodiment, in the protective cover 400, the conductive structure 401 can be a columnar structure distributed within the corresponding through-hole V, and the height direction of the conductive structure 401 is parallel to the thickness direction of the insulating protective layer 402. The conductive structure 401 cannot be higher than or lower than the insulating protective layer 402. When the conductive structure 401 is higher than the insulating protective layer 402, after the user's finger makes full contact with the protective cover 400, the fingerprint ridges in the user's finger will be compressed and deformed by the higher conductive structure 401, resulting in lower accuracy of the fingerprint information sensed by the fingerprint sensor 000. When the conductive structure 401 is lower than the insulating protective layer 402, after the user's finger makes full contact with the protective cover 400, the fingerprint ridges in the user's finger are difficult to contact the conductive structure 401, thus causing the fingerprint sensor 000 to fail to sense the fingerprint information.

[0066] Therefore, the height of the conductive structure 401 in the protective cover 400 can be the same as the thickness of the insulating protective layer 402. In this way, when the user's finger presses the fingerprint sensor 000, the user's finger makes full contact with the protective cover 400, the fingerprint ridge in the user's finger will not be squeezed and deformed, and the fingerprint ridge in the finger can make normal contact with the conductive structure 401, so that the fingerprint information sensed by the fingerprint sensor 000 is more accurate.

[0067] In the embodiments of this application, please refer to Figure 6 , Figure 6 This is a top view of a protective cover provided in an embodiment of this application. Figure 6 The illustration is based on the example where the orthographic projections of the plurality of vias V in the insulating protective layer 402 onto the substrate 100 are all circular. In other possible implementations, the orthographic projections of the plurality of vias V in the insulating protective layer 402 onto the substrate 100 may also be polygonal, rectangular, or other shapes, and this embodiment does not limit this.

[0068] When the orthographic projection of the through-hole V in the insulating protective layer 402 onto the substrate 100 is circular, the diameter of each through-hole V in the insulating protective layer 402 can be the same, and the distance h between any two adjacent through-holes V in the insulating protective layer 402 is greater than or equal to the diameter r of the through-hole V. In this way, even though the protective cover plate 400 has multiple through-holes V, the strength of the protective cover plate 400 can still be high, ensuring that the protective cover plate 400 is not easily broken.

[0069] In this embodiment, since conductive structures 401 are provided within each through-hole V in the protective cover 400, and these conductive structures 401 are typically made of metallic material, the thickness of the insulating protective layer 402 in the protective cover 400 ranges from 0.1 mm to 0.5 mm to ensure high strength. For example, the thickness of the insulating protective layer 402 in the protective cover 400 can be 0.25 mm.

[0070] It should be noted that the insulating protective layer 402 in the protective cover 400 can be a sheet structure made of at least one of glass, ceramic, and polycarbonate. In other possible implementations, the insulating protective layer 402 can be made of other thinner materials, which is not limited in this application embodiment. The conductive structure 401 can be prepared from at least one of conductive materials such as copper, silver, aluminum, and iron. For example, when the insulating protective layer 402 in the protective cover 400 is made of glass, multiple through holes V can be etched in the insulating protective layer 402 using a laser etching process. Then, the conductive structure 401 can be deposited in the through holes V in the insulating protective layer 402 using an electroplating process. Finally, the conductive structure 401 in the protective cover 400 that is higher than the insulating protective layer 402 can be etched away using an etching process, so that the height of the conductive structure 401 in the protective cover 400 can be the same as the thickness of the insulating protective layer 402.

[0071] In the embodiments of this application, please refer to Figure 7 , Figure 7 This is a schematic diagram of another fingerprint sensor structure provided in an embodiment of this application. The fingerprint sensor 000 may further include an adhesive layer 500 located between the protective cover plate 400 and the light-emitting module 300, wherein the orthographic projection of the adhesive layer 500 on the substrate 100 does not coincide with the orthographic projection of the conductive structure 401 on the substrate 100. In this way, the protective cover plate 400 can be bonded to the side of the light-emitting module 300 away from the substrate 100 by means of the adhesive layer 500, and there is no adhesive layer 500 between the conductive structure 401 in the protective cover plate 400 and the light-emitting module 300, so that the conductive structure 401 can be normally electrically connected to the light-emitting module 300.

[0072] It should be noted that since the thickness of the adhesive layer 500 typically ranges from 10 micrometers to 25 micrometers, which is much smaller than the thickness of the protective cover plate 400, the adhesive layer 500 will not affect the electrical connection between the conductive structure 401 and the light-emitting module 300. That is, even with the adhesive layer 500 between the protective cover plate 400 and the light-emitting module 300, the conductive structure 401 in the protective cover plate 400 can still make normal contact with the light-emitting module 300. Furthermore, after the adhesive layer 500 is placed between the protective cover plate 400 and the light-emitting module 300, a high-pressure degassing machine is needed to perform a vacuum treatment on the fingerprint sensor 000. This ensures that the air in the space between the protective cover plate 400 and the light-emitting module 300 where the adhesive layer 500 is not distributed is expelled, allowing the conductive structure 401 in the protective cover plate 400 to make contact with the light-emitting module 300, thus resulting in a better electrical connection between the conductive structure 401 and the light-emitting module 300. For example, after an adhesive layer 500 is provided between the protective cover plate 400 and the light-emitting module 300, the fingerprint sensor 000 is placed in a high-pressure degassing machine. Then, the pressure in the high-pressure degassing machine is reduced to negative pressure so that the air in the space between the protective cover plate 400 and the light-emitting module 300 where the adhesive layer 500 is not distributed is extracted, ensuring that the conductive structure 401 in the protective cover plate 400 can contact the light-emitting module 300.

[0073] It should also be noted that the adhesive layer 500 can be either a thermosetting adhesive or a UV-curing adhesive. A thermosetting adhesive is an adhesive that forms a bond by curing with heat; for example, it could be a modified epoxy adhesive. A UV-curing adhesive is an adhesive that forms a bond by curing under light; for example, it could be a UV adhesive that cures under ultraviolet light. In this embodiment, either type of adhesive can be used to bond the protective cover 400 and the light-emitting module 300.

[0074] In the embodiments of this application, please refer to Figure 8 , Figure 8 This is a schematic diagram of a light-emitting module emitting light according to an embodiment of this application. The light-emitting module 300 in the fingerprint sensor 000 may include: a first light-transmitting electrode 301, a light-emitting layer 302, and a dielectric layer 303 stacked along a direction perpendicular to and away from the substrate 100, wherein the dielectric layer 303 is electrically connected to the conductive structure 401. Here, the first light-transmitting electrode 301, the light-emitting layer 302, and the dielectric layer 303 can all be integral film structures.

[0075] In this application, an AC driving unit applies a certain amount of AC current to the first light-transmitting electrode 301 in the light-emitting module 300, and the human body needs to be in contact with the ground terminal of the AC driving unit. For example, the AC driving unit can apply an AC voltage in the range of 30 volts to 110 volts to the first light-transmitting electrode 301 in the light-emitting module 300 to keep the light-emitting module 300 in an on state. Thus, when a user's finger presses the fingerprint sensor 000, the fingerprint ridge W in the finger becomes conductive with the dielectric layer 303 in the light-emitting module 300, forming a circuit between the user's finger, the first light-transmitting electrode 301, and the dielectric layer 033. This allows the fingerprint ridge V, which is conductive with the dielectric layer 303, to form an electric field with the first light-transmitting electrode 301. Under the action of this electric field, the portion of the light-emitting layer 302 corresponding to the fingerprint ridge W emits light.

[0076] In this application embodiment, the dielectric layer 303 in the light-emitting module 300 can be implemented in a variety of ways. This application embodiment only uses the following two cases as examples for illustrative explanation.

[0077] In the first scenario, the dielectric layer 303 in the light-emitting module 300 can be a light-shielding dielectric layer. Here, the light-shielding dielectric layer can prevent ambient light from shining on the light-emitting layer 303 and interfering with the light-emitting module 300.

[0078] For the second scenario, please refer to [the relevant documentation / reference]. Figure 9 , Figure 9 This is a schematic diagram of the film structure of a light-emitting module provided in an embodiment of this application. The dielectric layer 303 in the light-emitting module 300 may include a protective dielectric layer 3031 and a light-shielding dielectric layer 3032 stacked together, wherein the protective dielectric layer 3031 may be closer to the protective cover plate 400 than the light-shielding dielectric layer 3032.

[0079] In both of the above scenarios, a black carbon black structure needs to be incorporated into the light-shielding dielectric layer 3032 to provide it with a certain light-shielding capability. In the second scenario, the dielectric constants of the protective dielectric layer 3031 and the light-shielding dielectric layer 3032 are the same. Since the carbon black structure in the light-shielding dielectric layer 3032 has a certain conductivity, a protective dielectric layer 3031 with better insulation needs to be added between the protective cover plate 400 and the light-shielding dielectric layer 3032 to ensure the security of the fingerprint sensor for the user.

[0080] It should be noted that the light-emitting layer 302 in the light-emitting module 300 may include: a combination structure of plexiglass, 8-hydroxyquinoline, aluminum, and coumarin 545T; a combination structure of plexiglass, 8-hydroxyquinoline, aluminum, and red-light doping material-organic fluorescent doping material; a combination structure of epoxy resin, zinc sulfide, and fluorene; a combination structure of polyvinylcarbazole, cadmium selenide, and copper oxide; and a combination structure of epoxy resin and calcium copper titanate. The dielectric layer 303 in the light-emitting module 300 may be a layered structure prepared from at least one material selected from barium titanate, zirconium dioxide, tantalum pentoxide, and carbon black located within a fixing adhesive.

[0081] In the embodiments of this application, please refer to Figure 10 , Figure 10 This is a schematic diagram of the film structure of a fingerprint sensor provided in an embodiment of this application. The photosensitive device 200 in the fingerprint sensor 000 may include: a first light-shielding electrode 201, a photoelectric conversion layer 202, and a second light-transmitting electrode 203 stacked along a direction perpendicular to and away from the substrate 100. Here, the photoelectric conversion layer 202 is a PIN structure composed of a P-type semiconductor layer, an intrinsic semiconductor layer, and an N-type semiconductor layer. The second light-transmitting electrode 203 can be electrically connected to a control component through a bias signal line. In this way, the control component can apply a bias voltage to the second light-transmitting electrode 203 through the bias signal line, so that the photosensitive device 200 is in an operating state. Thus, when the photoelectric conversion layer 202 senses the target light, the photoelectric conversion layer 202 can respond to the received target light and generate and store a photocurrent signal, and export the photocurrent signal from the first light-shielding electrode 201 as an electrical signal. Here, the target light is the light emitted from the light-emitting module 300.

[0082] In this application, the fingerprint sensor 000 may further include: a light-transmitting shielding electrode 600 located between the first light-transmitting electrode 301 and the second light-transmitting electrode 203, wherein the light-transmitting shielding electrode 600 is insulated from the first light-transmitting electrode 301 and from the second light-transmitting electrode 203.

[0083] In this embodiment, the fingerprint sensor 000 may further include: a transparent substrate 700 located on the side of the first light-transmitting electrode 301 near the substrate 100, and a transparent insulating layer 800 on the side of the second light-transmitting electrode 203 away from the substrate 100. Here, the transparent substrate 700 may be a layered structure made of transparent insulating materials such as glass, polyethylene terephthalate, polyethylene naphthalate, or polyimide. Thus, the light-transmitting shielding electrode 600 is insulated from the first light-transmitting electrode 301 through the transparent substrate 700 and from the second light-transmitting electrode 203 through the transparent insulating layer 800. In this way, the light-transmitting shielding electrode 600 prevents interference between the AC signal applied to the first light-transmitting electrode 301 and the bias voltage applied to the second light-transmitting electrode 203, ensuring that both the light-emitting module 300 and the photosensitive device 200 can operate normally. Furthermore, the light-transmitting shielding electrode 600 also prevents static electricity from being generated in the fingerprint sensor 000, which could affect the light-emitting module 300 and the photosensitive device 200.

[0084] In this case, after the conductive structure 401 comes into contact with the fingerprint ridge in the user's finger, the part of the light-emitting module 300 corresponding to the conductive structure 401 emits light. The light can pass through the first light-transmitting electrode 301, the light-transmitting shielding electrode 600 and the second light-transmitting electrode 203 in sequence and be directed to the photoelectric conversion layer 202. This allows the photoelectric conversion layer 202 to generate and store a photocurrent signal in response to the received light, and to export the photocurrent signal from the first light-shielding electrode 201 as an electrical signal.

[0085] It should be noted that the first transparent electrode 301, the transparent shielding electrode 600, and the second transparent electrode 203 can all be layered structures made of transparent conductive materials such as indium tin oxide (ITO), indium-doped zinc oxide (IZO), poly(3,4-ethylenedioxythiophene) (PEDOT), or silver nanowires.

[0086] In the embodiments of this application, such as Figure 10As shown, the fingerprint sensor 000 may further include a driving circuit on the substrate 100 and electrically connected to the first light-shielding electrode 201 in the photosensitive device 200. Here, the driving circuit has at least one thin-film transistor 900, which may include a gate 901, a first electrode 902, a second electrode 903, and an active layer 904. Both the first electrode 902 and the second electrode 903 are connected to the active layer 904, and the active layer 904 is insulated from the gate 901. For example, the active layer 904 and the gate 901 may be insulated from each other by a gate insulating layer 905. It should be noted that the first electrode 902 in the thin-film transistor 900 can be one of the source and drain electrodes, and the second electrode 903 can be the other of the source and drain electrodes.

[0087] In this configuration, the first electrode 902 can be electrically connected to the control component via a signal line, and the first light-shielding electrode 201 can be electrically connected to the second electrode 903 in the thin-film transistor. Thus, when the photosensitive device 200 senses the target light, it can generate and store a photocurrent signal. If this photocurrent signal needs to be transmitted from the first light-shielding electrode 201 to the control component, a bias voltage needs to be applied to the gate 901 of the thin-film transistor to turn it on, allowing the photocurrent signal from the first light-shielding electrode 201 to be transmitted from the first electrode 902 as an electrical signal to the control component via a signal line.

[0088] It should be noted that the fingerprint sensor 000 may further include: a first planarization layer 1000 and a second planarization layer 1100. The first planarization layer 1000 has multiple openings K, and within each opening K, the portion of the photoelectric conversion layer 202 located within that opening K can be electrically connected to the first light-shielding electrode 201. The second planarization layer 1100 is located between the first planarization layer 1000 and the second light-transmitting electrode 203. The first light-shielding electrode 201 may be disposed in the same layer and made of the same material as the second electrode 903 in the thin-film transistor.

[0089] In this embodiment, the photosensitive device 200 may further include a second light-shielding electrode 1200 located on the side of the second light-transmitting electrode 203 facing away from the substrate 100. The orthographic projection of the second light-shielding electrode 1200 on the substrate 100 does not coincide with the orthographic projection of the photoelectric conversion layer 202 on the substrate 100, and the orthographic projection of the active layer 904 in the thin-film transistor 900 on the substrate 100 lies within the orthographic projection of the second light-shielding electrode 1200 on the substrate 100. In this way, the second light-shielding electrode 1200 can shield the active layer 904 to prevent the active layer 904 from experiencing voltage threshold shift under light irradiation.

[0090] It should be noted that the second light-shielding electrode 1200, the first light-shielding electrode 201, the first electrode 902 in the thin film transistor 900, the second electrode 903 in the thin film transistor 900, and the gate electrode 901 in the thin film transistor 900 can all be electrodes made of metallic materials.

[0091] In summary, the fingerprint sensor provided in this application includes: a substrate, a photosensitive device, a light-emitting module, and a protective cover. Because the protective cover has multiple conductive structures electrically connected to the light-emitting module, and the orthographic projection of each conductive structure on the substrate at least partially overlaps with the orthographic projection of the corresponding photosensitive device on the substrate, the protective cover protects the light-emitting module while ensuring that the fingerprint ridge of the user's finger can be electrically connected to the light-emitting module through the conductive structures, allowing the fingerprint sensor to normally detect the user's fingerprint. This effectively reduces the probability of the side of the light-emitting module facing away from the substrate being easily scratched, thereby improving the sensing performance of the fingerprint sensor.

[0092] This application also provides an electronic device, please refer to... Figure 11 , Figure 11 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device 111 may include: a control component 010, and any of the aforementioned fingerprint sensors 000 electrically connected to the control component 010. Here, the control component 010 may control the AC power supply electrically connected to the light-emitting module 300 in the fingerprint sensor 000, and may also control the driving circuit electrically connected to the photosensitive device 200 in the fingerprint sensor 000.

[0093] In the embodiments of this application, please refer to Figure 12 , Figure 12 This is a top view of an electronic device provided in an embodiment of this application. The electronic device 111 may further include: a housing 011 connected to the edge region of the fingerprint sensor 000, and a metal sheet 012 located on the housing 011. Here, the metal sheet 012 is on the same surface as the front of the fingerprint sensor 000.

[0094] In this application, the control component 010 includes an AC drive unit 0101. The power line of the AC drive unit 0101 is electrically connected to the first light-transmitting electrode 301 in the light-emitting module 300, and the ground wire of the AC drive unit 0101 is electrically connected to the metal plate 012. Thus, when a user uses the electronic device 111 to collect fingerprints, a part of the user's body (e.g., the palm) can contact the metal plate 012, and the user's finger can contact the protective cover 400, causing the portion of the light-emitting module 300 that contacts the fingerprint ridge to emit light. During this process, the dielectric layer 303 in the light-emitting module 300 ensures that the current in the user's finger is within a safe range (e.g., the current in the user's finger is less than or equal to 10 mA). For example, when the voltage range of the AC drive unit 0101 can be 30V to 110V, and the AC voltage frequency range can be 5Hz to 30kHz, the dielectric constant of the dielectric layer 303 can be 2000F / m to 3000F / m, which can keep the current in the user's finger within a safe range.

[0095] In this embodiment, the electronic device 111 may further include an anti-static damage module 013 electrically connected to the AC drive unit 0101. The anti-static damage module 013 may be distributed around the light-emitting module 300 to prevent electrostatic breakdown of the light-emitting module 300, thereby extending the service life of the electronic device 111.

[0096] It should be noted that the dimensions of layers and regions may be exaggerated in the accompanying drawings for clarity. Furthermore, it is understood that when an element or layer is referred to as being "on" another element or layer, it can be directly on the other element, or there may be intermediate layers. Additionally, it is understood that when an element or layer is referred to as being "below" another element or layer, it can be directly below the other element, or there may be more than one intermediate layer or element. Furthermore, it is also understood that when a layer or element is referred to as being "between" two layers or two elements, it can be the only layer between the two layers or two elements, or there may be more than one intermediate layer or element. Similar reference numerals throughout indicate similar elements.

[0097] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0098] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A fingerprint sensor, characterized in that, include: Substrate; Multiple photosensitive devices located on the substrate; A light-emitting module located on the side of the plurality of photosensitive devices facing away from the substrate; Additionally, a protective cover plate is located on the side of the light-emitting module facing away from the substrate. The protective cover plate has multiple conductive structures, which are electrically connected to the light-emitting module. Each conductive structure corresponds one-to-one with a plurality of photosensitive devices. The orthographic projection of the conductive structure on the substrate at least partially overlaps with the orthographic projection of the corresponding photosensitive device on the substrate. The light-emitting module includes: a first light-transmitting electrode, a light-emitting layer, and a dielectric layer stacked along a direction perpendicular to and away from the substrate, wherein the dielectric layer is electrically connected to the conductive structure; The photosensitive device includes: a first light-shielding electrode, a photoelectric conversion layer, and a second light-transmitting electrode stacked along a direction perpendicular to and away from the substrate; The fingerprint sensor further includes: a light-transmitting shielding electrode located between the first light-transmitting electrode and the second light-transmitting electrode, a transparent substrate located on the side of the first light-transmitting electrode near the substrate, and a transparent insulating layer located on the side of the second light-transmitting electrode away from the substrate. The light-transmitting shielding electrode is insulated from the first light-transmitting electrode through the transparent substrate and from the second light-transmitting electrode through the transparent insulating layer.

2. The fingerprint sensor according to claim 1, characterized in that, The orthographic projection of the conductive structure on the substrate is located within the orthographic projection of the corresponding photosensitive device on the substrate. The area of ​​the orthographic projection of the conductive structure on the substrate is less than or equal to the area of ​​the orthographic projection of the corresponding photosensitive device on the substrate. The width of the orthographic projection of the conductive structure on the substrate in the target direction is equal to the width of the orthographic projection of the corresponding photosensitive device on the substrate in the target direction. Alternatively, the width of the orthographic projection of the conductive structure onto the substrate in the target direction is equal to half the width of the orthographic projection of the corresponding photosensitive device onto the substrate in the target direction. Wherein, the target direction is the row or column arrangement direction of the plurality of photosensitive devices, the shape of the orthographic projection of the conductive structure on the substrate is circular, and the shape of the orthographic projection of the corresponding photosensitive device on the substrate is square.

3. The fingerprint sensor according to claim 1, characterized in that, The protective cover plate includes: an insulating protective layer and the plurality of conductive structures. The insulating protective layer has a plurality of through holes that correspond one-to-one with the plurality of conductive structures, and the conductive structures are located in the corresponding through holes.

4. The fingerprint sensor according to claim 3, characterized in that, The conductive structure is a columnar structure distributed within the corresponding through-hole, and the thickness of the insulating protective layer is the same as the height of the conductive structure.

5. The fingerprint sensor according to claim 3, characterized in that, The orthographic projection of the via on the substrate is circular, and the distance between any two adjacent vias in the insulating protective layer is greater than or equal to the diameter of the via.

6. The fingerprint sensor according to any one of claims 2 to 5, characterized in that, The insulating protective layer is a sheet structure made of at least one of glass, ceramic and polycarbonate materials.

7. The fingerprint sensor according to any one of claims 2 to 5, characterized in that, The thickness of the insulating protective layer ranges from 0.1 mm to 0.5 mm.

8. The fingerprint sensor according to any one of claims 1 to 5, characterized in that, The conductive structure is a columnar structure made of at least one of copper, silver, aluminum and iron.

9. The fingerprint sensor according to any one of claims 1 to 5, characterized in that, The fingerprint sensor further includes an adhesive layer located between the protective cover and the light-emitting module, wherein the orthographic projection of the adhesive layer on the substrate does not coincide with the orthographic projection of the conductive structure on the substrate.

10. The fingerprint sensor according to claim 9, characterized in that, The dielectric layer is a light-shielding dielectric layer.

11. The fingerprint sensor according to claim 9, characterized in that, The dielectric layer includes a protective dielectric layer and a light-shielding dielectric layer stacked together, wherein the protective dielectric layer is closer to the protective cover plate than the light-shielding dielectric layer.

12. The fingerprint sensor according to claim 9, characterized in that, The fingerprint sensor further includes a driving circuit on the substrate and electrically connected to a first light-shielding electrode in the photosensitive device.

13. The fingerprint sensor according to claim 12, characterized in that, The driving circuit has at least one thin-film transistor, and the photosensitive device further includes: a second light-shielding electrode located on the side of the second light-transmitting electrode opposite to the substrate, wherein the orthographic projection of the second light-shielding electrode on the substrate does not coincide with the orthographic projection of the photoelectric conversion layer on the substrate, and the orthographic projection of the active layer in the thin-film transistor on the substrate is located within the orthographic projection of the second light-shielding electrode on the substrate.

14. An electronic device, characterized in that, It includes: a control component, and a fingerprint sensor according to any one of claims 1 to 13, which is electrically connected to the control component.

15. The electronic device according to claim 14, characterized in that, The electronic device further includes: a housing connected to the edge region of the fingerprint sensor, and a metal sheet located on the housing; The control component has an AC drive unit, the power line of which is electrically connected to the first light-transmitting electrode in the light-emitting module, and the ground line of which is electrically connected to the metal sheet.

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