A fingerprint recognition device and its manufacturing and recognition methods

Abstract

This invention provides a fingerprint recognition device, a manufacturing method, and a recognition method thereof. The fingerprint recognition device includes a substrate, an image sensor layer, a pressure-emitting film layer, an encapsulation layer, and a backlight module. The substrate includes a first surface and a second surface disposed opposite to each other. The image sensor layer is located on the first surface of the substrate; the pressure-emitting film layer is located on the side of the image sensor layer facing away from the substrate; the encapsulation layer is located on the side of the pressure-emitting film layer facing away from the image sensor layer; and the backlight module is located on the second surface of the substrate. This invention achieves high-precision fingerprint recognition by utilizing the characteristics of pressure transmission through the encapsulation layer, fluorescence generation in the pressure-emitting film layer under pressure, and the conversion of fluorescence into electrical charge by the image sensor layer, which can then be processed by an external algorithm circuit to obtain bright field image information.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fingerprint identification, and relates to a fingerprint identification device and a manufacturing method and an identification method thereof. BACKGROUND

[0002] In recent years, the fingerprint identification technology has developed rapidly and has become a relatively mature identification method among many biological identification technologies, and is widely applied in access control systems, attendance systems, notebook computers, bank internal processing, bank payment and the like. The fingerprint identification technology mainly uses the inherent fingerprint characteristics of a human body to perform personal identity verification.

[0003] At present, there are mainly four kinds of fingerprint identification technologies applied in the market, namely, an optical fingerprint identification technology, a temperature difference sensing type fingerprint identification technology, a capacitive fingerprint identification technology and an ultrasonic fingerprint identification technology. The optical fingerprint identification is now widely applied in smart phones, access control systems and safety fields. Since the optical fingerprint identification uses an image sensor to take a photo for identification, it is easily disturbed under strong light, especially under the sun outdoors, resulting in an increased error rate of identification, and even cannot be used. The temperature difference sensing type fingerprint identification technology is usually applied to a sliding type fingerprint identification. Since the temperature difference sensing type fingerprint identification technology uses the temperature difference between a sensing finger and a chip imaging area to generate an electric signal representing image information, it is limited by temperature and time, and if the finger and the chip are at the same temperature for a long time, the phenomenon of unidentifiable fingerprint will occur. The capacitive fingerprint identification technology is widely used in the fields of mobile phones, computer touch screens and the like, but will cause false triggering or even cannot be used under the condition of dirt on the finger. The ultrasonic fingerprint identification technology identifies the fingerprint through ultrasonic wave reflection, but has the disadvantages of poor precision and difficulty in thinning.

[0004] Therefore, it is urgent to develop a fingerprint identification device which is less disturbed by strong light, temperature and dirt, has high identification precision and is thin. SUMMARY

[0005] In view of the above-mentioned disadvantages of the prior art, the present application aims to provide a fingerprint identification device and a manufacturing method and an identification method thereof, which are used to solve the problem that the identification ability of the fingerprint identification device in the prior art is greatly affected by strong light, temperature and dirt, and it is difficult to balance the identification precision and the thinness of the device.

[0006] To achieve the above object and other related objects, the present application provides a manufacturing method of a fingerprint identification device, comprising the following steps:

[0007] providing a substrate, wherein the substrate comprises a first surface and a second surface arranged oppositely;

[0008] forming an image sensor layer, a pressure luminescent film layer and an encapsulation layer which are sequentially stacked on the first surface of the substrate;

[0009] A backlight module is formed on the second surface of the substrate.

[0010] Optionally, the material of the substrate comprises one of glass, polyimide and polyethylene terephthalate.

[0011] Optionally, the method for forming the image sensor layer comprises forming a semiconductor layer on the first surface of the substrate, and forming a transistor in the semiconductor layer.

[0012] Optionally, the image sensor layer comprises one of an amorphous silicon-based TFT image sensor layer, a CMOS-based crystalline silicon image sensor layer and an organic photoelectric material-based image sensor layer.

[0013] Optionally, the pressure luminescent film layer comprises a pressure luminescent material, and the pressure luminescent material comprises one or more of ZnS:Cu 2+ , SrAl2O4:Eu 2+ and CaZnOS:Eu 3+ .

[0014] Optionally, the method for forming the pressure luminescent film layer comprises dispersing the pressure luminescent material in water or an organic solvent, coating and drying.

[0015] Optionally, the method for forming the pressure luminescent film layer comprises dispersing the pressure luminescent material in a polymer material, coating and curing.

[0016] Optionally, the encapsulation layer comprises an Al2O3 / SiO2 alternating structure layer and a light shielding layer, the Al2O3 / SiO2 alternating structure layer is located between the pressure luminescent film layer and the light shielding layer, the material of the light shielding layer comprises one or more of Al, Mo, Ag and Au, and the thickness of the light shielding layer ranges from 20 to 100 nm.

[0017] The application further provides a fingerprint identification device, comprising:

[0018] a substrate comprising a first surface and a second surface arranged oppositely;

[0019] an image sensor layer located on the first surface of the substrate;

[0020] a pressure luminescent film layer located on the side of the image sensor layer away from the substrate;

[0021] an encapsulation layer located on the side of the pressure luminescent film layer away from the image sensor layer;

[0022] a backlight module located on the second surface of the substrate.

[0023] Optionally, the pixel size of the image sensor in the image sensor layer ranges from 70 to 100 μm.

[0024] Optionally, the pressure luminescent film layer comprises a pressure luminescent material, and the pressure luminescent material comprises one or more of ZnS:Cu 2+ , SrAl2O4:Eu 2+ and CaZnOS:Eu 3+ .

[0025] Optionally, the film thickness of the pressure luminescent film layer ranges from 50 to 500 nm.

[0026] Optionally, the thickness of the encapsulation layer is not greater than 300 nm, and the water and oxygen permeability of the encapsulation layer is less than or equal to 10 -3 g·m -2 ·day -1 .

[0027] Optionally, the encapsulation layer comprises an Al2O3 / SiO2 alternating structure layer and a light shielding layer, the Al2O3 / SiO2 alternating structure layer is located between the pressure luminescent film layer and the light shielding layer, and the thickness of the light shielding layer ranges from 20 to 100 nm.

[0028] The present application also provides a recognition method of a fingerprint recognition device, which recognizes fingerprints by using the fingerprint recognition device, and the recognition method comprises the following steps:

[0029] Pressing the encapsulation layer;

[0030] The encapsulation layer transmits the pressure to the pressure luminescent film layer to make the pressure point of the pressure luminescent film layer produce fluorescence;

[0031] The image sensor layer converts the fluorescence signal into electric charge, and the electric charge is processed by an external algorithm circuit to obtain a bright field image of the pressed part of the fingerprint texture;

[0032] Comparing and matching the bright field image information with the fingerprint information in a fingerprint database.

[0033] As described above, the fingerprint identification device, the manufacturing method thereof and the identification method thereof of the present application, by sequentially arranging the image sensor layer, the pressure luminescent film layer and the encapsulation layer on the first surface of the substrate in the direction away from the second surface of the substrate, the finger presses the encapsulation layer to make the pressure luminescent film layer produce fluorescence under pressure, the image sensor layer receives the fluorescence and converts it into electric charge for processing to obtain the image information of the fingerprint, and then compares the fingerprint information with the fingerprint database to realize the identification of the fingerprint; a backlight module is arranged on the second surface of the substrate, and the light emitted by the backlight module is used to charge the luminescent film layer to realize the long-term stable operation of the fingerprint identification device. In addition, since the fingerprint identification device works by finger pressure, and the encapsulation layer has the characteristics of light shielding and water and oxygen permeability less than or equal to 10 - 3 g·m -2 ·day -1 , therefore, the fingerprint identification device has small interference of strong light, temperature and dirt, high identification accuracy and light and thin device, and has high industrial utilization value. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The flow chart of the manufacturing method of the fingerprint identification device of the present application is shown.

[0035] Figure 2 The cross-sectional structure schematic diagram of the substrate of the fingerprint identification device of the present application is shown.

[0036] Figure 3 The cross-sectional structure schematic diagram of forming the image sensor layer on the first surface of the substrate of the manufacturing method of the fingerprint identification device of the present application is shown.

[0037] Figure 4 The cross-sectional structure schematic diagram of forming the pressure luminescent film layer of the manufacturing method of the fingerprint identification device of the present application is shown.

[0038] Figure 5 The cross-sectional structure schematic diagram of forming the encapsulation layer of the manufacturing method of the fingerprint identification device of the present application is shown.

[0039] Figure 6 The cross-sectional structure schematic diagram of forming the backlight module on the second surface of the substrate of the manufacturing method of the fingerprint identification device of the present application is shown.

[0040] Figure 7 The dark field diagram of the fingerprint identification device of the present application without pressing is shown.

[0041] Figure 8 The gray value promotion diagram of the pressed point of the fingerprint identification device of the present application under pressure is shown.

[0042] Element number explanation

[0043] 1 substrate

[0044] 2 image sensor layer

[0045] 3 pressure luminescent film layer

[0046] 4 encapsulation layer

[0047] 5 backlight module

[0048] 6 pressure point DETAILED DESCRIPTION

[0049] The present application is herein described, by way of example only, with reference to certain embodiments thereof. It is to be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting, since the scope of the present application will be limited only by the appended claims.

[0050] Reference will now be made to the drawings, wherein: Figures 1 to 8 It is to be understood that the above-mentioned arrangement is merely to illustrate the basic concept of the present application, and thus the drawing only shows the components related to the present application, rather than being drawn according to the number, shape and size of the components in actual implementation. The shape, number and ratio of the components in actual implementation can be arbitrarily changed, and the layout pattern of the components can be more complicated.

[0051] Embodiment 1

[0052] The present embodiment provides a method for manufacturing a fingerprint recognition device, as shown in Figure 1 , which is a flow chart of the method for manufacturing the fingerprint recognition device, and includes the following steps:

[0053] S1: providing a substrate, the substrate including a first surface and a second surface arranged oppositely;

[0054] S2: forming an image sensor layer, a pressure luminescent film layer and an encapsulation layer in sequence on the first surface of the substrate;

[0055] S3: forming a backlight module on the second surface of the substrate.

[0056] First, refer to Figures 2 to 4 , the step S1 and the step S2 are performed: providing a substrate 1, the substrate 1 including a first surface and a second surface arranged oppositely; forming an image sensor layer 2, a pressure luminescent film layer 3 and an encapsulation layer 4 in sequence on the first surface of the substrate 1.

[0057] As an example, as shown in Figure 2As shown, the material of the substrate 1 includes one of glass, polyimide (PI) and polyethylene terephthalate (PET), or other suitable transparent materials.

[0058] Specifically, the substrate 1 is used to support the image sensor layer 2, and the substrate 1 includes one of flexible material and rigid material.

[0059] As an example, such as Figure 3 As shown, the image sensor layer 2 is formed on the first surface of the substrate 1.

[0060] As an example, a method for forming the image sensor layer 2 includes forming a semiconductor layer on a first surface of the substrate 1 and forming transistors in the semiconductor layer to obtain the image sensor layer 2.

[0061] Specifically, the semiconductor layer is a transparent semiconductor material.

[0062] Specifically, the method for forming the semiconductor layer includes one of physical vapor deposition and chemical vapor deposition, or other suitable methods.

[0063] Specifically, the method for forming the transistors in the image sensor layer 2 includes ion implantation or other suitable methods.

[0064] As an example, the image sensor layer 2 includes one of an amorphous silicon-based TFT image sensor layer, a CMOS-based crystalline silicon image sensor layer, and an image sensor layer based on organic optoelectronic materials, or other suitable image sensor layers.

[0065] Specifically, when the image sensor layer 2 is an image sensor layer based on amorphous silicon (A-Si) and organic optoelectronic materials, and the substrate 1 is made of PI, the fingerprint recognition device can be made into a flexible device.

[0066] Specifically, such as Figure 4 As shown, the pressure-emitting film layer 3 is formed on the side of the image sensor layer 2 that is opposite to the second surface of the substrate 1.

[0067] As an example, the pressure-emitting film layer 3 includes a pressure-emitting material, which comprises ZnS:Cu. 2+ SrAl2O4:Eu 2+ and CaZnOS:Eu 3+ It can be one or more of the following, or other suitable pressure-emitting materials or combinations of pressure-emitting materials.

[0068] Specifically, the pressure luminescent material in the pressure luminescent film layer 3 has a large number of defects, and the energy level of the defects is 0.6-1.2 eV to ensure that the carriers cannot spontaneously release energy to generate fluorescence at ambient temperature, and the defects can capture carriers (such as electrons or holes); when the pressure luminescent material is subjected to pressure, the carriers stored in the defects are released due to the disturbance of mechanical force, and the electrons or holes migrate to the luminescent center in the lattice to generate a compound, thereby releasing energy and emitting fluorescence.

[0069] For example, the method for forming the pressure luminescent film layer 3 includes coating or other suitable methods. In this embodiment, the pressure luminescent material is uniformly coated on the side of the image sensor layer 2 away from the second surface of the substrate 1 by using the coating method.

[0070] For example, the method for forming the pressure luminescent film layer 3 includes dispersing the pressure luminescent material in water or an organic solvent, then coating, and drying.

[0071] For example, the method for forming the pressure luminescent film layer 3 includes dispersing the pressure luminescent material in a polymer material, then coating, and curing.

[0072] Specifically, the pressure luminescent material is uniformly dispersed in a solvent or resin / gel, and then the solution containing the pressure luminescent material is coated on the side of the image sensor layer 2 away from the second surface of the substrate 1, and dried or cured to form the pressure luminescent film layer 3.

[0073] Specifically, the solvent includes one of water, ethanol, and n-heptane, and can also be other suitable non-toxic or low-toxic solvents.

[0074] Specifically, the pressure luminescent material is dispersed in the solvent to form a solution, and then the solution is coated on the surface of the image sensor layer 2, and dried at a drying temperature of 50-250°C to form the pressure luminescent film layer 3.

[0075] Specifically, the resin / gel includes one of epoxy resin, polydimethylsiloxane (PDMS), PET, and PI, and can also be other suitable materials.

[0076] Specifically, the pressure luminescent material is dispersed in the resin / gel to form a solution, and then the solution is coated on the surface of the image sensor layer 2, and the solution is cured by ultraviolet curing, thermal curing, or other suitable methods to form the pressure luminescent film layer 3.

[0077] Specifically, when the solution is cured by the thermal curing method, the curing temperature of the thermal curing ranges from 50 to 250°C.

[0078] As an example, the encapsulation layer 4 includes an Al2O3 / SiO2 alternating structure layer (not shown) and a light-shielding layer (not shown). The light-shielding layer includes a metal layer or other suitable film layer. The Al2O3 / SiO2 alternating structure layer is located between the pressure luminescent film layer and the light-shielding layer. The material of the light-shielding layer includes one or more of Al, Mo, Ag, and Au, or other suitable metal materials. The thickness of the light-shielding layer ranges from 20 to 100 nm.

[0079] As an example, the method for forming the encapsulation layer 4 includes at least one of atomic layer deposition, evaporation, physical vapor deposition, chemical vapor deposition, electroplating, and electroless plating. In this embodiment, firstly, an atomic layer deposition method is used to alternately deposit Al2O3 / SiO2 atomic deposition films on the side of the pressure luminescent film layer 3 away from the substrate 1, and the deposition is repeated twice, so that the thickness of the atomic deposition film layer is approximately 200 nm. Then, a metal layer is evaporated on the side of the atomic deposition film layer away from the substrate 1 as a light-shielding layer, and the thickness of the metal layer ranges from 20 to 100 nm.

[0080] Specifically, the encapsulation layer 4 is used to protect the pressure-emitting film layer 3 and the image sensor layer 2.

[0081] Specifically, the light-shielding layer in the encapsulation layer 4 has light-shielding properties to keep the image sensor layer 2 in a dark state, preventing ambient light from interfering with the recognition of the image sensor layer 2. Furthermore, without affecting the fingerprint recognition device, the side of the encapsulation layer 4 facing away from the substrate 1 can be further light-shielded. In this embodiment, to ensure absolute light shielding of the encapsulation layer 4, black paint is sprayed onto the side of the encapsulation layer 4 facing away from the substrate 1.

[0082] Please see again Figure 6 Step S3 is performed: a backlight module 5 is formed on the second surface of the substrate 1.

[0083] Specifically, when the pressure-emitting material is subjected to pressure, the charge carriers (electrons or holes) stored in its defects are released, resulting in a reduction of charge carriers in the defects. During subsequent pressing, the material's luminous efficiency is greatly reduced. In order to prevent the luminous efficiency of the pressure-emitting material from decreasing, a backlight module 5 is formed on the second surface of the substrate 1.

[0084] As an example, the method of fixing the backlight module 5 to the second surface of the substrate 1 includes mounting or other suitable methods.

[0085] Specifically, the photon energy emitted by the backlight in the backlight module 5 is matched with the absorption of the activator in the pressure luminescent material.

[0086] Specifically, the backlight in the backlight module 5 includes one of LED, quantum dot, and perovskite, or other suitable light sources. In this embodiment, SrAl2O4:Eu is selected. 2+ As a pressure-emitting material, due to Eu 2+ The excited state level (5d level) of the pressure-emitting material is relatively close to the bottom of the conduction band (approximately 0.3 eV), therefore an LED backlight with a wavelength of 460 nm was selected. The photons generated by the LED backlight will direct the light to the luminescent center Eu of the pressure-emitting material. 2+ Excited to the 5d level, Eu 2+ Electrons will transition from the 5d energy level to the conduction band. Subsequently, electrons move freely in the conduction band and are captured and stored by defects, thereby replenishing the charge carriers in the defects. This ensures that the luminous efficiency of the pressure-emitting material remains unchanged, thus enabling the long-term use of the fingerprint recognition device.

[0087] The fingerprint recognition device manufacturing method of this embodiment utilizes the characteristics of the pressure-emitting film layer 3 generating fluorescence under pressure and the image sensor layer 2 converting the received fluorescence into charge and further processing it to obtain image information. The image sensor layer 2, the pressure-emitting film layer 3, and the encapsulation layer 4 are sequentially formed on the first surface of the substrate 1 along the direction away from the second surface of the substrate 1. The encapsulation layer 4 is used to block the interference of ambient light, thereby realizing fingerprint recognition, and is less affected by strong light fingerprints, temperature, and dirt. A backlight module 5 is fixed on the second surface of the substrate 1 to compensate for the loss of charge carriers after the pressure-emitting material layer emits light, thereby realizing the long-term stable operation of the fingerprint recognition device.

[0088] Example 2

[0089] This embodiment provides a fingerprint recognition device, such as... Figure 6 The diagram shows a cross-sectional view of the fingerprint recognition device, including a substrate 1, an image sensor layer 2, a pressure-emitting film layer 3, an encapsulation layer 4, and a backlight module 5. The substrate 1 includes a first surface and a second surface disposed opposite to each other. The image sensor layer 2 is located on the first surface of the substrate 1. The pressure-emitting film layer 3 is located on the side of the image sensor layer 2 facing away from the substrate 1. The encapsulation layer 4 is located on the side of the pressure-emitting film layer 3 facing away from the image sensor layer 2. The backlight module 5 is located on the second surface of the substrate 1.

[0090] As an example, the pixel size range of the image sensor in the image sensor layer 2 is 70 to 100 μm.

[0091] Specifically, in order to ensure the resolution of the image processed by the image sensor and to enable the fingerprint recognition device to adapt to the fingerprint recognition of different groups of people, the pixel size of the image sensor is no greater than 100μm.

[0092] Specifically, the sensitivity of the fingerprint recognition device affects fingerprint recognition. When the sensitivity of the fingerprint recognition device is too low, the signal-to-noise ratio (the ratio of signal to noise) of the obtained image deteriorates, causing the fingerprint recognition device to be unable to recognize the fingerprint. In order to ensure the sensitivity of the fingerprint recognition device, the pixel size of the image sensor is not less than 70μm.

[0093] As an example, the pressure-emitting film layer 3 includes a pressure-emitting material, which comprises ZnS:Cu. 2+ SrAl2O4:Eu 2+ and CaZnOS:Eu 3+ One or more of these, or other suitable combinations of materials.

[0094] As an example, the thickness of the pressure-emitting film layer 3 ranges from 50 to 500 nm.

[0095] As an example, the thickness of the encapsulation layer 4 is no greater than 300 nm, and the water and oxygen permeability of the encapsulation layer 4 is less than or equal to 10. -3 g·m -2 ·day -1 .

[0096] Specifically, the encapsulation layer 4 includes an Al2O3 / SiO2 alternating structure layer and a light-shielding layer. The Al2O3 / SiO2 alternating structure layer is located between the pressure luminescent film layer and the light-shielding layer, and the thickness of the light-shielding layer ranges from 20 to 100 nm.

[0097] Specifically, the encapsulation layer 4 transmits the pressure applied to the texture of the finger to the pressure-emitting film layer 3.

[0098] Specifically, the encapsulation layer 4 has good sealing reliability to prevent liquids and dirt from the external environment from entering the device and affecting the operation of the fingerprint recognition device.

[0099] Specifically, the encapsulation layer 4 has light-shielding properties to prevent ambient light from affecting the image sensor layer 2's recognition of the fluorescence emitted by the pressure-emitting film layer 3.

[0100] The fingerprint recognition device in this embodiment achieves a thinner and lighter design through the design of the substrate 1, the image sensor layer 2, the pressure luminescent film layer 3, the encapsulation layer 4, and the backlight module. Furthermore, through the reasonable design of the pixel size of the image sensor in the image sensor layer 2, it achieves fingerprint recognition suitable for different groups of people, and the fingerprint recognition accuracy is high.

[0101] Example 3

[0102] This embodiment provides a fingerprint recognition method using a fingerprint recognition device. The fingerprint recognition device from Embodiment 2 is used for fingerprint recognition, and the fingerprint recognition method includes the following steps:

[0103] A pressing operation is performed on the encapsulation layer;

[0104] The encapsulation layer transmits pressure to the pressure-emitting film layer, causing the pressure-receiving points of the pressure-emitting film layer to fluoresce.

[0105] The image sensor layer converts the fluorescence signal into electrical charge, which is then processed by an external algorithm circuit to obtain a bright field image of the area where the finger texture is pressed.

[0106] The bright field image information is compared and matched with the fingerprint information in the fingerprint database.

[0107] Specifically, such as Figure 7 As shown, when there is no pressing operation on the encapsulation layer 4, the pressure-emitting film layer 3 does not produce fluorescence, the image sensor layer 2 cannot receive fluorescence, and cannot generate conversion charge. Therefore, after algorithm processing, a dark field image is displayed.

[0108] Specifically, such as Figure 8 As shown, when the encapsulation layer 4 is pressed, the encapsulation layer 4 transmits pressure to the pressure-emitting film layer 3. The pressure-receiving point 6 of the pressure-emitting film layer 3 generates fluorescence. The image sensor layer 2 receives the fluorescence emitted by the pressure-receiving point 6 and converts the received fluorescence signal into charge. After processing by the external algorithm circuit, the gray value of the pressure-receiving point 6 is increased, resulting in a bright field image of the finger texture pressing area that is higher than the background value, i.e., the fingerprint image information. The bright field image information is then compared and matched with the fingerprint information in the fingerprint database, thereby realizing fingerprint recognition.

[0109] The fingerprint recognition method of this embodiment utilizes the characteristics of the encapsulation layer 4 transmitting pressure, the pressure-emitting film layer 3 generating fluorescence under pressure, and the image sensor layer 2 receiving fluorescence and converting it into charge, which can be processed by external algorithm circuits to obtain bright field image information. Fingerprint recognition is achieved through the combination of the encapsulation layer 4, the pressure-emitting film layer 3, the image sensor layer 2, and the external circuit.

[0110] In summary, the fingerprint recognition device, manufacturing method, and recognition method of the present invention utilize the characteristics of the encapsulation layer transmitting pressure, the pressure-emitting film layer generating fluorescence under pressure, and the image sensor layer receiving the fluorescence and converting it into charge, which can then be processed by an external algorithm circuit to obtain bright field image information. Fingerprint recognition is achieved through the combination of the encapsulation layer, the pressure-emitting film layer, the image sensor layer, and the external algorithm circuit. Furthermore, by utilizing the light-shielding and sealing properties of the encapsulation layer and the reasonable control of the pixel size of the image sensor layer, the fingerprint recognition device is less affected by strong light, temperature, and dirt, resulting in high recognition accuracy and a thin and lightweight design. In addition, by setting up a backlight module to compensate for the loss of charge carriers in the defects after the pressure-emitting material emits light, the fingerprint recognition device achieves long-term stable operation. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0111] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method of fabricating a fingerprint recognition device, the method comprising: The method comprises the following steps: ​ providing a substrate comprising a first surface and a second surface arranged oppositely; forming an image sensor layer, a pressure luminescent film layer and an encapsulation layer on the first surface of the substrate in sequence, wherein the encapsulation layer comprises an Al2O3 / SiO2 alternating structure layer and a light shielding layer, the Al2O3 / SiO2 alternating structure layer is located between the pressure luminescent film layer and the light shielding layer, and the thickness of the encapsulation layer is not greater than 300 nm; forming a backlight module on the second surface of the substrate to compensate for the loss of carriers after the pressure luminescent film layer emits light.

2. The method of claim 1, wherein: The material of the substrate comprises one of glass, polyimide and polyethylene terephthalate.

3. The method of claim 1, wherein: The method for forming the image sensor layer comprises forming a semiconductor layer on the first surface of the substrate and forming a transistor in the semiconductor layer.

4. The method of claim 1, wherein: The image sensor layer comprises one of an amorphous silicon-based TFT image sensor layer, a CMOS-based crystalline silicon image sensor layer and an organic photoelectric material-based image sensor layer.

5. The method of claim 1, wherein: The pressure luminescent film layer includes a pressure luminescent material including one or more of ZnS:Cu 2+ , SrAl2O4:Eu 2+ , and CaZnOS:Eu 3+ .

6. The method of claim 1, wherein: The method for forming the pressure luminescent film layer comprises dispersing pressure luminescent material in water or an organic solvent, coating and drying.

7. The method of claim 1, wherein: The method for forming the pressure luminescent film layer comprises dispersing pressure luminescent material in a polymer material, coating and curing.

8. The method of claim 1, wherein: The material of the light shielding layer comprises one or more of Al, Mo, Ag and Au, and the thickness of the light shielding layer ranges from 20 to 100 nm.

9. A fingerprint recognition device, characterized by The method comprises: a substrate comprising a first surface and a second surface arranged oppositely; an image sensor layer located on the first surface of the substrate; a pressure luminescent film layer located on the side of the image sensor layer away from the substrate; an encapsulation layer located on the side of the pressure luminescent film layer away from the image sensor layer, wherein the encapsulation layer comprises an Al2O3 / SiO2 alternating structure layer and a light shielding layer, the Al2O3 / SiO2 alternating structure layer is located between the pressure luminescent film layer and the light shielding layer, and the thickness of the encapsulation layer is not greater than 300 nm; a backlight module located on the second surface of the substrate and used to compensate for the loss of carriers after the pressure luminescent film layer emits light.

10. The fingerprint recognition apparatus according to claim 9, wherein: The pixel size of the image sensor in the image sensor layer ranges from 70 to 100 μm.

11. The fingerprint recognition apparatus according to claim 9, wherein: The pressure luminescent film layer includes a pressure luminescent material including one or more of ZnS:Cu 2+ , SrAl2O4:Eu 2+ , and CaZnOS:Eu 3+ .

12. The fingerprint recognition apparatus of claim 9, wherein: The film thickness of the pressure luminescent film layer ranges from 50 to 500 nm.

13. The fingerprint recognition apparatus of claim 9, wherein: The encapsulation layer has a water oxygen transmission rate of less than or equal to 10 -3 g·m -2 ·day -1 .

14. The fingerprint recognition apparatus of claim 9, wherein: The thickness of the light shielding layer ranges from 20 to 100 nm.

15. A method of identification of a fingerprint recognition device, characterized by: The method for identifying a fingerprint using the fingerprint identification device according to any one of claims 9-14 comprises the following steps: performing a pressing operation on the encapsulation layer; the encapsulation layer transmits pressure to the pressure luminescent film layer to make the pressure luminescent film layer generate fluorescence at the pressure point; the image sensor layer converts the fluorescence signal into electric charge, which is processed by an external algorithm circuit to obtain a bright field image of the pressed part of the fingerprint texture; comparing and matching the bright field image information with the fingerprint information in a fingerprint database.

Images