Ultrasonic fingerprint recognition device

Abstract

The present invention provides an ultrasonic fingerprint recognition device comprising a conductive layer and a piezoelectric material layer. The conductive layer comprises a plurality of layout metals and conductive pads, and the layout metals are fabricated to a relatively large first width, ranging from 10 microns to 150 microns. The piezoelectric material layer is positioned on the conductive layer and covers all of the layout metals and a portion of the conductive pads. This solves the problem of bubbles caused by lamination when forming a transparent conductive layer on piezoelectric material, thereby reducing product defects and increasing product yield.

Description

Technical Field

[0001] The present invention relates to a biometric identification device, and in particular to an ultrasonic fingerprint identification device. Background Art

[0002] In recent years, fingerprint recognition has become a mainstream biometric authentication method in portable electronic devices. Current fingerprint recognition technologies are broadly categorized as capacitive touch, resistive touch, ultrasonic touch, and optical touch. Ultrasonic touch's greatest strengths lie in its low cost and simple hardware. Ultrasonic touch utilizes the reflective properties of ultrasound. The generated ultrasound waves, after reflecting off the ridges and grooves, are then transmitted back, and algorithms can be used to infer the fingerprint pattern.

[0003] Ultrasonic fingerprint recognition technology uses ultrasound to scan fingerprints. Compared to traditional fingerprint recognition methods, it provides a deeper analysis of fingerprints. Even dirt on the finger surface does not hinder ultrasonic sampling, and the ultrasonic wave can even penetrate beneath the skin's surface to identify the fingerprint's unique 3D features. Accurate recognition is possible even with water or sweat on the hands. Because panels are thick, the ultrasonic wave's energy is attenuated during transmission. Excessive attenuation can cause inaccurate recognition results.

[0004] However, some development projects, such as those requiring curved surfaces for augmented reality (AR) glasses or ultrasonic under-display fingerprint applications, require the development of flexible fingerprint sensors, replacing panels with polyvinylidene difluoride (PVDF) or polyvinylidene fluoride-cotrifluoroethylene (PVDF-TrFE). However, the surface of PVDF is highly susceptible to scratching, and subsequent circuit layer fabrication using scratched PVDF can easily result in yield loss. Solving these issues has long been a goal for the industry. Summary of the Invention

[0005] The present invention aims to provide an ultrasonic fingerprint recognition device that increases production efficiency by using a metal layout in a conductive layer to form a larger first width and fully covering the conductive layer with a piezoelectric material layer to replace the complex process of making a transparent conductive layer.

[0006] The present invention aims to provide an ultrasonic fingerprint recognition device that solves the problem of bubbles caused by lamination during the production of a transparent conductive layer, thereby reducing product defects and increasing product yield.

[0007] To achieve the above-mentioned objectives, the present invention provides an ultrasonic fingerprint recognition device, comprising a piezoelectric film layer, the piezoelectric film layer further comprising: a conductive layer and a piezoelectric material layer. The conductive layer comprises a bonding surface and a first top plane on two side surfaces, respectively, and the bonding surface and the first top plane are separated by a first height. The conductive layer comprises a plurality of layout metals and a conductive pad, the layout metals having a first width, and the conductive pad is located on one side of the conductive layer. The piezoelectric material layer is located on the conductive layer, and the piezoelectric material layer covers all of the layout metals and a portion of the conductive pad. A first top surface of the piezoelectric material layer is separated from the bonding surface by a second height, and the second height is greater than the first height.

[0008] In a preferred embodiment of the present invention, the first width is between 10 μm and 150 μm, the first height is between 30 nm and 50 μm, and the second height is between 1 μm and 300 μm.

[0009] In a preferred embodiment of the present invention, the piezoelectric material layer is made of polyvinylidene difluoride (PVDF) or Polyvinylidene fluoride-cotrifluoroethylene (PVDF-TrFE).

[0010] In a preferred embodiment of the present invention, the ultrasonic fingerprint recognition device further includes a carrier layer, the piezoelectric film layer is located on the carrier layer, and the bonding surface is attached to one surface of the carrier layer. The carrier layer is one of a thin-film transistor (TFT), a wafer, and a transparent conductive film (ITOFILM). The conductive layer is one of a metal material such as silver, copper, ITO, or Ag nanowires, and is coated on the entire surface of the carrier layer. A plurality of the layout metals and the conductive pads are fabricated on the carrier layer in an array pattern.

[0011] In a preferred embodiment of the present invention, the ultrasonic fingerprint recognition device further includes a second piezoelectric film layer, which is located on the piezoelectric film layer and further includes: a second conductive layer and a second piezoelectric material layer. The second conductive layer is located on the first top surface side of the piezoelectric material layer, and a second top plane of the second conductive layer is at the first height away from the first top surface side; the second conductive layer has a plurality of second layout metals and a second conductive pad, the second layout metal has the second width that is in contact with the first top surface side, and there is a second spacing between the two second layout metals, and the second conductive pad is located on one side of the second conductive layer. The second piezoelectric material layer is located on the second conductive layer, and the second piezoelectric material layer covers all of the second layout metals and part of the second conductive pad. A second top surface side of the second piezoelectric material layer is at the second height away from the first top surface side, and the second height is greater than the first height.

[0012] In a preferred embodiment of the present invention, there is a first spacing between the two layout metals, when the first spacing and the second spacing are equal in size, and the first width and the second width are equal in size; when the first spacing is smaller than the second spacing, and the first width is larger than the second width; the first spacing is larger than the second spacing, and the first width is smaller than the second width. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a side view structural diagram of the first preferred embodiment of the ultrasonic fingerprint recognition device of the present invention.

[0014] Figure 2 2 is a side view of the second preferred embodiment of the ultrasonic fingerprint recognition device of the present invention.

[0015] Figure 3 2 is a side view of the third preferred embodiment of the ultrasonic fingerprint recognition device of the present invention.

[0016] Figure 4 2 is a side view of the fourth preferred embodiment of the ultrasonic fingerprint recognition device of the present invention.

[0017] Figure 5 FIG1 is a flow chart of a first preferred embodiment of a method for manufacturing an ultrasonic fingerprint recognition device according to the present invention.

[0018] Figure 6 FIG. 2 is a flow chart of a second preferred embodiment of a method for manufacturing an ultrasonic fingerprint recognition device according to the present invention.

[0019] Figure 7FIG. 1 is a flow chart of a third preferred embodiment of a method for manufacturing an ultrasonic fingerprint recognition device according to the present invention.

[0020] Figure 8 FIG. 4 is a flow chart of a fourth preferred embodiment of a method for manufacturing an ultrasonic fingerprint recognition device according to the present invention.

[0021] The accompanying drawings are:

[0022] 1: Piezoelectric film layer 312: Second top plane

[0023] 11: Conductive layer 313: Second layout metal

[0024] 111: Laminating surface 314: Second conductive pad

[0025] 112: first top plane 32: second piezoelectric material layer

[0026] 113: Layout Metal 321: Second Top Surface Side

[0027] 114: Conductive pad H1: first height

[0028] 12: Piezoelectric material layer H2: second height

[0029] 121: First top surface side W1: First width

[0030] 2: Bearing layer W2: second width

[0031] 21: Surface S1: First spacing

[0032] 3: Second piezoelectric film layer S2: Second spacing

[0033] 31: Second conductive layer DETAILED DESCRIPTION

[0034] In order to achieve the above-mentioned purpose and effect, the technical means and structure adopted by the present invention are illustrated in detail with respect to the preferred embodiment of this invention, and its features and functions are as follows, so as to facilitate a complete understanding. However, it should be noted that the content described does not constitute a limitation of the present invention. In addition, in this specification, the numerical range represented by "~" refers to the range that includes the numerical values ​​recorded before and after "~" as the lower limit and upper limit. Moreover, in the numerical range recorded in the stages in this specification, the upper limit or lower limit recorded in a certain numerical range can be replaced with the upper limit or lower limit of the numerical range recorded in other stages. Moreover, in the numerical range recorded in this specification, the upper limit or lower limit recorded in a certain numerical range can be replaced with the value shown in the embodiment. Moreover, the term "step" in this specification is not only an independent step, but also is included in this term as long as the desired purpose of the step can be achieved even if it cannot be clearly distinguished from other steps. Furthermore, although the terms "step" and / or "block" may be used herein or in the drawings to imply different elements of the methods employed, these terms should not be construed as implying any specific order among or between the various steps disclosed herein unless and until the order of the individual steps is explicitly stated.

[0035] See also Figure 1 As shown, it is a schematic side view of the structure of the first preferred embodiment of the ultrasonic fingerprint recognition device of the present invention. The present invention provides an ultrasonic fingerprint recognition device, which includes a piezoelectric film layer 1, and the piezoelectric film layer 1 further includes: a conductive layer 11 and a piezoelectric material layer 12. The conductive layer 11 is made of a metal material such as silver, copper, indium tin oxide (ITO) and silver nanowires. The two side surfaces of the conductive layer 11 are respectively a bonding surface 111 and a first top plane 112, and the bonding surface 111 and the first top plane 112 are separated by a first height H1, and the first height H1 is preferably between 30 nanometers (nm) and 50 micrometers (μm).

[0036] The conductive layer 11 has a plurality of layout metals 113 and a conductive pad 114. The layout metal 113 has a first width W1. Conventional ultrasonic fingerprint recognition devices typically require the production of adjacent transparent conductive layers and metal layers, thus limiting the first width of the metal layer to less than 10 microns (μm). However, the present invention only requires the production of a single conductive layer 11, eliminating the need for adjacent transparent conductive layers and metal layers. Therefore, the present invention can set the first width W1 between 10 μm and 150 μm to facilitate production. The conductive pad 114 is located on one side of the conductive layer 11.

[0037] The piezoelectric material layer 12 is located on the conductive layer 11 and is made of polyvinylidene difluoride (PVDF). The piezoelectric material layer 12 covers all of the layout metal 113 and a portion of the conductive pad 114. A first top surface 121 of the piezoelectric material layer 12 is spaced a second height H2 from the bonding surface 111. The second height H2 is greater than the first height H1. In a preferred embodiment of the present invention, the second height H2 is between 1 micron (μm) and 300 microns (μm).

[0038] See also Figure 2 As shown, it is a schematic side view of the second preferred embodiment of the ultrasonic fingerprint recognition device of the present invention. Different from the above embodiment, the ultrasonic fingerprint recognition device of the present invention further includes a carrier layer 2, and the piezoelectric film layer 1 is located on the carrier layer 2, and the bonding surface 111 is attached to one surface 21 of the carrier layer 2. The carrier layer 2 is one of a thin film transistor (TFT), a wafer, and a transparent conductive film (ITO FILM). The conductive layer 11 is a metal material such as silver, copper, indium tin oxide (ITO) and silver nanowires, and is coated on the entire surface of the carrier layer 2. A plurality of the layout metals 113 and the conductive pads 114 are made on the carrier layer 2 in an array pattern.

[0039] See also Figure 3 As shown, it is a side view of the third preferred embodiment of the ultrasonic fingerprint recognition device of the present invention. In order to increase the initial energy of the ultrasonic wave and reduce the misjudgment of the recognition result, the above Figure 1 Unlike the previous embodiment, the ultrasonic fingerprint recognition device further includes a second piezoelectric film layer 3 located on the piezoelectric film layer 1. The second piezoelectric film layer 3 further includes a second conductive layer 31 and a second piezoelectric material layer 32. The second conductive layer 31 is located on the first top surface 121 of the piezoelectric material layer 12, and a second top plane 312 of the second conductive layer 31 is separated from the first top surface 121 by a first height H1. The first height H1 is preferably between 30 nanometers (nm) and 50 micrometers (μm).

[0040] The second conductive layer 31 comprises a plurality of second layout metal layers 313 and a second conductive pad 314. The second layout metal layers 313 have a second width W2 aligned with the first top surface 121, and the second width W2 ranges from 10 μm to 150 μm. The second conductive pad 314 is located on one side of the second conductive layer 31. The second piezoelectric material layer 32 is located on the second conductive layer 31, covering all of the second layout metal layers 313 and a portion of the second conductive pad 314. A second top surface 321 of the second piezoelectric material layer 32 is separated from the first top surface 121 by a second height H2, which ranges from 1 μm to 300 μm and is greater than the first height H1. The second conductive layer 31 is entirely coated on the piezoelectric film layer 1 with a metal material selected from the group consisting of silver, copper, indium tin oxide (ITO), and silver nanowires. A plurality of second layout metals 313 and the second conductive pads 314 are fabricated on the piezoelectric film layer 1 in an array pattern.

[0041] In a preferred embodiment of the present invention, the two layout metals 113 are separated by a first spacing S1. To facilitate the manufacture of the ultrasonic fingerprint recognition device of the present invention, the first spacing S1 and the second spacing S2 are equal in size, and the first width W1 and the second width W2 are equal in size. This equal spacing design simplifies the design and is easy to implement in the manufacture of the ultrasonic fingerprint recognition device.

[0042] Of course, in another feasible embodiment of the present invention, a non-equidistant design may be adopted, that is, the first spacing S1 is smaller than the second spacing S2, and the first width W1 is larger than the second width W2; or the first spacing S1 is larger than the second spacing S2, and the first width W1 is smaller than the second width W2. This non-equidistant design can make the design more flexible, and the layout and stacking of the second piezoelectric film layer 3 can be closer to the piezoelectric film layer 1, which can be expected to improve the resolution and touch recognition capabilities of the ultrasonic fingerprint recognition device of the present invention.

[0043] See also Figure 4 As shown, it is a side view structural diagram of the fourth preferred embodiment of the ultrasonic fingerprint recognition device of the present invention. Figure 3Unlike the previous embodiments, the ultrasonic fingerprint recognition device of the present invention further includes a carrier layer 2. The piezoelectric film layer 1 is located on the carrier layer 2, with the bonding surface 111 abutting against a surface 21 of the carrier layer 2. The carrier layer 2 is one of a thin-film transistor (TFT), a wafer, and a transparent conductive film (ITO film). The conductive layer 11 is a metal material such as silver, copper, indium tin oxide (ITO), and silver nanowires, and is entirely coated on the carrier layer 2. A plurality of layout metals 113 and conductive pads 114 are fabricated in an array pattern on the carrier layer 2.

[0044] See also Figure 5 FIG. 1 is a block diagram of a first preferred embodiment of a method for manufacturing an ultrasonic fingerprint recognition device according to the present invention. The method for manufacturing an ultrasonic fingerprint recognition device according to the present invention comprises the following steps:

[0045] Step S91: providing a carrier layer, wherein the carrier layer is one of a thin-film transistor (TFT), a wafer, and a transparent conductive film (ITO FILM).

[0046] Step S92: forming a conductive layer on a surface of the carrier layer, wherein the conductive layer has a plurality of layout metals and a conductive pad. The layout metal is in contact with the surface, and the conductive pad is located on one side of the conductive layer.

[0047] Step S93: forming a piezoelectric material layer covering all the layout metal and part of the conductive pad. Figure 2 The ultrasonic fingerprint recognition device shown.

[0048] See also Figure 6 The manufacturing method of the ultrasonic fingerprint recognition device of the present invention, in addition to the above steps S91 to S93, further comprises a step S94: removing the conductive layer and the piezoelectric material layer from the surface, and producing the following: Figure 1 The ultrasonic fingerprint recognition device shown.

[0049] See also Figure 7As shown, the flowchart of the third preferred embodiment of the manufacturing method of the ultrasonic fingerprint recognition device of the present invention is shown. In addition to the above steps S91 to S93, the manufacturing method of the ultrasonic fingerprint recognition device of the present invention further includes step S95: forming a second conductive layer on a first top surface side of a top surface side of the piezoelectric material layer, the second conductive layer having a plurality of second layout metals and a second conductive pad, the second layout metal is in contact with the first top surface side of the top surface side, and the second conductive pad is located on one side of the second conductive layer. Step S96: forming a second piezoelectric material layer covering all the second layout metals and part of the second conductive pad. Figure 4 The ultrasonic fingerprint recognition device shown.

[0050] See also Figure 8 The fourth preferred embodiment of the manufacturing method of the ultrasonic fingerprint recognition device of the present invention is shown in FIG. The manufacturing method of the ultrasonic fingerprint recognition device of the present invention sequentially includes steps S91, S92, S93, S95, and S96, and further includes step S97: removing the conductive layer, the piezoelectric material layer, the second conductive layer, and the second piezoelectric material layer from the surface to produce the following: Figure 3 The ultrasonic fingerprint recognition device shown.

[0051] The above detailed description fully demonstrates that the present invention is progressive in its purpose and efficacy, has great industrial value, and fully meets the requirements for invention patents. Therefore, an application is filed in accordance with the law. However, the above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should be aware that any equivalent substitutions and obvious changes made using the present description and illustrations should be included within the scope of protection of the present invention.

Claims

1. An ultrasonic fingerprint recognition device, characterized in that: include: The piezoelectric film layer further includes: A conductive layer, wherein two side surfaces are a bonding surface and a first top plane, and the bonding surface and the first top plane are separated by a first height; the conductive layer has a plurality of layout metals and a conductive pad, the layout metal has a first width, and the first width is between 10 microns and 150 microns. The conductive pad is located on one side of the conductive layer; The piezoelectric material layer is located on the conductive layer and covers all the layout metals and part of the conductive pad. The first top surface of the piezoelectric material layer is at a second height away from the bonding surface, and the second height is greater than the first height.

2. The ultrasonic fingerprint recognition device according to claim 1, wherein: The first height is between 30 nanometers and 50 micrometers, and the second height is between 1 micrometer and 300 micrometers.

3. The ultrasonic fingerprint recognition device according to claim 1, wherein: The piezoelectric material layer is made of polyvinylidene fluoride or polyvinylidene fluoride-co-trifluoroethylene.

4. The ultrasonic fingerprint recognition device according to claim 1, wherein: The ultrasonic fingerprint recognition device further includes a supporting layer. The piezoelectric film layer is located on the supporting layer, and the laminating surface is attached to the surface of the supporting layer.

5. The ultrasonic fingerprint recognition device according to claim 4, wherein: The carrier layer is one of a thin film transistor, a wafer and a transparent conductive film.

6. The ultrasonic fingerprint recognition device according to claim 4, wherein: The conductive layer is a metal material selected from among silver, copper, indium tin oxide and silver nanowires and is entirely coated on the supporting layer.

7. The ultrasonic fingerprint recognition device according to claim 4, wherein: A plurality of the layout metals and the conductive pads are fabricated on the carrier layer in an array pattern.

8. The ultrasonic fingerprint recognition device according to claim 1 or 4, wherein: The ultrasonic fingerprint recognition device further includes a second piezoelectric film layer, which is located on the piezoelectric film layer and further includes: a second conductive layer, located on the first top surface side of the piezoelectric material layer, and a second top plane of the second conductive layer is spaced apart from the first top surface side by the first height; the second conductive layer comprises a plurality of second layout metals and a second conductive pad, the second layout metals having a second width aligned with the first top surface side, and a second spacing between the second layout metals, and the second conductive pad is located on one side of the second conductive layer; A second piezoelectric material layer is located on the second conductive layer, and the second piezoelectric material layer covers all of the second layout metal and part of the second conductive pad. The second top surface side of the second piezoelectric material layer is at the second height away from the first top surface side, and the second height is greater than the first height.

9. The ultrasonic fingerprint recognition device according to claim 8, wherein: The second width is between 10 micrometers and 150 micrometers, the first height is between 30 nanometers and 50 micrometers, and the second height is between 1 micrometer and 300 micrometers.

10. The ultrasonic fingerprint recognition device according to claim 8, wherein: There is a first distance between the two layout metals. The first distance is equal to the second distance, and the first width is equal to the second width.

11. The ultrasonic fingerprint recognition device according to claim 8, wherein: There is a first distance between the two layout metals, the first distance is smaller than the second distance, and the first width is larger than the second width.

12. The ultrasonic fingerprint recognition device according to claim 8, wherein: There is a first distance between the two layout metals, the first distance is larger than the second distance, and the first width is smaller than the second width.

Images