KR20200065894A - Ultrasonic sensor and display device - Google Patents

Abstract

Embodiments of the present invention relate to an ultrasonic sensor and a display device. The process efficiency of the ultrasonic sensor can be improved by coating the electrode layer and the piezoelectric material on the base film and bonding the substrate to the thin film transistor array. In addition, by forming a via hole in a state where an electrode layer and a piezoelectric material are disposed on the base film and disposing a conductive filler inside the via hole, the electrode layer and the pad portion disposed on the substrate can be easily electrically connected in the above-described process.

Description

Ultrasonic sensor and display device {ULTRASONIC SENSOR AND DISPLAY DEVICE}

Embodiments of the present invention relate to an ultrasonic sensor and a display device.

As the information society develops, the demand for a display device displaying an image is increasing, and various types of display devices such as a liquid crystal display device and an organic light emitting display device are being used.

In order to provide a variety of functions to the user, such a display device recognizes a user's touch on the display panel, recognizes biometric information (eg, fingerprint) that is in contact with or close to the display panel, and processes input based on the recognized information. It provides the ability to perform.

For recognition of such biometric information, for example, an optical sensor or the like may be used, but when the optical sensor is disposed in the bezel area of the display panel, there is a problem that the active area is narrowed. In addition, when the optical sensor is disposed in the active area, there is a problem that may affect display driving or lower the accuracy of sensing.

Accordingly, there is a need for a method capable of improving the accuracy of sensing biometric information for the display panel while preventing the reduction of the active area of the display panel.

An object of the embodiments of the present invention is to provide an ultrasonic sensor, a display panel, and a device that can recognize biometric information in contact with the display panel in an active area of the display panel.

An object of the embodiments of the present invention is to provide an ultrasonic sensor having a process method of an ultrasonic sensor capable of increasing the process efficiency of an ultrasonic sensor and a structure manufactured through such a process method.

An object of the embodiments of the present invention is to provide an ultrasonic sensor having an electrode structure capable of improving the sensing sensitivity of the ultrasonic sensor while increasing the process efficiency of the ultrasonic sensor.

In one aspect, embodiments of the present invention include a base film, a reflective layer disposed on the base film, an electrode layer positioned on the reflective layer and disposed in an electrode region and a pad region, a piezoelectric material disposed on the electrode layer, and a piezoelectric material An ultrasonic sensor including at least one hole disposed on the substrate and including a substrate on which a thin film transistor array is disposed, positioned in a pad region, penetrating the base film, the reflective layer, the electrode layer, and the piezoelectric material and having conductive filler disposed therein to provide.

The ultrasonic sensor may further include a protective layer disposed on a lower portion of the base film and disposed in an area including an area corresponding to at least one hole.

The protective layer may be disposed under the conductive filler and may be disposed in an area including a region in which the conductive filler is disposed around at least one hole.

In addition, the ultrasonic sensor may further include an insulating layer disposed between the reflective layer and the electrode layer, and the hole disposed at a position corresponding to at least one hole.

In another aspect, embodiments of the present invention provide a display panel and a display device in which the above-described ultrasonic sensor is disposed on at least one surface of the display panel or embedded in the display panel.

According to embodiments of the present invention, by sequentially stacking a reflective layer, an insulating layer, an electrode layer, and a piezoelectric material on a base film and adhering to a substrate on which a thin film transistor array is disposed, it is possible to increase the process efficiency of the ultrasonic sensor.

In addition, by forming a via hole in the pad region after each layer is stacked, it is possible to easily achieve electrical connection between the electrode layer and the pad portion on the substrate.

In addition, by separating and arranging a portion disposed in the electrode region to correspond to all or a portion of the pixel in the electrode layer, the sensing sensitivity of the ultrasonic sensor can be improved.

1 is a view showing an example of a structure of an ultrasonic sensor disposed in a display device according to embodiments of the present invention.
2 is a diagram illustrating an example of a circuit structure of a pixel array of an ultrasonic sensor according to embodiments of the present invention.
3 is a view showing another example of the structure of an ultrasonic sensor according to embodiments of the present invention.
4A to 4D are views illustrating an example of a process of the ultrasonic sensor illustrated in FIG. 3.
5 is a view showing an example of a process of the ultrasonic sensor shown in FIG. 3 in a planar structure.
6 is a view showing another example of the structure of an ultrasonic sensor according to embodiments of the present invention.
7 is a view showing an example of a process of the ultrasonic sensor shown in FIG. 6 in a planar structure.
8 is a view showing an example of the structure of the electrode pad portion in the ultrasonic sensor shown in FIG. 6.
9 is a view illustrating an example of a structure in which a via hole is disposed in the electrode pad portion shown in FIG. 8.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, the same components may have the same reference numerals as possible even though they are displayed on different drawings. In addition, in describing the present invention, when it is determined that detailed descriptions of related well-known structures or functions may obscure the subject matter of the present invention, detailed descriptions thereof may be omitted.

In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the component from other components, and the essence, order, order, or number of the component is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, the component may be directly connected to or connected to the other component, but different components between each component It should be understood that the "intervenes" may be, or each component may be "connected", "coupled" or "connected" through other components.

1 is a diagram illustrating an example of a structure of an ultrasonic sensor 200 disposed in a display device according to embodiments of the present invention.

Referring to FIG. 1, a display device according to embodiments of the present invention includes a display panel 110 in which a plurality of gate lines, a plurality of data lines, and a plurality of subpixels are disposed, and a display panel 110. Various driving circuits for driving signal lines or voltage lines may be included.

On at least one surface of the display device, an ultrasonic sensor 200 or an ultrasonic sensing device for sensing biometric information (eg, a fingerprint) or a gesture that is in contact with or close to the display panel 110 may be disposed. Alternatively, the ultrasonic sensor 200 may be embedded in the display panel 110.

For example, the ultrasonic sensor 200 may be disposed on the opposite side of the surface on which the image is displayed on the display panel 110. The ultrasonic sensor 200 may be bonded to the display panel 110 through the adhesive unit 300, and the adhesive unit 300 may be made of resin, for example.

The ultrasonic sensor 200 may generate ultrasonic waves and sense ultrasonic waves reflected on the fingerprints in contact with the cover glass 120 to recognize the fingerprints in contact with the cover glass 120.

Specifically, when the ultrasonic wave generated by the ultrasonic sensor 200 reaches the valley portion of the fingerprint, it contacts the air existing between the human skin and the cover glass 120. Here, due to the difference in the acoustic impedance value between the cover glass 120 and the air, most of the ultrasonic waves hitting the air are reflected.

Then, when the ultrasonic waves generated by the ultrasonic sensor 200 reach the ridge portion of the fingerprint, they come into contact with the skin of a person in contact with the cover glass 120. Here, a part of the ultrasound may be reflected, but most of the ultrasound is transmitted inside the skin and is reflected inside the skin.

Accordingly, the bone portion and the floor portion of the fingerprint can be distinguished and the fingerprint can be sensed based on the intensity and timing of ultrasonic waves that reach and reflect on the valley portion and the floor portion of the fingerprint.

As described above, since the ultrasonic sensor 200 senses the inside of the skin, it is not sensitive to contamination or condition of the skin surface and provides excellent security. In addition, the display device allows the display device to sense the fingerprint without reducing the area where the image is displayed on the display panel 110.

The ultrasonic sensor 200 may include a material for generating ultrasonic waves and various circuit elements for generating and sensing ultrasonic waves.

For example, the ultrasonic sensor 200 may include a substrate 210, a thin film transistor array 221 disposed on the substrate 210, a first pad portion 231, and a second pad portion 232. . In addition, the thin film transistor array 221 may include pixel electrodes (or sensing electrodes) disposed in each pixel, and the piezoelectric material 222 and the electrode layer 223 may be sequentially disposed in the thin film transistor array 221. Can be.

The piezoelectric material 222 may be, for example, PZT, ZnO, perovskite, or the like, but is not limited thereto.

The electrode layer 223 may be adhered to the reflective layer 250 through the adhesive layer 240, and the cover layer 260 may be disposed on the reflective layer 250.

The controller 290 for supplying signals, voltages, and the like to the thin film transistor array 221 and the electrode layer 223 includes a second pad disposed on the substrate 210 through the flexible printed circuit 280 and the bonding unit 270. It may be electrically connected to the unit 232.

In the thin film transistor array 221, a transistor for driving an ultrasonic wave and sensing of ultrasonic waves reflected on a fingerprint, a pixel electrode, and the like may be disposed.

The pixel electrode disposed on the thin film transistor array 221 may form the electrode layer 223 and the capacitor C.

Also, the piezoelectric material 222 may be vibrated by the voltage applied to the pixel electrode and the electrode layer 223 disposed in the thin film transistor array 221 to generate ultrasonic waves.

The thin film transistor array 221 including the pixel electrode, the piezoelectric material 222, and the electrode layer 223 may also be viewed as a circuit pixel array.

The electrode layer 223 may be disposed, for example, through a method of coating silver ink, and in some cases, may be disposed in a form that covers the entire piezoelectric material 222 or may be disposed in a constant pattern.

The reflective layer 250 may be made of copper, for example, and may function to reflect ultrasonic waves reflected from the fingerprint and return to the thin film transistor array 221.

The cover layer 260 may be formed of, for example, polyimide, and may function to cap the pixel array and the reflective layer 250 of the ultrasonic sensor 200.

Signals and voltages for driving the pixel array are supplied from the controller 290, but in some cases, signals that do not require high voltage may be supplied from a driving circuit arranged for driving the display panel 110.

2 is a diagram showing an example of a circuit structure of a pixel array of an ultrasonic sensor 200 according to embodiments of the present invention.

Referring to FIG. 2, a plurality of scan lines SSL and a plurality of sensing lines SSL may be disposed in the pixel array of the ultrasonic sensor 200. The scan line SSL and the sensing line SSL may be disposed to cross each other, and a plurality of pixels may be disposed in an area defined by the intersection of the scan line SSL and the sensing line SSL.

In addition, a voltage line that supplies a driving voltage DV, a sensing voltage SV, and the like for ultrasonic generation and sensing of pixels may be arranged.

In addition, the ultrasonic sensor 200 may include a circuit for driving a plurality of scan lines arranged in the pixel array, a circuit for detecting a sensing signal through the plurality of sensing lines, and the like.

In each pixel, various circuit elements for ultrasonic generation and sensing may be arranged.

For example, each pixel is controlled by voltages of the first transistor T1, the third transistor T3, and the first node N1 controlled by the scan signal SCO applied to the scan line SCL. The second transistor T2 and one capacitor C may be disposed.

Here, the first transistor T1, the second transistor T2, and the third transistor T3 are all illustrated as an N type, but may be implemented as a P type in some cases. Alternatively, only the first transistor T1 and the third transistor T3 may be implemented with the same type, and the second transistor T2 may be implemented with different types.

The first transistor T1 is controlled by the scan signal SCO applied to the scan line SCL, and may be electrically connected between the first driving voltage line DVL1 and the first node N1.

Here, the first driving voltage line DVL1 may supply the first driving voltage DV1 for ultrasonic generation to a pixel. The first driving voltage DV1 may be a pulsed AC voltage having a high voltage level, for example, an AC voltage swinging from +100V to -100V.

The third transistor T3 is controlled by the scan signal SCO applied to the scan line SCL, and may be electrically connected between the sensing line SSL and the second transistor T2.

Here, the first transistor T1 and the third transistor T3 disposed in adjacent pixels may be driven by the same scan line SCL.

That is, as illustrated in FIG. 2, the first transistor T1 arranged in column A and the third transistor T3 arranged in column B are connected to the same n-th scan line SCL(n) to perform n-th scan. The n-th scan signal SCO(n) applied to the line SCL(n) may be simultaneously driven.

The second transistor T2 is controlled according to the voltage level of the first node N1 and may be electrically connected between the sensing voltage line SVL and the third transistor T3.

In addition, the sensing voltage SV applied to the sensing voltage line SVL may be a constant voltage.

The capacitor C may be electrically connected between the first node N1 and the second driving voltage line DVL2.

That is, the electrode of the capacitor C connected to the first node N1 may mean a pixel electrode for forming the capacitance disposed in the thin film transistor array 221 described above, and the second driving voltage line DVL2 ), the electrode of the capacitor C connected may mean the electrode layer 223.

In addition, the electrode layer 223 may be commonly disposed in at least two or more pixels.

The second driving voltage line DVL2 may supply the second driving voltage DV2 for ultrasonic generation to the pixel, and the second driving voltage DV2 may be a constant voltage lower than the maximum voltage of the first driving voltage DV1. Can be.

The scan signal SCO is sequentially applied to the scan lines SCL arranged in the pixel array, and ultrasonic generation and sensing may be performed.

For example, when the n-th scan signal SCO(n) having a level that turns on the first transistor T1 by the n-th scan line SCL(n) is applied, the first transistor T1 disposed in the A column ) Will turn on.

Since the first transistor T1 is turned on, the first driving voltage DV1 is applied to the first node N1.

Since high voltage and low constant voltage in the form of pulses are applied to both electrodes of the capacitor C, the piezoelectric material 222 disposed between the electrodes of the capacitor C may vibrate to generate ultrasonic waves.

That is, ultrasonic waves are generated in column A where the first transistor T1 is turned on.

At this time, since the n-th scan signal SCO(n) having a level that turns on the first transistor T1 is applied to the n-th scan line SCL(n), the third transistor T3 arranged in the B column is applied. It will also turn on.

In a state in which the first transistor T1 disposed in the B column is turned off, the voltage level of the first node N1 of the pixel disposed in the B column may fluctuate when the ultrasound reflected on the fingerprint reaches the B column.

That is, the polarization state of the piezoelectric material 222 disposed between the pixel electrode and the electrode layer 223 is changed by the reflected ultrasonic waves, thereby changing the voltage level of the pixel electrode, that is, the first node N1. .

And, as the voltage level of the first node N1 changes, the second transistor T2 is turned on and off, and since the third transistor T3 is turned on, the sensing voltage SV is the sensing line SSL ).

That is, it is possible to sense ultrasonic waves reflected from the fingerprint and returned from the column B where the third transistor T3 is turned on.

As described above, by driving the first transistor T1 and the third transistor T3 disposed in adjacent pixel columns by the same scan line SCL, ultrasonic generation and sensing can be performed in adjacent pixel columns.

Meanwhile, the above-described ultrasonic sensor 200 may be manufactured by sequentially stacking or coating a piezoelectric material 222, an electrode layer 223 on the substrate 210 on which the thin film transistor array 221 is disposed. .

Embodiments of the present invention, after manufacturing a portion including the piezoelectric material 222 and the electrode layer 223 in the ultrasonic sensor 200 in a separate process, the substrate 210 on which the thin film transistor array 221 is disposed It provides a method to increase the process efficiency of the ultrasonic sensor 200 by bonding with.

3 is a view showing another example of the structure of the ultrasonic sensor 200 according to embodiments of the present invention.

Referring to FIG. 3, the ultrasonic sensor 200 according to embodiments of the present invention includes a base film 400, a reflective layer 250 disposed on the base film 400, and a reflective layer 250 It may include an insulating layer 500, an electrode layer 223 disposed on the insulating layer 500, and a piezoelectric material 222 disposed on the electrode layer 223.

In addition, the ultrasonic sensor 200 may include a substrate 210 disposed on the piezoelectric material 222 and on which a thin film transistor array 221 is disposed.

In addition, a via hole VH penetrating the base film 400, the reflective layer 250, the insulating layer 500, the electrode layer 223, and the piezoelectric material 222 may be included.

The via hole VH may be located in the pad area PA of the electrode area EA and the pad area PA of the ultrasonic sensor 200.

The electrode region EA and the pad region PA may be divided based on the electrode layer 223.

That is, as an example, an area corresponding to the thin film transistor array 221 in which pixels for generating and sensing ultrasound is disposed in the electrode layer 223 is called an electrode area EA, and the electrode area EA in the electrode layer 223 The area excluding) may be referred to as a pad area PA.

Alternatively, a region corresponding to the first pad portion 231 disposed on the substrate 210 among regions excluding the electrode region EA in the electrode layer 223 may be referred to as a pad region PA.

A conductive filler 600 may be disposed inside the via hole VH formed in the pad area PA, and the conductive filler 600 may be electrically connected to the first pad portion 231 disposed on the substrate 210. Can be. The conductive filler 600 may be directly connected to the first pad portion 231 disposed on the substrate 210, or may be connected by an adhesive material or the like.

That is, the electrode layer 223 and the first pad portion 231 may be electrically connected by the conductive filler 600.

And, the ultrasonic sensor 200 is located on the lower surface of the base film 400, is located under the conductive filler 600, the conductive filler 600 includes an area disposed around the via hole (VH) A protective layer 700 disposed in the region may be included.

The protective layer 700 may prevent corrosion due to external exposure of the conductive filler 600 and provide an insulating function.

The controller 290 that controls the ultrasonic sensor 200 and supplies signals, voltages, and the like to the thin film transistor array 221 is a product disposed on the substrate 210 by a flexible printed circuit 280, a bonding unit 270, or the like. 2 may be electrically connected to the pad unit 232.

The ultrasonic sensor 200 having such a structure is manufactured by sequentially laminating or coating the reflective layer 250, the insulating layer 500, the electrode layer 223, and the piezoelectric material 222 on the base film 400. Can be.

In addition, the ultrasonic sensor 200 may be completed by bonding the portion produced through the above-described process to the substrate 210 on which the thin film transistor array 221 is disposed.

That is, the thin film transistor array 221 is formed on the substrate 210, and the electrode layer 223 is formed on the base film 400, rather than sequentially stacking the piezoelectric material 222 and the electrode layer 223. By manufacturing the ultrasonic sensor 200 in a manner of bonding to the substrate 210 in a state in which the piezoelectric material 222 is formed, the process efficiency of the ultrasonic sensor 200 can be increased.

In addition, by forming the via hole (VH) in a state in which the electrode layer 223, the piezoelectric material 222, etc. are disposed on the base film 400, the manufacturing process of the ultrasonic sensor 200 is simplified and the electrode layer 223 and The first pad portion 231 disposed on the substrate 210 can be easily made an electrical connection.

4A to 4D are views showing an example of a process of the ultrasonic sensor 200 shown in FIG. 3.

Referring to FIG. 4A, the reflective layer 250, the insulating layer 500, the electrode layer 223, and the piezoelectric material 222 are sequentially laminated or coated on the base film 400.

The base film 400 may be, for example, colored (colorless) Pi, PET, PC, COP, or the like.

The base film 400 may function as a film for stacking the components of the ultrasonic sensor 200, and protect the electrode layer 223 and the piezoelectric material 222 in the completed ultrasonic sensor 200 You can also do

The reflective layer 250 disposed on the base film 400 may be, for example, a metal material such as copper or silver.

The reflective layer 250 may provide a function of reflecting the reflected ultrasonic waves back to the thin film transistor array 221 when the ultrasonic waves generated by the ultrasonic sensor 200 return to the object.

An insulating layer 500 may be disposed on the reflective layer 250.

That is, as the process is performed by sequentially stacking the reflective layer 250 and the electrode layer 223 on the base film 400, the electrode layer 223 is disposed after the insulating layer 500 is disposed on the reflective layer 250. Can be placed.

The electrode layer 223 is disposed on the insulating layer 500, and the electrode layer 223 may be formed of, for example, silver, and may be disposed in a manner in which silver ink or the like is coated on the insulating layer 500.

A piezoelectric material 222 is disposed on the electrode layer 223, and a material having piezoelectric properties such as PZT described above may be disposed as the piezoelectric material 222.

The piezoelectric material 222 may be disposed on the front surface of the electrode layer 223 by a slit coating method or the like.

That is, according to the above-described process, the electrode layer 223 and the piezoelectric material 222 are disposed on the base film 400, and the electrode layer 223 and the piezoelectric material 222 are disposed by coating the entire surface. You can make this easier.

As such, when the arrangement of the electrode layer 223 and the piezoelectric material 222 on the base film 400 is completed, at least one via hole VH is formed in a partial region of the entire structure including the base film 400. can do.

Referring to FIG. 4B, at least one via hole (VH) is formed in some regions while the base film 400, the reflective layer 250, the insulating layer 500, the electrode layer 223, and the piezoelectric material 222 are stacked. Can form.

The via hole VH may be formed using a laser method or a CNC method.

In addition, the via hole VH may be formed in the pad area PA of the electrode area EA and the pad area PA.

That is, in the state in which the electrode layer 223, the piezoelectric material 222, and the like are disposed on the base film 400, the electrical connection between the electrode layer 223 and the first pad portion 231 disposed on the substrate 210 is performed. For this, at least one via hole VH may be formed in a region corresponding to the first pad portion 231.

As described above, after sequentially placing the electrode layer 223, the piezoelectric material 222, and the like on the base film 400 by the front coating, the via hole VH may be formed to facilitate the process.

Referring to FIG. 4C, after the via hole VH is formed in the pad area PA, the conductive filler 600 is disposed inside the via hole VH formed in the pad area PA.

The conductive filler 600 may be made of silver constituting the electrode layer 223, and the conductive filler 600 may be disposed by filling silver inside the via hole VH.

At this time, the conductive filler 600, the base film 400 is disposed so that the lower surface, that is, the electrode layer 223, the piezoelectric material 222 on the base film 400 is sequentially stacked vias It may be filled in the hole (VH).

Alternatively, the conductive filler 600 may be filled in the via hole VH in a state where the base film 400 is disposed to be an upper surface.

That is, the conductive filler 600 disposed on the side of the piezoelectric material 222 must be electrically connected to the first pad portion 231 disposed on the substrate 210. Accordingly, the conductive filler 600 is disposed inside the via hole VH in a state where the piezoelectric material 222 is disposed to be the lower surface, so that the conductive filler 600 and the first pad portion 231 of the substrate 210. It can be made to fill the contacted portion sufficiently.

In this case, since the conductive filler 600 is disposed in a sufficient amount inside the via hole VH, a portion of the conductive filler 600 may be disposed on the base film 400 disposed on the top surface.

That is, the conductive filler 600 may be disposed in the peripheral region of the via hole VH in the base film 400.

Referring to FIG. 4D, after arranging the conductive filler 600 inside the via hole VH, the protective layer 700 may be disposed in a portion where the via hole VH is disposed in the base film 400. .

The protective layer 700 may be disposed in an area where the via hole VH is disposed in the base film 400, and an area including an area where the conductive filler 600 is disposed around the via hole VH. Can be placed on.

Here, the conductive filler 600 disposed inside the via hole VH may shrink in the process of curing to have a concave surface, and accordingly, slightly between the conductive filler 600 and the protective layer 700 You may have space.

In addition, the protective layer 700 may prevent corrosion of the conductive filler 600 by preventing the conductive filler 600 disposed inside the via hole VH from being exposed to the outside.

In addition, the protective layer 700 may provide a function of insulating the conductive filler 600 exposed to the outside of the via hole VH.

The protective layer 700 may be disposed in consideration of the spreading phenomenon of the conductive filler 600 disposed around the via hole VH.

For example, when the diameter of the via hole VH is L1 (eg, 125 µm), the conductive filler 600 falling on the via hole VH to fill the inside of the via hole VH is the via hole VH ) From the boundary of L2 (eg, 200㎛).

In addition, the conductive filler 600, which is dropped on the base film 400, may be disposed to a region that is separated by L3 (eg, 100 to 300 μm) from the boundary of the region where the conductive filler 600 is separated due to spreading phenomenon.

Therefore, in the protective layer 700, considering the range in which the conductive filler 600 is disposed around the via hole VH of the base film 400, the conductive filler 600 is disposed around the via hole VH. It can be arranged in an area including an area.

As such, in the state in which the conductive filler 600 is filled in the via hole VH of the structure in which the electrode layer 223, the piezoelectric material 222, etc. are disposed on the base film 400, and the protective layer 700 is disposed , The ultrasonic sensor 200 may be manufactured by bonding to the substrate 210 on which the thin film transistor array 221 is disposed.

Here, the bonding of the substrate 210 and the piezoelectric material 220 may be performed by disposing the bonding portion 270 between the thin film transistor array 221 on the substrate 210 and the piezoelectric material 222, but the piezoelectric material 222 ) Has a bonding property, the piezoelectric material 222 and the thin film transistor array 221 may be directly bonded without arranging the bonding portion 270.

According to the above-described process, the electrode layer 223 and the piezoelectric material 220 are formed on the base film 400 and then bonded to the substrate 221, thereby forming the piezoelectric material 222 and the electrode layer 223 on the substrate 221. ) Can provide an advantage in terms of process yield compared to a method of laminating.

5 is a view showing an example of the process of the ultrasonic sensor 200 shown in FIG. 3 in a planar structure.

Referring to FIG. 5, the reflective layer 250 and the insulating layer 500 are disposed on the base film 400.

Looking at the part constituting one ultrasonic sensor 200, the electrode layer 223 is disposed on the insulating layer 500 (①). Here, the electrode layer 223 may be integrally disposed without being separated from the electrode region EA and the pad region PA.

Then, the piezoelectric material 222 may be coated and disposed on the electrode layer 223 (②).

As such, since the electrode layer 223 is disposed integrally and the piezoelectric material 222 is entirely coated on the electrode layer 223, the electrode layer 223 and the piezoelectric material 222 can be easily disposed.

In the state in which the electrode layer 223 and the piezoelectric material 222 are disposed, at least one via hole VH is formed in a portion corresponding to the pad area PA (③).

At this time, in the region where the electrode layer 223 and the piezoelectric material 222 are disposed, the position where the via hole VH is formed can be easily changed.

That is, since the electrode layer 223 is disposed integrally without being separated from the electrode region EA and the pad region PA, the thin film transistor array 221 and the first pad portion 231 disposed on the substrate 210 are disposed. According to the structure, the position of the via hole VH can be easily changed and formed.

When the via hole VH is formed, a conductive filler 600 is disposed inside the via hole VH (④).

Then, a protective layer 700 is disposed on an area including a region where the conductive filler 600 is disposed around the via hole VH and the via hole VH on the lower surface of the base film 400 (⑤).

As described above, by forming the electrode layer 223, the piezoelectric material 222, and the like, by bonding to the substrate 210 on which the thin film transistor array 221 is disposed, the ultrasonic sensor 200 can be easily manufactured.

That is, the portion of the ultrasonic sensor 200 in which the electrode layer 223 and the piezoelectric material 222 are stacked is easily formed in a simplified process and bonded to the substrate 210, thereby increasing the process yield of the ultrasonic sensor 200. Can give.

Meanwhile, in the above-described process of the ultrasonic sensor 200, in order to improve the sensing sensitivity of the ultrasonic sensor 200, a portion in which the electrode layer 223 is disposed in the electrode region EA may be implemented in a patterned structure.

6 is a view showing another example of the structure of the ultrasonic sensor 200 according to embodiments of the present invention.

Referring to FIG. 6, the ultrasonic sensor 200 according to embodiments of the present invention includes a base film 400, a reflective layer 250 disposed on the base film 400, an insulating layer 500, and an electrode layer ( 223) and a piezoelectric material 222. In addition, the substrate 210 may be disposed on the piezoelectric material 222 and on which the thin film transistor array 221 or the like is disposed.

In addition, in the portion where the electrode layer 223 and the piezoelectric material 222 are disposed on the base film 400, a via hole VH formed in the pad area PA may be included.

In addition, a conductive filler 600 is disposed inside the via hole VH, and a conductive filler 600 is disposed around the via hole VH and the via hole VH on the bottom surface of the base film 400. The protective layer 700 may be disposed in the region including the.

The protective layer 700 may prevent the conductive filler 600 disposed in the via hole VH from being exposed to the outside of the via hole VH.

At this time, the electrode layer 223 is composed of a plurality of electrode parts 223a and a plurality of electrode parts 223a that are separated and arranged in a certain pattern in the electrode area EA, and a plurality of wiring parts 223b connecting the electrode parts 223a to each other. Can be.

The width of the electrode portion 223a may be wider than that of the wiring portion 223b, and the thickness of the electrode portion 223a may be thicker than that of the wiring portion 223b.

In addition, each of the plurality of electrode portions 223a may be disposed to correspond to a whole region or a partial region of pixels disposed in the thin film transistor array 221.

That is, the electrode layer 223 to which the second driving voltage DV2 is applied during driving for generating ultrasonic waves may be separately arranged to correspond to the pixel to which the first driving voltage DV1 is applied.

Pixels to which the first driving voltage DV1 for vibration of the piezoelectric material 222 is applied, that is, pixel electrodes and electrode portions 223a of the electrode layer 223 to which the second driving voltage DV2 is applied correspond to each other By being arranged in a structure, it is possible to increase the accuracy of the ultrasonic generation region due to the application of the driving voltage.

In addition, it is possible to improve the sensing sensitivity of reflected ultrasonic waves by improving the accuracy of the ultrasonic generation region.

That is, through the patterning structure of the electrode layer 223, interference with a signal generated and received in an adjacent pixel region is reduced, so that the sensing performance of ultrasonic waves can be improved.

In addition, even in the above-described structure, the electrode layer 223 and the piezoelectric material 222 are sequentially disposed on the base film 400, and the electrode layer 223 and the substrate 210 are via via holes VH. By allowing the first pad portion 231 to be electrically connected, the sensing performance of the ultrasonic sensor 200 may be improved while providing a process advantage.

7 is a view showing an example of a process of the ultrasonic sensor 200 shown in FIG. 6 in a planar structure.

Referring to FIG. 7, the reflective layer 250 is disposed on the base film 400, and the insulating layer 500 is disposed on the reflective layer 250. In addition, the electrode layer 223 may be disposed on the insulating layer 500.

Here, the electrode layer 223 is disposed separately from the electrode region EA into a plurality of electrode portions 223a, and the plurality of electrode portions 223a can be connected by a plurality of wiring portions 223b (①). . At this time, since the electrode layer 223 is disposed by patterning a portion disposed in the electrode region EA, at least one alignment key 800 for the patterning process of the electrode layer 223 may be disposed on the insulating layer 500. have.

In addition, the electrode layer 223 may be integrally disposed in the pad area PA. That is, the electrode layer 223 is disposed in a structure separated only from the electrode region EA, and may be disposed without being separated from the pad region PA.

In addition, a portion disposed in the electrode region EA and a portion disposed in the pad region PA in the electrode layer 223 may be connected by a wiring part 223b.

The piezoelectric material 222 may be disposed on the electrode layer 223 by being coated with the electrode region EA and the pad region PA on the entire surface (②).

That is, since the electrode layer 223 and the first pad portion 231 of the substrate 210 are electrically connected through the via hole VH, the piezoelectric material 222 may be disposed on the front surface of the electrode layer 223. have.

When the piezoelectric material 222 is disposed on the electrode layer 223, a via hole VH is formed in the pad area PA (③-1).

At this time, the pad region PA in the electrode layer 223 may be formed at various locations, so that the via hole VH may be formed at another location according to the arrangement structure of the electrode layer 223 (③-2).

Then, the conductive filler 600 may be disposed inside the via hole VH, and the protective layer 700 may be disposed on the lower surface of the base film 400.

As described above, while sequentially stacking the electrode layer 223 and the piezoelectric material 222 on the base film 400, patterning the portion where the electrode layer 223 is disposed in the electrode region EA, increases the process efficiency while increasing the ultrasonic wave. The sensing sensitivity of the sensor 200 may be improved.

In addition, the part in which the electrode layer 223 is disposed in the pad area PA is integrally disposed, and the piezoelectric material 222 is coated on the front surface of the electrode layer 223 to facilitate the placement of the piezoelectric material 222 and the electrode layer ( 223) and the first pad portion 231 of the substrate 210 can be easily connected.

In addition, the pad area PA may be disposed at various positions in the electrode layer 223, and in some cases, a portion in which the electrode layer 223 is disposed in the pad area PA may be disposed in a pad shape.

8 is a view showing an example of the structure of the electrode pad unit 900 in the ultrasonic sensor 200 shown in FIG. 6.

Referring to FIG. 8, an example in which the electrode layer 223 is disposed in the form of a plurality of electrode pad portions 900 in the pad area PA is illustrated, and the electrode layer 223 and the piezoelectric layer are formed on the insulating layer 500. Only the portion where the material 222 is disposed is shown by way of example.

The electrode layer 223 is disposed on the insulating layer 500, and the electrode layer 223 may be patterned and disposed as a plurality of electrode portions 223a in the electrode region EA. Therefore, the alignment key 800 may be disposed outside the electrode layer 223 on the insulating layer 500.

In addition, the plurality of electrode portions 223a may be connected to each other by a plurality of wiring portions 223b.

The electrode layer 223 may be disposed in the form of a plurality of electrode pad parts 900 in the pad area PA.

Here, although the shape of the plurality of electrode pad portions 900 is shown as an example, the shape of the electrode pad portion 900 may have various other shapes.

On the electrode layer 223, the piezoelectric material 222 may be entirely disposed in an area including the electrode area EA and the pad area PA.

That is, even though the electrode layer 223 is patterned and arranged in the form of a plurality of electrode parts 223a in the electrode area EA, and disposed in the form of a plurality of electrode pad parts 900 in the pad area PA, the electrode layer ( Since the 223 is electrically connected to the first pad portion 231 of the substrate 210 through the via hole VH, the piezoelectric material 222 may be disposed on the front surface of the electrode layer 223.

Therefore, the piezoelectric material 222 can be easily disposed regardless of the structure of the electrode layer 223.

When the piezoelectric material 222 is disposed on the electrode layer 223, a via hole VH may be formed at a position where the electrode pad portion 900 is disposed in the pad area PA.

Then, the conductive filler 600 may be disposed inside the via hole VH, and the protective layer 700 may be disposed in a region including the via hole VH and its surroundings on the lower surface of the base film 400. .

Therefore, even when the electrode layer 223 is disposed in the form of the electrode pad portion 900 in the pad area PA, the electrode layer 223, the piezoelectric material 222, and the like are sequentially stacked on the base film 400. Through the method of forming the via hole (VH), it is possible to increase the process efficiency.

9 is a diagram illustrating an example of a structure in which a via hole VH is disposed in the electrode pad portion 900 shown in FIG. 8.

Referring to FIG. 9, as illustrated in (a), one via hole VH may be formed in each of the plurality of electrode pad parts 900.

Alternatively, as illustrated in (b), a plurality of via holes VH may be formed in each of the plurality of electrode pad parts 900.

In addition, when a plurality of via holes VH are formed in each of the plurality of electrode pad parts 900, the via holes VH may be disposed on a straight line in one direction, as illustrated in (c), It can also be arranged in zigzag.

Further, in the electrode pad unit 900, the width of the portion where the via hole VH is disposed may be different from the width of the remaining portion.

That is, as illustrated in (d), the width W1 of the portion where the via hole VH is disposed in the electrode pad portion 900 may be wider than the width W2 of the portion where the via hole VH is not disposed.

Therefore, when forming the via hole VH in a structure in which the electrode pad unit 900 is disposed, it is possible to facilitate the process of forming the via hole VH.

In addition, in addition to the above-described example, the via hole VH may be variously disposed in the electrode pad unit 900.

According to the above-described embodiments of the present invention, the electrode layer 223 and the piezoelectric material 222 are coated on the base film 400, and are disposed on the substrate 210 on which the thin film transistor array 221 is disposed. By bonding, it is possible to increase the process efficiency of the ultrasonic sensor 200.

In addition, by forming the via hole VH in a state in which the electrode layer 223 and the piezoelectric material 222 are disposed on the base film 400, and disposing the conductive filler 600 inside the via hole VH, Electrical connection between the electrode layer 223 and the first pad portion 231 of the substrate 210 may be facilitated.

In addition, the portion where the electrode layer 223 is disposed in the electrode region EA is patterned, and the portion disposed in the pad region PA is integrally disposed, and the piezoelectric material 222 is coated on the electrode layer 223 by the entire surface, It is possible to improve the sensing sensitivity while improving the process efficiency.

In addition, the electrode layer 223 may be disposed in the form of the electrode pad portion 900 in the pad area PA. In this case, the electrode pad portion 900 and the substrate 210 may be formed through the via hole VH. One pad unit 231 is electrically connected to the ultrasound sensor 200 to be configured.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention. In addition, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain the scope of the technical spirit of the present invention. The protection scope of the present invention should be interpreted by the following claims, and all technical spirits within the equivalent scope should be interpreted as being included in the scope of the present invention.

110: display panel 120: cover glass
200: ultrasonic sensor 210: substrate
221: thin film transistor array 222: piezoelectric material
223: electrode layer 223a: electrode portion
223b: wiring section 231: first pad section
232: second pad portion 240: adhesive layer
250: reflective layer 260: cover layer
270: bonding portion 280: flexible printed circuit
290: controller 300: adhesive
400: base film 500: insulating layer
600: conductive filler 700: protective layer
800: alignment key 900: electrode pad portion

Claims (15)

Base film;
A reflective layer disposed on the base film;
An electrode layer positioned on the reflective layer and disposed in the electrode region and the pad region;
A piezoelectric material disposed on the electrode layer; And
A substrate on which the thin film transistor array is disposed, and disposed on the piezoelectric material,
An ultrasonic sensor including at least one hole positioned in the pad area, penetrating the base film, the reflective layer, the electrode layer, and the piezoelectric material, and having a conductive filler disposed therein.
According to claim 1,
An ultrasonic sensor further comprising a protective layer positioned under the base film and disposed in an area including an area corresponding to the at least one hole.
According to claim 2,
The protective layer,
An ultrasonic sensor disposed under the conductive filler and disposed in an area including the area in which the conductive filler is disposed around the at least one hole.
According to claim 1,
The conductive filler,
An ultrasonic sensor electrically connected to a pad portion disposed outside the thin film transistor array on the substrate.
According to claim 1,
The electrode layer,
An ultrasonic sensor in which a portion disposed in the electrode region and a portion disposed in the pad region are integrally disposed.
According to claim 1,
The electrode layer,
The electrode region includes a plurality of electrode parts disposed separately from each other and a plurality of wiring parts connecting the plurality of electrode parts to each other,
An ultrasonic sensor integrally disposed in the pad area.
The method of claim 6,
The width of each of the plurality of wiring portions is narrower than the width of each of the plurality of electrode portions, and the thickness of each of the plurality of wiring portions is thinner than the thickness of each of the plurality of electrode portions.
According to claim 1,
The electrode layer,
It includes two or more electrode pads disposed separately from each other in the pad area,
The at least one hole,
At least one ultrasonic sensor disposed on each of the two or more electrode pad parts.
The method of claim 8,
Each of the two or more electrode pad portions,
The ultrasonic sensor in which the width of the portion where the at least one hole is disposed is wider than the width of the remaining portion.
According to claim 1,
The ultrasonic sensor further includes an insulating layer disposed between the reflective layer and the electrode layer, and having a hole disposed at a position corresponding to the at least one hole.
Display panel; And
Includes an ultrasonic sensor disposed on at least one surface of the display panel, or embedded in the display panel,
The ultrasonic sensor,
Base film;
A reflective layer disposed on the base film;
An insulating layer disposed on the reflective layer;
An electrode layer disposed on the insulating layer and disposed in the electrode region and the pad region;
A piezoelectric material disposed on the electrode layer; And
A substrate on which the thin film transistor array is disposed, and disposed on the piezoelectric material,
A display device positioned in the pad area, penetrating the base film, the reflective layer, the insulating layer, the electrode layer, and the piezoelectric material, and including at least one hole in which a conductive filler is disposed.
The method of claim 11,
A display device positioned under the base film and further comprising a protective layer disposed in an area including an area corresponding to the at least one hole.
The method of claim 12,
The protective layer,
A display device positioned below the conductive filler and disposed in an area including the area in which the conductive filler is disposed around the at least one hole.
The method of claim 11,
The conductive filler,
A display device electrically connected to a pad portion disposed outside the thin film transistor array on the substrate.
The method of claim 11,
The electrode layer,
A display device in which a portion disposed in the electrode region and a portion disposed in the pad region are integrally disposed.

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