WO2019033353A1 - Photoelectric sensing apparatus and electronic device - Google Patents

Abstract

The invention relates to a photoelectric detection apparatus (20) and an electronic device. The photoelectric detection apparatus (20) comprises a semiconductor substrate (24), the semiconductor substrate (24) having a first surface (240) and a second surface (242) arranged facing one of the other; a plurality of photosensitive pixels (22) being formed on the first surface (240) of the semiconductor substrate (24); a plurality of through holes (241) passing through the semiconductor substrate (24) to the first surface (240) being formed on the second surface (242) of the semiconductor substrate (24); and the through holes (241) corresponding to the photosensitive pixels (22). The electronic device comprises the photoelectric detection apparatus (20).

Description

Photoelectric sensing device and electronic device Technical field

The utility model relates to the field of photoelectric sensing, in particular to a photoelectric sensing device and an electronic device.

Background technique

At present, biometric information sensors, especially fingerprint recognition sensors, have gradually become the standard components of electronic products such as mobile terminals. Since the optical fingerprint recognition sensor has stronger penetration ability than the capacitive fingerprint recognition sensor, an optical fingerprint recognition module applied to the mobile terminal has been proposed. As shown in FIG. 1, the optical fingerprint recognition module includes an optical fingerprint sensor 400 and a light source 402. The optical fingerprint sensor 400 is disposed under the protective cover 401 of the mobile terminal. The light source 402 is disposed adjacent to one side of the optical fingerprint sensor 400. When the user's finger F contacts the protective cover 401, the light signal emitted by the light source 402 passes through the protective cover 401 and reaches the finger F, is reflected by the valleys and ridges of the finger F, and is received by the optical fingerprint sensor 400, and A fingerprint image of the finger F is formed.

However, the above optical fingerprint recognition module cannot obtain a clear image and needs to be improved.

Utility model content

The embodiments of the present invention aim to at least solve one of the technical problems existing in the prior art. To this end, the embodiments of the present invention need to provide a photoelectric sensing device and an electronic device.

An optoelectronic sensing device according to an embodiment of the present invention includes a semiconductor substrate including a first surface and a second surface disposed oppositely, and a plurality of photosensitive pixels are formed on the first surface of the semiconductor substrate. A plurality of through holes penetrating the semiconductor substrate toward the first surface are formed on a second surface of the semiconductor substrate, and the through holes correspond to the photosensitive pixels.

In the embodiment of the present invention, by forming a photosensitive pixel and a through hole corresponding to the photosensitive pixel on the semiconductor substrate, only the optical signal within the predetermined range passes through the through hole and is absorbed by the photosensitive pixel due to the light absorption characteristic of the semiconductor substrate. The optical signals received between adjacent photosensitive pixels are not aliased, and the images obtained by the photosensitive pixels after performing light sensing are relatively clear, thereby improving the sensing accuracy of the photoelectric sensing device. The photosensitive pixels and the through holes are formed on the same semiconductor substrate, thereby reducing the thickness of the photoelectric sensing device, thereby reducing the cost of the photoelectric sensing device.

In some embodiments, the photosensitive pixel includes at least one photosensitive device, and a photosensitive surface of the photosensitive device is disposed corresponding to the through hole.

The photosensitive device is disposed corresponding to the through hole to ensure that the optical signal passing through the through hole is completely received by the photosensitive device, thereby improving the sensing accuracy of the photoelectric sensing device.

In some embodiments, the semiconductor substrate is a silicon wafer of a predetermined thickness.

In some embodiments, the semiconductor substrate is formed by thinning a silicon wafer to a predetermined thickness.

In some embodiments, the vias are formed by etching on a semiconductor substrate.

In some embodiments, the vias are formed using gas etching or ion beam etching.

The anti-aliasing effect is achieved by forming through-vias on the semiconductor substrate, which not only makes the processing process relatively simple, but also ensures an anti-aliasing effect.

In certain embodiments, the through holes are evenly distributed. By providing a small aperture through hole and evenly distributing the through hole, not only the through hole is ensured for the photosensitive pixel, but also the preparation process of the semiconductor substrate is relatively simple. In addition, the small aperture through hole makes the anti-aliasing effect of the semiconductor substrate better, thereby improving the sensing accuracy of the photoelectric sensing device.

In some embodiments, the through holes are filled with a transparent material. Filling the transparent material through the through hole not only increases the strength of the semiconductor substrate, but also prevents impurities from entering the through hole and affecting the light transmission effect.

In some embodiments, each of the photosensitive devices corresponds to a plurality of the through holes. Through the corresponding plurality of through holes on the photosensitive device, the photosensitive device can sense sufficient light signals, thereby ensuring the sensing effect of the photoelectric sensing device.

In some embodiments, the second surface is provided with a filter film for filtering light signals outside the predetermined wavelength band.

In some embodiments, the predetermined band is a band corresponding to a blue and green light signal. Through the setting of the filter film, the interference signal in the ambient light can be effectively filtered, thereby improving the sensing accuracy.

In some embodiments, the optoelectronic sensing device further includes a package housing for encapsulating the semiconductor substrate and the photosensitive pixels.

In some embodiments, the optoelectronic sensing device is a fingerprint sensing device.

In some embodiments, the photosensor device is a sensor chip for sensing biometric information.

An electronic device according to an embodiment of the present invention includes the photoelectric sensor device of any of the above embodiments. Since the electronic device has the photoelectric sensing device of any of the above embodiments, it has all the advantageous effects of the photoelectric sensing device.

The additional aspects and advantages of the embodiments of the invention will be set forth in part in the description in the written description

DRAWINGS

The above and/or additional aspects and advantages of the embodiments of the invention will be apparent from the

1 is a schematic diagram of an optical sensing structure applied to an electronic device in the prior art;

2 is a schematic view showing the front structure of a photoelectric sensing device applied to an electronic device according to an embodiment of the present invention;

3 is a cross-sectional structural view of the electronic device of FIG. 2 taken along line I-I, in which only a partial structure of the electronic device is shown;

4 is a schematic structural view of a photoelectric sensing device according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of ambient light interference when an electronic device performs light sensing according to an embodiment of the present invention; FIG.

6 is a schematic structural view of a photoelectric sensing device according to another embodiment of the present invention;

7 is a schematic structural view of a photoelectric sensing device according to still another embodiment of the present invention;

8 is a block diagram showing the structure of a photoelectric sensing device according to an embodiment of the present invention;

9 is a schematic circuit diagram of a photosensitive pixel according to an embodiment of the present invention;

FIG. 10 is a schematic diagram showing the circuit structure of a photosensitive pixel according to another embodiment of the present invention; FIG.

Figure 11 is a partially enlarged schematic view of the display screen and the photoelectric sensing device shown in Figure 3 at the A area;

12 is a schematic diagram showing relative positions of a display pixel and a photosensitive device in an electronic device according to an embodiment of the present invention;

13 is a cross-sectional structural view of an electronic device according to another embodiment of the present invention, in which only a partial structure of the electronic device is shown;

FIG. 14 is a schematic diagram showing the correspondence relationship between the display area of the display screen and the sensing area of the photosensitive panel according to an embodiment of the present invention.

Detailed ways

The embodiments of the present invention are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are intended to be illustrative of the invention and are not to be construed as limiting.

In the description of the present invention, it is to be understood that the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. . Thus, features defining "first" or "second" may include one or more of the described features either explicitly or implicitly. In this practical In the novel description, the meaning of "a plurality" is two or more, unless specifically defined otherwise. "Contact" or "touch" includes direct or indirect contact. For example, the photoelectric sensing device disclosed hereinafter is disposed inside the electronic device, such as under the display screen, and the user's finger indirectly contacts the photoelectric sensing device through the protective cover and the display screen.

In the description of the present invention, it should be noted that the terms "installation", "connected", and "connected" are to be understood broadly, and may be, for example, a fixed connection or a Disassembling the connection, or connecting integrally; may be mechanical connection, electrical connection or communication with each other; may be directly connected, or may be indirectly connected through an intermediate medium, may be internal communication of two elements or mutual interaction of two elements Role relationship. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of the specific examples are described below. Of course, they are merely examples and are not intended to limit the invention. In addition, the present invention may repeat reference numerals and/or reference numerals in different examples, which are for the purpose of simplicity and clarity, and do not in themselves indicate the relationship between the various embodiments and/or settings discussed. Moreover, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the use of other processes and/or the use of other materials.

Further, the described features, structures may be combined in one or more embodiments in any suitable manner. In the following description, numerous specific details are set forth However, those skilled in the art will appreciate that the technical solution of the present invention may be practiced without one or more of the specific details or other structures, components, and the like. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring the invention.

Embodiments of the present invention provide a photoelectric sensing device disposed in an electronic device, such as, but not limited to, an OLED display panel or the like having a display device that emits an optical signal. When the electronic device is working, the display screen emits an optical signal to achieve the corresponding display effect. At this time, if the target object touches the electronic device, the light signal emitted by the display screen reaches the target object and then reflects, and the reflected light signal passes through the display screen and is received by the photoelectric sensing device, and the photoelectric sensing device receives the received signal. The optical signal is converted into an electrical signal corresponding to the optical signal. Based on the electrical signals generated by the photoelectric sensing device, predetermined biometric information of the target object can be obtained.

The above electronic device is, for example, but not limited to, a suitable type of electronic product such as a consumer electronic product, a home electronic product, a vehicle-mounted electronic product, or a financial terminal product. Among them, consumer electronic products such as mobile phones, tablets, notebook computers, desktop monitors, computer integrated machines. Home-based electronic products such as smart door locks, TVs, refrigerators, wearable devices, etc. Vehicle-mounted electronic products such as car navigation systems, car DVDs, etc. Financial terminal products such as ATM Machines, terminals for self-service business, etc. The following embodiments are described by taking a mobile terminal of the mobile phone as an example. However, as described above, the following embodiments are also applicable to other suitable electronic products, and are not limited to mobile terminals.

The predetermined biometric information (or image information) of the target object is, for example but not limited to, skin texture information such as fingerprints, palm prints, ear prints, and soles, and other suitable biometric information such as heart rate, blood oxygen concentration, veins, and arteries. . The predetermined biometric information may be any one or more of the aforementioned enumerated information. The target object may be, for example but not limited to, a human body, and may be other suitable types of organisms.

Referring to FIG. 2 and FIG. 3, FIG. 2 shows a front structure of an embodiment of an electronic device to which the photoelectric sensor device of the present invention is applied, and FIG. 3 shows a partial cross-sectional structure of the electronic device of FIG. 2 along the line I-I. The photoelectric sensor device 20 of the embodiment of the present invention is applied to a mobile terminal 100. The front surface of the mobile terminal 100 is provided with a display screen 10, and a protective cover 30 is disposed above the display screen 10. Optionally, the screen of the display screen 10 is relatively high, for example, 80% or more. The screen ratio refers to the ratio of the display area S1 of the display screen 10 to the front area of the mobile terminal 100. The photoelectric sensing device 20 is disposed correspondingly below the display screen 10 and is disposed corresponding to a partial region of the display region S1 of the display screen 10. The area defining the front side of the mobile terminal 100 corresponding to or facing the photoelectric sensing device 20 is the sensing area S2. The photoelectric sensing device 20 is configured to sense predetermined biometric information contacting or approaching a target object above the sensing region S2. It can be understood that the photoelectric sensing device 20 can also be disposed under the protective cover 30 and located in the front non-display area of the mobile terminal.

The sensing area S2 can be any position on the display area. For example, the sensing area S2 is disposed at a mid-lower position corresponding to the display area of the display screen 10. It can be understood that the sensing area S2 is disposed at a middle-lower position corresponding to the display screen 10 for the convenience of the user. For example, when the user holds the mobile terminal 100, the thumb of the user can conveniently touch the location of the sensing area S2. Of course, the sensing area S2 can also be placed at other suitable locations that are convenient for the user to touch.

When the mobile terminal 100 is in a bright screen state and is in the biometric information sensing mode, the display screen 10 emits an optical signal. When an object contacts or approaches the sensing area S2, the photoelectric sensing device 20 receives the light reflected by the object, converts the received light into a corresponding electrical signal, and acquires a predetermined creature of the object according to the electrical signal. Feature information, for example, fingerprint image information. Thus, the photoelectric sensing device 20 can sense a target object that contacts or approaches a local area above the display area.

Please refer to FIG. 4. FIG. 4 shows a partial structure of a photoelectric sensing device according to an embodiment of the present invention. The optoelectronic sensing device 20 includes a semiconductor substrate 24, and the semiconductor substrate 24 includes a first surface 240 and a second surface 242 that are disposed opposite each other. A plurality of photosensitive pixels 22 are formed on the first surface 240 of the semiconductor substrate 24, and a plurality of through holes 241 are formed on the second surface 242 of the semiconductor substrate 24 to penetrate the semiconductor substrate 24 toward the first surface 240, and the through holes 241 and the photosensitive The pixel 22 corresponds.

Since the reflection of the light signal is different between different parts of the target object, and the surface of the target object is uneven, some parts of the target object are in contact with the protective cover 30 (see FIG. 3), and some parts are not in contact with the protective cover 30, thereby causing contact. A diffuse reflection occurs at a position where specular reflection occurs at an uncontacted position, and an optical signal sensed between adjacent photosensitive pixels 22 may be aliased, thereby causing blurring of the obtained sensing image. Therefore, in the embodiment of the present invention, by forming the photosensitive pixel 22 and the through hole 241 corresponding to the photosensitive pixel 22 on the semiconductor substrate 24, the photosensitive pixel 22 receives the optical signal passing through the through hole 241, and converts the received optical signal into Corresponding electrical signals, such as the arrangement of the through holes 241, can prevent the optical signals received by the adjacent photosensitive pixels 22 from being aliased, thereby making the obtained sensing images clear, improving the sensing accuracy of the photoelectric sensing device 20. .

In addition, since the through hole 241 is directly formed on the semiconductor substrate 24, the thickness of the photoelectric sensing device 20 is reduced, thereby reducing the cost of the photoelectric sensing device 20, which facilitates the development of the electronic device in the direction of thinning.

In some embodiments, since the semiconductor material has light absorbing characteristics, most of the optical signals irradiated onto the semiconductor substrate 24 are absorbed by the semiconductor substrate 24, and only optical signals within a predetermined range can pass through the through holes 241 and are The photosensitive pixel 22 is received. The optical signal within the predetermined range is an optical signal that is approximately perpendicular to the semiconductor substrate 24. In this way, it is possible to prevent aliasing of optical signals received between adjacent photosensitive pixels 22. It should be noted that the optical signal that is approximately perpendicular to the semiconductor substrate 24 includes an optical signal that is perpendicular to the semiconductor substrate 24, and is offset from the vertical direction of the semiconductor substrate 24 by an optical signal within a predetermined angular range. The preset angle range is within ±20°.

In some embodiments, the smaller the aperture of the through hole 241, the better the anti-aliasing effect. Thus, a small aperture through hole 241 can be provided on the semiconductor substrate 24, and the through hole 241 is disposed corresponding to the photosensitive pixel 22, so that the anti-aliasing effect can be improved.

Further, the plurality of through holes 241 on the semiconductor substrate 24 are evenly distributed, so that the preparation process of the semiconductor substrate 24 is relatively simple, and each of the photosensitive pixels 22 will correspond to the plurality of through holes 241, so that the photosensitive pixels 22 can sense sufficient. The light signal ensures the sensing effect of the photoelectric sensing device 20.

Further, the semiconductor substrate 24 is a silicon wafer of a predetermined thickness, and by a predetermined thickness setting, it is possible to effectively prevent aliasing of optical signals received between adjacent photosensitive pixels 22. If the thickness of the silicon wafer is larger than the predetermined thickness, the silicon wafer may be first thinned to achieve a predetermined thickness.

In some embodiments, the vias 241 are formed by etching on the semiconductor substrate 24. Since the silicon wafer has a certain hardness, the process of forming a via hole on the silicon wafer is relatively simple and easier to implement. Specifically, the etching method may be a dry etching method such as gas etching or ion beam etching, so that the effective formation of the through holes 241 can be ensured, and the anti-aliasing effect is ensured.

In some embodiments, the transparent holes may be filled in the through holes 241 to increase the strength of the semiconductor substrate 24, and impurities may be prevented from entering the through holes 241 to affect the light transmission effect. In order to ensure the light transmission effect of the through hole 241, As the transparent material, a material having a large light transmittance such as glass, PMMA (acrylic), PC (polycarbonate) or the like can be used.

In some embodiments, please refer to FIG. 5, which illustrates a situation in which an electronic device is affected by ambient light when performing sensing. Taking the target object F as a finger as an example, when the finger is located on the protective cover 30, if ambient light is irradiated on the finger, and the finger has many tissue structures, such as epidermis, bones, meat, blood vessels, etc., the part in the ambient light The light signal will penetrate the finger and some of the light signal will be absorbed by the finger. The light signal penetrating the finger will be transmitted to the protective cover 30 under the finger and reach the photoelectric sensing device 20. At this time, the photoelectric sensing device 20 not only senses the light signal reflected by the target object F, but also senses the environment. Light penetrates the light signal of the finger, so that accurate sensing cannot be performed. Therefore, in order to prevent the ambient light from affecting the sensing of the target object F by the photoelectric sensing device 20, as shown in FIG. 6, FIG. 6 shows the structure of the photoelectric sensing device 20 of another embodiment of the present invention. A filter film 23 is disposed on the semiconductor substrate 24, that is, the filter film 23 is disposed on the second surface 242 of the semiconductor substrate 24. The filter film 23 is for filtering optical signals other than the predetermined wavelength band. In this embodiment, the optical signal other than the preset wavelength band is an interference signal formed by ambient light, that is, an optical signal that can penetrate the finger in the ambient light. The filter film 23 filters out the interference signal in the reflected light signal, thereby improving the sensing accuracy of the photoelectric sensor device 20.

In some embodiments, the optical signal other than the optical signal of the preset wavelength band is the optical signal of the longer wavelength band in the ambient light, because the optical signal of the longer wavelength band can penetrate the target object, and the optical signal of the shorter wavelength band is The target object is absorbed. Therefore, by filtering out the optical signal of the longer wavelength band in the ambient light, the optical signal penetrating the finger in the ambient light can be filtered out, thereby achieving the purpose of eliminating the interference signal of the ambient light.

In some embodiments, the predetermined wavelength band is a wavelength band corresponding to the blue light signal, that is, the filter film 23 filters out optical signals other than the blue light signal.

In some embodiments, the predetermined band is a band corresponding to the green light signal, that is, the filter film 23 filters out the light signals other than the green light signal.

Among the red light signal, the blue light signal, and the green light signal of the ambient light, the target object F such as a finger absorbs the weakest red light signal, and the green light signal, and the blue light signal absorbs the strongest. That is, ambient light illuminates the finger, and a large amount of blue light signal is absorbed by the finger, and only a small amount or even no blue light signal penetrates the finger. Therefore, selecting the optical signal of the band other than the blue light signal or the green light signal for filtering can greatly eliminate the interference of the ambient light and improve the sensing accuracy of the photoelectric sensing device 20.

In some embodiments, please refer to FIG. 7. FIG. 7 shows the structure of a photoelectric sensing device 20 according to still another embodiment of the present invention. In some embodiments, the photosensor device 20 further includes a package 30 for packaging the semiconductor substrate 24 and all devices on the semiconductor substrate 24, such as the photosensitive pixels 22 And a filter film 23. In particular, the package body 30 can fill the through holes 282 together.

Please refer to FIG. 8. FIG. 8 shows the structure of the photoelectric sensing device 20 of one embodiment. The semiconductor substrate 24 is further formed with a scan line group and a data line group electrically connected to the photosensitive pixel 22, the scan line group is for receiving a corresponding driving signal to drive the photosensitive pixel 22 to perform light sensing, and the data line group is used for sensitizing The pixel 22 performs an electrical signal output generated by light sensing. The semiconductor substrate 24 is, for example but not limited to, a silicon substrate or the like.

Specifically, in some embodiments, with continued reference to FIG. 8, the photosensitive pixels 22 are distributed in an array, such as a matrix distribution. Of course, it can also be distributed in other rule manners or in an irregular manner. The scan line group includes a plurality of scan lines 201. The data line group includes a plurality of data lines 202. The plurality of scan lines 201 and the plurality of data lines 202 are disposed to cross each other and disposed between adjacent photosensitive pixels 22. For example, a plurality of scanning lines G1, G2, ..., Gm are arranged at intervals in the Y direction, and a plurality of data lines S1, S2, ..., Sn are arranged at intervals in the X direction. However, the plurality of scanning lines 201 and the plurality of data lines 202 are not limited to the vertical arrangement shown in FIG. 8, and may be disposed at an angle, for example, 30°, 60°, or the like. In addition, due to the conductivity of the scan lines 201 and the data lines 202, the scan lines 201 and the data lines 202 at the intersections are separated by an insulating material.

It should be noted that the distribution and the number of the scan lines 201 and the data lines 202 are not limited to the above-exemplified embodiments, and the corresponding scan line groups and data line groups may be correspondingly set according to the structure of the photosensitive pixels. .

Further, referring to FIG. 8 , a plurality of scan lines 201 are connected to a driving circuit 25 , and a plurality of data lines 202 are connected to a signal processing circuit 27 . The driving circuit 25 is configured to provide a corresponding scan driving signal and transmit it to the corresponding photosensitive pixel 22 through the corresponding scanning line 201 to activate the photosensitive pixel 22 to perform light sensing. The driving circuit 25 is formed on the substrate 26, and of course, it can also be electrically connected to the photosensitive pixels 22 through a flexible circuit board, that is, a plurality of scanning lines 201 are connected. The signal processing circuit 27 receives an electrical signal generated by the corresponding photosensitive pixel 22 performing light sensing through the data line 202, and acquires biometric information of the target object based on the electrical signal.

In some embodiments, the photoelectric sensing device 20 further includes a controller 29 for controlling the driving circuit to output a corresponding scan driving signal, such as, but not limited to, progressively activating the photosensitive pixel 22 to perform light sensing. . The controller 29 is further configured to control the signal processing circuit 27 to receive the electrical signal output by the photosensitive pixel 22, and after receiving the electrical signal output by all the photosensitive pixels 22 performing the light sensing, generate biometric information of the target object based on the electrical signal. .

Further, the signal processing circuit 27 and the controller 29 may be formed on the semiconductor substrate 24 or may be electrically connected to the photosensitive pixel 22 through a flexible circuit board.

In some embodiments, as shown in FIG. 9, FIG. 9 shows the circuit configuration of the photosensitive pixel 22 of one embodiment. The photosensitive pixel 22 includes a photosensitive device 220 and a switching device 222. The switching device 222 has a control terminal C and two signal terminals, such as a first signal terminal Sn1 and a second signal terminal Sn2. Wherein, the control of the switching device 222 The terminal C is connected to the scan line 201. The first signal terminal Sn1 of the switching device 222 is connected to a reference signal L via the photosensitive device 220, and the second signal terminal Sn2 of the switching device 222 is connected to the data line 202. It should be noted that the photosensitive pixel 22 shown in FIG. 9 is for illustrative purposes only and is not limited to other constituent structures of the photosensitive pixel 22.

Specifically, the above-mentioned photosensitive device 220 is, for example but not limited to, any one or several of a photodiode, a phototransistor, a photodiode, a photo resistor, and a thin film transistor. Taking a photodiode as an example, a negative voltage is applied across the photodiode. At this time, if the photodiode receives the optical signal, a photocurrent is generated in a proportional relationship with the optical signal, and the received optical signal is more intense. Larger, the larger the photocurrent generated, the faster the voltage drop on the negative pole of the photodiode. Therefore, by collecting the voltage signal on the negative pole of the photodiode, the intensity of the optical signal reflected from different parts of the target object is obtained, and the target is obtained. Biometric information of the object. It can be understood that in order to increase the photosensitive effect of the photosensitive device 220, a plurality of photosensitive devices 220 may be disposed.

Further, the switching device 222 is, for example but not limited to, any one or several of a triode, a MOS transistor, and a thin film transistor. Of course, the switching device 222 can also include other types of devices, and the number can also be two, three, and the like.

In some embodiments, in order to further improve the sensing accuracy of the photosensor device 20, the photosensitive device 220 having high sensitivity to the blue light signal may also be selected. The light sensing is performed by selecting the photosensitive device 220 having high sensitivity to the blue light signal and the green light signal, so that the photosensitive device 220 is more sensitive to the light of the blue light signal and the green light signal, and thus the ambient light is also avoided to some extent. The interference caused by the red light signal improves the sensing accuracy of the photoelectric sensing device 20.

Taking the structure of the photosensitive pixel 22 shown in FIG. 9 as an example, the gate of the thin film transistor TFT serves as the control terminal C of the switching device 222, and the source and the drain of the thin film transistor TFT correspond to the first signal terminal Sn1 of the switching device 222 and The second signal terminal Sn2. The gate of the thin film transistor TFT is connected to the scanning line 201, the source of the thin film transistor TFT is connected to the negative electrode of the photodiode D1, and the drain of the thin film transistor TFT is connected to the data line 202. The anode of the photodiode D1 is connected to a reference signal L, which is, for example, a ground signal or a negative voltage signal.

When the photosensitive pixel 22 performs light sensing, a driving signal is applied to the gate of the thin film transistor TFT through the scanning line 201 to drive the thin film transistor TFT to be turned on. At this time, the data line 202 is connected to a positive voltage signal. When the thin film transistor TFT is turned on, the positive voltage signal on the data line 202 is applied to the negative electrode of the photodiode D1 via the thin film transistor TFT. Since the positive electrode of the photodiode D1 is grounded, the photoelectric A reverse voltage is applied across diode D1 such that photodiode D1 is reverse biased, i.e., in operation. At this time, when an optical signal is irradiated to the photodiode D1, the reverse current of the photodiode D1 rapidly increases, thereby causing a change in current on the photodiode D1, which can be obtained from the data line 202. Since the intensity of the optical signal is larger, the reverse current generated is larger, so that the intensity of the optical signal can be obtained according to the current signal acquired on the data line 202. Further, biometric information of the target object is obtained.

In some embodiments, the reference signal L may be a positive voltage signal, a negative voltage signal, a ground signal, or the like. As long as the electrical signal provided on the data line 202 and the reference signal L are applied across the photodiode D1 such that a reverse voltage is formed across the photodiode D1 to perform photo sensing, it is within the scope of protection defined by the present invention.

It can be understood that the connection manner of the thin film transistor TFT and the photodiode D1 in the above-mentioned photosensitive pixel 22 is not limited to the connection manner shown in FIG. 9, and may be other connection methods. For example, as shown in FIG. 10, FIG. 10 shows a circuit configuration of a photosensitive pixel of another embodiment. The gate G of the thin film transistor TFT is connected to the scanning line 201, the drain D of the thin film transistor TFT is connected to the anode of the photodiode D1, and the source S of the thin film transistor TFT is connected to the data line 202. The negative electrode of the photodiode D1 is connected to the positive voltage signal Vcc.

Further, the above-mentioned photosensitive device 220 is disposed corresponding to the through hole 282 to ensure that the optical signals passing through the through hole 282 are all received by the photosensitive device 220, thereby improving the sensing accuracy of the photoelectric sensing device 20.

Referring to FIG. 3 and FIG. 4 together, the photoelectric sensing device 20 is a photosensitive chip located under the display screen 10 for sensing biometric information. Specifically, the first surface 240 of the photoelectric sensing device 20 is remote from the display screen 10, and the second surface 242 of the photoelectric sensing device 20 is adjacent to the display screen 10. When the photoelectric sensing device 20 performs sensing, the photoelectric sensing device 20 uses the optical signal emitted by the display screen 10 as a light source, and after the optical signal emitted by the display screen 10 reaches the finger, the optical signal reflected by the finger passes through the display screen 10. Thereafter, it passes through the through hole 241 on the semiconductor substrate 24 to be received by the photosensitive pixel 22.

Please refer to FIG. 11. FIG. 11 shows a partially enlarged structure of the photoelectric sensing device 20 and the display screen 10 shown in FIG. Display screen 10 includes a plurality of display pixels 12. Optionally, in an embodiment, the photosensitive pixels 22 are disposed corresponding to the display pixels 12. Of course, the photosensitive pixels 22 located under the display screen 10 are not limited to the corresponding setting of the display pixels 12, and may be other setting manners. For example, please refer to FIG. 12, which shows a relative position of a display pixel and a photosensitive device in an electronic device according to an embodiment. A gap H is provided between adjacent display pixels 12, and the gap H has a light-transmitting region. The photosensitive device 220 in the photosensitive pixel 22 is disposed below the gap H between adjacent display pixels. The lower part here is, for example but not limited to, directly below, and it is possible to ensure that sufficient light signals are received at the position. It can be understood that the more the optical signal passes through the gap H, the higher the sensing accuracy of the photoelectric sensing device 20. The display pixels shown in FIG. 12 are not limited to the structure of the display screen 10. The display pixels of the display screen 10 may also include other types, and the display pixels 12 in the display screen 10 are not limited to the arrangement shown in FIG. There are other arrangements, such as the pentiel arrangement.

Since the photosensitive pixel 22 receives the light signal passing through the display screen 10, the display screen 10 has a corresponding light-transmitting area, and as long as the photosensitive surface of the photosensitive pixel 22 is disposed in the light-transmitting area, sufficient optical signal can be ensured. The photosensitive pixel 22 is sensed to perform light sensing efficiently.

Further, the display screen 10 further includes a driving circuit for driving the display pixels 12 to emit light and a corresponding driving circuit (not shown), and the driving circuit and the corresponding driving circuit can be disposed between the display pixels 12, It can be disposed below each display pixel 12. For better display effect, the area where the display pixel, the driving circuit and the corresponding driving line are set is the opaque area, and the remaining area is the light transmitting area. Photosensitive device 220 is located below the light transmissive region for better light sensing. It can be understood that the light transmissive area and the opaque area in the display screen 10 are not strictly limited, and whether the light transmission is determined by the composition of the display screen 10 and the distribution of the constituent structures. For example, when the structure in which the display pixels 12 are formed adopts a transparent structure, the area in which the display pixels are disposed will become a light-transmitting area.

In one embodiment, please refer to FIG. 13 and FIG. 14. FIG. 13 and FIG. 14 show a partial structure of an electronic device according to another embodiment of the present invention. The electronic device includes a protective cover 30, a display screen 10, and a photoelectric sensing device 20. The protective cover 30 is located above the display screen 10, and the photoelectric sensing device 20 is located below the display screen 10. The photoelectric sensing device 20 is a photosensitive panel, and the photosensitive panel is stacked on the display screen 10. In addition, the composition and sensing principle of the photoelectric sensing device 20 are described with reference to the previous embodiments, and details are not described herein again.

In some embodiments, the optoelectronic sensing device 20 is configured to perform biometric information sensing of a target object at any location within a display area of the display screen. Specifically, for example, the display screen 10 has a display area 105 defined by the light-emitting areas of all the display pixels 12 of the display screen 10, and a non-display area 106, which is not displayed. The area 106 is for providing a circuit such as a display driving circuit for driving the display pixels 12 or a line bonding area for connecting the flexible circuit boards. The photosensitive panel has a sensing area 203 and a non-sensing area 204. The sensing area 203 is defined by the sensing areas of all the photosensitive pixels 22, and the area other than the sensing area 203 is the non-sensing area 204, and the non-sensing area 204 A circuit for connecting a photosensitive driving circuit that drives the photosensitive pixel 22 to perform light sensing or a line bonding region for connecting the flexible circuit board. The shape of the sensing region 203 coincides with the shape of the display region 105, and the size of the sensing region 203 is greater than or equal to the size of the display region 105, such that the photosensitive panel can be positioned at or near any position of the display region 105 of the display screen 10. Sensing of predetermined biometric information of an object. Further, the area of the photosensitive panel is less than or equal to the area of the display screen 10, and the shape of the photosensitive panel is consistent with the shape of the display screen 10, so that the assembly of the photosensitive panel and the display screen 10 is facilitated. However, in some embodiments, the area of the photosensitive panel may also be larger than the area of the display screen 10.

In some embodiments, the sensing area 203 of the photosensitive panel may also be smaller than the display area 105 of the display screen 10 to achieve sensing of predetermined biometric information of the target object of the local area of the display area 105 of the display screen 10. .

In the description of the present specification, reference is made to the terms "one embodiment", "some embodiments", "illustrative implementation" The description of the embodiments, the "examples", the "specific examples", or the "some examples" and the like are intended to include the specific features, structures, materials, or characteristics described in connection with the embodiments or examples. In the present specification, the schematic representation of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or features described may be in any one or more embodiments or The examples are combined in a suitable manner.

Moreover, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may include at least one of the features, either explicitly or implicitly. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless specifically defined otherwise.

While the embodiments of the present invention have been shown and described above, it is understood that the foregoing embodiments are illustrative and are not to be construed as limiting the scope of the invention Variations, modifications, substitutions and variations of the embodiments described above are possible.

Claims (15)

An optoelectronic sensing device, comprising: a semiconductor substrate, wherein the semiconductor substrate comprises a first surface and a second surface disposed oppositely, and a plurality of photosensitive pixels are formed on the first surface of the semiconductor substrate, the semiconductor A plurality of through holes penetrating the semiconductor substrate toward the first surface are formed on the second surface of the substrate, and the through holes correspond to the photosensitive pixels. The photoelectric sensor device according to claim 1, wherein said photosensitive pixel comprises at least one photosensitive device, and a photosensitive surface of said photosensitive device is disposed corresponding to said through hole. The photoelectric sensor device according to claim 1, wherein said semiconductor substrate is a silicon wafer having a predetermined thickness. The photoelectric sensor device according to claim 3, wherein said semiconductor substrate is formed by thinning a silicon wafer to a predetermined thickness. The photoelectric sensor device according to claim 1, wherein said through hole is formed by etching on a semiconductor substrate. The photoelectric sensor device according to claim 5, wherein the through hole is formed by gas etching or ion beam etching. The photoelectric sensor device according to claim 1, wherein said through holes are evenly distributed. The photoelectric sensor device according to claim 1, wherein said through hole is filled with a transparent material. A photoelectric sensor device according to claim 2, wherein each of the photosensitive members corresponds to a plurality of said through holes. The photoelectric sensor device according to any one of claims 1 to 9, wherein the second surface is provided with a filter film for filtering an optical signal other than the predetermined wavelength band. The photoelectric sensing device according to claim 8, wherein the predetermined wavelength band is a wavelength band corresponding to the blue and green light signals. The optoelectronic sensing device of claim 1 wherein said optoelectronic sensing device further comprises a package housing for encapsulating said semiconductor substrate and said photosensitive pixel. The photoelectric sensor device of claim 1 wherein said photosensor device is a fingerprint sensing device. The photoelectric sensing device according to claim 1, wherein said photoelectric sensing device is a photosensitive chip for sensing biometric information. An electronic device comprising the photoelectric sensing device of any of claims 1-14.

Images