TWI791938B - Optical sensor, optical sensing system and manufacturing method of optical sensor - Google Patents

Abstract

An optical sensor includes a substrate having a plurality of sensor pixels. The optical sensor also includes a first light-shielding layer disposed on the substrate and having a plurality of first apertures corresponding to the sensor pixels. The optical sensor further includes a transparent medium layer disposed on the first light-shielding layer. The optical sensor includes a plurality of light-directing structures. Each of the light-directing structures includes a micro-prism and a micro-lens. The micro-prism is disposed in the transparent medium layer and corresponds to one of the first apertures. The micro-lens is disposed on the micro-prism.

Description

Optical sensor, optical sensing system and manufacturing method of optical sensor

Embodiments of the present disclosure relate to an optical sensor, an optical sensing system using the same and a manufacturing method thereof, and in particular to an angle controllable light (energy) directing structure (angle controllable light (energy) directing structure), an optical sensing system using the same, and a manufacturing method thereof.

Today's mobile electronic devices (such as mobile phones, tablet computers, notebook computers, etc.) are usually equipped with biometric identification systems, such as fingerprint recognition, face recognition, iris recognition, etc., to protect personal data security. Due to the popularization of mobile payment, biometric identification has become a standard function.

With the trend of mobile electronic devices moving toward larger display areas and narrower frames, a new optical imaging device has been developed to be disposed under the screen. This optical imaging device can partially transmit light through a screen (for example, an organic light emitting diode (OLED) screen) to capture an image of an object pressed on the screen (for example, a fingerprint image, which can be called It is fingerprint on display (FOD) under the screen.

However, the module of the aforementioned optical imaging device cannot be thinned due to its internal structure (for example, its thickness is at least 3 mm). The areas overlap, and the size of the battery must be reduced to make room for the optical imaging device, which may lead to a decrease in battery life of the mobile electronic device. In addition, with the development of technology, the power consumption of mobile electronic devices is increasing. Therefore, how to reduce the thickness of optical imaging devices without sacrificing battery space is the focus of various efforts.

Embodiments of the present disclosure provide an optical sensor with a light energy guiding structure (light guiding element) with a controllable angle, an optical sensing system using the same, and a manufacturing method thereof. In some embodiments, unnecessary stray light can be eliminated by the light guiding element, and the thickness of the optical sensor can be effectively reduced.

Embodiments of the disclosure include an optical sensor. The optical sensor includes a substrate with a plurality of sensing pixels. The optical sensor also includes a first light-shielding layer. The first light-shielding layer is disposed on the substrate and has a plurality of first through holes, and the first through holes correspond to the sensing pixels. The optical sensor further includes a transparent medium layer, and the transparent medium layer is disposed on the first light-shielding layer. The optical sensor includes a plurality of light guiding elements. Each of the light guiding elements includes a microlens and a microlens. The micro-plate is disposed in the transparent medium layer and corresponds to one of the first through holes. The microlens is disposed on the microplate.

Embodiments of the present disclosure include an optical sensing system. The optical sensing system includes a frame, and the frame has an accommodating groove. The optical sensing system also includes the aforementioned optical sensor, and the optical sensor is arranged in the accommodating groove. The optical sensing system further includes a display disposed on the optical sensor.

Embodiments of the disclosure include a method of manufacturing an optical sensor. The manufacturing method includes providing a substrate. The substrate has a plurality of sensing pixels. The manufacturing method also includes forming a first light-shielding layer on the substrate. The first light shielding layer has a plurality of first through holes, and the first through holes correspond to the sensing pixels. The manufacturing method further includes forming a transparent medium layer on the first light shielding layer. The manufacturing method includes forming a plurality of micro-panels in the transparent medium layer, and the micro-panes correspond to sensing pixels. The manufacturing method also includes forming a plurality of microlenses on the micropanel.

Different embodiments disclosed below may reuse the same reference symbols and/or signs. These repetitions are for simplicity and clarity and are not intended to limit a particular relationship between the different embodiments and/or structures discussed.

In some embodiments of the present disclosure, the light-shielding layer and the light-guiding element in the optical sensor can be used to enable the sensing pixels to receive light from a specific incident angle range, eliminate unnecessary stray light, and effectively Reduce the thickness of the optical sensor. Therefore, the optical sensor of the disclosed embodiment can be easily arranged between the battery and the display of mobile electronic devices such as mobile phones, and the light source of the display can be used to realize optical sensing under the screen.

FIG. 1 to FIG. 4 are a series of cross-sectional views illustrating a manufacturing method of the optical sensor 200 according to an embodiment of the present disclosure. It should be noted that, in order to clearly illustrate the features of the embodiments of the present disclosure, some components may be omitted in FIGS. 1 to 4 .

Referring to FIG. 1 , first, a substrate 201 is provided, and the substrate 201 may have a plurality of sensor pixels (sensor pixels) 203 . In some embodiments, the substrate 201 may be a semiconductor substrate, such as a silicon substrate. In addition, in some embodiments, the aforementioned semiconductor substrate may also include elemental semiconductors, such as germanium; compound semiconductors, such as gallium nitride and silicon carbide. ), gallium arsenide, gallium phosphide, indium phosphide, indium arsenide and/or indium antimonide; alloy semiconductor , such as: silicon germanium alloy (SiGe), gallium arsenic phosphorus alloy (GaAsP), aluminum arsenic indium alloy (AlInAs), aluminum gallium arsenic alloy (AlGaAs), indium gallium arsenic alloy (GaInAs), indium gallium arsenic alloy (GaInP) and / or Indium Gallium Arsenide Phosphorus (GaInAsP) or a combination of the aforementioned materials.

In some embodiments, the substrate 201 may also be a semiconductor on insulator substrate, and the aforementioned semiconductor on insulator substrate may include a base plate, a buried oxide layer disposed on the base plate, and a semiconductor on insulator disposed on the buried oxide layer. semiconductor layer. In addition, the conductivity type of the substrate 201 can be n-type or p-type.

In some embodiments, the substrate 201 may include various isolation components (not shown) for defining active regions and electrically isolating active region components in/on the substrate 201 . In some embodiments, the isolation features include shallow trench isolation (STI) features, local oxidation of silicon (LOCOS) features, other suitable isolation features, or combinations thereof.

In some embodiments, the substrate 201 may include various p-type doped regions and/or n-type doped regions (not shown) formed by ion implantation and/or diffusion processes. In some embodiments, the doped region can form elements such as transistors, photodiodes, and the like. In addition, the substrate 201 may also include various active components, passive components, and various conductive components (eg, conductive pads, wires, or vias).

In some embodiments, the sensing pixels 203 may be connected to a signal processing circuit (not shown). In some embodiments, the number of sensing pixels 203 depends on the size of the area of the optical sensing region (such as the area SR of the optical sensing region shown in FIG. 4 ). Each sensing pixel 203 may include one or more photodetectors. In some embodiments, the photodetector may include a photodiode. The photodiode may include a photoelectric material with a three-layer structure of a p-type semiconductor layer, an intrinsic layer, and an n-type semiconductor layer. The intrinsic layer can absorb light to generate excitons, and the excitons will be divided into electrons and holes at the junction of the p-type semiconductor layer and the n-type semiconductor layer, thereby generating current signals. In some embodiments, the light detector can be a CMOS image sensor, such as a front-side illumination (FSI) CMOS image sensor or a back-side illumination (BSI) CMOS image sensor. detector. In some other embodiments, the light detector may also include a charged coupling device (CCD) sensor, an active sensor, a passive sensor, other suitable sensors, or a combination of the foregoing. In some embodiments, the sensing pixel 203 can convert the received light signal into an electrical signal through a photodetector, and process the aforementioned electrical signal through a signal processing circuit.

In some embodiments, the sensing pixels 203 may be arranged in an array to form a sensing pixel array, but the embodiments of the present disclosure are not limited thereto. The cross-sectional views shown in the drawings of the present disclosure only show one column of the array of sensing pixels 203 , which is located below the upper surface of the substrate 201 . It should be noted that the number and arrangement of the sensing pixels 203 shown in the drawings of all embodiments are only exemplary, and the embodiments of the present disclosure are not limited thereto. The sensing pixels 203 can be arranged in an array with any number of rows or columns or in other arrangements.

Referring to FIG. 2 , a dielectric layer 202 is formed on a substrate 201 . As shown in FIG. 2 , the dielectric layer 202 may cover the sensing pixels 203 . In some embodiments, the material of the dielectric layer 202 may include transparent photoresist, polyimide, epoxy resin, other suitable materials or a combination of the aforementioned materials, but the embodiments of the present disclosure are not limited thereto. In some embodiments, the dielectric layer 202 may include a photo-curable material, a thermal-curable material, or a combination thereof. For example, a spin-on coating process can be used to coat the dielectric layer 202 on the substrate 201 and the sensing pixels 203 , but the disclosed embodiments are not limited thereto.

Next, a first light shielding layer 204 is formed on the dielectric layer 202 . That is, the dielectric layer 202 is formed between the substrate 201 and the first light-shielding layer 204 , but the embodiments of the present disclosure are not limited thereto. In some other embodiments, the first light-shielding layer 204 may also be directly formed on the substrate 201 without the dielectric layer 202 . As shown in FIG. 2 , the first light shielding layer 204 may have a plurality of first apertures 204A, and the first apertures 204A may correspond to the sensing pixels 203 . The first light-shielding layer 204 may include a light-shielding material whose transmittance for light below the wavelength range of 1200 nm is less than 1%, but the embodiments of the present disclosure are not limited thereto.

In some embodiments, the first light-shielding layer 204 may include metal materials such as tungsten (W), chromium (Cr), aluminum (Al) or titanium (Ti), but the embodiments of the present disclosure are not limited thereto. In this embodiment, for example, chemical vapor deposition (chemical vapor deposition, CVD), physical vapor deposition (physical vapor deposition, PVD) (for example: vacuum evaporation (vacuum evaporation), sputtering (sputtering), pulse The first light-shielding layer 204 is formed on the substrate 201 by laser deposition (pulsed laser deposition, PLD), atomic layer deposition (atomic layer deposition, ALD), other suitable deposition or a combination thereof. In some embodiments, the first light-shielding layer 204 may include polymer materials with light-shielding properties, such as epoxy resin, polyimide, and the like. In this embodiment, the first light-shielding layer 204 can be formed on the substrate 201 by, for example, spin-coating, chemical vapor deposition (CVD), other suitable methods, or a combination thereof. The thickness of the first light-shielding layer 204 formed by the aforementioned method is in the range of about 0.3 μm to about 5 μm, for example, 2 μm. In some embodiments, the thickness of the first light shielding layer 204 depends on the light shielding ability of the material of the first light shielding layer 204 . For example, the light-shielding ability of the light-shielding material included in the first light-shielding layer 204 may be negatively correlated with its thickness.

Next, a patterning process may be performed on the first light shielding layer 204 to form a plurality of first through holes 204A having a first aperture A1. The aforementioned patterning process may include a photolithography process and an etching process. The photolithography process may include photoresist coating (e.g. spin coating), soft bake, pattern exposure, post exposure bake, photoresist development, cleaning and drying (e.g. hard bake), other suitable processes or the foregoing The combination. The etching process may include a wet etching process, a dry etching process (such as reactive ion etching (RIE) , plasma etching, ion milling), other suitable processes, or a combination thereof. The first aperture A1 of the first through hole 204A formed by the aforementioned method is in the range of about 0.3 μm to about 50 μm, for example, about 4 μm to about 5 μm, but the embodiment of the present disclosure is not limited thereto.

It should be noted that the first through holes 204A and the sensing pixels 203 shown in FIG. 2 are arranged in a one-to-one correspondence. However, in other embodiments of the present disclosure, the first through holes 204A and the sensing pixels 203 may also be arranged correspondingly in a one-to-many or many-to-one manner. For example, more than two sensing pixels 203 may be exposed from one first through hole 204A, or one sensing pixel 203 may be exposed from more than two first through holes 204A. FIG. 2 only shows an exemplary arrangement, and the embodiments of the present disclosure are not limited thereto. According to some embodiments of the present disclosure, by controlling the first aperture A1 of the patterned first light-shielding layer 204 , the field of view (FOV) range of the incident light can be adjusted.

Referring to FIG. 3 , a protective layer 205 and an optical filter layer 206 are sequentially formed on the first light shielding layer 204 . In some embodiments, the protective layer 205 can be used as a protective layer of the integrated circuit, and the material of the protective layer 205 can include silicon oxide, silicon nitride, other suitable materials or a combination of the foregoing, but the embodiments of the present disclosure do not limit. In some embodiments, for example, if the material of the first light-shielding layer 204 includes a polymer material with light-shielding properties, the protective layer 205 may not be formed. In some embodiments, the optical filter layer 206 may be an infrared filter layer (infrared cut filter, ICF). Visible light has high transmittance to the infrared filter layer, while infrared light has high reflectivity to the infrared filter layer, which can reduce infrared interference from sunlight, for example.

Referring to FIG. 4 , a transparent medium layer 207 is formed on the optical filter layer 206 . That is, the optical filter layer 206 can be formed between the first light shielding layer 204 and the transparent medium layer 207 , but the disclosure is not limited thereto. In some other embodiments, the transparent medium layer 207 may also be directly formed on the first light shielding layer 204 without the optical filter layer 206 or the optical filter layer 206 is provided in other forms. For example, the optical filter layer 206 can be disposed on the transparent medium layer 207 in the form of an independent optical filter plate (similar to the structure shown in FIG. 8 ).

In some embodiments, the transparent medium layer 207 may include a UV-curable material, a thermosetting material, or a combination thereof. For example, the transparent medium layer 207 may include, for example, polymethyl methacrylate (poly(methyl methacrylate), PMMA), polyethylene terephthalate (polyethylene terephthalate, PET), polyethylene naphthalate (polyethylene naphthalate, PEN) polycarbonate (polycarbonate, PC), perfluorocyclobutyl (perfluorocyclobutyl, PFCB) polymer, polyimide (polyimide, PI), acrylic resin, epoxy resin (epoxy resins), Polypropylene (polypropylene, PP), polyethylene (polyethylene, PE), polystyrene (polystyrene, PS), polyvinyl chloride (polyvinyl chloride, PVC), other appropriate materials or combinations of the foregoing, but the disclosed embodiments are not This is the limit.

In some embodiments, spin-coating, dry film (dry film) process, casting mold (casting), bar coating (bar coating), blade coating (blade coating), roller coating ( Roller coating), wire bar coating (wire bar coating), dip coating (dip coating), chemical vapor deposition (CVD) or other suitable methods, the transparent medium layer 207 is formed on the first light-shielding layer 204, However, the embodiments of the present disclosure are not limited thereto. In some embodiments, the thickness of the transparent dielectric layer 207 formed through the aforementioned process is in the range of about 1 μm to about 100 μm, for example, 10 μm to 50 μm. According to some embodiments of the present disclosure, the transparent dielectric layer 207 formed through the aforementioned process can have high yield and good quality. In addition, controlling the thickness of the transparent medium layer 207 can increase or decrease the deviation distance of the light after passing through the subsequently formed light guiding element ( 210 ), thereby improving the accuracy of the incident light angle that the array of sensing pixels 203 can receive.

As shown in Figure 4, a plurality of microlenses 212 are formed in the transparent medium layer 207 and a plurality of microlenses 211 are formed on the transparent medium layer 207, for example, microlenses 211 can be formed on the microlenses 212 . In some embodiments, the microlenses 211 and the microlenses 212 may correspond to the sensing pixels 203 . Specifically, each of the micro-lenses 212 corresponds to one of the plurality of first through holes 204A of the first light-shielding layer 204, and the micro-lenses 212 can be connected (directly contacted) to the micro-lenses 211, but the present disclosure implements Examples are not limited to this. In some other embodiments, the microlens 211 and the microplate 212 can also be separated from each other, that is, the microlens 211 and the microplate 212 can be separated by a distance.

In some embodiments, the transparent medium layer 207 , the microlenses 211 and the microplates 212 can be made of homogeneous materials or heterogeneous materials, and an appropriate combination of materials can be selected according to actual requirements. For example, a gray-scale photomask can be used to fill the transparent medium layer 207 with suitable materials after performing processes such as exposure, development, etching, etc., to form the micro-mass 212 .

In some embodiments, a thick film of polymer material can be formed on the transparent medium layer 207 through high-temperature reflow, and form a hemispherical structure through its cohesive force to form the microlens 211, but the disclosed embodiment is not This is the limit. In some embodiments, the transparent medium layer 207 , the microlenses 211 and the microplates 212 may also include dielectric materials, such as glass, which can further improve the light transmittance, but the embodiments of the present disclosure are not limited thereto. In these embodiments, the effect of surface tension can be used to form hemispherical microlenses 211 during the drying (such as hard baking) step of the photolithography process, and the required microlenses can be adjusted by controlling the heating temperature. 211 radius of curvature. In some embodiments, the thickness of the microlens 211 ranges from about 1 µm to about 50 µm. It should be noted that the profile of the microlens 211 is not limited to a hemispherical shape, and the embodiment of the present disclosure can also adjust the profile of the microlens 211 according to the required incident light angle, for example, it can be aspheric.

In the embodiment of the present disclosure, the microlens 211 and the microplate 212 can be regarded as a light guiding element 210, and the light guiding element 210 can be arranged in an array, but the embodiment of the present disclosure is not limited thereto. That is to say, the light guiding element 210 and the sensing pixels 203 can be arranged correspondingly in a one-to-one, one-to-many or many-to-one manner, but the embodiment of the present disclosure is not limited thereto. After the light guiding element 210 is formed, the optical sensor 200 of the disclosed embodiment is completed. In some other embodiments, the optical filter layer 206 of the optical sensor 200 can be in the form of an independent optical filter plate, disposed on the light guide element 210 (similar to the structure shown in FIG. 8 ), but this The disclosed embodiments are not limited thereto.

As shown in FIG. 4 , in some embodiments of the present disclosure, the micro-panel 212 may have a top surface 212T and a bottom surface 212B, and the top surface 212T and the bottom surface 212B may form an included angle θ. In some embodiments, the angle θ formed by the top surface 212T and the bottom surface 212B is variable, and can be adjusted according to the position of the micro-plate 212 . In addition, as shown in FIG. 4 , among the light guide elements 212 , the closer to the center of the optical sensor 200 is the micro-pan 212 , the smaller the angle θ formed by the top surface 212T and the bottom surface 212B is, but the implementation of the present disclosure Examples are not limited to this.

Since each light guide element is different with its installed position, for the convenience of explanation, 210_N will represent each light guide element, TA_N will represent the light energy transmission axis of each light guide element, and ANG_N will represent the receiving axis of each light guide element. Light azimuth, L_N represents the parallel target incident light of each light guide element, LX_N represents the parallel non-target incident light of each light guide element, and ANGX_N represents the parallel non-target incident light of each light guide element relative to its The azimuth angle of the light transmission axis TA_N. Wherein, "_N" is the number of each light energy guiding element.

FIG. 5 is a partially enlarged view of the optical sensor 200 shown in FIG. 4 . Referring to FIG. 5 , the light guiding element 210_N may include a microlens 211_N and a microlens 212_N, the microlens 211_N may be used for converging light, and the microlens 212_N may be used for deflecting light. There is an inclination angle ANG_212_N between the bottom surface 212_NB (or called the inclined surface) of the micro-panel 212_N and the plane perpendicular to the normal NORM of the optical sensor 200 (or formed by the top surface 212_NT and the bottom surface 212_NB of the micro-panel 212_N angle), which can make the incident light converged by the microlens 211_N be deflected when incident on the bottom surface 212_NB.

As shown in FIG. 5, the light guiding element 210_N may have a light energy transmission axis TA_N, and a light receiving azimuth ANG_N corresponding to the light energy transmission axis TA_N is the normal line NORM of the optical sensor 200 and the light energy transmission axis TA_N. The azimuth angle at the junction of the microlenses 211_N towards the target. If the incident light is transmitted along the light energy transmission axis TA_N, the light guiding element 210_N can guide the incident light to be incident to the corresponding sensing pixel 203 at last. Therefore, the aforesaid multiple parallel target incident lights are the incident light L_N incident on the microlens 211_N parallel to each light energy transmission axis TA_N; and the aforementioned multiple parallel non-target incident lights are not parallel to each light energy transmission axis TA_N is incident to the incident light LX_N of the microlens 211_N. In addition, the non-target incident light LX_N has an azimuth angle of deviation ANGX_N from each light energy transmission axis TA_N.

In the embodiment shown in FIG. 5 , the target incident light L_N travels along the light energy transmission axis TA_N (that is, parallel to the light energy transmission axis TA_N), but the embodiments of the present disclosure are not limited thereto. In some embodiments, the angle between the target incident light L_N and the light energy transmission axis TA_N that can be received by the sensing pixels 203 through the light guiding element 210_N can range from -3.5 degrees to 3.5 degrees, -4 degrees to Between +4 degrees or between -5 degrees and +5 degrees; the deviation azimuth angle ANGX_N can be between 3.5 degrees and 90 degrees, between 4 degrees and 90 degrees, or between 5 degrees and 90 degrees. That is, the non-target incident light LX_N having an angle greater than 3.5 degrees (or greater than 4 degrees, or greater than 5 degrees) with the light energy transmission axis TA_N cannot enter the sensing pixel 203 .

In simple terms, the light guide element 210_N of the optical sensor 200 can direct the target incident light L_N entering the optical sensor 200 from the outside into the sensing pixel 203 through the transparent medium layer 207 , and direct the incident light L_N entering the optical sensor 203 from the outside into the sensor pixel 203 . The non-target incident light LX_N of the detector 200 is incident on the outside of the sensing pixel 203, thereby sensing an image of the target object. For example, the target incident light L_N can enter the sensing pixel 203 through the first through hole 204A, and the non-target incident light LX_N will not pass through the first through hole 204A (such as entering the first light shielding layer 204 minus the first pass other areas of hole 204A).

The optical sensor 200 of the disclosed embodiment can pass through the relative positions of the lens 211 of the light guide element 210, the micro-plate 212 and the first aperture 204A (and the sensing pixel 203) (for example, aligning with the light energy transmission axis). Only by controlling the angle of the specific incident light (parallel to the transmission axis of light energy) can the sensing pixels 203 be sensed, so the quality of the optical sensor 200 can be effectively improved. Compared with conventional optical sensors, the optical sensors of the disclosed embodiments can effectively reduce the manufacturing cost and simplify the manufacturing process.

Since each light guiding element is different with its position, the target incident light and non-target incident light of each light guiding element may be different. For example, as shown in FIG. 4 , the light guiding element 210_1 and the light guiding element 210_K have different light energy transmission axis TA_1 and light energy transmission axis TA_K respectively. Although the target incident light L_1 of the light guiding element 210_1 and the target incident light L_K of the light guiding element 210_K come from different light-receiving azimuth angles, they are directed to the corresponding sensing pixels through the light guiding element 210_1 and the light guiding element 210_K respectively. 203. The non-target incident light LX_1 of the light guiding element 210_1 and the non-target incident light LX_K of the light guiding element 210_K have deviation azimuth angle ANGX_1 and deviation azimuth angle ANGX_K respectively. into the corresponding sensing pixel 203 .

As shown in FIG. 4, in the array of sensing pixels 203, the light energy transmission axes of the light guide element 210 corresponding to the center to the periphery (for example, TA_1, TA_K, TA_I and TA_J in FIG. 4 ), the light-receiving azimuth angle of each light-guiding element can be shifted from 0 degrees to a predetermined oblique angle (for example, 35 degrees) through the micro-piercing of each light-guiding element. For example, the incident oblique angle can be changed gradually (continuous change of the light receiving azimuth of the light energy transmission axis). As shown in FIG. 4, the optical sensor 200 can sense a larger area CR of the object under test (such as a fingerprint contact area) with a smaller area SR of the array of sensing pixels 203, thereby increasing the accuracy of sensing degree and effectively reduce the cost, but the embodiments of the present disclosure are not limited thereto.

FIG. 6 shows a cross-sectional view of an optical sensor 200-1 according to another embodiment of the disclosure. The difference from the optical sensor 200 shown in FIG. 4 is that the optical sensor 200 - 1 can sense a smaller area CR of the object under test with a larger area SR of the array of sensing pixels 203 . The position of the light-guiding element 210 (miniature 212 ) can be adjusted according to actual needs, so as to achieve different light-receiving effects.

FIG. 7 shows a cross-sectional view of an optical sensing system 600 according to an embodiment of the present disclosure. In some embodiments, the optical sensing system 600 may be an electronic device such as a mobile phone or a tablet computer, which may include a frame 400, an optical sensor 200 and a display 300, but the embodiments of the present disclosure are not limited thereto. .

Referring to FIG. 7 , in some embodiments, the optical sensing system 600 may further include a base 610 , which may be, for example, a part of the housing of an electronic device. The battery 500 can be disposed on the base 610 . The frame 400 can be disposed above the battery 500 and has an accommodating slot 410 , but the embodiment of the present disclosure is not limited thereto. In some other embodiments, the frame 400 may not have the accommodating slot 410 , depending on actual needs.

The optical sensor 200 can be disposed on the frame 400 . As shown in FIG. 7 , the optical sensor 200 can be disposed in the accommodation groove 410 of the frame 400 and on a bottom 420 of the accommodation groove 410 for sensing an image of an object F. Referring to FIG. The structure of the optical sensor 200 can be as described above, and will not be repeated here. The display 300 can be disposed above the optical sensor 200 for displaying information. The target F can be located on or above the display 300 . In some embodiments, the optical sensor 200 can sense the image of the target F through the display 300 , and the battery 500 can supply power to the optical sensor 200 and the display 300 to maintain the operation of the electronic device.

In some embodiments, a distance d between the bottom 420 of the receiving groove 410 and the display 300 may be between 0.1 mm to 0.5 mm, between 0.2 to 0.5 mm, between 0.3 to 0.5 mm, or between 0.4 to 0.5 mm. mm, but the embodiments of the present disclosure are not limited thereto. Here, the distance d can be defined as the shortest distance between the bottom 420 of the receiving groove 410 and the display 300 in a direction ND parallel to the normal direction of the frame 400 .

In some embodiments, applying the optical sensor 200 to the optical sensing system 600 can make the overall height or thickness of the module less than 0.5 mm to meet the thinning requirement, so the configuration of the battery 500 can be not affected. Next, the optical sensor 200 is disposed between the screen (such as the display 300 ) of the electronic device and the battery. It should be noted that the optical sensor and the optical sensing system applied thereto of the disclosed embodiments are not limited to fingerprint recognition, and can also be applied to detection of veins, blood flow velocity and blood oxygen, for example. Alternatively, the optical sensor of the disclosed embodiments and the optical sensing system applied thereto can be used for non-contact image capture (such as an under-screen camera, etc.) to capture, for example, human faces (for example, for face recognition) or eyes (for example, for iris recognition) or perform general camera functions.

In some embodiments, the display 300 may include an organic light-emitting diode (OLED) display, a micro LED display, or other various displays. In some embodiments, the display 300 in the optical sensing system 600 can be used as a light source, and the light emitted by it will illuminate the target F that is in contact with or not in contact with the upper surface of the display 300, and the target F will reflect the light to The optical sensor 200 disposed under the display 300 is used to sense and identify contour features of the target F (eg, fingerprint features of a finger). It should be noted that the optical sensor 200 in the optical sensing system 600 can also be used with light sources of other forms and wavelengths (for example, infrared light sources), but the embodiments of the present disclosure are not limited thereto. In some embodiments, the optical sensor can also perform passive image capture, that is, it does not need to project a light source to the target (object) F to be measured.

As shown in FIG. 7 , in some embodiments, the optical sensor 200 can be configured to be included in an optical sensor module 1300 . For example, the optical sensor module 1300 may include a carrier board 1301, a flexible circuit board 1302, and a bonding wire 1303 electrically connecting the optical sensor 200 to the flexible circuit board 1302. The bonding wire 1303 It can be encapsulated and protected by the sealant layer 1306 . The top surface of the sealant layer 1306 can be flush with the top surface of the transparent medium layer 207 , but the embodiment of the present disclosure is not limited thereto. In some embodiments, the material of the bonding wire 1303 may include aluminum (Al), copper (Cu), gold (Au), the aforementioned alloys, other suitable conductive materials, or a combination of the aforementioned, but the embodiments of the present disclosure do not limit.

FIG. 8 shows a cross-sectional view of an optical sensing system 600' according to another embodiment of the present disclosure. The difference from the optical sensing system 600 shown in FIG. 7 is that the optical sensing system 600' replaces the optical filtering layer 206 with an optical filtering plate 900. For example, the optical filter board 900 can be an independent optical filter board, and the optical filter board 900 can be supported by a dam structure or frame 1305 disposed on the flexible circuit board 1302 . That is, the optical filter plate 900 can be disposed above the microlens 210 through the optical sensor module 1300 . As shown in FIG. 8 , in this embodiment, the transparent medium layer 207 is disposed on the protection layer 250 . The optical filter plate 900 is disposed above the light guiding element 210 and filters the wavelength of the incident light. The remaining parts that are the same as those in Fig. 7 will not be repeated here.

It should be noted that although the optical sensor module 1300 and the optical filter plate 900 shown in FIG. 8 are disposed on the frame 400 and separated from the display 300 , the embodiments of the present disclosure are not limited thereto. In some other embodiments, the optical sensor module 1300 and the optical filter plate 900 can also be adhered to the lower surface 300B of the display 300 .

FIG. 9 shows a cross-sectional view of an optical sensor 200-2 according to an embodiment of the present disclosure. The difference from the optical sensor 200 shown in FIG. 4 is that the optical sensor 200-2 shown in FIG. 9 further includes a lens shading layer 213 (which can be regarded as a second shading layer), and the lens shading layer 213 is disposed on the first light shielding layer 204 . In more detail, the lens shielding layer 213 can be disposed on the transparent medium layer 207 and located in a plurality of gaps G between the microlenses 211 . The lens shielding layer 213 may, for example, expose (at least part of) the curved surface area of the microlens 211 . In other words, the lens shielding layer 213 may have a plurality of through holes (corresponding to the gap G), and the microlenses 211 of the light guiding element 210 may be disposed in these through holes, but the embodiment of the disclosure is not limited thereto.

In some cases, there may be light (such as the stray light L1 shown in Figure 9) incident from the blank area between the microlenses 211 (such as the area indicated by the gap G), and incident to the sensor through the first through hole 204A. The pixel 203 is detected, thus causing interference and degrading the image quality. In the optical sensor 200 - 2 shown in FIG. 9 , the lens shielding layer 213 can block the aforementioned stray light L1 from entering the sensing pixels 203 , effectively preventing the interference of stray light and improving image quality.

FIG. 10 is a cross-sectional view of an optical sensor 200-3 according to another embodiment of the disclosure. The difference from the optical sensor 200 shown in FIG. 4 is that the optical sensor 200-3 shown in FIG. 10 further includes a second light-shielding layer 208 and a transparent medium layer 209. The second light-shielding layer 208 and the transparent medium layer 209 are both disposed on the first light shielding layer 204 . In more detail, the second light-shielding layer 208 is located on the transparent medium layer 207, the transparent medium layer 209 is located on the second light-shielding layer 208, and the light guiding element 210 is located on the transparent medium layer 209 (for example, the microlens 211 is disposed on the transparent medium layer 209). layer 209, and the micro-plate 212 is disposed in the transparent medium layer 209).

Referring to FIG. 10 , the second light shielding layer 208 may have a plurality of second through holes 208A, the second through holes 208A may correspond to the first through holes 204A, and each second through hole 208A may have a second aperture A2. In some embodiments, the second diameter A2 of the second through hole 208A is larger than the first diameter A1 of the first through hole 204 , but the embodiments of the present disclosure are not limited thereto. In some embodiments, the thickness of the second light shielding layer 208 is different from the thickness of the first light shielding layer 204 . For example, the thickness of the second light-shielding layer 208 may be greater than that of the first light-shielding layer 204 , but the embodiments of the present disclosure are not limited thereto. As shown in FIG. 10 , in some embodiments, the microplate 212 of the light guiding element 210 is disposed in the second through hole 208A. For example, the micro-plate 212 can be completely or only partially disposed in the second through hole 208A, but the embodiment of the present disclosure is not limited thereto.

In some cases, cross talk may occur between adjacent light guiding elements 210 (not limited to the nearest adjacent light guiding elements 210). That is to say, the stray light (for example, the stray light L2 shown in FIG. 10 ) of the adjacent light guide elements of a target light guide element may be coupled into the target incident light of the target light guide element, and are incident together through the first through hole 204A. to the sensing pixel 203 corresponding to the target light-guiding element, thus causing interference and degrading the image quality. In the optical sensor 200-3 shown in FIG. 10, the second light-shielding layer 208 can shield the stray light L2 that enters these adjacent light-guiding elements from the outside and enters the sensing pixels 203, effectively preventing stray light interference, and improve image quality.

In some embodiments, the optical sensor 200-2 shown in FIG. 9 or the optical sensor 200-3 shown in FIG. 10 can replace the optical sensor 200 shown in FIG. In the optical sensing system 600 shown in the figure (or the optical sensing system 600' shown in FIG. 8 ), details are not repeated here.

To sum up, the embodiments of the present disclosure, through the light guide element, can achieve the sensing pixels to receive the incident light from a specific range of viewing angles without an additional light-shielding layer, and can reduce the optical sensing device thickness.

The components of several embodiments are summarized above, so that those skilled in the art of the present disclosure can better understand the viewpoints of the embodiments of the present disclosure. Those with ordinary knowledge in the technical field of the present disclosure should understand that they can design or modify other processes and structures based on the embodiments of the present disclosure to achieve the same purpose and/or advantages as the embodiments described herein. Those with ordinary knowledge in the technical field to which this disclosure belongs should also understand that such equivalent structures do not depart from the spirit and scope of this disclosure, and they can make various changes without departing from the spirit and scope of this disclosure. Various changes, substitutions and substitutions. Therefore, the scope of protection of this disclosure should be defined by the scope of the appended patent application. In addition, although the present disclosure has been disclosed above with several preferred embodiments, it is not intended to limit the present disclosure.

Reference throughout this specification to features, advantages, or similar language does not imply that all features and advantages that may be realized with the present disclosure should or can be achieved in any single embodiment of the disclosure. Conversely, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, discussions of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment.

Furthermore, the described features, advantages, and characteristics of the present disclosure may be combined in any suitable manner in one or more embodiments. Based on the description herein, one skilled in the relevant art will recognize that the present disclosure can be practiced without one or more of the specific features or advantages of a particular embodiment. In other cases, additional features and advantages may be recognized in certain embodiments, which may not be present in all embodiments of the present disclosure.

200, 200-1, 200-2, 200-3: optical sensor 201: Substrate 202: dielectric layer 203: Sensing pixels 204: the first shading layer 204A: first through hole 205: protective layer 206: Optical filter layer 207: transparent medium layer 208: the second shading layer 208A: Second through hole 209: transparent medium layer 210, 210_1, 210_K, 210_N: light guide elements 211, 211_1, 211_K, 211_N: micro lens 212,212_1,212_K,212_N: Weeds 212T, 212_NT: top surface 212B, 212_NB: bottom surface 213: Lens shading layer 300: display 300B: lower surface 400: frame 410: storage tank 420: bottom 500: battery 600,600': Optical sensing system 610: base 900: Optical filter board 1300 Optical Sensor Module 1301: Loading board 1302: flexible circuit board 1303: welding wire 1305: frame 1306: sealing layer A1: The first aperture A2: Second aperture ANG_1, ANG_N: receiving azimuth ANG_212_N: Tilt angle ANGX_1, ANGX_K, ANGX_N: deviation from azimuth CR: the area of the object to be tested d: distance F: Target G: Gap L1: stray light L2: stray light L_1, L_K, L_N: target incident light LX_1, LX_K, LX_N: Non-target incident light NORM: the normal of the optical sensor SR: Area of the array of sensing pixels TA_1, TA_I, TA_J, TA_K, TA_N: light energy transmission axis θ: included angle

Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that the various features are not drawn to scale and are used for illustrative purposes only. In fact, the dimensions of elements may be enlarged or reduced to clearly show the technical features of the embodiments of the present disclosure. FIG. 1 to FIG. 4 are a series of cross-sectional views illustrating a manufacturing method of an optical sensor according to an embodiment of the present disclosure. FIG. 5 is a partially enlarged view of the optical sensor shown in FIG. 4 . FIG. 6 shows a cross-sectional view of an optical sensor according to another embodiment of the disclosure. FIG. 7 illustrates a cross-sectional view of an optical sensing system according to an embodiment of the present disclosure. FIG. 8 is a cross-sectional view of an optical sensing system according to another embodiment of the disclosure. FIG. 9 shows a cross-sectional view of an optical sensor according to an embodiment of the present disclosure. FIG. 10 shows a cross-sectional view of an optical sensor according to another embodiment of the disclosure.

200: Optical sensor

201: Substrate

202: dielectric layer

203: Sensing pixels

204: the first shading layer

204A: first through hole

205: protective layer

206: Optical filter layer

207: transparent medium layer

210, 210_1, 210_K: light guiding element

211, 211_1, 211_K: microlens

212, 212_1, 212_K: Weeds

212T: top surface

212B: bottom surface

A1: The first aperture

ANGX_1, ANGX_K: deviation azimuth angle

CR: the area of the object to be measured

L_1, L_K: target incident light

LX_1, LX_K: Non-target incident light

SR: Area of the array of sensing pixels

TA_1, TA_I, TA_J, TA_K: optical energy transmission axis

θ: included angle

Claims (21)

An optical sensor, comprising: a substrate having a plurality of sensing pixels; a first light-shielding layer disposed on the substrate and having a plurality of first through holes corresponding to the first through holes Sensing pixels; a transparent medium layer, disposed on the first light-shielding layer; and a plurality of light-guiding elements, wherein each of the light-guiding elements includes: a microplate, disposed in the transparent medium layer and corresponding to one of the first through holes; and a microlens disposed on the micro-membrane. The optical sensor as described in item 1 of the scope of application, wherein the microplate is connected to the microlens. The optical sensor as described in item 1 of the scope of the patent application, wherein the micro-panel has a top surface and a bottom surface, and the top surface and the bottom surface form an included angle. The optical sensor as described in claim 3, wherein the included angle is variable. The optical sensor as described in item 4 of the scope of the patent application, wherein among the light guide elements, the angle between the micro-pigs nearer to the center of the optical sensor is smaller. The optical sensor described in item 1 of the scope of the patent application further includes: a dielectric layer disposed between the substrate and the first light-shielding layer and covering the sensing pixels. The optical sensor as described in claim 1 of the patent application further includes: an optical filter layer disposed between the first light-shielding layer and the transparent medium layer. The optical sensor described in Item 1 of the scope of the patent application further includes: An optical filter board is arranged on the light guide elements. The optical sensor described in item 1 of the scope of the patent application further includes: at least one second light-shielding layer, disposed on the first light-shielding layer, and has a plurality of second through holes. The optical sensor as described in claim 9, wherein the diameter of each of the second through holes is larger than the diameter of each of the first through holes. The optical sensor as described in claim 9, wherein the thickness of the second light-shielding layer is different from that of the first light-shielding layer. The optical sensor as described in claim 9 of the patent application, wherein the second light-shielding layer is disposed on the transparent medium layer, and the microlenses of the light guiding elements are disposed in the second through holes. The optical sensor as described in claim 9 of the patent application, wherein the second light-shielding layer is disposed in the transparent medium layer, and the second through holes correspond to the first through holes. The optical sensor as described in claim 13 of the patent application, wherein some of the microns in the light guiding elements are located in the second through holes. An optical sensing system, comprising: a frame with an accommodating groove; the optical sensor as described in any one of items 1 to 14 of the scope of the patent application is set in the accommodating groove; and a display, set on the optical sensor. The optical sensing system as described in claim 15 of the patent application, wherein the distance between the bottom of the accommodating groove and the display is between 0.1mm and 0.5mm. A method of manufacturing an optical sensor, comprising: A substrate is provided, wherein the substrate has a plurality of sensing pixels; a first light-shielding layer is formed on the substrate, wherein the first light-shielding layer has a plurality of first through holes, and the first through holes correspond to the some sensing pixels; forming a transparent medium layer on the first light-shielding layer; forming a plurality of micro-ribs in the transparent medium layer, wherein the micro-ribs correspond to the sensing pixels; and on the micro-ribs A plurality of microlenses are formed on the mirror. The method for manufacturing an optical sensor as described in claim 17 of the scope of the patent application further includes: forming a dielectric layer between the substrate and the first light-shielding layer, wherein the dielectric layer covers the sensing pixels . The manufacturing method of the optical sensor as described in claim 17 of the patent application further includes: forming an optical filter layer between the first light-shielding layer and the transparent medium layer. The manufacturing method of the optical sensor as described in item 17 of the scope of the patent application further includes: forming an optical filter plate on the micro-lenses. The method for manufacturing an optical sensor as described in claim 17 of the scope of the patent application further includes: forming at least one second light-shielding layer on the first light-shielding layer, wherein the second light-shielding layer has a plurality of second through holes .

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