CN209803814U - photosensitive chip and electronic equipment - Google Patents

Abstract

The utility model discloses a sensitization chip and electronic equipment. The photosensitive chip comprises a photosensitive bare chip and a filter film, the filter film is arranged on the photosensitive bare chip, and an anti-aliasing imaging element is further arranged above the photosensitive bare chip. The electronic equipment comprises the photosensitive chip.

Description

Photosensitive chip and electronic equipment

Technical Field

The utility model relates to a photoelectric sensing field especially relates to a realize image information or biological characteristic information sensing's sensitization chip.

Background

At present, a biological information sensor, especially a fingerprint sensor, has gradually become a standard component of electronic products such as mobile terminals. Because optical fingerprint identification sensor has stronger penetrability than capacitanc fingerprint identification sensor, consequently someone proposes an optical fingerprint identification module who is applied to mobile terminal. 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 a protective cover 401 of the mobile terminal. The light source 402 is disposed adjacent to one side of the optical fingerprint recognition sensor 400. When the finger F of the user touches the protective cover 401, the light signal emitted from 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 recognition sensor 400, and forms a fingerprint image of the finger F.

however, the optical fingerprint recognition module 400 is used when the ambient light is strong, and an accurate fingerprint image cannot be obtained, and still needs to be improved.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides a aim at solving one of the technical problem that exists among the prior art at least. For this reason, the utility model discloses the embodiment needs to provide a sensitization chip.

The utility model discloses embodiment's a sensitization chip, including sensitization bare chip and filter coating, just the filter coating sets up on the sensitization bare chip, sensitization bare chip top still is equipped with anti-aliasing formation of image component.

The utility model discloses embodiment through setting up the filter coating, has eliminated the interference of ambient light, has improved the image sensing precision of sensitization chip.

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

In some embodiments, the filter is used for filtering light signals outside a predetermined wavelength band.

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

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

In some embodiments, the photosensitive chip includes a plurality of photosensitive devices, and the photosensitive devices have high sensitivity to the optical signals of the preset wavelength band.

In some embodiments, the light sensing device comprises any one or more of a photodiode, a photoresistor, a photodiode, a phototriode.

In some embodiments, the photosensitive chip is a biological sensing chip for sensing biological characteristic information of a target object.

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

Because there is the difference in the reflection of the different positions of target object light signal, the aliasing can exist to the light signal that sensing between the adjacent sensitization unit to cause the sensing image that acquires to blur, consequently the utility model discloses embodiment has prevented that the light signal that adjacent sensitization device received from producing the aliasing through setting up anti-aliasing imaging element on the sensitization bare chip, has improved the image sensing precision of sensitization chip.

In some embodiments, the filter is disposed on the photosensitive die in a stack with the anti-aliasing imaging component, wherein the filter is disposed between the anti-aliasing imaging component and the photosensitive die, or wherein the anti-aliasing imaging component is disposed between the filter and the photosensitive die. .

In some embodiments, the anti-aliasing imaging element comprises an optical absorption wall and a plurality of light transmission areas enclosed by the optical absorption wall.

In some embodiments, the light absorbing wall is formed by stacking a plurality of light absorbing layers. Because the thickness of each light absorption layer is smaller than that of the light absorption wall, the process of etching to form the light transmission area is relatively easy, so that the process of the anti-aliasing imaging element is easy, and the light transmission performance of the light transmission area can be ensured.

In some embodiments, a support layer is disposed between adjacent light absorbing layers. The utility model discloses among the embodiment, through transparent supporting layer for the preparation speed of anti-aliasing imaging element, through the distance setting between the adjacent two-layer light-absorbing layer, still guarantee the anti-aliasing effect of anti-aliasing imaging element moreover.

In some embodiments, the light-transmissive region is filled with a transparent material. Transparent materials are filled in the light transmission area, so that the strength of the anti-aliasing imaging element is increased, and the influence of impurities in the light transmission area on the light transmission effect can be avoided.

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

In some embodiments, the photosensitive chip further includes a package body for packaging the photosensitive die, the anti-aliasing imaging element and the filter film above the photosensitive die, wherein the package body fills the light-transmitting region.

The utility model discloses embodiment's an electronic equipment, including the sensitization chip of any preceding embodiment. The electronic equipment has all the beneficial effects of the photosensitive chip due to the photosensitive chip with any structure.

In some embodiments, the electronic device further includes a display panel, the light sensing chip is disposed corresponding to a local area below the display panel, and the sensing chip is configured to receive a light signal transmitted through the display area of the display panel to obtain corresponding biometric information according to the received light signal.

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

Additional aspects and advantages of embodiments of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of embodiments of the invention.

Drawings

The above and/or additional aspects and advantages of embodiments of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

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

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

FIG. 3 is a schematic cross-sectional view of the electronic device of FIG. 2 along line I-I, wherein only a portion of the electronic device is shown;

Fig. 4 is a schematic view of a partial structure of a photosensitive chip according to an embodiment of the present invention;

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

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

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

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

FIG. 9 is a schematic diagram of the range of light signals that can be passed through by the anti-aliasing imaging component of one embodiment of the photosensitive chip shown in FIG. 8;

FIG. 10 is a schematic diagram of the range of optical signals that can be passed through by another embodiment of the anti-aliasing imaging element in the photosensitive chip shown in FIG. 8;

FIG. 11 is a schematic structural diagram of an anti-aliasing imaging element according to an embodiment of the invention;

Fig. 12 is a schematic structural diagram of a photosensitive chip according to still another embodiment of the present invention.

FIG. 13 is a schematic structural diagram of an anti-aliasing imaging element according to another embodiment of the invention;

Fig. 14 is a schematic structural view of a photosensitive chip according to still another embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise. "contact" or "touch" includes direct contact or indirect contact. For example, the photosensitive chip disclosed below, which is disposed inside the electronic device, such as under the display screen or the protective cover, 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 is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

The following disclosure provides many different embodiments or examples for implementing different features of the 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 present invention. Furthermore, the present invention may repeat reference numerals and/or reference letters in the various examples, which are repeated for purposes of simplicity and clarity and do not by themselves dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present disclosure provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

Further, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other structures, components, and so forth. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring the invention.

The utility model discloses embodiment provides a sensitization chip, this sensitization chip set up in an electronic equipment that has the display function, and the light signal that sends when this sensitization chip utilizes electronic equipment to show realizes image sensing. It can be understood that the photosensitive chip may be correspondingly disposed in a display area of the electronic device, and may also be disposed in a non-display area of the electronic device. And the photosensitive chip is arranged in the display area, so that the image sensing of the target object at the local position in the screen of the electronic equipment can be realized through the photosensitive chip. It is understood that an independent light source may be disposed in the electronic device for the photosensitive chip to perform image sensing.

The electronic device is, for example, a consumer electronic product, a home-use electronic product, a vehicle-mounted electronic product, and a financial terminal product. The consumer electronic products are various electronic products applying biometric identification technology, such as mobile phones, tablet computers, notebook computers, desktop displays, all-in-one computers and the like. The household electronic products are various electronic products applying biological identification technology, such as intelligent door locks, televisions, refrigerators, wearable equipment and the like. The vehicle-mounted electronic products are vehicle-mounted navigators, vehicle-mounted DVDs and the like. The financial terminal products are ATM machines, terminals for self-service business handling and the like.

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 sole prints, 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 listed information. The target object is, for example, but not limited to, a human body, but 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, fig. 3 shows a partial cross-sectional structure of the electronic device in fig. 2 along the line I-I, wherein fig. 3 only shows a partial structure of the electronic device. The utility model discloses embodiment's photosensitive chip 20 is applied to a mobile terminal 100, and this mobile terminal 100's front is equipped with a display screen 10, and this display screen 10 top is equipped with protection apron 30. Optionally, the screen content of the display screen 10 is high, for example, more than 80%. The screen occupation ratio refers to a 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 correspondingly disposed below the display screen 10, and is correspondingly disposed in a partial area of the display area S1 of the display screen 10. The area of the front surface of the mobile terminal 100 corresponding to or facing the photosensitive chip 20 is defined as a sensing region S2. The sensor chip 20 is used to sense predetermined biometric information of a target object in contact with or in proximity to the sensing region S2.

The sensing region S2 can be any position on the display region. For example, the sensing region S2 is disposed at a middle-lower position corresponding to the display region of the display screen 10. It is understood that the sensing region 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 user' S thumb may facilitate touching the location of the sensing region S2. Of course, the sensing region S2 may be placed at other suitable locations where a user may conveniently touch.

When the mobile terminal 100 is in a bright screen state and in the biometric information sensing mode, the display screen 10 emits an optical signal. When an object contacts or approaches the sensing region S2, the sensor chip 20 receives light reflected by the object, converts the received light into a corresponding electrical signal, and obtains predetermined biometric information of the object, such as fingerprint image information, according to the electrical signal. Thus, the photosensitive chip 20 can sense a target object contacting or approaching a local area above the display area.

Further, referring to fig. 4, fig. 4 shows a 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 24, and the filter 24 is disposed on the photosensitive die 22. Specifically, the filter 24 is disposed on a side of the photosensitive die 22 having a photosensitive function, and is used for filtering the light signal from above the photosensitive die 22.

The embodiment of the present invention provides a filter film 24 on the photosensitive bare chip 22, so as to filter the interference signal when performing image sensing, thereby improving the image sensing precision of the photosensitive chip 20.

In some embodiments, the filter 24 is formed on the photosensitive die 22 by evaporation. Alternatively, the filter 24 may be formed separately and then disposed on the photo-sensing die 22 by, for example, but not limited to, pasting, so that the existing structure of the filter 24 can be utilized and the process is simple.

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

in some embodiments, the filter 24 is used to filter out the interference signals in the ambient light. Specifically, with reference to fig. 3, when the target object F is located on the protective cover 30, if there is ambient light on the target object, taking a finger as an example, since the finger has many tissue structures, such as epidermis, bone, flesh, blood vessels, etc., part of the light signal in the ambient light penetrates through the finger, and part of the light signal is absorbed by the finger. The light signal penetrating through the finger is transmitted to the protective cover 30 below the finger and reaches the photo sensor 20, and at this time, the photo sensor 20 senses not only the light signal reflected by the target object but also the light signal of the environment light penetrating through the finger, so that accurate sensing cannot be performed. Thus, 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 avoid the influence of the ambient light on the image sensing of the photosensitive chip 20 on the target object, the filter 24 is disposed in this embodiment for filtering the light signal in the long wavelength band of the ambient light, that is, the short wavelength band signal in the ambient light can pass through the filter 24. The light signal penetrating through the finger in the ambient light is filtered by the filter 24, so as to achieve the purpose of eliminating the interference signal of the ambient light, thereby improving the image sensing precision of the photosensitive chip 20.

In some embodiments, the predetermined wavelength band is a wavelength band corresponding to the blue light signal, i.e., the filter 24 filters out light signals other than the blue light signal.

In some embodiments, the predetermined wavelength band is a wavelength band corresponding to the green light signal, i.e., the filter 24 filters out light signals other than the green light signal.

in the ambient light, the target object F such as a finger absorbs a light signal in a long wavelength band weakly, for example, a red light signal; the absorption of short-wavelength light signals, such as blue light signals and green light signals, is strong. Therefore, the filter 24 for filtering the light signals in the wavelength bands other than the blue light signal or the green light signal is selected, so that the interference of the ambient light can be greatly eliminated, and the image sensing accuracy of the photo sensor chip 20 can be improved.

In some embodiments, referring to fig. 4 and 5 in combination, the photosensitive die 22 includes a substrate 220 and a plurality of photosensitive units 222 distributed in an array, and the plurality of photosensitive units 222 are disposed on the substrate 220. A scan line group and a data line group electrically connected to the light sensing units 222 are disposed between the adjacent light sensing 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 light-sensing units 222 are distributed in a matrix, for example, but not limited thereto. Of course, other regular or irregular distributions are also possible. The plurality of scan lines 201 and the plurality of data lines 202 electrically connected to the light sensing units 222 are disposed to cross each other and disposed between the adjacent light sensing units 222. For example, a plurality of scan 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 scan lines 201 and the plurality of data lines 202 may be arranged at a certain angle, for example, 30 ° or 60 °, instead of being arranged perpendicularly as shown in fig. 5. In addition, since the scan lines 201 and the data lines 202 have conductivity, the scan lines 201 and the data lines 202 at the crossing positions are isolated from each other by an insulating material.

it should be noted that the arrangement of the distribution and number of the scanning lines 201 and the data lines 202 is not limited to the above-mentioned exemplary embodiment, and corresponding scanning line groups and data line groups may be correspondingly arranged according to the structure of the photosensitive unit 222.

in the photosensitive chip 20, a scan driving signal is provided through the scan line 201 to drive the photosensitive unit 222 to perform light sensing. The light sensing unit 222 receives the optical signal reflected by the target object, converts the received optical signal into a corresponding electrical signal, and outputs the electrical signal through the data line 202.

In some embodiments, as shown in fig. 6, a circuit structure of the photosensitive unit 222 according to an embodiment of the present invention is shown. The light sensing unit 222 includes a light sensing device 224 and a switching device 226. The switch device 226 has a control terminal C and two signal terminals, such as a first signal terminal Sn1 and a second signal terminal Sn 2. 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 photo sensor 224, and the second signal terminal Sn2 of the switching device 226 is connected to the data line 202.

Specifically, the photosensitive device 224 is, for example, but not limited to, any one or more of a photodiode, a phototransistor, a photodiode, a photoresistor, and a Thin Film Transistor (TFT). Taking a photodiode as an example, negative voltages are applied to two ends of the photodiode, at this time, when the photodiode receives an optical signal, a photocurrent proportional to the optical signal is generated, and the larger the intensity of the received optical signal is, the higher the generated photocurrent is, the higher the speed of voltage drop on the cathode of the photodiode is, so that by collecting voltage signals on the cathode of the photodiode, the intensities of optical signals reflected by different parts of a target object are obtained, and further image information of the target object is obtained. It is understood that a plurality of photo-sensing devices 224 may be provided in order to increase the photo-sensing effect of the photo-sensing devices 224.

Further, the switching device 226 is, for example, but not limited to, any one or more of a triode, a MOS transistor, and a thin film transistor. Of course, the switching device 226 may include other types of devices, and the number may be 2, 3, etc.

In some embodiments, in order to further improve the image sensing accuracy of the photo-sensing chip 20, the photo-sensing device 224 with high photo-sensing sensitivity to the blue light signal may also be selected. By selecting the photo-sensing device 224 with high photo-sensing sensitivity for the light signals of the preset waveband to perform photo-sensing, for example, sensing of the blue light signal or the green light signal is more sensitive, so that interference caused by the red light signal in the ambient light is also avoided to a certain extent, thereby improving the image sensing precision of the photo-sensing chip 20.

Taking the structure of the light sensing 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 signal terminal Sn2 serving as the switching device 226. 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 cathode 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 the light sensing, a driving signal is applied to the gate of the tft through the scan line 201 to drive the tft to be turned on. At this time, the data line 202 is connected to a positive voltage signal, when the tft is turned on, the positive voltage signal on the data line 202 is applied to the cathode of the photodiode D1 through the tft, and since the anode of the photodiode D1 is grounded, a reverse voltage is applied across the photodiode D1, so that the photodiode D1 is in a reverse bias state, i.e., in an operating state. 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 current change on the photodiode D1, which can be obtained from the data line 202. Since the larger the intensity of the optical signal is, the larger the generated reverse current is, the intensity of the optical signal can be obtained according to the current signal acquired on the data line 202, and thus the image information of the target object can be 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 to the two ends of the photodiode D1, so that the two ends of the photodiode D1 form a reverse voltage to perform the light sensing, the present invention is within the scope of the present invention.

It should be understood that the connection method of the thin film transistor and the photodiode D1 in the light receiving unit 222 is not limited to the connection method shown in fig. 6, and other connection methods may be used. For example, as shown in fig. 7, fig. 7 shows another connection structure of one light sensing unit to a scan line and a data line, a gate G of a thin film transistor is connected to the scan line 201, a drain D of the thin film transistor is connected to the anode of a photodiode D1, and a source S of the thin film transistor TFT is connected to the data line 202. The cathode of the photodiode D1 is connected to a positive voltage signal. The photosensitive unit 222 is not limited to the above-described circuit configuration, and may include other circuit configurations, which are not illustrated here.

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 may be made of a rigid material or a flexible material, such as a flexible film. If the substrate 220 is made of a flexible material, the thickness of the photo sensor chip 20 is reduced, and the photo sensor chip can be applied to an electronic device having a curved display screen.

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

In some embodiments, the photosensitive chip 20 further includes a controller 225, and the controller 225 is configured to control the driving circuit 221 to output a corresponding scanning driving signal, such as, but not limited to, activating the photosensitive units 222 line by line to perform the light sensing. The controller 225 is further configured to control the signal processing circuit 223 to receive the electrical signals output by the light sensing units 222, and generate an image of the target object according to the electrical signals after receiving the electrical signals output by all the light sensing units 222 performing light sensing.

In some embodiments, the driving circuit 221 may 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. Therefore, the connection line between the driving circuit 241 and the scanning line 201 is shortened, which not only facilitates the connection between the driving circuit 221 and the scanning line 201, but also reduces the signal interference in the signal transmission process. Of course, the driving circuit 221 may 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 may also be directly formed on the substrate 220, and of course, the signal processing circuit 223 may be electrically connected to the light sensing unit 222, that is, the data lines 202, through a flexible circuit board.

In some embodiments, due to the differences in the reflection of the optical signals from different portions of the target object and the unevenness of the surface of the target object, some portions of the target object are in contact with the protective cover 30, some portions of the target object are not in contact with the protective cover 30, so that the contact position is subjected to diffuse reflection, and the non-contact position is subjected to specular reflection, so that the optical signals sensed between adjacent photosensitive units 222 are mixed, and the acquired sensed image is blurred. In this regard, referring to fig. 8, fig. 8 shows a structure of a photosensitive chip according to another embodiment of the present invention. The embodiment of the present invention provides an anti-aliasing imaging element 26 on the photosensitive die 22. The anti-aliasing imaging element 26 is used for preventing the adjacent light-sensing units 222 from receiving the light signals to generate aliasing, thereby improving the image sensing precision of the light-sensing chip 20. In the embodiment of the present invention, the filter 24 and the anti-aliasing imaging element 26 are stacked on the photosensitive bare chip 22. Wherein the filter 24 is located between the anti-aliasing imaging component 26 and the photosensitive die 22. Alternatively, the anti-aliasing imaging component 26 may be disposed between the filter 24 and the photosensitive die 22.

Because the reflection of the optical signal at different parts of the target object is different, and the surface of the target object is uneven, some parts of the target object are in contact with the protective cover plate 30 (see fig. 3), some parts are not in contact with the protective cover plate 30, so that the contact position is subjected to diffuse reflection, and the non-contact position is subjected to specular reflection, and therefore the optical signal sensed between the adjacent photosensitive units 222 is subjected to aliasing, so that the acquired sensed image is blurred. Therefore, the embodiment of the present invention provides an anti-aliasing imaging element 26 on the photosensitive bare chip 22, so that the image obtained after the photosensitive unit 222 performs the light sensing is clearer, thereby improving the sensing precision of the photosensitive chip 20.

in some embodiments, the anti-aliasing imaging element 26 has light absorption characteristics, and of the light signals incident on the anti-aliasing imaging element 26, only the light signals approximately perpendicular to the photosensitive die 22 can pass through the anti-aliasing imaging element 26 and be received by the photosensitive unit 222, and the rest of the light signals are absorbed by the anti-aliasing imaging element 26. In this way, aliasing of the received optical signals between adjacent light sensing units 222 can be prevented. It should be noted that the optical signal approximately perpendicular to the photosensitive die 22 includes an optical signal perpendicular to the photosensitive die 22 and an optical signal within a predetermined angle offset from the perpendicular direction of the photosensitive die 22. 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 transmitting regions 262 surrounded by the light absorbing wall 261. The light absorbing wall 261 is formed of a light absorbing material. The light absorbing material includes metal oxides, carbon black paint, black ink, and the like. The metal in the metal oxide is, for example, but not limited to, one or more of chromium (Cr), nickel (Ni), iron (Fe), tantalum (Ta), tungsten (W), titanium (Ti), and molybdenum (Mo). The light-transmitting region 262 extends in a direction perpendicular to the photosensitive die 22, so that, of the light signals irradiated to the anti-aliasing imaging element 26, the light signals in a direction approximately perpendicular to the photosensitive die 22 can pass through the light-transmitting region 262, and the rest of the light signals are absorbed by the light-absorbing wall 261.

In some embodiments, as shown in FIG. 9, FIG. 9 illustrates the range of optical signals passing through the anti-aliasing imaging elements 26. Due to the light absorption characteristics of the anti-aliasing imaging element 26, only the light signal between the light signal L1 and the light signal L2 can reach the light sensing unit 222 through the light-transmitting region 262, and the rest of the light signal is absorbed by the light-absorbing wall 261 of the anti-aliasing imaging element 26. 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 optical signal passing through the light-transmitting region 262, and therefore the better the anti-aliasing effect of the anti-aliasing imaging element 26. In this way, the anti-aliasing effect of the anti-aliasing imaging element 26 can be improved by the smaller 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 light-sensing unit 222 corresponds to a plurality of light-transmitting regions 262, so that the light-sensing unit 222 can sense sufficient light signals, and the sensing accuracy of the light-sensing chip 20 is improved.

Further, referring to fig. 10, fig. 10 shows a structure of the anti-aliasing imaging element 26 according to an embodiment of the present invention. The light absorbing wall 261 has a multi-layered structure, and includes light absorbing blocks 261a and block-ups 261b alternately stacked. In one embodiment, the light absorbing block 261a is formed of a light absorbing material. Such as, but not limited to, metal oxides, carbon black coatings, black inks, and the like. The metal in the metal oxide is, for example, but not limited to, one or more of chromium (Cr), nickel (Ni), iron (Fe), tantalum (Ta), tungsten (W), titanium (Ti), and molybdenum (Mo). The 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 light-absorbing blocks 261a in the same layer are spaced apart, and the region corresponding to the space 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 block-ups 261b of the same layer may be manufactured at one time. Specifically, by providing a mask, the mask is an integrally formed membrane, and an opening is formed on the membrane corresponding to the position of the light absorption block 261a, and the shape and size of the opening are consistent with the shape and size of the light absorption block 263. The light absorbing blocks 261a and the block-up blocks 261b alternately arranged are sequentially vapor-deposited on a support through the mask, thereby forming the anti-aliasing imaging element 26.

By setting the block 261b, the process of the anti-aliasing imaging element 26 is accelerated, and the anti-aliasing effect of the anti-aliasing imaging element 26 can be ensured by setting the height of the block 261 b.

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 to prevent impurities from entering the transparent region 262 and affecting the light transmission effect. In order to ensure the light-transmitting effect of the light-transmitting region 262, the transparent material may be a material with a relatively high light transmittance, such as glass, PMMA (acrylic), PC (polycarbonate), or the like.

in some embodiments, referring to fig. 11, fig. 11 shows a structure of an anti-aliasing imaging element according to another embodiment of the present invention. The anti-aliasing imaging element 26 is a multilayer structure, and the anti-aliasing imaging element 26 comprises light absorbing layers 263 and transparent support layers 264 which are alternately stacked; the light absorbing layer 263 comprises a plurality of light absorbing blocks 263a arranged at intervals; the transparent support layer 264 is formed by filling a transparent material, and also fills the spaces 263b between the light absorption blocks 263 a; wherein the area corresponding to the space 263b forms the light-transmitting area 262.

Further, referring to fig. 12, fig. 12 shows a process for manufacturing an anti-aliasing imaging element according to an embodiment of the present invention. Specifically, when the anti-aliasing imaging element 26 is prepared, a layer of light absorbing material is coated on a support, and the light-transmitting region 262 is etched away from the light absorbing material layer, and the unetched portion forms a plurality of light absorbing blocks 263 a. Such as, but not limited to, photolithography, X-ray lithography, electron beam lithography, and ion beam lithography. And the etching type may include both dry etching and wet etching. Then, a layer of transparent material is coated on the etched light absorption blocks 263, and the transparent material not only covers the plurality of light absorption blocks 263a, but also fills the spaces 263b between the plurality of light absorption blocks 263a, thereby forming the transparent support layer 264. Then, a plurality of light absorbing blocks 263a are formed on the transparent support layer 264 in the manner of the formation of the light absorbing layer 263, and so on, a plurality of light absorbing layers 263 and transparent support layers 264 alternately laminated are formed, thereby forming the anti-aliasing imaging element 26.

Further, in order to ensure the light-transmitting effect of the light-transmitting region 262, the transparent material forming the transparent supporting layer 264 may be a material with a relatively high light transmittance, such as glass, PMMA (acrylic), PC (polycarbonate), epoxy resin, or the like.

In some embodiments, referring to fig. 13, fig. 13 shows a structure of an anti-aliasing imaging element according to another embodiment of the invention. The anti-aliasing imaging element 26 comprises light absorbing layers 263 and transparent support layers 264 arranged alternately in a stack, and the thickness of each transparent support layer 264 is not equal. I.e., thicknesses h1, h2, and h3 in fig. 13 are not equal in value. Optionally, the thickness of the transparent support layer 264 increases layer by layer, i.e., h1< h2< h 3. In this way, optical signals which are not shifted by ± 20 ° from the substrate vertical direction can be prevented from passing through the transparent support layer 264 between the light absorption blocks 263a, thereby improving the sensing accuracy of the photo sensor chip 20. It should be noted that the thickness parameter of each transparent supporting layer 264, and the width and height parameters of the light absorption block 263a can be set differently and in various combinations to improve the sensing accuracy of the light sensing chip 20.

In some embodiments, the anti-aliasing imaging element 26 is directly formed on the photosensitive die 22, that is, the above-mentioned carrier of the anti-aliasing imaging element 26 is the photosensitive die 22 provided with the photosensitive unit 222. Alternatively, the anti-aliasing imaging element 26 is separately fabricated and then disposed on the photosensitive die 22 having the photosensitive unit 222, thereby speeding up the manufacturing process of the photosensitive chip 20.

In some embodiments, the plurality of light-transmissive regions 262 in the anti-aliasing imaging component 26 are uniformly distributed, thereby making the fabrication process of the anti-aliasing imaging component 26 simpler. Moreover, the anti-aliasing imaging element 26 may be, for example, an integrally formed film, which is separately fabricated and then attached to the photosensitive die 22, thereby speeding up the fabrication process of the photosensitive chip 20.

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

In some embodiments, referring to fig. 14, fig. 14 shows a 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, and the package 30 is used for packaging the photosensitive die 22 and all devices above the photosensitive die 22, such as the anti-aliasing imaging element 26 and the filter 24. In particular, when the anti-aliasing imaging device 26 is located above the filter 24, the package 30 can also fill the transparent region 262.

In the description herein, references to the description of the terms "one embodiment," "certain embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.

Claims (19)

1. A photosensitive chip, characterized in that: including sensitization bare chip and filter coating, just the filter coating sets up on the sensitization bare chip, sensitization bare chip top still is equipped with anti-aliasing imaging element.

2. the photosensitive chip of claim 1, wherein: the light filter film is evaporated on the photosensitive die, or the light filter film is adhered on the photosensitive die.

3. The photosensitive chip of claim 1, wherein: the filter membrane is used for filtering light signals outside a preset wave band.

4. The photosensitive chip of claim 3, wherein: the preset wave band is a short wave band signal in the ambient light.

5. The photosensitive chip of claim 4, wherein: the preset wave band is a wave band corresponding to blue or green light signals.

6. The photosensitive chip of claim 1, wherein: the photosensitive bare chip comprises a plurality of photosensitive devices, and the photosensitive devices are photosensitive devices with high sensitivity for sensing the optical signals of the preset wave band.

7. The photo-sensing chip of claim 6, wherein the photo-sensing device comprises any one or more of a photodiode, a photo-resistor, a photodiode, and a photo-transistor.

8. The photosensitive chip of claim 1, wherein: the photosensitive chip is a biological sensing chip and is used for sensing biological characteristic information of a target object.

9. The photosensitive chip of claim 8, wherein: the biometric information includes: any one or more of fingerprint, palm print, pulse, blood oxygen concentration and heart rate.

10. The photosensitive chip of claim 1, wherein: the filter film and the anti-aliasing imaging element are arranged on the photosensitive bare chip in a laminating mode, wherein the filter film is arranged between the anti-aliasing imaging element and the photosensitive bare chip, or the anti-aliasing imaging element is arranged between the filter film and the photosensitive bare chip.

11. The photosensitive chip of any one of claims 1 to 10, wherein: the anti-aliasing imaging element comprises an optical absorption wall and a plurality of light transmission areas enclosed by the optical absorption wall.

12. The photosensitive chip of claim 11, wherein: the light absorption wall is formed by laminating a plurality of light absorption layers.

13. The photosensitive chip of claim 12, wherein: and a supporting layer is arranged between the adjacent light absorption layers.

14. The photosensitive chip of claim 11, wherein: and transparent materials are filled in the light-transmitting areas.

15. The photosensitive chip of claim 1, wherein: the photosensitive chip further comprises a packaging body used for packaging the photosensitive bare chip, the anti-aliasing imaging element above the photosensitive bare chip and the filter film.

16. The photosensitive chip of claim 11, wherein: the photosensitive chip further comprises a packaging body used for packaging the photosensitive bare chip, the anti-aliasing imaging element and the filter film above the photosensitive bare chip, wherein the packaging body is filled in the light-transmitting area.

17. An electronic device, characterized in that: the electronic device comprising the photosensitive chip of any one of claims 1-16.

18. The electronic device of claim 17, wherein: the electronic device further comprises a display panel, the photosensitive chip is arranged corresponding to a local area below the display panel, and the sensing chip is used for receiving the optical signal transmitted from the display area of the display panel so as to acquire corresponding biological characteristic information according to the received optical signal.

19. the electronic device of claim 18, wherein: the electronic equipment is a mobile phone or a tablet computer.