Display substrate comprising fingerprint recognition sensors, method for manufacturing the same, and display device
11476312 · 2022-10-18
Assignee
- CHENGDU BOE OPTOELECTRONICS TECHNOLOGY CO., LTD. (Sichuan, CN)
- Beijing BOE Technology Development Co., Ltd. (Beijing, CN)
Inventors
Cpc classification
H10K59/00
ELECTRICITY
H10K71/00
ELECTRICITY
H10N30/852
ELECTRICITY
H10N39/00
ELECTRICITY
H10N30/20
ELECTRICITY
International classification
Abstract
Embodiments of the present disclosure relate to a display substrate, a method for manufacturing the same, and a display device. The display substrate includes a substrate, a pixel definition layer for defining pixels on the substrate, the pixel definition layer including a plurality of inter-pixel portions located between adjacent pixels, and a fingerprint recognition sensor located in the inter-pixel portions.
Claims
1. A method for manufacturing a display substrate comprising: providing a substrate; forming a pixel definition layer for defining pixels on the substrate, wherein each pixel comprises a light emitting device; and forming the light emitting devices on the substrate and in the pixel definition layer, the pixel definition layer comprising a plurality of inter-pixel portions located between adjacent light emitting devices, wherein forming the pixel definition layer comprises forming a fingerprint recognition sensor in at least one of the inter-pixel portions, and wherein the fingerprint recognition sensor is an ultrasonic fingerprint recognition sensor, wherein the ultrasonic fingerprint recognition sensor comprises a generator and a receiver, wherein forming the ultrasonic fingerprint recognition sensor comprises positioning the generator and the receiver in different inter-pixel portions, the inter-pixel portion comprising a first inter-pixel portion and a second inter-pixel portion located on opposite sides of each pixel, and wherein forming the first inter-pixel portion, the second inter-pixel portion, and the ultrasonic fingerprint recognition sensor comprises: forming a first lower electrode in a region for forming the first inter-pixel portion on the substrate, and forming a second lower electrode in a region for forming the second inter-pixel portion on the substrate; forming a first portion of the first inter-pixel portion covering the substrate and the first lower electrode in the region for forming the first inter-pixel portion, and forming a first portion of the second inter-pixel portion covering the substrate and the second lower electrode in the region for forming the second inter-pixel portion; forming a first hole exposing the first lower electrode in the first portion of the first inter-pixel portion, and forming a second hole exposing the second lower electrode in the first portion of the second inter-pixel portion; forming a first piezoelectric material in the first hole, and forming a second piezoelectric material in the second hole; forming a first upper electrode on the first portion of the first inter-pixel portion and the first piezoelectric material, and forming a second upper electrode on the first portion of the second inter-pixel portion and the second piezoelectric material; and forming a second portion of the first inter-pixel portion on the first upper electrode and the first portion of the first inter-pixel portion, and forming a second portion of the second inter-pixel portion on the second upper electrode and the first portion of the second inter-pixel portion.
2. The method according to claim 1, wherein forming the first lower electrode and the second lower electrode comprises: forming a first conductive layer on the substrate; and patterning the first conductive layer to form the first lower electrode in the region for forming the first inter-pixel portion and to form the second lower electrode in the region for forming the second inter-pixel portion, and wherein forming the first upper electrode and the second upper electrode comprises: forming a second conductive layer covering the first portion of the first inter-pixel portion and the first piezoelectric material and covering the first portion of the second inter-pixel portion and the second piezoelectric material; and patterning the second conductive layer to form the first upper electrode on the first portion of the first inter-pixel portion and the first piezoelectric material and to form the second upper electrode on the first portion of the second inter-pixel portion and the second piezoelectric material.
3. The method according to claim 2, wherein forming each light emitting device comprises: forming an anode on the substrate, wherein the anode is formed simultaneously with the first lower electrode and the second lower electrode; forming a light emitting layer on the anode; and forming a cathode on the light emitting layer and the pixel definition layer.
4. The method according to claim 3, further comprising: forming a TFT layer on the substrate before forming the pixel definition layer and the fingerprint recognition sensor; forming a planarization layer on the TFT layer; forming an encapsulation layer on the cathode after forming the cathode; and forming a touch layer on the encapsulation layer.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present application.
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(10) Corresponding reference numerals indicate corresponding parts or features throughout the several views of the drawings.
DETAILED DESCRIPTION
(11) As used herein and in the appended claims, the singular form of a word includes the plural, and vice versa, unless the context clearly dictates otherwise. Thus, the references “a”, “an”, and “the” are generally inclusive of the plurals of the respective terms. Similarly, the words “comprise”, “comprises”, and “comprising” are to be interpreted inclusively rather than exclusively. Likewise, the terms “include”, “including” and “or” should all be construed to be inclusive, unless such a construction is clearly prohibited from the context. The term “example” used herein, particularly when followed by a listing of terms, is merely exemplary and illustrative and should not be deemed to be exclusive or comprehensive.
(12) Additionally, further to be noted, when the elements and the embodiments thereof of the present application are introduced, the articles “a/an”, “one”, “the” and “said” are intended to represent the existence of one or more elements. Unless otherwise specified, “a plurality of” means two or more. The expressions “comprise”, “include”, “contain” and “have” are intended as inclusive and mean that there may be other elements besides those listed. The terms such as “first” and “second” are used herein only for purposes of description and are not intended to indicate or imply relative importance and the order of formation.
(13) In addition, in the drawings, the thickness of each layer and the region where each layer positioned are exaggerated for clarity. It should be understood that when referring to a layer, a region, or a component being located “on” another part, it means that the layer, the region or the component is directly located on another part, or there may be other components located between the layer, the region or the component and another part. In contrast, when a component is referred to as being “directly” located on another component, it means that no other component is located between them.
(14) The flowchart depicted in present disclosure is only an example. There may be many variations to this flowchart or the steps described therein without departing from the spirit of the present disclosure. For example, the depicted steps may be performed in a different order, or steps may be added, deleted, or modified. These variations are considered as part of the claimed aspect.
(15) Exemplary embodiments will now be described more fully with reference to the accompanying drawings.
(16) Currently, there are three main technologies for fingerprint recognition applied to smart phones: capacitive, optical, and ultrasonic technologies. At present, the most mature fingerprint mobile phones on the market are basically capacitive. However, with the launch of full-screen phones, the location of the capacitive sensor needs to be designed to avoid occupying the area of the body of the mobile phone. In addition, because the optical and ultrasonic sensors can be directly attached to the lower part of back of the display, and thus no more restrictions will be applied to the appearance of the mobile phone, major mobile phone manufacturers and scientific research institutions actively carry out technical research on it.
(17) Ultrasonic fingerprint recognition technology refers to perform fingerprint recognition by employing ultrasonic waves to scan fingerprint. Compared with capacitive touch screen fingerprint technology, ultrasonic fingerprint technology has many unique advantages including the ability to scan through a smartphone case made of glass, stainless steel, sapphire, or plastic and overcome the problem that fingerprints cannot unlock mobile phone due to sweat, oil, and dirt, thereby providing a more stable and accurate authentication method. In addition, ultrasonic waves can penetrate directly through the skin surface, so as to recognize three-dimensional details and unique fingerprint features including fingerprint ridges and sweat pores that cannot be recognized by current capacitive touch screen based fingerprint technology. Thus, fingerprint surface maps which are rich in detail and difficult to imitate can be generated. However, the current ultrasonic fingerprint recognition module needs to be attached to the lower part of back of the display, which will increase cost including module equipment, labor, time, etc. Therefore, while developing the ultrasonic fingerprint recognition technology, it is also necessary to develop the manufacturing process for mass production about the technology.
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(21) In an embodiment of the present disclosure, as shown in
(22) In an embodiment of the present disclosure, the fingerprint recognition sensor is an ultrasonic fingerprint recognition sensor. In an embodiment of the present disclosure, as shown in
(23) On one hand, in an embodiment of the present disclosure, as shown in
(24) Specifically, as shown in
(25) In an embodiment of the present disclosure, the first lower electrode 211 is disposed in the same layer as the second lower electrode 221, and the first upper electrode 213 is disposed in the same layer as the second upper electrode 223. Here, the “being disposed in the same layer” means that they are formed of the same material layer.
(26) In an embodiment of the present disclosure, the first piezoelectric material 212 is disposed in the same layer as the second piezoelectric material 222. It should be noted that the first piezoelectric material 212 and the second piezoelectric material 222 may also be formed of different piezoelectric materials, and those skilled in the art may choose the piezoelectric material according to actual needs.
(27) In an embodiment of the present disclosure, the first piezoelectric material 212 and the second piezoelectric material 222 may include an organic material, an inorganic material, a semiconductor material, or a combination thereof.
(28) In an exemplary embodiment of the present disclosure, the organic material may include polyvinylidene fluoride (Ethene, 1,1-difluoro-, homopolymer, or PVDF), polyvinyl fluoride (PVF), or polyvinyl chloride (PVC).
(29) In an exemplary embodiment of the present disclosure, the inorganic material may include quartz or piezoelectric ceramic.
(30) In an exemplary embodiment of the present disclosure, the semiconductor material may include ZnS, CdTe, or GaAs.
(31) As an example, the first piezoelectric material 212 and the second piezoelectric material 222 can be obtained by dissolving polyvinylidene fluoride in N, N-dimethylformamide (DMF) or N-methyl pyrrolidone (NMP) to form a solution, followed by processes including coating the solution, baking, annealing, etc.
(32) As another example, the first piezoelectric material 212 and the second piezoelectric material 222 may be a composite piezoelectric material including polyvinylidene fluoride and lead zirconate titanate piezoelectric ceramic transducer (PZT), so as to obtain more excellent piezoelectric performance.
(33) In an embodiment of the present disclosure, the cross-sectional shape of the generator 210 and the receiver 220 parallel to the surface of the substrate 101 include a square, a circle, a triangle, or a rhombus.
(34) In an embodiment of the present disclosure, as shown in
(35) In an embodiment of the present disclosure, the anode 1041 is disposed in the same layer as the first lower electrode 211 and the second lower electrode 221.
(36) In an embodiment of the present disclosure, as shown in
(37) In an exemplary embodiment of the present disclosure, the light emitting device 104 may be an OLED light emitting device or a QLED light emitting device.
(38) In an exemplary embodiment of the present disclosure, the TFT layer 102 may include a low temperature poly-silicon (LTPS) layer, an indium gallium zinc oxide (IGZO) layer, or an a-Si layer.
(39) In an embodiment of the present disclosure, the substrate 101 may be a flexible substrate or a rigid substrate. In an exemplary embodiment of the present disclosure, the rigid substrate may include glass, plastic, or metal.
(40) In an embodiment of the present disclosure, a display device is also provided. The display device includes the display substrate as described above.
(41) In an embodiment of the present disclosure, a method for manufacturing a display substrate is also provided. The display substrate manufactured by this method is shown in
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(43) In an embodiment of the present disclosure, forming a pixel definition layer includes forming a fingerprint recognition sensor in the inter-pixel portion.
(44) In an embodiment of the present disclosure, the fingerprint recognition sensor is an ultrasonic fingerprint recognition sensor. The ultrasonic fingerprint recognition sensor includes a generator and a receiver.
(45) In one aspect, in an embodiment of the present disclosure, forming an ultrasonic fingerprint recognition sensor includes positioning the generator and the receiver in different inter-pixel portions. In this embodiment, the manufactured display substrate is shown in
(46) Next, a method for forming the inter-pixel portion and the ultrasonic fingerprint recognition sensor so as to position the generator and the receiver in different inter-pixel portions will be described in detail with reference to
(47) In an embodiment of the present disclosure, the inter-pixel portion may include a first inter-pixel portion 1051 and a second inter-pixel portion 1052.
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(49) As shown in
(50) Specifically, forming the first lower electrode 211 and the second lower electrode 221 includes forming a first conductive layer (not shown) on the substrate 101, and patterning the first conductive layer to form the first lower electrode 211 in the region 105a for forming the first inter-pixel portion and form the second lower electrode 221 in the region 105b for forming the second inter-pixel portion.
(51) It should be noted that, as shown in
(52) In an embodiment of the present disclosure, the bonding region is used for bonding a corresponding flexible printed circuit (FPC) board or a chip on film (COF). Specifically, the pads a and b in the bonding region are used to bond the corresponding FPC and COF. The pads a and b may be generally referred to “gold fingers”.
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(54) As shown in
(55) In an embodiment of the present disclosure, the first hole 1051a′ and the second hole 1052a′ may be formed using a patterning process including exposure, development, etc.
(56) In an embodiment of the present disclosure, the first portion 1051a of the first inter-pixel portion and the first portion 1052a of the second inter-pixel portion also cover the wiring in the bonding region, thereby avoiding being connected to subsequently formed wiring for the first upper electrode 213 and the second upper electrodes 223 (to be described later).
(57)
(58) As shown in
(59) It should be noted that, for specific materials of the first piezoelectric material 212 and the second piezoelectric material 222, reference may be made to the above descriptions of
(60) As an example, the first piezoelectric material 212 and the second piezoelectric material 222 can be prepared by dissolving polyvinylidene fluoride in N, N-dimethylformamide or N-methylpyrrolidone to obtain a solution, coating the first hole 1051a′ and the second hole 1052a′ with this solution, annealing the structure thus obtained in an oven under the temperature of 30-80° C., thereby obtaining the first piezoelectric material 212 and the second piezoelectric material 222.
(61) As another example, a lead zirconate titanate piezoelectric ceramic transducer may be added to the above solution, and other steps are the same as those in the above example, thereby obtaining the first piezoelectric material 212 and the second piezoelectric material 222 having a composite piezoelectric material, so as to achieve more excellent piezoelectric performance.
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(63) As shown in
(64) Specifically, forming the first upper electrode 213 and the second upper electrode 223 includes forming a second conductive layer (not shown) covering the first portion 1051a of the first inter-pixel portion and the first piezoelectric material 212 and covering the first portion 1052a of the second inter-pixel portion and the second piezoelectric material 222, and patterning the second conductive layer to form the first upper electrode 213 on the first portion 1051a of the first inter-pixel portion and the first piezoelectric material 212 and form the second upper electrode 223 on the first portion 1052a of the second inter-pixel portion and the second piezoelectric material 222.
(65) In an embodiment of the present disclosure, the first lower electrode 211, the first piezoelectric material 212, and the first upper electrode 213 constitute the generator 210 of the ultrasonic fingerprint recognition sensor. The second lower electrode 221, the second piezoelectric material 222, and the second upper electrode 223 constitute the receiver 220 of the ultrasonic fingerprint recognition sensor.
(66) In an embodiment of the present disclosure, the first lower electrode 211, the second lower electrode 221, the first upper electrode 213, and the second upper electrode 223 may be prepared through processes such as sputtering, exposure, and etching, etc.
(67) It should be noted that, as shown in
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(69) As shown in
(70) In an embodiment of the present disclosure, the second portion 1051b of the first inter-pixel portion and the second portion 1052b of the second inter-pixel portion also cover the wiring in the bonding region.
(71) On the other hand, in an embodiment of the present disclosure, forming the ultrasonic fingerprint recognition sensor includes positioning the generator and the receiver in the same inter-pixel portion. In this embodiment, the manufactured display substrate is shown in
(72) Next, a method for forming the inter-pixel portion and the ultrasonic fingerprint recognition sensor so as to position the generator and the receiver in the same inter-pixel portion will be described in detail with reference to
(73)
(74) As shown in
(75) Specifically, forming the first lower electrode 211 and the second lower electrode 221 includes forming a first conductive layer (not shown) on the substrate 101, and patterning the first conductive layer to form the first lower electrode 211 and the second lower electrode 221 in the region 105′ for forming the inter-pixel portion.
(76) It should be noted that, as shown in
(77) In an embodiment of the present disclosure, the bonding region is used for bonding a corresponding flexible printed circuit board or a chip on film.
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(79) As shown in
(80) In an embodiment of the present disclosure, the first hole 105c′ and the second hole 105c″ may be formed using processes such as exposure, development, etc.
(81) In an embodiment of the present disclosure, the first portion 105c of the inter-pixel portion also covers the wiring in the bonding region, thereby avoiding being connected to subsequently formed wiring for the first upper electrode 213 and the second upper electrodes 223 (to be described later).
(82)
(83) As shown in
(84) For the detailed description of the first piezoelectric material 212 and the second piezoelectric material 222, reference may be made to the above descriptions of
(85)
(86) As shown in
(87) Specifically, forming the first upper electrode 213 and the second upper electrode 223 includes forming a second conductive layer (not shown) covering the first portion 105c of the inter-pixel portion, the first conductive material 212 and the second conductive material 222, and patterning the second conductive layer to form the first upper electrode 213 on the first portion 105c of the inter-pixel portion and the first piezoelectric material 212 and form the second upper electrode 223 on the first portion 105c of the inter-pixel portion and the second piezoelectric material 222.
(88) In an embodiment of the present disclosure, the first lower electrode 211, the first piezoelectric material 212, and the first upper electrode 213 constitute the generator 210 of the ultrasonic fingerprint recognition sensor. The second lower electrode 221, the second piezoelectric material 222, and the second upper electrode 223 constitute the receiver 220 of the ultrasonic fingerprint recognition sensor.
(89) In an embodiment of the present disclosure, the first lower electrode 211, the second lower electrode 221, the first upper electrode 213, and the second upper electrode 223 may be prepared through processes such as sputtering, exposure, and etching, etc.
(90) It should be noted that, as shown in
(91)
(92) As shown in
(93) In an embodiment of the present disclosure, the second portion 105d of the inter-pixel portion also covers the wiring in the bonding region.
(94) Further, referring to
(95) Furthermore, in an embodiment of the present disclosure, referring to
(96) It should be noted that, in the case where the light emitting layer 1042 emits white light, the touch layer 107 further includes a color film layer, so that the display substrate 100 can implement color display.
(97) For detailed descriptions of the substrate 101 and the TFT layer 102, reference may be made to the above description of
(98) The foregoing description of the embodiment has been provided for purpose of illustration and description. It is not intended to be exhaustive or to limit the application. Even if not specifically shown or described, individual elements or features of a particular embodiment are generally not limited to that particular embodiment, are interchangeable when under a suitable condition, can be used in a selected embodiment and may also be varied in many ways. Such variations are not to be regarded as a departure from the application, and all such modifications are included within the scope of the application.