WO2021175101A1 - Mousse électroconductrice, module d'empreinte digitale ultrasonore, ensemble écran d'affichage et appareil électronique - Google Patents

Mousse électroconductrice, module d'empreinte digitale ultrasonore, ensemble écran d'affichage et appareil électronique Download PDF

Info

Publication number
WO2021175101A1
WO2021175101A1 PCT/CN2021/075723 CN2021075723W WO2021175101A1 WO 2021175101 A1 WO2021175101 A1 WO 2021175101A1 CN 2021075723 W CN2021075723 W CN 2021075723W WO 2021175101 A1 WO2021175101 A1 WO 2021175101A1
Authority
WO
WIPO (PCT)
Prior art keywords
conductive foam
layer
fingerprint module
particle size
ultrasonic
Prior art date
Application number
PCT/CN2021/075723
Other languages
English (en)
Chinese (zh)
Inventor
刘宣宣
Original Assignee
欧菲光集团股份有限公司
江西欧迈斯微电子有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 欧菲光集团股份有限公司, 江西欧迈斯微电子有限公司 filed Critical 欧菲光集团股份有限公司
Publication of WO2021175101A1 publication Critical patent/WO2021175101A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0073—Shielding materials
    • H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/04—Carbon
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/08—Metals
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V40/00—Recognition of biometric, human-related or animal-related patterns in image or video data
    • G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
    • G06V40/12—Fingerprints or palmprints
    • G06V40/13—Sensors therefor
    • G06V40/1306—Sensors therefor non-optical, e.g. ultrasonic or capacitive sensing
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/08—Metals
    • C08K2003/085—Copper
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/08—Metals
    • C08K2003/0862—Nickel

Definitions

  • the invention relates to the technical field of fingerprint identification, in particular to a conductive foam, an ultrasonic fingerprint module, a display screen assembly and an electronic device.
  • the ultrasonic fingerprint module is attached to the display panel of the electronic device using glue, so that the display panel can have a fingerprint recognition function.
  • the ultrasonic fingerprint module is very easy to radiate a large number of electromagnetic waves when it is working, and it becomes a radiation interference source. If the ultrasonic fingerprint module is not protected from EMI, it will not only affect the performance of the ultrasonic fingerprint module itself, if the signal strength may be reduced, the fingerprint image collected will not be affected. It is clear, and it will also cause electromagnetic interference to other electronic components in the electronic equipment, which will affect the normal operation.
  • the present invention provides a conductive foam.
  • the conductive foam includes the following mass percentages of components uniformly mixed: 1.5% to 2.5% carbon powder, 3% to 5% copper powder, 3% to 5% nickel powder, and For the remainder of the resin, the particle size of the carbon powder is less than or equal to 0.005 mm, the particle size of the copper powder is less than or equal to 0.01 mm, and the particle size of the nickel powder is less than or equal to 0.01 mm.
  • the above-mentioned conductive foam can be used to make a shielding layer.
  • the shielding layer can be attached to the substrate in the ultrasonic fingerprint module.
  • the shielding layer can reflect the ultrasonic waves emitted by the piezoelectric layer toward the side of the substrate.
  • the ultrasonic waves emitted from the piezoelectric layer can resonate with the ultrasonic waves emitted from the piezoelectric layer toward the side of the electrode layer, thereby enhancing the signal strength of the ultrasonic waves used to collect fingerprint images, making the collected fingerprint images clearer.
  • the shielding layer also has a good electromagnetic shielding effect and can realize EMI protection.
  • the mass percentage of the carbon powder is 2% to 2.5%. In this way, the carbon powder of this mass percentage not only enables the conductive foam to have a good conductive effect, but also has a small influence on the foaming of the conductive foam.
  • the particle size of the carbon powder is ⁇ 0.001 mm.
  • the shielding layer made of conductive foam made of carbon powder within the particle size range value can increase the SNR value of the ultrasonic fingerprint module, so that the fingerprint image collected by the ultrasonic fingerprint module is clearer.
  • the mass percentage of the copper powder is 3%-4%. In this way, the copper powder of this mass percentage will not excessively increase the surface resistance value of the conductive foam, and the foaming effect of the conductive foam is also small.
  • the particle size of the copper powder is less than or equal to 0.005 mm.
  • the shielding layer made of conductive foam formed of copper powder in the particle size range value can increase the SNR value of the ultrasonic fingerprint module, so that the fingerprint image collected by the ultrasonic fingerprint module is clearer.
  • the mass percentage of the nickel powder is 3%-4%. In this way, the nickel powder of this mass percentage will not excessively increase the surface resistance of the conductive foam, and it will have a small influence on the foaming of the conductive foam.
  • the particle size of the nickel powder is less than or equal to 0.005 mm.
  • the shielding layer made of conductive foam made of nickel powder in the particle size range value can increase the SNR value of the ultrasonic fingerprint module, so that the fingerprint image collected by the ultrasonic fingerprint module is clearer.
  • the density of the conductive foam is less than or equal to 18 kg/m 3 . In this way, the impedance value of the conductive foam in this density range is closer to the impedance value of air.
  • the shielding layer made of conductive foam and the substrate acoustic impedance of the ultrasonic fingerprint module have a large difference, and the ultrasonic signal can be greatly affected. reflection.
  • the present invention also provides an ultrasonic fingerprint module, including:
  • a piezoelectric layer which is attached to the substrate
  • An electrode layer which is attached to the side of the piezoelectric layer away from the substrate;
  • the shielding layer is made of the above-mentioned conductive foam, the shielding layer is attached to the side of the substrate away from the piezoelectric layer, and the shielding layer can be grounded to shield electromagnetic signals.
  • the shielding layer can reflect the ultrasonic waves emitted by the piezoelectric layer toward the side of the substrate, and the reflected ultrasonic waves and the ultrasonic waves emitted by the piezoelectric layer toward the side of the electrode layer can form resonance, thereby enhancing the collection of fingerprint images.
  • the signal strength of the ultrasonic wave makes the collected fingerprint image clearer.
  • the shielding layer also has a good electromagnetic shielding effect and can realize EMI protection.
  • the ultrasonic fingerprint module further includes a circuit board, the circuit board is electrically connected to the substrate and the electrode layer, and the shielding layer is electrically connected to the circuit board to pass The circuit board realizes the grounding of the shielding layer.
  • the electrode layer can transmit and receive ultrasonic waves under the circuit board, and the shielding layer can be connected to the circuit board to realize convenient and fast grounding of the shielding layer, thereby realizing EMI protection.
  • the present invention also provides a display screen assembly, including:
  • the electrode layer is attached to the display panel through the adhesive layer, and the piezoelectric layer can emit ultrasonic waves that penetrate the display panel and receive reflected ultrasonic waves.
  • the shielding layer can reflect the ultrasonic waves emitted from the piezoelectric layer toward the side where the substrate is located, and the reflected ultrasonic waves and the ultrasonic waves emitted from the piezoelectric layer toward the side where the electrode layer is located can form resonance, thereby enhancing the fingerprint image collection.
  • the signal strength of the ultrasound makes the captured fingerprint image clearer.
  • the shielding layer also has a good electromagnetic shielding effect and can realize EMI protection.
  • the display screen assembly further includes a protective cover plate connected to a side of the display panel facing away from the adhesive layer.
  • the protective cover can enhance the structural strength.
  • the adhesive layer is a black adhesive layer.
  • the black adhesive layer can prevent light leakage of the display panel from causing different colors, and easily form an integrated black effect with the display panel.
  • the present invention also provides an electronic device, including:
  • the above-mentioned display screen assembly is connected with the terminal body.
  • the ultrasonic fingerprint module can collect clear and uniform fingerprint images.
  • FIG. 1 is a schematic structural diagram of an electronic device provided by an embodiment of the present invention.
  • FIG. 2 is a schematic diagram of the structure of the display screen assembly in FIG. 1;
  • Figure 3 shows the fingerprint image tested with the ultrasonic fingerprint function software.
  • the present invention will take a smart phone as an example to describe the electronic device 10.
  • the electronic device 10 of the present invention can be any device with communication and storage functions, such as a smart phone, a tablet computer, a notebook computer, a portable phone, a video phone, a digital still camera, an e-book reader,
  • the presentation form of the electronic device 10 such as a portable multimedia player (PMP), a mobile medical device, and other smart terminals is not limited in any way.
  • PMP portable multimedia player
  • wearable devices such as smart watches, it is also applicable to the electronic device 10 of each embodiment of the present invention.
  • the electronic device 10 includes a terminal body 11 and a display screen assembly 12 connected to the terminal body 11.
  • the terminal body 11 includes a middle frame 13 and a back cover 14.
  • the display screen assembly 12 and the back cover 14 are respectively connected to opposite sides of the middle frame 13 and enclosed to form a receiving space, which can be used for installation
  • the middle frame 13 and the back cover 14 may be integrally formed or detachably connected.
  • the side of the display screen assembly 12 facing away from the back cover 14 includes a displayable area 121.
  • the displayable area 121 can constitute all or a part of the side of the display screen assembly 12 facing away from the back cover 14.
  • the displayable area 121 is used for displaying image information.
  • the display screen assembly 12 includes a display panel 100 and a protective cover 200.
  • the protective cover 200 is connected to a side of the display panel 100 facing away from the rear cover 14.
  • the protective cover 200 may be A glass cover plate or a plastic cover plate is used to protect the display panel 100 from external interference.
  • the displayable area 121 may be formed on all or a part of the protective cover plate 200 on the side facing the back cover 14.
  • the protective cover 200 may be omitted.
  • a light-shielding layer 110 is provided on the periphery of the display panel 100, and the light-shielding layer 110 is attached to the protective cover 200.
  • the light-shielding layer 110 may be black graphite, and the black graphite may be formed on the protective cover 200 by printing. In order to absorb the light from the periphery of the display panel 100, the devices inside the containing space are shielded.
  • the display panel 100 may adopt an LCD (Liquid Crystal Display) screen for displaying information.
  • the LCD screen may be a TFT (Thin Film Transistor) screen or an IPS (In-Plane Switching) screen. Conversion) screen or SLCD (Splice Liquid Crystal Display) screen.
  • the display panel 100 may use an OLED (Organic Light-Emitting Diode, organic electro-laser display) screen for displaying information, and the OLED screen may be an AMOLED (Active Matrix Organic Light-Emitting Diode, active matrix organic light emitting diode). Diode) screen or Super AMOLED (Super Active Matrix Organic Light Emitting Diode) screen or Super AMOLED Plus (Super Active Matrix Organic Light Emitting Diode Plus, Magic screen) screen, here No longer.
  • AMOLED Active Matrix Organic Light Emitting Diode
  • Magic screen Super Active Matrix Organic Light Emitting Diode Plus
  • the display screen assembly 12 includes an ultrasonic fingerprint module 300, and the ultrasonic fingerprint module 300 is disposed in the accommodating space and located below the display panel 100 in the drawing shown in FIG. 2.
  • the ultrasonic fingerprint module 300 can be manufactured first, and after the manufacturing is completed, the ultrasonic fingerprint module 300 can be attached to the bottom of the display panel 100.
  • the ultrasonic fingerprint module 300 can scan a user's fingerprint using ultrasonic waves and recognize the fingerprint. Taking the embodiment shown in FIG. 2 as an example, the top surface of the ultrasonic fingerprint module 300 faces the display panel 100, and the ultrasonic fingerprint module 300 can transmit ultrasonic waves penetrating the display panel 100 and receive reflections from the user's finger touching the display panel 100 The ultrasonic waves, while converting the reflected ultrasonic waves into electrical signals.
  • the top surface of the ultrasonic fingerprint module 300 is shown in FIG. 2 as the surface where the ultrasonic fingerprint module 300 and the display panel 100 are attached.
  • the display panel 100 can conduct ultrasonic waves, when the user touches the position on the outer surface of the display panel 100 opposite to the ultrasonic fingerprint module 300, the ultrasonic waves emitted by the ultrasonic fingerprint module 300 are transmitted to the user's finger through the display panel 100.
  • the reflected ultrasonic waves can be generated, and then the ultrasonic fingerprint module 300 receives the reflected ultrasonic waves and converts the reflected ultrasonic waves into electrical signals.
  • the ultrasonic fingerprint module 300 can generate the collected fingerprint images according to these electrical signals and perform fingerprint identification.
  • the above fingerprint recognition process uses the difference in acoustic impedance when the ultrasonic wave propagates between the fingerprint ridge (skin) and the fingerprint ridge (air), so that the location of the fingerprint ridge and the ridge can be distinguished, and the fingerprint recognition of the user can be realized.
  • the ultrasonic fingerprint module 300 can compare the collected fingerprints with the standard fingerprints stored in the database. It is understandable that the standard fingerprint refers to the correct fingerprint stored in the database by the user himself.
  • the electronic device 10 is provided with a controller, which may be a central processing unit of the electronic device 10, and the controller is electrically connected to the ultrasonic fingerprint module 300.
  • the ultrasonic fingerprint module 300 can send the comparison result to the controller, and the controller controls whether the display panel 100 is activated according to the comparison result, or whether the application software in the display panel 100 confirms the payment.
  • the ultrasonic fingerprint module 300 sends the comparison result to the controller, and the controller controls the display panel 100 to light up.
  • the ultrasonic fingerprint module 300 sends the comparison result to the controller, and the controller controls the display panel 100 to close.
  • the fingerprint collected by the ultrasonic fingerprint module 300 is the characteristic information of the user's fingerprint
  • the characteristic information of the user's fingerprint is collected by the ultrasonic fingerprint module 300, and the characteristic information of the collected fingerprint is combined with the standard characteristic information in the database. Comparison.
  • the ultrasonic waves emitted by the ultrasonic fingerprint module 300 can be reflected after passing through the display panel 100, and the ultrasonic fingerprint module 300 can perform fingerprint identification based on the reflected ultrasonic waves. , Achieve fingerprint recognition under the screen. Since the ultrasonic fingerprint module 300 does not need to be arranged in the frame of the electronic device 10, the area of the visible area of the electronic device 10 is increased.
  • the ultrasonic fingerprint module 300 includes a substrate 310, a piezoelectric layer 320, an electrode layer 330 and a circuit board 340.
  • the substrate 310 may be a TFT substrate.
  • the TFT substrate includes a base layer, a plurality of thin film transistors arranged in an array on the base layer, and lines for connecting the thin film transistors on the base layer.
  • the TFT substrate can perform processing such as amplifying the electrical signal.
  • a thin film can be selected as the base layer for the TFT substrate.
  • the TFT substrate with a thin film as the base layer can meet the flexibility requirements of the entire electronic device 10.
  • the piezoelectric layer 320 is attached to the substrate 310.
  • the piezoelectric layer 320 is composed of piezoelectric material and is used to transmit and receive ultrasonic waves through the piezoelectric effect.
  • the material of the piezoelectric layer 320 is a ferroelectric polymer.
  • the material of the piezoelectric layer 320 can be It is P (VDF-TrFE) (polyvinylidene chloride and trifluoroethylene polymer). It can be understood that the material of the piezoelectric layer 320 is not limited to the above materials.
  • the material of the piezoelectric layer 320 may also be a homopolymer of polyvinylidene chloride (PVDC), a copolymer of polyvinylidene chloride, or polytetrafluoroethylene.
  • PVDC polyvinylidene chloride
  • DTPAB diisopropylamine bromide
  • the electrode layer 330 is attached to the side of the piezoelectric layer 320 away from the substrate 310, and the electrode layer 330 and the substrate 310 cooperate to accommodate the piezoelectric layer 320.
  • the material of the electrode layer 330 may be silver.
  • the electrode layer 330 may be prepared by screen printing silver paste on one side of the piezoelectric layer 320 and then sintering.
  • the electrode layer 330 is attached to the inner surface of the display panel 100, that is, the electrode layer 330 is attached to the side of the display panel 100 away from the protective cover 200.
  • the display screen assembly 12 includes an adhesive layer 400, the electrode layer 330 is attached to the display panel 100 through the adhesive layer 400, and the adhesive layer 400 may be a double-sided adhesive.
  • the adhesive layer 400 is a black adhesive layer, and the black adhesive layer can prevent the display panel 100 from leaking light and cause different colors, and it is easy to form an integrated black effect with the display panel 100.
  • the circuit board 340 is electrically connected to the substrate 310, and the circuit board 340 is also electrically connected to the electrode layer 330.
  • FIG. 2 illustrates that the circuit board 340 is electrically connected to the substrate 310 through the first anisotropic conductive adhesive 301, and the circuit board 340 is also electrically connected to the electrode layer 330 through the second anisotropic conductive adhesive 302.
  • the circuit board 340 may specifically be a flexible circuit board, and the technical feature of the circuit board 340 may be applied to other embodiments.
  • the circuit board 340 When assembling the display screen assembly 12, the circuit board 340 can be placed outside the path through which the ultrasonic wave is transmitted to the outer surface of the display panel 100, that is, the ultrasonic wave will not pass through the circuit board 340 during the process of transmitting the ultrasonic wave to the contact object, which can avoid The influence of the circuit board 340 on the conduction of ultrasonic waves.
  • a driver chip is provided on the circuit board 340, and the driver chip is, for example, an ASIC (Application Specific Integrated Circuit) chip.
  • the driving chip provides a control signal to the piezoelectric layer 320, for example, sends a high-frequency electrical signal to the piezoelectric layer 320, so that the piezoelectric layer 320 emits ultrasonic waves.
  • the driving chip also receives the electrical signal obtained by converting the reflected ultrasonic wave by the piezoelectric layer 320 to identify the fingerprint.
  • Both the substrate 310 and the electrode layer 330 are electrically connected to the driving chip. Take the example shown in FIG.
  • the circuit board 340 is installed in this way to avoid interference with ultrasonic conduction.
  • the working principle of the above-mentioned ultrasonic fingerprint module 300 is: when performing fingerprint recognition, the user places a finger on the outer surface of the display panel 100, and the driving chip applies corresponding high-frequency electricity to the electrode layer 330 through the second anisotropic conductive glue 302 At the same time, a high-frequency electrical signal is applied to the substrate 310 through the first anisotropic conductive adhesive 301, and the piezoelectric layer 320 is activated under the excitation of the electrode layer 330 and the substrate 310, so that the piezoelectric layer 320 emits ultrasonic waves. The ultrasonic wave propagates upwards until it reaches the outer surface of the display panel 100 and is reflected after touching the user's finger.
  • the piezoelectric layer 320 receives the reflected ultrasonic wave and converts it into an electrical signal, which is then processed (for example, amplified) by the substrate 310. It is transferred to the driver chip and converted into an image to identify the fingerprint. Due to the difference in ultrasonic acoustic wave impedance between the skin and the air, the location of the fingerprint ridge and the fingerprint valley can be distinguished, and the user's fingerprint can be collected according to the difference of the reflected ultrasonic waves.
  • circuit board 340 in the ultrasonic fingerprint module 300 of each embodiment of the present invention can be omitted.
  • the substrate 310 and the electrode layer 330 can be directly connected to the electronic device.
  • the circuit main board in 10 is electrically connected.
  • the ultrasonic fingerprint module 300 can realize fingerprint recognition under the screen, because the ultrasonic fingerprint module 300 emits ultrasonic waves under high-frequency and high-pressure conditions, it is extremely easy to generate a large number of electromagnetic waves and become a radiation interference source. If the ultrasonic fingerprint module 300 is not treated with EMI protection, the performance of the ultrasonic fingerprint module 300 may be easily affected, for example, the signal strength (SNR value) of the ultrasonic fingerprint module 300 may be reduced, and noise may be generated. In addition, the electromagnetic waves radiated by the ultrasonic fingerprint module 300 will affect the operation of other electronic components. Based on this, in an embodiment, the ultrasonic fingerprint module 300 further includes a shielding layer 350.
  • the shielding layer 350 is attached to the side of the substrate 310 away from the piezoelectric layer 320.
  • the shielding layer 350 can reflect the ultrasonic waves emitted by the piezoelectric layer 320 toward the side where the substrate 310 is located, and the reflected ultrasonic waves and the piezoelectric layer 320 toward the electrode layer 330
  • the ultrasonic wave emitted from the side where it is located can form resonance, thereby enhancing the signal strength of the ultrasonic wave collecting the fingerprint image, making the fingerprint image collected more clear.
  • the shielding layer 350 can be grounded to achieve EMI shielding protection and improve the quality of fingerprint images collected by the ultrasonic fingerprint module 300.
  • the shielding layer 350 is electrically connected to the circuit board 340, and the shielding layer 350 can be specifically connected to the bare copper area ground of the circuit board 340, so as to realize the grounding of the shielding layer 350 through the circuit board 340.
  • FIG. 2 illustrates that the shielding layer 350 is connected to the ground wire of the bare copper area of the circuit board 340 through the conductive member 360.
  • the conductive member 360 may be a conductive cloth or a metal tape (such as a copper foil tape).
  • the shielding layer 350 may also be connected to the ground wire of the bare copper area of the display panel 100 to realize the grounding of the shielding layer 350.
  • the shielding layer 350 can also be connected to the terminal body 11 (for example, the middle frame 13 or the back cover 14) to realize the grounding of the shielding layer 350.
  • the shielding layer 350 of each embodiment of the present invention is made of conductive foam.
  • the conductive foam includes the following mass percentages of components uniformly mixed: 1.5% to 2.5% carbon powder, 3% to 5% copper powder, 3% to 5% nickel powder, and the balance of resin.
  • the particle size is less than or equal to 0.005mm
  • the particle size of the copper powder is less than or equal to 0.01mm
  • the particle size of the nickel powder is less than or equal to 0.01mm.
  • the resin can be, for example, polyurethane or acrylic resin.
  • carbon powder, copper powder, and nickel powder in the above particle size range are added to the resin to be uniformly mixed with the resin during production, so that the resin is foamed to form conductive foam .
  • the formed conductive foam can realize all-round conductivity, that is, the conductive foam can conduct electricity in the three directions of X, Y, and Z. This is precisely because the resin is uniformly filled with carbon powder, copper powder, and nickel powder. Achievable.
  • carbon powder as a conductive material has low conductive resistance, and carbon powder is used for EMI protection. Since the surface roughness of the shielding layer 350 formed of conductive foam will affect the performance of the fingerprint test image, the particle size of the carbon powder is kept within 0.005 mm. Further, the particle size of the carbon powder is ⁇ 0.001mm.
  • the conductive foam with the above-mentioned particle size carbon powder can prepare a shielding layer 350 with a smooth surface and a small roughness, and the roughness can achieve Rz ⁇ 0.001mm. If the mass percentage of the carbon powder filled in the conductive foam is too low, the surface impedance of the shielding layer 350 will be larger after the formation of the shielding layer 350, which cannot meet the conductive performance requirements.
  • the mass percentage of the carbon powder is too high, the conductive foam will be In the production process, it is more difficult to disperse the toner, and there is a risk of agglomeration. Therefore, the mass percentage of the carbon powder filled in the conductive foam of the present invention can be controlled at 1.5% to 2.5%. Further, in an embodiment, the mass percentage of the carbon powder can be controlled at 2% to 2.5%.
  • Copper powder and nickel powder can further improve the conductive performance of the conductive foam.
  • the particle size of the copper powder and nickel powder is kept within 0.01 mm. In an embodiment, the particle size of the copper powder is less than or equal to 0.005 mm, and the particle size of the nickel powder is less than or equal to 0.005 mm.
  • the surface impedance of the shielding layer 350 will be large after the formation of the shielding layer 350, which cannot meet the conductive performance requirements, and if the mass percentage of copper powder and nickel powder is too high If it is high, it will affect the foaming process of the conductive foam, which is not conducive to the foaming of the conductive foam. The foaming of the conductive foam is affected and the density cannot be reduced.
  • the mass percentage of copper powder and nickel powder filled in the conductive foam of the present invention is controlled within a relatively small range.
  • the mass percentage of copper powder and nickel powder can be controlled between 3% and 5%. Further, the mass percentage of copper powder and nickel powder can be controlled within 3% to 4%.
  • the shielding layer 350 made of the above conductive foam is attached to the substrate 310 in the ultrasonic fingerprint module 300, when the ultrasonic fingerprint module 300 is working, the shielding layer 350 can emit the piezoelectric layer 320 toward the side where the substrate 310 is located.
  • the reflected ultrasonic waves can resonate with the ultrasonic waves emitted from the piezoelectric layer 320 toward the side of the electrode layer 330, thereby enhancing the signal strength of the ultrasonic waves used to collect fingerprint images, making the collected fingerprint images clearer.
  • the formed shielding layer 350 also has a good electromagnetic shielding effect and can realize EMI protection.
  • Table 1 lists the impact of the conductive foam on the clarity of the fingerprint test image when the density is different.
  • the fingerprint test can be performed by attaching the shielding layer 350 to the substrate 310, and then attaching the electrode layer 330 to the display panel 100, by attaching a real finger or a fake finger with fingerprint lines to the display panel 100 for testing.
  • the clarity of the fingerprint test image can be obtained by measuring the SNR value (signal-to-noise ratio). The larger the SNR value, the closer the fingerprint test image is to clear.
  • the fingerprint test image clarity can also be obtained by visual observation.
  • the SNR value (signal-to-noise ratio) is the ratio of the output signal power of the amplifier to the noise power output at the same time, usually expressed in decibels. The higher the signal-to-noise ratio of the device, the less noise it produces, that is, the larger the signal-to-noise ratio, which means that the smaller the noise mixed in the signal, the higher the sound quality of the sound playback, and the stronger the signal, otherwise the opposite is true.
  • the SNR value of the ultrasonic fingerprint module 300 is measured by the ultrasonic fingerprint function test software.
  • the fingerprint ridge of the fake finger (the white area in the test image shown in FIG. 3) and the fingerprint The signal ratio of Yu (the black area in the test image in Figure 3) is the SNR value.
  • the SNR value of experiment 3 is the largest. This is because the smaller the density of the conductive foam, the closer its acoustic impedance is to air, the greater the difference between the acoustic impedance and the substrate 310, and the ultrasonic signal is greatly affected. It reflects back, so the fingerprint test image is close to clear. But the final test result shows that the test image of Experiment 3 is still very blurry, and the test background is very dirty. This is because the clarity of the test images in the three sets of experiments is affected by the mass percentage and particle size of the carbon powder, copper powder and nickel powder filled in the conductive foam.
  • the present invention uses conductive foam with a density of 18kg/m 2 to carry out multiple sets of experimental verification (in actual application, conductive foam The density can be ⁇ 18kg/m 2 ) to verify the surface impedance and electromagnetic shielding performance of the shielding layer 350 formed by conductive foam, and the clarity of the fingerprint image collected by the ultrasonic fingerprint module 200 during EMI protection.
  • the measurement of the electromagnetic shielding performance of the shielding layer 350 formed by the conductive foam of the present invention can be measured by the effectiveness of the shielding effectiveness SE, and the definition of the shielding effectiveness SE is as follows:
  • E1 represents the field strength without shielding
  • E2 represents the field strength with shielding. If the magnetic field strength is used in the shielding effectiveness calculation formula, it is called the magnetic field shielding effectiveness. If the shielding effectiveness calculation formula uses It is the electric field strength, which is called electric field shielding effectiveness, and the unit of shielding effectiveness is decibels (dB).
  • Example 3 Comparing Example 3, Example 4 and Comparative Example 2, it can be seen that when the content of copper powder is 3% to 5%, the prepared shielding layer 350 has low surface impedance, high shielding performance, and little influence on the fingerprint test process.
  • Example 5 Comparing Example 5, Example 6 and Comparative Example 3, it can be seen that when the content of nickel powder is 3% to 5%, the prepared shielding layer 350 has low surface impedance, high shielding performance, and little influence on the fingerprint test process.
  • Example 9 Comparing Example 9, Example 10 and Comparative Example 5, it can be seen that when the particle size of the copper powder is less than or equal to 0.01 mm, the prepared shielding layer 350 has low surface impedance, high shielding performance, and little impact on the fingerprint test process.
  • Example 11 Comparing Example 11, Example 12 and Comparative Example 6, it can be seen that when the particle size of the nickel powder is less than or equal to 0.01 mm, the prepared shielding layer 350 has low surface impedance, high shielding performance, and little influence on the fingerprint test process.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Medicinal Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Multimedia (AREA)
  • Theoretical Computer Science (AREA)
  • Human Computer Interaction (AREA)
  • Electromagnetism (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)

Abstract

La présente invention concerne une mousse électroconductrice, un module d'empreinte digitale ultrasonore, un ensemble écran d'affichage et un appareil électronique. La mousse électroconductrice comprend les constituants uniformément mixés suivants, en pourcentages en masse : 1,5 % à 2,5 % d'une poudre de carbone ; 3 % à 5 % d'une poudre de cuivre ; 3 % à 5 % d'une poudre de nickel ; le reste étant une résine, la taille des particules de poudre de carbone étant inférieure ou égale à 0,005 mm, la taille des particules de poudre de cuivre étant inférieure ou égale à 0,01 mm, et la taille des particules de poudre de nickel étant inférieure ou égale à 0,01 mm. La mousse électroconductrice de la présente invention peut être utilisée pour former une couche de protection qui peut être fixée à un substrat d'un module d'empreinte digitale ultrasonore. Lorsque le module d'empreinte digitale ultrasonore est dans un état de fonctionnement, la couche de protection peut réfléchir une onde ultrasonore émise par une couche piézoélectrique vers un côté où se situe le substrat. L'onde ultrasonore réfléchie résonne avec une onde ultrasonore émise par la couche piézoélectrique vers un côté où se situe une couche d'électrode de façon à augmenter l'intensité de signal d'une onde ultrasonore utilisée pour capturer une image d'empreinte digitale, ce qui permet d'obtenir une image d'empreinte digitale capturée nette. De plus, la couche de protection présente des performances de protection électromagnétique favorables, assurant ainsi une protection contre les interférences électromagnétiques (EMI).
PCT/CN2021/075723 2020-03-06 2021-02-07 Mousse électroconductrice, module d'empreinte digitale ultrasonore, ensemble écran d'affichage et appareil électronique WO2021175101A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010151788.1A CN111417295A (zh) 2020-03-06 2020-03-06 导电泡棉、超声波指纹模组、显示屏组件和电子设备
CN202010151788.1 2020-03-06

Publications (1)

Publication Number Publication Date
WO2021175101A1 true WO2021175101A1 (fr) 2021-09-10

Family

ID=71494307

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/075723 WO2021175101A1 (fr) 2020-03-06 2021-02-07 Mousse électroconductrice, module d'empreinte digitale ultrasonore, ensemble écran d'affichage et appareil électronique

Country Status (2)

Country Link
CN (1) CN111417295A (fr)
WO (1) WO2021175101A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114927057A (zh) * 2022-03-14 2022-08-19 友达光电股份有限公司 显示装置及其组装方法
CN115534456A (zh) * 2022-09-16 2022-12-30 苏州旺顺源光电科技有限公司 一种阻燃型导电泡棉及其制备工艺

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111417295A (zh) * 2020-03-06 2020-07-14 南昌欧菲生物识别技术有限公司 导电泡棉、超声波指纹模组、显示屏组件和电子设备
CN111914776B (zh) * 2020-08-07 2023-12-22 业泓科技(成都)有限公司 显示装置
CN112711150B (zh) * 2020-12-22 2022-11-22 业泓科技(成都)有限公司 显示装置
CN113762167B (zh) * 2021-09-09 2024-02-27 业泓科技(成都)有限公司 屏下指纹辨识装置及电子设备

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1620845A (zh) * 2002-02-19 2005-05-25 S&K聚合物技术株式会社 高聚物微孔泡沫导电衬垫及其制造方法
CN203582791U (zh) * 2013-11-11 2014-05-07 烟台德邦科技有限公司 一种泡棉基材电磁屏蔽胶带
CN105451527A (zh) * 2014-06-30 2016-03-30 浙江三元电子科技有限公司 一种导电泡棉及其制备方法
CN107216476A (zh) * 2017-07-18 2017-09-29 深圳森阳环保材料科技有限公司 一种电磁屏蔽用导电泡棉
CN109491552A (zh) * 2017-09-12 2019-03-19 南昌欧菲生物识别技术有限公司 电子设备
CN111417295A (zh) * 2020-03-06 2020-07-14 南昌欧菲生物识别技术有限公司 导电泡棉、超声波指纹模组、显示屏组件和电子设备

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101885923B (zh) * 2009-05-13 2014-04-23 鸿富锦精密工业（深圳）有限公司 导电泡棉及其使用方法
CN105199565B (zh) * 2015-10-31 2018-03-20 安徽神剑新材料股份有限公司 一种碳纤维热固性粉末电磁屏蔽涂料
CN109492494A (zh) * 2017-09-12 2019-03-19 南昌欧菲生物识别技术有限公司 电子设备
CN109679352A (zh) * 2018-12-28 2019-04-26 深圳德邦界面材料有限公司 一种导电泡棉及其制备方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1620845A (zh) * 2002-02-19 2005-05-25 S&K聚合物技术株式会社 高聚物微孔泡沫导电衬垫及其制造方法
CN203582791U (zh) * 2013-11-11 2014-05-07 烟台德邦科技有限公司 一种泡棉基材电磁屏蔽胶带
CN105451527A (zh) * 2014-06-30 2016-03-30 浙江三元电子科技有限公司 一种导电泡棉及其制备方法
CN107216476A (zh) * 2017-07-18 2017-09-29 深圳森阳环保材料科技有限公司 一种电磁屏蔽用导电泡棉
CN109491552A (zh) * 2017-09-12 2019-03-19 南昌欧菲生物识别技术有限公司 电子设备
CN111417295A (zh) * 2020-03-06 2020-07-14 南昌欧菲生物识别技术有限公司 导电泡棉、超声波指纹模组、显示屏组件和电子设备

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114927057A (zh) * 2022-03-14 2022-08-19 友达光电股份有限公司 显示装置及其组装方法
CN114927057B (zh) * 2022-03-14 2024-03-01 友达光电股份有限公司 显示装置及其组装方法
CN115534456A (zh) * 2022-09-16 2022-12-30 苏州旺顺源光电科技有限公司 一种阻燃型导电泡棉及其制备工艺

Also Published As

Publication number Publication date
CN111417295A (zh) 2020-07-14

Similar Documents

Publication Publication Date Title
WO2021175101A1 (fr) Mousse électroconductrice, module d'empreinte digitale ultrasonore, ensemble écran d'affichage et appareil électronique
WO2021175138A1 (fr) Module d'affichage et dispositif électronique
US10788912B2 (en) Touch display module and electronic device using same
US20180203562A1 (en) Electronic device with light source
US10929637B2 (en) Electronic device including filler for filling a space between biological sensor disposed under a display and the display
CN109390694B (zh) 用于动态改变其多个天线的接地点的电子设备及方法
US11689834B2 (en) Portable electronic device
JP6819778B2 (ja) 携帯型電子機器
CN108881539A (zh) 显示屏组件及电子设备
CN211698983U (zh) 可穿戴设备
KR102589247B1 (ko) 디스플레이 장치
WO2021175100A1 (fr) Encre électroconductrice, module d'affichage et appareil électronique
CN109492457A (zh) 显示模组及其制造方法与电子装置
CN109492489A (zh) 电子设备
US7813138B2 (en) Electronic device
TW201228102A (en) Antenna module
CN207690101U (zh) 超声波指纹识别模组及电子设备
CN109496085A (zh) 盖板组件及其制造方法与电子装置
WO2021142888A1 (fr) Structure d'antenne et borne utilisant ladite structure
CN211506526U (zh) 超声波指纹模组、显示屏组件和电子设备
CN108810208A (zh) 显示屏组件及电子设备
CN210324234U (zh) 超声波指纹模组和电子设备
CN111668585B (zh) 电子设备及天线控制方法
CN207560514U (zh) 盖板组件及电子装置
WO2021081777A1 (fr) Module d'empreintes digitales ultrasonore, son procédé de fabrication et dispositif électronique

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21764670

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21764670

Country of ref document: EP

Kind code of ref document: A1