WO2019033358A1

WO2019033358A1 - Photosensitive chip and electronic device

Info

Publication number: WO2019033358A1
Application number: PCT/CN2017/097919
Authority: WO
Inventors: 李问杰
Original assignee: 深圳信炜科技有限公司
Priority date: 2017-08-17
Filing date: 2017-08-17
Publication date: 2019-02-21
Also published as: CN209803814U

Abstract

Disclosed are a photosensitive chip and an electronic device. The photosensitive chip comprises a photosensitive bare chip and a filtering film, wherein the filtering film is arranged on the photosensitive bare chip. The electronic device also comprises the photosensitive chip.

Description

Photosensitive chip and electronic device

Technical field

The utility model relates to the field of photoelectric sensing, in particular to a photosensitive chip for realizing image information or biometric information sensing.

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 400 is used when the ambient light is strong, and an accurate fingerprint image cannot be obtained, which still 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 photosensitive chip.

A photosensitive chip according to an embodiment of the present invention includes a photosensitive die and a filter film, and the filter film is disposed on the photosensitive die.

According to the embodiment of the present invention, by setting the filter film, the interference of the ambient light is eliminated, and the image sensing accuracy of the photosensitive chip is improved.

In some embodiments, the filter film is evaporated on the photosensitive die, or the filter film is adhered to the photosensitive die.

In some embodiments, the filter film is used to filter out optical signals outside of a predetermined band.

In some embodiments, the predetermined band is a short band signal in ambient light.

In some embodiments, the predetermined band is a band corresponding to a blue or green light signal.

In some embodiments, the photosensitive chip includes a plurality of photosensitive devices, and the photosensitive device is a photosensitive device having high sensitivity to sensing optical signals of the predetermined wavelength band.

In some embodiments, the photosensitive device comprises any one or more of a photodiode, a photo resistor, a photodiode, and a phototransistor.

In some embodiments, the sensor chip is a biosensor chip for sensing biometric information of a target object.

In some embodiments, the biometric information includes any one or more of a fingerprint, a palm print, a pulse, a blood oxygen concentration, and a heart rate.

In some embodiments, an anti-aliasing imaging element is also disposed over the photosensitive die.

Since the reflection of the optical signal is different between different parts of the target object, the optical signals sensed between the adjacent photosensitive cells may be aliased, thereby causing the acquired sensing image to be blurred, so the embodiment of the present invention The anti-aliasing imaging element is arranged on the chip to prevent aliasing of the optical signals received by the adjacent photosensitive devices, thereby improving the image sensing accuracy of the photosensitive chip.

In some embodiments, the filter film and the anti-aliasing imaging element are stacked on the photosensitive die, wherein the filter film is disposed on the anti-aliasing imaging element and the photosensitive bare Between the sheets, or the anti-aliasing imaging element is disposed between the photosensitive film and the photosensitive die. .

In certain embodiments, the anti-aliasing imaging element includes a light absorbing wall and a plurality of light transmissive regions surrounded by a light absorbing wall.

In some embodiments, the light absorbing wall is laminated from a plurality of light absorbing layers. Since the thickness of each light absorbing layer is smaller than the thickness of the light absorbing wall, the process of etching to form the light transmitting area is relatively easy, so that the process of anti-aliasing imaging element is easy, and the light transmission property of the light transmitting area is also ensured. .

In some embodiments, a support layer is disposed between adjacent ones of the light absorbing layers. In the embodiment of the present invention, the preparation speed of the anti-aliasing imaging element is accelerated by the transparent supporting layer, and the anti-aliasing effect of the anti-aliasing imaging element is also ensured by the distance setting between the adjacent two layers of the light absorbing layer. .

In some embodiments, the light transmissive region is filled with a transparent material. Filling the transparent material in the light-transmitting region not only increases the strength of the anti-aliasing imaging element, but also prevents impurities from entering the light-transmitting region and affecting the light-transmitting effect.

In some embodiments, the sensor chip further includes a package for encapsulating the photosensitive die, and the anti-aliasing imaging element and the filter film over the photosensitive die.

In some embodiments, the sensor chip further includes a package for encapsulating the photosensitive die, and an anti-aliasing imaging element and a filter film over the photosensitive die, wherein the package The body fills the light transmissive area.

An electronic device according to an embodiment of the present invention includes the photosensitive chip of any of the above embodiments. The electron Since the device has the photosensitive chip of any of the above structures, it has all of the above-described advantageous effects of the photosensitive chip.

In some embodiments, the electronic device further includes a display panel corresponding to a local area under the display panel, the sensing chip is configured to receive an optical signal transmitted from a display area of the display panel And acquiring corresponding biometric information according to the received optical signal.

In some embodiments, the electronic device is a cell phone or tablet.

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 image sensing structure applied to an electronic device in the prior art;

2 is a schematic front view showing an embodiment of an electronic device to which the photosensitive chip of the present invention is applied;

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 partial structural schematic view of a photosensitive chip according to an embodiment of the present invention;

5 is a structural block diagram of a photosensitive chip according to another embodiment of the present invention;

6 is a schematic circuit diagram of a photosensitive unit of an embodiment of the photosensitive chip shown in FIG. 5;

7 is a schematic circuit diagram of a photosensitive unit of another embodiment of the photosensitive chip shown in FIG. 5;

8 is a schematic structural view of a photosensitive chip according to still another embodiment of the present invention;

9 is a schematic diagram of a range of optical signals through which an anti-aliasing imaging element of an embodiment of the photosensitive chip shown in FIG. 8 can pass;

10 is a schematic diagram of a range of optical signals through which an anti-aliasing imaging element of another embodiment of the photosensitive chip shown in FIG. 8 can pass;

11 is a schematic structural view of an anti-aliasing imaging element according to an embodiment of the present invention;

FIG. 12 is a schematic structural view of a photosensitive chip according to still another 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. Below The embodiments described with reference to the drawings are exemplified and are not to be construed as limiting the invention.

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 the description of the present invention, the meaning of "a plurality" is two or more unless specifically and specifically defined otherwise. "Contact" or "touch" includes direct or indirect contact. For example, the photosensitive chip disclosed hereinafter is disposed inside the electronic device, such as under the display screen or the protective cover, and the user's finger indirectly contacts the photosensitive chip through the display screen or the protective cover.

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.

The embodiment of the present invention provides a photosensitive chip disposed in an electronic device having a display function, and the photosensitive chip realizes image sensing by using an optical signal emitted when the electronic device displays. It can be understood that the photosensitive chip can be correspondingly disposed in the display area of the electronic device, or can be disposed in the non-display area of the electronic device. Moreover, the photosensitive chip is disposed in the display area, and the image sensing of the target object at a local position in the screen of the electronic device can be realized by the photosensitive chip. It can be understood that an independent light source can also be disposed in the electronic device for the sensor chip. Perform image sensing use.

The above electronic devices are, for example, consumer electronic products, home-based electronic products, vehicle-mounted electronic products, and financial terminal products. Among them, consumer electronic products such as mobile phones, tablets, notebook computers, desktop monitors, computer integrated machines and other electronic products using biometric identification technology. Home-based electronic products such as smart door locks, televisions, refrigerators, wearable devices and other electronic products that use biometric technology. 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 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 photosensitive chip of the present invention is applied, and FIG. 3 shows a partial cross-sectional structure of the electronic device of FIG. 2 along line II, wherein 3 shows only a partial structure of the electronic device. The photosensitive chip 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 photosensitive chip 20 is disposed correspondingly below the display screen 10, and is disposed corresponding to a partial area of the display area S1 of the display screen 10. The area corresponding to or facing the front side of the mobile terminal 100 is defined as the sensing area S2. The sensor chip 20 is configured to sense predetermined biometric information contacting or approaching a target object above the sensing area S2.

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 photosensitive chip 20 receives the light reflected by the object, converts the received light into a corresponding electrical signal, and acquires predetermined biometric information of the object according to the electrical signal. For example, fingerprint image information. Thereby, the photosensitive chip 20 can realize sensing of a target object that contacts or approaches a local area above the display area.

Further, please refer to FIG. 4. FIG. 4 shows the structure of a photosensitive chip according to an embodiment of the present invention. The photosensitive chip 20 includes a photosensitive die 22 and a filter film 24, and the filter film 24 is disposed on the photosensitive die 22. Specific The filter film 24 is disposed on the photosensitive surface of the photosensitive die 22 for filtering the optical signal from above the photosensitive die 22.

In the embodiment of the present invention, by providing the filter film 24 on the photosensitive die 22, the interference signal during image sensing is filtered, and the image sensing accuracy of the photosensitive chip 20 is improved.

In some embodiments, the filter film 24 is formed on the photosensitive die 22 by evaporation. However, the filter film 24 can be separately formed, and is, for example, but not limited to, disposed on the photosensitive die 22 by bonding, so that the structure of the existing filter film 24 can be utilized, and the process can be utilized. It is also simpler.

In some embodiments, the filter film 24 is used to filter out optical signals outside of the predetermined band. The preset band may be an optical signal in ambient light, and the optical signal is a short band signal. However, the preset wavelength band may also be other signals that need to be filtered, and the filter film with different filtering effects may be set according to actual needs. For example, if the photosensitive chip 20 performs image sensing using an optical signal emitted from a separately disposed light source, and the light source emits an optical signal of a specific wavelength, the filter film 24 is used to filter out the optical signal other than the specific wavelength. In order to achieve the purpose of eliminating interference signals.

In some embodiments, the filter film 24 is used to filter out interfering signals in ambient light. Specifically, with continued reference to FIG. 3, when the target object F is located on the protective cover 30, if ambient light is irradiated onto the target object, taking the finger as an example, since the finger has many organizational structures, such as epidermis, bones, meat, blood vessels, etc. Therefore, part of the light signal in the ambient light will penetrate the finger, and part 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 photosensitive chip 20. At this time, the photosensitive chip 20 not only senses the light signal reflected by the target object, but also senses that the ambient light penetrates the finger. The optical signal is so impossible to accurately sense. Therefore, the interference signal in the ambient light is a long-band signal that can penetrate the finger, such as a red light signal. In order to prevent the ambient light from affecting the image sensing of the target object by the photosensitive chip 20, the filter film 24 is disposed in the embodiment for filtering the optical signal of the long wavelength band in the ambient light, that is, the short-band signal in the ambient light can pass through the Filter film 24. The filter film 24 filters out the light signal passing through the finger in the ambient light to achieve the purpose of eliminating the interference signal of the ambient light, thereby improving the image sensing accuracy of the photosensitive chip 20.

In some embodiments, the predetermined band is a band corresponding to the blue light signal, that is, the filter film 24 filters out the light 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 24 filters out the light signal other than the green light signal.

In ambient light, a target object F such as a finger absorbs light signals of a long wavelength band, such as a red light signal, and absorbs light signals of a short wavelength band, such as a blue light signal or a green light signal. Therefore, selecting the filter film 24 for filtering the optical signal of the wavelength band other than the blue light signal or the green light signal can greatly eliminate the interference of the ambient light and improve The image sensing accuracy of the photosensitive chip 20.

In some embodiments, referring to FIG. 4 and FIG. 5 , the photosensitive die 22 includes a substrate 220 and a plurality of photosensitive cells 222 distributed in an array, and the plurality of photosensitive cells 222 are disposed on the substrate 220 . A scan line group and a data line group electrically connected to the photosensitive unit 222 are disposed between the adjacent photosensitive units 222, wherein the scan line group includes a plurality of scan lines 201, and the data line group includes a plurality of data lines 202. The plurality of photosensitive cells 222 are, for example but not limited to, a matrix distribution. Of course, it can also be distributed in other rule manners or in an irregular manner. The plurality of scanning lines 201 and the plurality of data lines 202 electrically connected to the photosensitive unit 222 are disposed to cross each other and disposed between adjacent photosensitive units 222. 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. 5, and may be disposed at an angle, for example, 30°, 60°, or the like. In addition, since the scan line 201 and the data line 202 are electrically conductive, the scan line 201 and the data line 202 at the intersection position 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 lines may be correspondingly set according to the structure of the photosensitive unit 222. group.

In the above-described photosensitive chip 20, a scan driving signal is supplied through the scanning line 201 to drive the photosensitive unit 222 to perform light sensing. The photosensitive unit 222 receives the optical signal reflected by the target object, and converts the received optical signal into a corresponding electrical signal, which is then output by the data line 202.

In some embodiments, as shown in FIG. 6, a circuit configuration of a photosensitive unit 222 according to an embodiment of the present invention is shown. The photosensitive unit 222 includes a photosensitive device 224 and a switching device 226. The switching device 226 has a control terminal C and two signal terminals, such as a first signal terminal Sn1 and a second signal terminal Sn2. The control terminal C of the switching device 226 is connected to the scan line 201. The first signal terminal Sn1 of the switching device 226 is connected to a reference signal L via the photosensitive device 224, and the second signal terminal Sn2 of the switching device 226 is connected to the data line 202.

Specifically, the above-mentioned photosensitive device 224 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 (TFT). 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. Image information of the object. It can be understood that in order to increase the photosensitive effect of the photosensitive device 224, a plurality of photosensitive devices 224 may be disposed.

Further, the switching device 226 is, for example but not limited to, any one of a triode, a MOS transistor, and a thin film transistor. One or several. Of course, the switching device 226 may also include other types of devices, and the number may also be two, three, and the like.

In some embodiments, in order to further improve the image sensing accuracy of the photosensitive chip 20, the photosensitive device 224 having high sensitivity to the blue light signal may also be selected. The light sensing is performed by selecting the photosensitive device 224 having high sensitivity to the optical signal of the preset wavelength band, for example, the sensing of the blue light signal or the green light signal is more sensitive, so that the red light signal in the ambient light is also avoided to some extent. The interference caused thereby improving the image sensing accuracy of the photosensitive chip 20.

Taking the structure of the photosensitive unit 222 shown in FIG. 6 as an example, the gate of the thin film transistor serves as the control terminal C of the switching device 226, and the source and the drain of the thin film transistor correspond to the first signal terminal Sn1 and the second of the switching device 226. Signal terminal Sn2. The gate of the thin film transistor is connected to the scanning line 201, the source of the thin film transistor is connected to the negative electrode of the photodiode D1, and the drain of the thin film transistor 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 unit 222 performs photo sensing, a driving signal is applied to the gate of the thin film transistor through the scanning line 201 to drive the thin film transistor to be turned on. At this time, the data line 202 is connected to a positive voltage signal. When the thin film transistor 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. Since the positive electrode of the photodiode D1 is grounded, the photodiode D1 is A reverse voltage will be applied across the terminals such that the photodiode D1 is in a reverse bias, ie, 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 also larger. Therefore, according to the current signal acquired on the data line 202, the intensity of the optical signal can be obtained, thereby obtaining image information of the target object.

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 and the photodiode D1 in the photosensitive unit 222 is not limited to the connection manner shown in FIG. 6, and may be other connection methods. For example, as shown in FIG. 7, FIG. 7 shows another connection structure of a photosensitive cell and a scan line and a data line. The gate G of the thin film transistor is connected to the scan line 201, and the drain D and the photodiode of the thin film transistor are connected. The anode of D1 is connected, and the source S of the thin film transistor TFT is connected to the data line 202. The negative terminal of the photodiode D1 is connected to a positive voltage signal. Further, the photosensitive unit 222 is not limited to the above-described circuit configuration, and may include other circuit configurations, which are not exemplified herein.

In some embodiments, the substrate 220 is, for example but not limited to, a silicon substrate, a metal substrate, or the like. In addition, the substrate 220 can be a rigid material or a flexible material such as a flexible film. If the substrate 220 is a flexible material, the photosensitive chip 20 is not only thinner in thickness, but also applicable to an electronic device having a curved display.

In some embodiments, with reference to FIG. 5, a plurality of scan lines 201 are connected to a driving circuit 221, and a plurality of data lines 202 are connected to a signal processing circuit 223. The driving circuit 221 is configured to provide a corresponding scan driving signal and transmit it to the corresponding photosensitive unit 222 through the corresponding scanning line 201 to activate the photosensitive unit 222 to perform light sensing. The signal processing circuit 223 receives an electrical signal generated by the corresponding photosensitive unit 222 performing light sensing through the data line 202, and acquires image information of the target object based on the electrical signal.

In some embodiments, the sensor chip 20 further includes a controller 225 for controlling the drive circuit 221 to output a corresponding scan drive signal, such as, but not limited to, progressively activating the photosensitive unit 222 to perform light sensing. The controller 225 is further configured to control the signal processing circuit 223 to receive the electrical signal output by the photosensitive unit 222, and generate an image of the target object based on the electrical signal after receiving the electrical signals output by all of the photosensitive cells 222 that perform light sensing.

In some embodiments, the driving circuit 221 can be directly formed on the substrate 220, and the driving circuit 221 and the photosensitive unit 222 are located on the same side of the substrate 220. Thus, the connection line between the driving circuit 241 and the scanning line 201 is shortened, which not only facilitates the connection of the driving circuit 221 and the scanning line 201, but also reduces signal interference during signal transmission. Of course, the driving circuit 221 can also be electrically connected to the photosensitive unit 222 through a flexible circuit board, that is, connected to the plurality of scanning lines 201.

In some embodiments, the signal processing circuit 223 can also be directly formed on the substrate 220. Of course, the signal processing circuit 223 can be electrically connected to the photosensitive unit 222 through a flexible circuit board, that is, connected to the plurality of data lines 202.

In some embodiments, due to the difference in the reflection of the optical signal by different parts of the target object, and the unevenness of the surface of the target object, some parts of the target object are in contact with the protective cover 30, and some parts are not in contact with the protective cover 30, thereby The position causing the contact is diffusely reflected, and the untouched position is specularly reflected, so that the light signal sensed between the adjacent photosensitive cells 222 may be aliased, thereby causing the acquired sensing image to be blurred. In this regard, please refer to FIG. 8. FIG. 8 shows the structure of a photosensitive chip according to another embodiment of the present invention. In an embodiment of the present invention, an anti-aliasing imaging element 26 is disposed on the photosensitive die 22. The anti-aliasing imaging element 26 serves to prevent aliasing of optical signals received by adjacent photosensitive cells 222, thereby improving image sensing accuracy of the photosensitive chip 20. In the embodiment of the present invention, the filter film 24 and the anti-aliasing imaging element 26 are stacked on the photosensitive die 22. The filter film 24 is located between the anti-aliasing imaging element 26 and the photosensitive die 22. However, the anti-aliasing imaging element 26 can also be disposed between the filter film 24 and the photosensitive die 22.

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 The position causing the contact is diffusely reflected, and the untouched position is specularly reflected, so that the light signal sensed between the adjacent photosensitive cells 222 may be aliased, thereby causing the acquired sensing image to be blurred. In this regard, the embodiment of the present invention provides an anti-aliasing imaging element 26 on the photosensitive die 22, so that the image obtained by the photosensitive unit 222 after performing light sensing is relatively clear, thereby improving the sensing accuracy of the photosensitive chip 20.

In some embodiments, the anti-aliasing imaging element 26 has light absorbing properties that illuminate the optical signal on the anti-aliasing imaging element 26, only the optical signal that is approximately perpendicular to the photosensitive die 22 can pass through the anti-aliasing The imaging element 26 is received by the photosensitive unit 222, and the remaining optical signals are all absorbed by the anti-aliasing imaging element 26. In this way, aliasing of the optical signals received between the adjacent photosensitive cells 222 can be prevented. It should be noted that the optical signal that is approximately perpendicular to the photosensitive die 22 includes an optical signal that is perpendicular to the photosensitive die 22, and is offset from the vertical direction of the photosensitive die 22 by a predetermined range of optical signals. The preset angle range is within ±20°.

Specifically, the anti-aliasing imaging element 26 includes a light absorbing wall 261 and a plurality of light transmissive regions 262 surrounded by a light absorbing wall 261. The light absorbing wall 261 is formed of a light absorbing material. The light absorbing material includes a metal oxide, a carbon black paint, a black ink, and the like. Wherein the metal in the metal oxide is, for example but not limited to, one of chromium (Cr), nickel (Ni), iron (Fe), tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo) or Several. The extending direction of the light-transmitting region 262 is a direction perpendicular to the photosensitive die 22 such that an optical signal in a direction approximately perpendicular to the photosensitive die 22 can be transmitted through the light signal irradiated to the anti-aliasing imaging element 26. In region 262, the remaining optical signals are absorbed by the light absorbing wall 261.

In certain embodiments, as shown in FIG. 9, FIG. 9 illustrates a range of optical signals that pass through the anti-aliasing imaging element 26. Due to the light absorption characteristics of the anti-aliasing imaging element 26, only the optical signal between the optical signal L1 and the optical signal L2 can reach the photosensitive unit 222 through the light-transmitting region 262, and the remaining optical signals are absorbed by the absorption wall 261 of the anti-aliasing imaging element 26. absorb. As can be seen from FIG. 9, the smaller the cross-sectional area of the light-transmitting region 262, the smaller the range of the angle α of the light signal passing through the light-transmitting region 262, and therefore the anti-aliasing effect of the anti-aliasing imaging element 26 is better. As such, the anti-aliasing effect of the anti-aliasing imaging element 26 can be improved by the relatively small area of the light-transmitting region 262 provided by the anti-aliasing imaging element 26. In addition, since the cross-sectional area of the light-transmitting region 262 of the anti-aliasing imaging element 26 is small, each photosensitive unit 222 will correspond to the plurality of light-transmitting regions 262, so that the photosensitive unit 222 can sense sufficient light signals, The sensing accuracy of the photosensitive chip 20 is improved.

Further, please refer to FIG. 10, which shows the structure of the anti-aliasing imaging element 26 of an embodiment of the present invention. The light absorbing wall 261 has a multi-layer structure, and the light absorbing wall includes a light absorbing block 261a and a height block 261b which are alternately stacked. In one embodiment, the light absorbing block 261a is formed of a light absorbing material. The light absorbing material is, for example but not limited to, a metal oxide, a carbon black paint, a black ink, or the like. Wherein the metal in the metal oxide is, for example but not limited to, one of chromium (Cr), nickel (Ni), iron (Fe), tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo) or Several. The height block 261b is, for example but not limited to, a transparent layer formed of a transparent material such as a translucent material, a light absorbing material, or the like.

In some embodiments, the plurality of light absorbing blocks 261a located in the same layer are spaced apart, and the area corresponding to the interval between the light absorbing blocks 261a in the same layer is the light transmitting region 262. Further, the plurality of light absorption blocks 261a and the plurality of height blocks 261b of the same layer may be fabricated at one time. Specifically, by providing a mask, the mask is an integrally formed diaphragm, and the diaphragm forms an opening corresponding to the position of the light absorbing block 261a, and the shape and size of the opening are consistent with the shape and size of the light absorbing block 263. . The light absorbing block 261a and the pad 261b which are alternately disposed are sequentially vapor-deposited on a carrier by the mask, thereby forming the anti-aliasing imaging element 26.

By the arrangement of the padding block 261b, not only the process of the anti-aliasing imaging element 26 is accelerated, but also the anti-aliasing effect of the anti-aliasing imaging element 26 can be ensured by the height setting of the padding block 261b.

In some embodiments, the transparent region 262 may be filled with a transparent material to increase the strength of the anti-aliasing imaging element layer, and also to prevent impurities from entering the light-transmitting region 262 to affect the light-transmitting effect. In order to ensure the light transmissive effect of the light-transmitting region 262, a material having a relatively high light transmittance such as glass, PMMA (acrylic), PC (polycarbonate) or the like may be selected as the transparent material.

In some embodiments, please refer to FIG. 11, which illustrates the structure of an anti-aliasing imaging element of another embodiment of the present invention. The anti-aliasing imaging element 26 is of a multi-layer structure, and the anti-aliasing imaging element 26 includes a light absorbing layer 263 and a transparent supporting layer 264 which are alternately stacked; the light absorbing layer 263 includes a plurality of spaced light absorbing blocks 263a; The transparent support layer 264 is formed by filling a transparent material and filling the space 263b between the light absorption blocks 263a together; wherein the area corresponding to the space 263b forms the light transmission area 262.

Further, please refer to FIG. 12, which illustrates a process of preparing an anti-aliasing imaging element according to an embodiment of the present invention. Specifically, in preparing the anti-aliasing imaging element 26, a light absorbing material is first coated on a carrier, and a corresponding portion of the light transmitting region 262 is etched away on the light absorbing material layer, and the unetched portion is formed. A plurality of light absorbing blocks 263a. The etching technique is, for example but not limited to, photolithography, X-ray etching, electron beam etching, and ion beam etching. Moreover, the etching type may include both dry etching and wet etching. Then, the etched light absorbing block 263 is coated with a transparent material, and the transparent material covers not only the plurality of light absorbing blocks 263a but also the space 263b between the plurality of light absorbing blocks 263a, thereby forming the transparent supporting layer 264. . Then, a plurality of light absorbing blocks 263a are formed on the transparent supporting layer 264 in the manner in which the light absorbing layer 263 is formed, and the light absorbing layer 263 and the transparent supporting layer 264 which are alternately stacked in a plurality of layers are sequentially formed, thereby forming the anti-aliasing imaging element 26.

Further, in order to ensure the light transmissive effect of the light-transmitting region 262, the transparent material forming the transparent supporting layer 264 may be selected from materials having a relatively high light transmittance, such as glass, PMMA, PC (polycarbonate), epoxy resin. Wait.

In some embodiments, please refer to FIG. 13, which illustrates the structure of an anti-aliasing imaging element of another embodiment of the present invention. The anti-aliasing imaging element 26 includes a light absorbing layer 263 and a transparent support layer 264 which are alternately stacked, and the thickness of each of the transparent support layers 264 is unequal. That is, the values of the thicknesses h1, h2, and h3 in FIG. 13 are not equal. Optionally, the thickness of the transparent support layer 264 is increased layer by layer, that is, h1 < h2 < h3. In this way, optical signals other than ±20° from the vertical direction of the substrate can be prevented from passing through the transparent supporting layer 264 between the light absorbing blocks 263a, thereby improving the sensing accuracy of the photosensitive chip 20. It should be noted that the thickness parameter of each transparent support layer 264 and the width and height parameters of the light absorbing block 263a can be differently set and combined in various combinations to improve the sensing accuracy of the photosensitive chip 20.

In some embodiments, the anti-aliasing imaging element 26 is formed directly on the photosensitive die 22, i.e., the carrier when the anti-aliasing imaging element 26 is formed is a photosensitive die 22 having a photosensitive unit 222. However, the anti-aliasing imaging element 26 can be modified, for example, to be disposed on the photosensitive die 22 provided with the photosensitive unit 222, thereby speeding up the process of the photosensitive chip 20.

In some embodiments, the plurality of light transmissive regions 262 in the anti-aliasing imaging element 26 are evenly distributed such that the fabrication process of the anti-aliasing imaging element 26 is relatively simple. Moreover, the anti-aliasing imaging element 26 can be, for example, an integrally formed film that is separately fabricated and then attached to the photosensitive die 22, thereby accelerating the process of the photosensitive chip 20.

In some embodiments, the sensor chip 20 is a biosensor chip for sensing biometric information of a target object. Specifically, the biometric information includes any one or more of a fingerprint, a palm print, a pulse, a blood oxygen concentration, and a heart rate.

In some embodiments, please refer to FIG. 14, which illustrates the structure of a photosensitive chip 20 according to still another embodiment of the present invention. In some embodiments, the photosensitive chip 20 further includes a package 30 for packaging the photosensitive die 22 and all devices above the photosensitive die 22, for example, anti-aliasing. The imaging element 26 and the filter film 24 are stacked. In particular, when the anti-aliasing imaging element 26 is positioned above the filter film 24, the package 30 can fill the light-transmissive region 262 together.

In the description of the present specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples", etc. The specific features, structures, materials or characteristics described in the embodiments or examples are included in at least one embodiment or example of the invention. In the present specification, the schematic representation of the above terms does not necessarily mean the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

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

A photosensitive chip characterized by comprising a photosensitive die and a filter film, and the filter film is disposed on the photosensitive die.
The photosensitive chip according to claim 1, wherein the filter film is evaporated on the photosensitive die, or the filter film is adhered to the photosensitive die.
The photosensitive chip according to claim 1, wherein said filter film is for filtering out an optical signal other than a predetermined wavelength band.
The photosensitive chip according to claim 3, wherein said predetermined wavelength band is a short-band signal in ambient light.
The photosensitive chip according to claim 4, wherein the predetermined wavelength band is a wavelength band corresponding to a blue or green light signal.
The photosensitive chip according to claim 1, wherein said photosensitive die comprises a plurality of photosensitive devices, and said photosensitive device is a photosensitive device having high sensitivity to sensing an optical signal of said predetermined wavelength band.
The photosensitive chip according to claim 6, wherein the photosensitive device comprises any one or more of a photodiode, a photo resistor, a photodiode, and a phototransistor.
The photosensitive chip according to claim 1, wherein the photosensitive chip is a biosensor chip for sensing biometric information of a target object.
The photosensitive chip according to claim 8, wherein the biometric information comprises any one or more of a fingerprint, a palm print, a pulse, a blood oxygen concentration, and a heart rate.
A photosensitive chip according to claim 1, wherein an anti-aliasing imaging element is further disposed above said photosensitive die.
The photosensitive chip according to claim 10, wherein said filter film and said anti-aliasing imaging element are laminated on said photosensitive die, wherein said filter film is disposed in said anti-aliasing Between the imaging element and the photosensitive die, or the anti-aliasing imaging element is disposed between the photosensitive film and the photosensitive die.
The photosensitive chip according to any one of claims 10 to 11, wherein the anti-aliasing imaging element comprises a light absorbing wall and a plurality of light transmitting regions surrounded by the light absorbing walls.
A photosensitive chip according to claim 12, wherein said light absorbing wall is formed by laminating a plurality of light absorbing layers.
The photosensitive chip according to claim 13, wherein a support layer is provided between adjacent ones of the light absorbing layers.
The photosensitive chip according to claim 12, wherein said light transmitting region is filled with a transparent material.
The photosensitive chip according to claim 10, wherein said photosensitive chip further comprises a package for The photosensitive die, and the anti-aliasing imaging element above the photosensitive die and the filter film are packaged.
The photosensitive chip according to claim 12, wherein said photosensitive chip further comprises a package for performing said photosensitive die, and said anti-aliasing imaging element and said filter film over said photosensitive die a package, wherein the package fills the light transmissive area.
An electronic device, comprising: the photosensitive chip according to any one of claims 1-17.
The electronic device according to claim 18, wherein the electronic device further comprises a display panel, wherein the photosensitive chip is disposed corresponding to a partial area under the display panel, and the sensing chip is configured to receive from the display panel The light signal transmitted through the display area is used to acquire corresponding biometric information according to the received optical signal.
The electronic device of claim 18, wherein the electronic device is a mobile phone or a tablet.