Photoelectric sensor and detection equipment

Abstract

The invention discloses a photoelectric sensor and detection equipment, and belongs to the technical field of photoelectric detection. The photoelectric sensor comprises a substrate, a circuit board, a wafer and a packaging cover plate, the surface of the substrate is provided with an open groove, the circuit board and the wafer are both arranged in the open groove, the wafer is arranged on the side, opposite to the substrate, of the circuit board, the packaging cover plate is arranged on the surface of the substrate to seal the open groove, and the wafer is opposite to the packaging cover plate; the packaging cover plate is provided with a first surface and a second surface which are opposite to each other, the second surface faces the wafer, and the first surface and the second surface are respectively provided with a first transmission film layer and a second transmission film layer which are used for transmitting light rays reflected by the wafer; a light absorption structure is arranged on the surface, opposite to the circuit board, of the wafer, is used for absorbing light rays reflected by the wafer and protrudes out of the surface of the wafer; a first light absorption layer is arranged on the surface, opposite to the packaging cover plate, of the second transmission film layer, at least part of the first light absorption layer is opposite to the circuit board, and the first light absorption layer is used for absorbing light reflected by the circuit board.

Description

Technical Field

[0001] This application belongs to the field of photoelectric detection technology, specifically relating to a photoelectric sensor and detection device. Background Technology

[0002] In fields of artificial intelligence such as autonomous driving, drones, and robotics, photoelectric sensors are typically used to detect target objects. Specifically, this involves a transmitter emitting light signals towards the target object, and a receiver identifying the target object.

[0003] In the prior art, the chip (silicon wafer) of the photoelectric sensor has multiple pixels arranged in an array. After the signal light is incident on the surface of the chip, the first reflected light is easily reflected a second time by other reflective surfaces and incident on other pixels. Therefore, there is a problem of optical crosstalk between adjacent pixels, which affects the detection effect of the photoelectric sensor. Summary of the Invention

[0004] The purpose of this application is to provide a photoelectric sensor and detection device that can solve the interference problem caused by optical crosstalk in photoelectric sensors in related technologies.

[0005] In a first aspect, embodiments of this application provide a photoelectric sensor, including a substrate, a circuit board, a wafer, and a packaging cover. The surface of the substrate is provided with a slot, and both the circuit board and the wafer are disposed in the slot. The wafer is disposed on the side of the circuit board facing away from the substrate. The substrate is used to electrically connect to an external circuit, and the substrate is electrically connected to the circuit board. The packaging cover is disposed on the surface of the substrate to close the slot, and the wafer is opposite to the packaging cover.

[0006] The encapsulation cover has a first surface and a second surface facing away from each other, with the second surface facing the wafer. The first surface and the second surface are respectively provided with a first transmission film layer and a second transmission film layer, which are used to allow light reflected by the wafer to pass through.

[0007] The surface of the wafer facing away from the circuit board is provided with a light-absorbing structure, which is used to absorb light reflected by the wafer, and the light-absorbing structure protrudes from the surface of the wafer;

[0008] The second transmissive film layer has a first light-absorbing layer on the surface facing away from the encapsulation cover plate. At least a portion of the first light-absorbing layer is opposite to the circuit board. The first light-absorbing layer is used to absorb light reflected by the circuit board.

[0009] Optionally, both the first transmission film layer and the second transmission film layer include a first organic film layer and a second organic film layer stacked together, wherein the refractive index of the first organic film layer is less than the refractive index of the second organic film layer, and the difference between the refractive indices of the second organic film layer and the first organic film layer is greater than 0.1.

[0010] This configuration, employing a structure with a first organic film layer and a second organic film layer stacked together, enables signal light to pass through uniformly within a certain wavelength range.

[0011] Optionally, both the first transmission film layer and the second transmission film layer include multiple film layer groups stacked sequentially. Each film layer group includes a first organic film layer and a second organic film layer stacked together. The refractive index of the first organic film layer is less than the refractive index of the second organic film layer, and the difference between the refractive indices of the second organic film layer and the first organic film layer is greater than 0.1.

[0012] With this configuration, there are multiple film layers, with the first organic film layer and the second organic film layer alternating, which helps to further increase the transmittance of incident light and reduce the reflectance.

[0013] Optionally, the wafer includes a pixel layer having a plurality of pixels arranged in an array. The array direction of the pixels includes a first direction, which is parallel to the plane on which the circuit board is located. The light-absorbing structure is laid on the surface of the wafer and has a plurality of light-transmitting holes. Each light-transmitting hole is spaced apart along the first direction and is opposite to the pixel.

[0014] With this configuration, the light-absorbing structure is a grid structure, thus increasing the volume of each light-absorbing structure, which is beneficial for increasing the light-absorbing area. The light-transmitting ports extend along the pixel array direction, and each light-transmitting port can correspond to multiple pixels. Moreover, the light-transmitting ports are spaced apart along the pixel array direction, which means that the light-absorbing area in the pixel array direction is increased. This is more conducive to the light-absorbing structure absorbing the reflected light from neighboring pixels, further increasing the probability that the light reflected by the chip will be absorbed by the light-absorbing structure, and avoiding optical path crosstalk between pixels.

[0015] Optionally, in the first direction, the size of the light-transmitting opening is larger than the size of the pixel.

[0016] This design results in a larger light-transmitting area for the light-absorbing structure, preventing the light-absorbing structure from absorbing signal light that should be received by the pixels due to an excessively small light-transmitting opening. This avoids affecting the pixel's signal reception and ensures the chip's working performance.

[0017] Optionally, the wafer includes a stacked pixel layer and a metal layer, the metal layer being located between the pixel layer and the light-absorbing structure, the metal layer having a plurality of metal structures arranged in an array, the array direction of the metal structures including a first direction, the first direction being parallel to the plane where the circuit board is located, the light-absorbing structure being laid on the surface of the wafer, the light-absorbing structure having a plurality of light-transmitting holes, each of the light-transmitting holes being spaced apart along the first direction, the portion of the light-absorbing structure located between two adjacent light-transmitting holes being opposite to the metal structure.

[0018] With this configuration, the portion of the light-absorbing structure located between two adjacent light-transmitting ports is opposite to different metal structures. This increases the light-absorbing area of ​​the light-absorbing structure in the array direction of the metal structures, which is more conducive to the light-absorbing structure absorbing the light reflected by the metal structures. This increases the probability that the light reflected by the metal structures will be absorbed by the light-absorbing structure, thus avoiding crosstalk between pixels.

[0019] Optionally, a second light-absorbing layer is provided on the surface of the first transmissive film layer facing away from the encapsulation cover plate, and the second light-absorbing layer is opposite to the first light-absorbing layer in the thickness direction of the encapsulation cover plate.

[0020] With this configuration, by adding a second light-absorbing layer, the first and second light-absorbing layers work together to absorb light reflected from components outside the chip, thereby improving the light absorption effect and preventing secondary reflected light from entering the chip and causing pixel crosstalk.

[0021] Optionally, the light-absorbing structure forms a light-absorbing region, and both the first light-absorbing layer and the second light-absorbing layer are provided with openings. In the thickness direction of the wafer, the openings are opposite to the light-absorbing region, and the edges of the openings are opposite to the edges of the light-absorbing region.

[0022] This configuration, which sets the light absorption range apart from the light absorption area corresponding to the light absorption structure, helps to narrow the range of signal light, reduce the impact of light reflected from components outside the chip on the chip, and ensure that the signal light can accurately enter the chip.

[0023] Optionally, the thickness of the first transmission film layer is less than the height of the light-absorbing structure protruding from the wafer, and / or, the thickness of the second transmission film layer is less than the height of the light-absorbing structure protruding from the wafer;

[0024] The height of the light-absorbing structure protruding from the wafer is less than the thickness of the first light-absorbing layer.

[0025] With this configuration, the first and second transmission film layers are relatively thin, which helps to improve light transmittance and reduce reflectivity; the protrusion height of the light-absorbing structure is relatively large, which helps the light-absorbing structure absorb light reflected from the chip at a large angle, and avoids the light reflected from the first reflection reaching the encapsulation layer and undergoing secondary reflection due to insufficient protrusion height of the light-absorbing structure; the first light-absorbing layer is relatively thick, which helps it absorb light reflected from other components besides the chip, resulting in better light absorption.

[0026] Secondly, embodiments of this application also provide a detection device, including the aforementioned photoelectric sensor.

[0027] In this embodiment, the first and second surfaces of the encapsulation cover are respectively provided with a first transmission film layer and a second transmission film layer. The first and second transmission film layers are used to allow light reflected from the wafer to pass through. Thus, the first and second transmission film layers increase the transmittance of light perpendicularly reflected from the wafer and light with small reflection angles, increasing the amount of light reflected from the wafer and passing through the encapsulation cover layer, and reducing the amount of light reflected from the wafer and then reflected a second time by the encapsulation cover layer. This prevents the light reflected from the wafer from being reflected again by the encapsulation cover layer to other locations on the wafer. Furthermore, the wafer surface is provided with a light-absorbing structure that protrudes from the wafer surface. The light-absorbing structure can absorb light reflected from the chip at a large angle, reducing the amount of light reflected from the chip and reaching the package cover, thus reducing the amount of light reflected twice and preventing light reflected twice from the package cover from reaching other parts of the chip. Furthermore, the package cover has a first light-absorbing layer on the side facing the chip. Since at least part of the first light-absorbing layer is opposite to the circuit board, the light reflected from the circuit board can reach the first light-absorbing layer and be absorbed by it, preventing the light reflected from the circuit board from being reflected twice by the package cover to other parts of the chip. This helps to narrow the range of signal light and reduce the impact of light reflected from components other than the chip on the chip.

[0028] Therefore, the photoelectric sensor in this embodiment combines a first transmission film layer, a second transmission layer, a light-absorbing structure, and a first light-absorbing layer, which can reduce the probability of light reflected from the wafer and light reflected from other components outside the wafer entering the wafer, effectively avoid optical crosstalk, and improve the detection effect of the photoelectric sensor. Attached Figure Description

[0029] Figure 1 This is a cross-sectional view of the photoelectric sensor disclosed in the embodiments of this application;

[0030] Figure 2 This is a schematic diagram of the structure of the first transmission film layer disclosed in the embodiments of this application;

[0031] Figure 3 This is a cross-sectional view of the wafer and light-absorbing structure disclosed in an embodiment of this application;

[0032] Figure 4 This is a cross-sectional view of the wafer and light-absorbing structure disclosed in another embodiment of this application;

[0033] Figure 5 This is a partial cross-sectional view of the photoelectric sensor disclosed in the embodiments of this application;

[0034] Figure 6 This is a cross-sectional view of the encapsulation cover and the film layer thereon disclosed in an embodiment of this application;

[0035] Figure 7 This is a cross-sectional view of the encapsulation cover and the film layer thereon disclosed in another embodiment of this application;

[0036] Figure 8 This is a schematic diagram of the structure of the first light-absorbing layer disclosed in the embodiments of this application;

[0037] Figure 9 This is a coordinate schematic diagram showing the transmittance of the first light-absorbing layer for different wavelengths of light disclosed in the embodiments of this application.

[0038] Explanation of reference numerals in the attached figures:

[0039] 100 - substrate, 110 - slot, 120 - solder ball

[0040] 200 - Circuit board, 210 - Electrical connection wire,

[0041] 300 - wafer, 310 - pixel layer, 311 - pixel, 320 - metal layer, 321 - metal structure, 330 - light-absorbing structure, 331 - light-transmitting aperture, 340 - anti-reflection layer, 350 - transparent passivation layer.

[0042] 400 - Encapsulation cover plate, 410 - First transmission film layer, 410a - Film layer group, 411 - First organic film layer, 412 - Second organic film layer, 420 - Second transmission film layer, 430 - First light-absorbing layer, 430a - Opening, 440 - Second light-absorbing layer,

[0043] A - First direction, B - Second direction. Detailed Implementation

[0044] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0045] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0046] The photoelectric sensor and detection device provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0047] Please refer to Figures 1-9 The photoelectric sensor disclosed in this application includes a substrate 100, a circuit board 200, a chip 300, and a package cover plate 400. The substrate 100 serves as the mounting base for the circuit board 200, the chip 300, and the package cover plate 400. The circuit board 200, the chip 300, and the package are all disposed on the substrate 100. The chip 300 is the core working device of the photoelectric sensor. The circuit board 200 is used to supply power to the chip 300. At the same time, the circuit board 200 serves as the mounting base for the chip 300. The package cover plate 400 is used to cover the surface of the substrate 100 to encapsulate the circuit board 200 and the chip 300, preventing the circuit board 200 and the chip 300 from being exposed.

[0048] Specifically, refer to Figure 1 As shown, the surface of the substrate 100 is provided with a groove 110. The groove 110 does not penetrate the substrate 100. The circuit board 200 and the chip 300 are both disposed in the groove 110. Moreover, the chip 300 is disposed on the side of the circuit board 200 facing away from the substrate 100. Optionally, the laying area of ​​the chip 300 is smaller than the laying area of ​​the circuit board 200. The bottom surface of the circuit board 200 is in contact with the bottom wall of the groove 110, the surface of the circuit board 200 is in contact with the chip 300, and there is a gap between the circuit board 200 and the side wall of the groove 110 to avoid the substrate 100 from affecting the circuit board 200.

[0049] Both the substrate 100 and the circuit board 200 have internal circuits for electrical connection. The substrate 100 is used to electrically connect external circuits other than the photoelectric sensor, and the substrate 100 is electrically connected to the circuit board 200. Optionally, the bottom of the substrate 100 has solder balls 120, which connect to the external circuits. The substrate 100 and the circuit board 200 are electrically connected via electrical connection wires 210, which can be gold wires. Of course, the substrate 100 can be electrically connected to the external circuits in other ways, and the substrate 100 and the circuit board 200 can also be electrically connected in other ways.

[0050] An encapsulation cover 400 is disposed on the surface of the substrate 100 to close the slot 110, and the chip 300 is opposite to the encapsulation cover 400. Optionally, the encapsulation cover 400 can be a glass plate or other plate-like structure capable of encapsulation. In this way, the encapsulation cover 400 and the substrate 100 cooperate to encapsulate the circuit board 200 and the chip 300, preventing the circuit board 200 and the chip 300 from being exposed, thereby preventing other components from affecting the circuit board 200 and the chip 300. Optionally, the encapsulation cover 400 can be made of materials such as plastic or rubber.

[0051] The encapsulation cover plate 400 has a first surface and a second surface facing away from each other. The second surface faces the wafer 300, that is, it faces the slot 110. A first transmission film layer 410 and a second transmission film layer 420 are respectively provided on the first and second surfaces. The first transmission film layer 410 and the second transmission film layer 420 are used to allow light reflected from the wafer 300 to pass through, that is, the first transmission film layer 410 and the second transmission film layer 420 can increase the transmittance of signal light and reduce the reflectance of signal light. In other words, the first transmission film layer 410, the encapsulation cover plate 400, and the second transmission film layer 420 are stacked sequentially, and the stacking direction is the same as the arrangement direction of the circuit board 200, the wafer 300, and the encapsulation cover plate 400. Both the first transmission film layer 410 and the second transmission film layer 420 are made of materials with high signal light transmittance. The first transmission film layer 410 and the second transmission film layer 420 can be made of the same material or different materials. Optionally, the area of ​​the first transmission film layer 410 and the second transmission film layer 420 can be equal to or less than the area of ​​the encapsulation cover plate 400.

[0052] Thus, through the first transmission film layer 410 and the second transmission film layer 420, the transmittance of light that is vertically reflected by the wafer 300 (i.e., the direction of reflection is parallel to the direction perpendicular to the wafer 300) and has a smaller reflection angle (i.e., the angle between the direction of reflection and the direction perpendicular to the wafer 300 is smaller) is increased. This increases the amount of light reflected by the wafer 300 and transmitted through the encapsulation cover plate 400, while reducing the amount of light reflected by the wafer 300 and then reflected a second time by the encapsulation cover plate 400. This prevents the light reflected by the wafer 300 from being reflected again by the encapsulation cover plate 400 to other positions of the wafer 300.

[0053] refer to Figure 1 , Figures 3-5 As shown, a light-absorbing structure 330 is provided on the surface of the chip 300 facing away from the circuit board 200. The light-absorbing structure 330 is used to absorb light reflected by the chip 300, and the light-absorbing structure 330 protrudes from the surface of the chip 300. Specifically, refer to... Figure 5 As shown, the light-absorbing structure 330 has a light-transmitting gap, through which most of the incident light is absorbed by the pixel and becomes effective signal light. For a small portion of the incident light that is not absorbed by the pixel and thus undergoes surface reflection at a small angle (i.e., the angle between the reflection direction and the direction perpendicular to the chip 300 is small), it will not undergo secondary reflection when it enters the surface of the packaging cover plate 400. Instead, it will pass through the second transmission layer, the packaging cover plate 400, and the first transmission layer in sequence. For light with a larger reflection angle (i.e., the angle between the reflection direction and the direction perpendicular to the chip 300 is large), it can directly enter the surface of the light-absorbing structure 330 (including the bottom and side surfaces of the light-absorbing structure 330) and be absorbed by the light-absorbing structure 330. In both cases, the reflected light will not return to the chip interior, thus avoiding secondary reflection through other reflective surfaces and reaching other pixels, preventing crosstalk and high reflection expansion problems.

[0054] Optionally, the light-absorbing structure 330 can be a black structure, as black has a better light-absorbing effect. Of course, other colors of light-absorbing structures 330 can also be used. The light-absorbing structure 330 can be photoresist or other materials with light-absorbing effects. This application embodiment does not limit the material of the light-absorbing structure 330.

[0055] In this way, the light-absorbing structure 330 can absorb light reflected by the chip 300 at a large angle, reduce the amount of light reflected by the chip 300 and incident on the package cover plate 400, that is, reduce the amount of light reflected twice, thereby preventing the light reflected twice by the package cover plate 400 from being incident on other parts of the chip 300.

[0056] refer to Figure 6 and Figure 7 As shown, a first light-absorbing layer 430 is provided on the surface of the second transmissive film layer 420 facing away from the encapsulation cover plate 400. At least a portion of the first light-absorbing layer 430 is opposite to the circuit board 200. This can be either the entire first light-absorbing layer 430 or only a portion of it. The first light-absorbing layer 430 is used to absorb light reflected by the circuit board 200. The first light-absorbing layer 430 can be a photoresist layer or other materials with light-absorbing properties. This embodiment does not limit the material of the first light-absorbing layer 430.

[0057] Optionally, the first light-absorbing layer 430 may be made of the same material as the light-absorbing structure 330, or it may be made of a different material; the first light-absorbing layer 430 may also be a black film layer to improve the light absorption effect.

[0058] refer to Figure 1 As shown, not only does the chip 300 reflect light, but other components besides the chip 300, such as the circuit board 200, also reflect light. The light reflected by the circuit board 200 is reflected a second time by the encapsulation cover plate 400 to the surface of the chip 300. Since at least a portion of the first light-absorbing layer 430 is opposite to the circuit board 200, the light reflected by the circuit board 200 can reach the first light-absorbing layer 430 and be absorbed by it. This prevents the light reflected by the circuit board 200 from being reflected a second time by the encapsulation cover plate 400 to other locations on the chip 300, which helps to narrow the range of the signal light and reduce the impact of light reflected by components other than the chip 300 on the chip 300.

[0059] Therefore, the photoelectric sensor in this embodiment, by combining the first transmission film layer 410, the second transmission film layer 420, the light-absorbing structure 330, and the first light-absorbing layer 430, can reduce the probability of light reflected from the chip 300 and light reflected from other components outside the chip 300 entering the chip 300, effectively avoiding optical crosstalk and improving the detection effect of the photoelectric sensor. Moreover, it does not affect the structure of the chip 300 and does not require changing the algorithm of the chip 300.

[0060] In this embodiment, the first transmission film layer 410 and the second transmission film layer 420 mainly transmit light reflected by the wafer 300 with a reflection angle of less than 30° (i.e., the angle between the reflection direction and the direction perpendicular to the wafer 300 is less than 30°), the light-absorbing structure 330 is mainly used to absorb light reflected by the wafer 300 with a reflection angle of greater than 30° (i.e., the angle between the reflection direction and the direction perpendicular to the wafer 300 is less than 30°), and the first light-absorbing layer 430 is mainly used to absorb reflected light from other components other than the wafer 300.

[0061] Optionally, the photoelectric sensor can be a SPAD (Single Photon Avalanche Diode), or other types of photoelectric sensors.

[0062] In an optional embodiment, both the first transmission film layer 410 and the second transmission film layer 420 include a stacked first organic film layer 411 and a second organic film layer 412. The refractive index of the first organic film layer 411 is less than the refractive index of the second organic film layer 412. That is, the refractive indices of the first organic film layer 411 and the second organic film layer 412 are different, with the first organic film layer 411 having a smaller refractive index and the second organic film layer 412 having a larger refractive index. Moreover, the difference in refractive index between the second organic film layer 412 and the first organic film layer 411 is greater than 0.1.

[0063] By utilizing the refractive index difference between the first organic film layer 411 and the second organic film layer 412, the incident light suffers half-wave loss on the surfaces of the first organic film layer 411, the second organic film layer 412, and the encapsulation cover plate 400. Therefore, by setting a film layer with an optical thickness of λ / 6 on the surface of the encapsulation cover plate 400, the reflectivity can be effectively reduced.

[0064] Optionally, the first organic film layer 411 can be silicon dioxide, Teflon, metal oxides (such as oxides of metals like aluminum, zirconium, and titanium), magnesium fluoride, etc., and the second organic film layer 412 can be silicon nitride, titanium oxide, hafnium oxide, tantalum oxide, zirconium oxide, gallium phosphide, and germanium, etc. In the embodiments of this application, the first organic film layer 411 is silicon dioxide, and the second organic film layer 412 is titanium oxide.

[0065] Of course, in other embodiments, the first transmission film layer 410 and the second transmission film layer 420 may also adopt other structures, which can increase the transmittance of signal light and reduce the reflectance of signal light.

[0066] In one optional embodiment, both the first transmission film layer 410 and the second transmission film layer 420 include a film layer group 410a, which includes a first organic film layer 411 and a second organic film layer 412 stacked together. The refractive index of the first organic film layer 411 is less than the refractive index of the second organic film layer 412, and the difference between the refractive indices of the second organic film layer 412 and the first organic film layer 411 is greater than 0.1.

[0067] In another embodiment, reference Figure 2 As shown, both the first transmission film layer 410 and the second transmission film layer 420 include multiple film layer groups 410a stacked sequentially. Each film layer group 410a includes a first organic film layer 411 and a second organic film layer 412 stacked. Thus, both the first transmission film layer 410 and the second transmission film layer 420 are multi-film layer structures. The first organic film layer 411 and the second organic film layer 412 are alternately arranged. A second organic film layer 412 is provided between two adjacent first organic film layers 411, and a first organic film layer 411 is provided between two adjacent second organic film layers 412.

[0068] Optionally, the thickness of each first organic film layer 411 can be 20nm-250nm, and the thickness of each first organic film layer 411 can be equal, unequal, or some of the first organic film layers 411 can be equal in thickness; the thickness of each second organic film layer 412 can be 20nm-250nm, and the thickness of each second organic film layer 412 can be equal, unequal, or some of the second organic film layers 412 can be equal in thickness.

[0069] Optionally, the first organic film layer 411 is silicon dioxide and the second organic film layer 412 is titanium oxide. In this case, the number of film layer groups 410a can be any number within the range of 2 to 40. Further optionally, the number of film layer groups 410a can be 8, and the thickness of the first transmission film layer 410 or the second transmission film layer 420 can be in the range of 0.2 μm to 1 μm. Alternatively, the first organic film layer 411 is silicon dioxide and the second organic film layer 412 is zirconium oxide. In this case, the number of film layer groups 410a can be any number within the range of 2 to 30. Alternatively, the first organic film layer 411 is gallium phosphide and the second organic film layer 412 is titanium oxide. In this case, the number of film layer groups 410a can be any number within the range of 2 to 15.

[0070] There are multiple film layer groups 410a, with the first organic film layer 411 and the second organic film layer 412 alternately arranged, which is beneficial to further increase the transmittance of incident light and reduce the reflectance.

[0071] The first organic film layer 411 and the second organic film layer 412 can be produced using thin film deposition processes, specifically chemical vapor deposition (enhanced ion-assisted chemical vapor deposition, high-density ion-assisted vapor deposition, etc.), physical vapor deposition (such as ion source-assisted electron gun evaporation coating, magnetron sputtering coating, ion plating, etc.), or atomic layer deposition, etc.

[0072] It should be noted that the light transmitted by the first transmission film layer 410 and the second transmission film layer 420 is the signal light of a specific wavelength emitted by the device, while the filtered light is ambient light. Because the first transmission film layer 410 and the second transmission film layer 420 employ a multi-layered structure, the transmittance of the target wavelength band can be improved. The transmittance of the first transmission film layer 410 and the second transmission film layer 420 for signal light can reach over 99%. Simultaneously, the first transmission film layer 410 and the second transmission film layer 420 exhibit strong angular selectivity for the transmittable wavelength band. The transmittance of light with an incident angle of 0° is over 99%, while the transmittance of light with an incident angle less than 30° decreases by about half. The incident angle is the angle between the direction of the incident light and the direction perpendicular to the encapsulation cover plate 400.

[0073] In the scheme of this application, reference is made to Figure 3 and Figure 4 As shown, the chip 300 includes a pixel layer 310, which has a plurality of pixels 311 arranged in an array. The array direction of the pixels 311 includes a first direction A, that is, a plurality of pixels 311 are spaced apart along the first direction A. The first direction A is parallel to the plane on which the circuit board 200 is located. The distance between any two adjacent pixels 311 can be equal or unequal. Optionally, the array direction of the pixels 311 also includes a second direction B, where the first direction A and the second direction B intersect. The second direction B is also parallel to the plane on which the circuit board 200 is located. Optionally, the first direction A and the second direction B can be perpendicular to each other.

[0074] A light-absorbing structure 330 is deposited on the surface of the chip 300. The light-absorbing structure 330 can be a layered structure. The light-absorbing structure 330 has multiple light-transmitting openings 331, which are spaced apart along a first direction A. That is, the arrangement direction of the light-transmitting openings 331 is the same as the arrangement direction of the pixels 311, and the light-transmitting openings 331 are opposite to the pixels 311. Optionally, the light-absorbing structure 330 has multiple light-transmitting openings 331 to form a grid structure. The light-absorbing structure 330 can have multiple light-transmitting openings 331 along both the first direction A and the second direction B. The extension direction of the light-transmitting openings 331 can be either the first direction A or the second direction B. Each light-transmitting opening 331 is opposite to at least one pixel 311. Further optionally, each light-transmitting opening 331 can correspond to multiple pixels 311 simultaneously. Each light-transmitting opening 331 can be opposite to 4 pixels 311, 9 pixels 311, 16 pixels 311, or 25 pixels 311.

[0075] In this embodiment, the light-absorbing structure 330 is a grid structure, so the volume of the light-absorbing structure 330 is increased, which is beneficial to increasing the light-absorbing area. The light-transmitting port 331 extends along the array direction of the pixels 311, and each light-transmitting port 331 can correspond to multiple pixels 311. Moreover, the light-transmitting ports 331 are spaced apart along the array direction of the pixels 311. That is, the light-absorbing area in the array direction of the pixels 311 is increased, which is more conducive to the light-absorbing structure 330 absorbing the reflected light of the neighboring pixels 311, further increasing the probability that the light reflected by the chip 300 is absorbed by the light-absorbing structure 330, and avoiding optical path crosstalk between pixels 311.

[0076] Of course, in other embodiments, the light-absorbing structure 330 may also adopt other structures besides the grid structure. Optionally, the light-absorbing structure 330 may adopt a block structure. The light-absorbing structures 330 may also be distributed at intervals along other directions besides the first direction A and the second direction B. The gap between two adjacent light-absorbing structures 330 is opposite to the pixel 311.

[0077] In one alternative embodiment, in the first direction A, the size of the light-transmitting opening 331 is smaller than the size of the pixel 311.

[0078] In another embodiment, in the first direction A, the size of the light-transmitting opening 331 is greater than or equal to the size of the pixel 311. Optionally, the size of the light-transmitting opening 331 can be equal to the size of the pixel 311, and the size of the light-transmitting opening 331 can be two or three times the size of the pixel 311.

[0079] In this embodiment, the light-absorbing structure 330 has a large light-transmitting area, which avoids the light-transmitting opening 331 being too small, causing the light-absorbing structure 330 to absorb the signal light that should be received by the pixel 311, thereby avoiding affecting the signal reception of the pixel 311 and ensuring the working performance of the chip 300.

[0080] In an optional embodiment, refer to Figure 3 As shown, the wafer 300 includes a stacked pixel layer 310 and a metal layer 320. The pixel layer 310 has a plurality of pixels 311, and the metal layer 320 has a plurality of metal structures 321. The metal layer 320 is located between the pixel layer 310 and the light-absorbing structure 330. The metal layer 320 has a plurality of metal structures 321 arranged in an array. The array direction of the metal structures 321 includes a first direction A, which is parallel to the plane of the circuit board 200. The light-absorbing structure 330 is laid on the surface of the wafer 300 and has a plurality of light-transmitting holes 331. The light-transmitting holes 331 are spaced apart along the first direction A. That is, the direction in which the light-transmitting holes 331 are spaced apart is the same as the array direction of the metal structures 321. Moreover, the portion of the light-absorbing structure 330 between two adjacent light-transmitting holes 331 is opposite to the metal structure 321. Specifically, the portion of the light-absorbing structure 330 between two adjacent light-transmitting holes 331 is opposite to the metal structure 321 in the thickness direction of the wafer 300. Optionally, in the first direction A, the size of the portion of the light-absorbing structure 330 located between two adjacent light-transmitting openings 331 is equal to the size of the metal structure 321.

[0081] In this embodiment, the portion of the light-absorbing structure 330 located between two adjacent light-transmitting ports 331 is opposite to different metal structures 321. Therefore, the light-absorbing area of ​​the light-absorbing structure 330 in the array direction of the metal structures 321 is increased, which is more conducive to the light-absorbing structure 330 absorbing the light reflected by the metal structures 321, increasing the probability that the light reflected by the metal structures 321 will be absorbed by the light-absorbing structure 330, and avoiding optical path crosstalk between pixels 311.

[0082] Of course, in other embodiments, the light-transmitting openings 331 can be spaced apart in other directions, and the portion of the light-absorbing structure 330 located between two adjacent light-transmitting openings 331 can be offset from the metal structure 321.

[0083] Optionally, the wafer 300 further includes an antireflection layer 340 and a transparent passivation layer 350. The antireflection layer 340 is used to reduce reflected light, and the transparent passivation layer 350 prevents the metal layer 320 from being oxidized. (See reference...) Figure 3 As shown, the antireflective layer 340 and the transparent passivation layer 350 are located between the light-absorbing structure 330 and the metal layer 320, or, as shown in the reference... Figure 4 As shown, the antireflection layer 340 and the transparent passivation layer 350 are located between the light-absorbing structure 330 and the pixel layer 310, with the antireflection layer 340 disposed on the side of the transparent passivation layer 350 facing the light-absorbing structure 330.

[0084] In the scheme of this application, reference is made to Figure 7 As shown, a second light-absorbing layer 440 is provided on the surface of the first transmissive film layer 410 facing away from the encapsulation cover plate 400. The second light-absorbing layer 440 is opposite to the first light-absorbing layer 430 in the thickness direction of the encapsulation cover plate 400. Optionally, the area of ​​the second light-absorbing layer 440 may be equal to or unequal to the area of ​​the first light-absorbing layer 430, and at least a portion of the second light-absorbing layer 440 is also opposite to the circuit board 200.

[0085] The second light-absorbing layer 440 can be a photoresist layer or other materials with light-absorbing effects. In this embodiment, the material of the second light-absorbing layer 440 is not limited. The material of the second light-absorbing layer 440 can be the same as or different from the material of the first light-absorbing layer 430.

[0086] By adding a second light-absorbing layer 440, the first light-absorbing layer 430 and the second light-absorbing layer 440 together absorb the light reflected from components outside the chip 300, improve the light absorption effect, and prevent secondary reflected light from entering the chip 300 and causing crosstalk in the pixel 311.

[0087] Of course, in other embodiments, the surface of the first transmissive film facing away from the encapsulation cover plate 400 may not have a second light-absorbing layer 440, that is, only the first light-absorbing layer 430 may be provided to absorb the light reflected from the circuit board 200, see reference. Figure 6 As shown.

[0088] In a further embodiment, reference is made to... Figure 7 As shown, the light-absorbing structure 330 forms a light-absorbing region. The first light-absorbing layer 430 and the second light-absorbing layer 440 are both provided with openings 430a. In the thickness direction of the wafer 300, that is, in the direction perpendicular to the plane where the wafer 300 is located, the openings 430a are opposite to the light-absorbing region, and the edges of the openings 430a are opposite to the edges of the light-absorbing region.

[0089] Optionally, the light-absorbing structure 330 can be a layered structure, and the light-absorbing area formed by the light-absorbing structure 330 is the laying area of ​​the light-absorbing structure 330. Each edge of the opening 430a is opposite to each edge of the light-absorbing area. Further optionally, the opening 430a can be a square opening, and the light-absorbing area forms a square area. Each edge of the square opening is opposite to each edge of the square area. That is, the shape of the opening 430a is the same as the shape of the light-absorbing area, and the area of ​​the opening 430a is equal to the area of ​​the light-absorbing area. Of course, the opening 430a and the light-absorbing area can also be other shapes.

[0090] The first light-absorbing layer 430 and the second light-absorbing layer 440 are provided with an opening 430a, which helps to narrow the range of the signal light, reduce the influence of reflected light from components other than the chip 300 on the chip 300, and ensure that the signal light can accurately enter the chip 300.

[0091] Of course, in other embodiments, in the thickness direction of the wafer 300, the light-absorbing region formed by the light-absorbing structure 330 is opposite to the opening 430a, and the area of ​​the opening 430a is slightly larger than the area of ​​the pixel array region.

[0092] In this embodiment, the structures of the first light-absorbing layer 430 and the second light-absorbing layer 440 are referenced. Figure 8 As shown, the first light-absorbing layer 430 and the second light-absorbing layer 440 can be a ring-shaped structure around the pixel array, with an opening 430a in the middle. The opening 430a can be a square opening. The transmittance of the first light-absorbing layer 430 and the second light-absorbing layer 440 for different wavelengths of light is referenced. Figure 9 The coordinate diagram shown indicates that the transmittance of the first light-absorbing layer 430 and the second light-absorbing layer 440 to different wavelengths of light is close to zero.

[0093] In an optional embodiment, the thickness of the first transmissive film layer 410 is less than the height of the light-absorbing structure 330 protruding from the wafer 300, and / or, the thickness of the second transmissive film layer 420 is less than the height of the light-absorbing structure 330 protruding from the wafer 300. Optionally, the thickness of the first transmissive film layer 410 is equal to the thickness of the second transmissive film layer 420, and both thicknesses are less than the height of the light-absorbing structure 330 protruding from the wafer 300. Moreover, the height of the light-absorbing structure 330 protruding from the wafer 300 is less than the thickness of the first light-absorbing layer 430.

[0094] Optionally, the first light-absorbing layer 430 and the second light-absorbing layer 440 have the same thickness, and the height of the light-absorbing structure 330 protruding from the wafer 300 is also less than the thickness of the second light-absorbing layer 440.

[0095] In other words, the first transmission film layer 410 and the second transmission film layer 420 have relatively small thicknesses, the light-absorbing structure 330 has a slightly larger height, and the first light-absorbing layer 430 and the second light-absorbing layer 440 have relatively large thicknesses. It should be noted that the "thickness" mentioned above refers to the dimension of each film layer in the direction perpendicular to the plane of the substrate 100.

[0096] In this embodiment, the first transmission film layer 410 and the second transmission film layer 420 are relatively thin, which helps to improve light transmittance and reduce reflectivity; the protrusion height of the light-absorbing structure 330 is relatively large, which helps the light-absorbing structure 330 absorb light reflected by the chip 300 at a large reflection angle, and avoids the light reflected by the first reflection reaching the encapsulation layer and undergoing secondary reflection due to insufficient protrusion height of the light-absorbing structure 330; the first light-absorbing layer 430 is relatively thick, which helps it absorb light reflected by other components other than the chip 300, resulting in better light absorption effect.

[0097] Of course, in other embodiments, the thicknesses of the first transmission film layer 410 and the second transmission film layer 420, the height of the light-absorbing structure 330 protruding from the wafer 300, and the thickness of the first light-absorbing layer 430 can be other relationships. Optionally, the thicknesses of the first transmission film layer 410 and the second transmission film layer 420 are equal, and their thicknesses are equal to the height of the light-absorbing structure 330 protruding from the wafer 300. At the same time, the height of the light-absorbing structure 330 protruding from the wafer 300 is equal to the thickness of the first light-absorbing layer 430.

[0098] In summary, the photoelectric sensor disclosed in this application has a first transmission film layer 410 and a second transmission film layer 420 respectively on the first and second surfaces of the encapsulation cover plate 400, which is the first innovation; the surface of the wafer 300 facing away from the circuit board 200 has a light-absorbing structure 330, which is the second innovation; the second transmission film layer 420 has a first light-absorbing layer 430 on the surface facing away from the encapsulation cover plate 400, and further, a second light-absorbing layer 440 can be provided on the surface of the first transmission film layer 410 facing away from the encapsulation cover plate 400, which is the third innovation.

[0099] The solutions of Innovation Point 1 and Innovation Point 2 complement and reinforce each other. Specifically, the solution of Innovation Point 1 is beneficial for significantly reducing reflectivity. For light that is perpendicularly reflected by the surface of the wafer 300 (i.e., the direction of reflection is parallel to the direction perpendicular to the wafer 300) and has a small reflection angle (i.e., the angle between the direction of reflection and the direction perpendicular to the wafer 300 is small), the double-sided coated packaging cover plate 400 has high transmittance, and the amount of light reflected by the wafer 300 and then reflected twice by the packaging cover plate 400 is reduced. The solution of Innovation Point 2 sets up a light-absorbing structure 330. The bottom of the light-absorbing structure 330 can absorb the primary reflected light, and the side of the light-absorbing structure 330 absorbs the light reflected by the wafer 300 with a large reflection angle, reducing the amount of light reflected by the wafer 300 and reaching the packaging cover plate 400, that is, reducing the amount of secondary reflected light.

[0100] Innovations one, two, and three complement and reinforce each other. Specifically, combining the solutions from Innovations one and two reduces the probability of various reflected light rays entering the chip 300, while Innovation three reduces the probability of light reflected from other components entering the chip 300, thus narrowing the signal light range. Therefore, the combination of Innovations one, two, and three effectively reduces the probability of various reflected light rays entering the chip 300, preventing optical crosstalk and improving detection performance.

[0101] Based on the photoelectric sensor disclosed in this application, embodiments of this application also disclose a detection device, which includes the aforementioned photoelectric sensor. Optionally, the detection device can be a TOF (Time of Flight) device, which is used to detect infrared light reflected back from a long distance. Of course, it can also be other types of detection devices.

[0102] In this embodiment, the optical sensor of the detection device reduces optical path crosstalk between pixels 311, avoids high anti-dilation phenomenon, and helps to improve the detection effect of the detection device.

[0103] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A photoelectric sensor, characterized in that, The assembly includes a substrate (100), a circuit board (200), a wafer (300), and a package cover plate (400). The surface of the substrate (100) is provided with a slot (110). The circuit board (200) and the wafer (300) are both disposed in the slot (110), and the wafer (300) is disposed on the side of the circuit board (200) facing away from the substrate (100). The substrate (100) is used for electrical connection to an external circuit, and the substrate (100) is electrically connected to the circuit board (200). The package cover plate (400) is disposed on the surface of the substrate (100) to close the slot (110), and the wafer (300) is opposite to the package cover plate (400). The encapsulation cover (400) has a first surface and a second surface facing away from each other, the second surface facing the wafer (300), the first surface and the second surface are respectively provided with a first transmission film layer (410) and a second transmission film layer (420), the first transmission film layer (410) and the second transmission film layer (420) are respectively used to allow light reflected by the wafer (300) to pass through; The wafer (300) has a light-absorbing structure (330) on its surface facing away from the circuit board (200). The light-absorbing structure (330) is used to absorb light reflected by the wafer (300), and the light-absorbing structure (330) protrudes from the surface of the wafer (300). The second transmissive film layer (420) has a first light-absorbing layer (430) on the surface facing away from the encapsulation cover plate (400). At least a portion of the first light-absorbing layer (430) is opposite to the circuit board (200). The first light-absorbing layer (430) is used to absorb light reflected by the circuit board (200).

2. The photoelectric sensor according to claim 1, characterized in that, Both the first transmission film layer (410) and the second transmission film layer (420) include a first organic film layer (411) and a second organic film layer (412) stacked together. The refractive index of the first organic film layer (411) is less than the refractive index of the second organic film layer (412), and the difference between the refractive indices of the second organic film layer (412) and the first organic film layer (411) is greater than 0.

1.

3. The photoelectric sensor according to claim 1 or 2, characterized in that, Both the first transmission film layer (410) and the second transmission film layer (420) include a plurality of sequentially stacked film layer groups (410a). Each film layer group (410a) includes a stacked first organic film layer (411) and a second organic film layer (412). The refractive index of the first organic film layer (411) is less than the refractive index of the second organic film layer (412), and the difference between the refractive indices of the second organic film layer (412) and the first organic film layer (411) is greater than 0.

1.

4. The photoelectric sensor according to any one of claims 1-3, characterized in that, The wafer (300) includes a pixel layer (310) having a plurality of pixels (311) arranged in an array. The array direction of the pixels (311) includes a first direction (A), which is parallel to the plane of the circuit board (200). The light-absorbing structure (330) is laid on the surface of the wafer (300) and has a plurality of light-transmitting holes (331). Each light-transmitting hole (331) is spaced apart along the first direction (A) and is opposite to the pixel (311).

5. The photoelectric sensor according to claim 4, characterized in that, In the first direction (A), the size of the light-transmitting opening (331) is greater than or equal to the size of the pixel (311).

6. The photoelectric sensor according to any one of claims 1-5, characterized in that, The wafer (300) includes a stacked pixel layer (310) and a metal layer (320). The metal layer (320) is located between the pixel layer (310) and the light-absorbing structure (330). The metal layer (320) has a plurality of metal structures (321) arranged in an array. The array direction of the metal structures (321) includes a first direction (A), which is parallel to the plane of the circuit board (200). The light-absorbing structure (330) is laid on the surface of the wafer (300). The light-absorbing structure (330) is provided with a plurality of light-transmitting holes (331). Each light-transmitting hole (331) is spaced apart along the first direction (A). The portion of the light-absorbing structure (330) located between two adjacent light-transmitting holes (331) is opposite to the metal structure (321).

7. The photoelectric sensor according to any one of claims 1-6, characterized in that, The first transmissive film layer (410) has a second light-absorbing layer (440) on the surface facing away from the encapsulation cover plate (400). In the thickness direction of the encapsulation cover plate (400), the second light-absorbing layer (440) is opposite to the first light-absorbing layer (430).

8. The photoelectric sensor according to claim 7, characterized in that, The light-absorbing structure (330) forms a light-absorbing region. Both the first light-absorbing layer (430) and the second light-absorbing layer (440) are provided with an opening (430a). In the thickness direction of the wafer (300), the opening (430a) is opposite to the light-absorbing region, and the edge of the opening (430a) is opposite to the edge of the light-absorbing region.

9. The photoelectric sensor according to any one of claims 1-8, characterized in that, The thickness of the first transmission film layer (410) is less than the height of the light-absorbing structure (330) protruding from the wafer (300), and / or the thickness of the second transmission film layer (420) is less than the height of the light-absorbing structure (330) protruding from the wafer (300); The height of the light-absorbing structure (330) protruding from the wafer (300) is less than the thickness of the first light-absorbing layer (430).

10. A detection device, characterized in that, Includes the photoelectric sensor described in any one of claims 1-9.

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