Electronic device with compact optical module

Abstract

The invention relates to an electronic device with a compact optical module. Specifically, an ambient light sensor module may be formed using a wafer level process in which a filter and a diffuser are stacked on a silicon substrate or a combined substrate comprising a plurality of photosensors. The stack may be cut, filled with opaque material, and re-cut to form a plurality of ambient light sensor modules. The resulting module may include a silicon substrate having a photosensor and a through-silicon via, an optical filter on the silicon substrate, and a diffuser coupled to the optical filter. There may be an air gap between a portion of the diffuser and the photosensor. The air gap may be formed by a recess in the diffuser or by a spacer between the filter and the diffuser. Alternatively, the diffuser may be applied as a coating on the filter. By forming an ambient light sensor module at a wafer level, the module may have a smaller footprint and / or volume.

Description

[0001] This application claims priority to U.S. Patent Application No. 18 / 767,001, filed on July 9, 2024, which claims the benefit of U.S. Provisional Patent Application No. 63 / 520,848, filed on August 21, 2023, which applications are hereby incorporated by reference in their entirety. Technical Field

[0002] The present invention relates generally to electronic devices, and more particularly to electronic devices having light sensors. Background Art

[0003] Electronic devices such as laptop computers, cell phones, and other equipment are sometimes provided with light sensors. For example, an ambient light sensor may be incorporated into a device to provide the device with information about current lighting conditions. The ambient light readings may be used to control the device. If, for example, bright daylight conditions are detected, the electronic device may increase the display brightness to compensate. A color ambient light sensor may detect changes in the color of the ambient light so that a compensating color cast adjustment may be made to the displayed content. Summary of the invention

[0004] An electronic device may have a display having an array of pixels forming an active display area. During operation of the device, the array of pixels may be used to display images to a user. In an inactive border region or other inactive display region without pixels, an opaque masking layer may be included in the display to prevent internal device components from being seen from the outside of the electronic device. Ambient light may pass through openings in the opaque masking layer.

[0005] The electronic device may have an ambient light sensor module aligned with the opening in the opaque masking layer. Control circuitry in the electronic device may adjust a brightness level associated with an image displayed by the display based on ambient light measurements from the ambient light sensor module.

[0006] Ambient light sensor modules can be formed using wafer-level processes, where filters and diffusers are stacked on a silicon substrate or a combined substrate including multiple photosensors. The stack can be cut, filled with opaque material, and cut again to form multiple ambient light sensor modules.

[0007] The resulting ambient light sensor module may include a silicon substrate having a photosensor and a through silicon via, a filter located on the silicon substrate, and solder bumps coupled to a diffuser of the filter and to opposing sides of the silicon substrate. An air gap may exist between a portion of the diffuser and the photosensor. The air gap may be formed by a recess in the diffuser or by a spacer between the filter and the diffuser. Alternatively, the diffuser may be applied as a coating on the filter.

[0008] By forming the ambient light sensor module at the wafer level, the module may have a smaller footprint and / or volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of an illustrative electronic device with an ambient light sensor module according to some embodiments.

[0010] Figure 2 and Figure 3 is a perspective view of an illustrative electronic device according to some embodiments.

[0011] Figure 4 is a side view of an illustrative ambient light sensor module beneath a light-transmissive hole in an opaque masking layer in a display according to an embodiment.

[0012] Figure 5 is a diagram of illustrative steps that may be used to form an ambient light sensor module, according to some implementations.

[0013] Figure 6 is a side view of an illustrative ambient light sensor module having opaque material on the side and rear surfaces of the module, according to some embodiments.

[0014] Figure 7 is a side view of an illustrative ambient light sensor module with a volume diffuser coating, according to some implementations.

[0015] Figure 8 is a side view of an illustrative ambient light sensor module having an air gap between a diffuser and a filter formed by a recess in the diffuser, according to some implementations.

[0016] Fig. 9 is a side view of an illustrative ambient light sensor module having an air gap formed by a spacer between a diffuser and an optical filter, according to some implementations.

[0017] Fig.10 is a side view of an illustrative ambient light sensor module having an air gap formed by a spacer and opaque material between a diffuser and an optical filter, according to some implementations.

[0018] Fig.11 is a schematic diagram of illustrative steps that may be used to form an ambient light sensor module using a combined substrate, according to some implementations.

[0019] Fig.12 is a side view of an illustrative ambient light sensor module having a combined substrate according to some implementations. DETAILED DESCRIPTION

[0020] Electronic devices, such as cellular phones, computers (e.g., laptop computers), tablet computers, and wearable devices (e.g., wristwatch devices or head-mounted devices), may include optical sensors, such as ambient light sensors. The ambient light sensor may generate a signal in response to ambient light, indicating the ambient brightness of the environment surrounding the device. In some examples, the ambient brightness may be used to adjust the brightness of a display.

[0021] However, it may be desirable to reduce the size of an ambient light sensor in an electronic device. Therefore, the ambient light sensor may be formed from an ambient light sensor module formed at the wafer level, rather than using cut portions. For example, a silicon layer including a through hole and a photosensor may be provided, and a filter and a diffuser may be provided above the silicon layer to form a stack. Solder bumps may be coupled to the back side of the silicon layer. The stack may be cut and backfilled with an opaque material between each of the photosensors. The stack may be cut again to separate the stack into individual ambient light sensor modules.

[0022] In some embodiments, an additional opaque material may be provided at the bottom of the silicon layer in addition to the sides of the ambient light sensor module. The diffuser may be provided as a glass layer or a diffuser coating. If the diffuser is provided as a glass layer, the glass layer may be patterned / etched to form an air gap that diffuses light incident on the ambient light sensor module.

[0023] Regardless of the layers used to form the ambient light sensor module, the module can be a small package, thereby reducing the volume required to incorporate the module into an electronic device.

[0024] Figure 1 An illustrative electronic device of the type that may be provided with one or more ambient light sensor modules is shown in FIG. Figure 1 The electronic device 10 may be a computing device such as a laptop computer, a computer monitor including an embedded computer, a tablet computer, a cellular telephone, a media player or other handheld or portable electronic device, a smaller device (such as a wristwatch device or other device worn on a user's wrist), a hanging device, a headset or earpiece device, a device embedded in glasses or other equipment worn on a user's head, or other wearable device or microdevice, a television, a computer display that does not include an embedded computer, a gaming device, a navigation device, an embedded system (such as a system in which electronic equipment with a display is installed in an information kiosk or a car), equipment that implements the functionality of two or more of these devices, or other electronic equipment.

[0025] like Figure 1As shown, the electronic device 10 may have a control circuit 16. The control circuit 16 may include storage and processing circuits for supporting the operation of the device 10. The storage and processing circuits may include storage devices, such as hard disk drive storage devices, non-volatile memory (e.g., flash memory or other electrically programmable read-only memory configured to form a solid-state drive), volatile memory (e.g., static or dynamic random access memory), etc. The processing circuit in the control circuit 16 can be used to control the operation of the device 10. The processing circuit may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application-specific integrated circuits, etc. The control circuit 16 may include communication circuits for supporting wired and / or wireless communications between the device 10 and external equipment. For example, the control circuit 16 may include wireless communication circuits, such as cellular phone communication circuits and wireless local area network communication circuits.

[0026] Input-output circuitry in device 10, such as input-output devices 12, may be used to allow data to be provided to device 10, and to allow data to be provided from device 10 to external devices. Input-output devices 12 may include buttons, joysticks, scroll wheels, touch pads, keypads, keyboards, microphones, speakers, audio generators, vibrators, cameras, light-emitting diodes and other status indicators, data ports, etc. A user may control the operation of device 10 by supplying commands through input-output devices 12, and may receive status information and other output from device 10 using the output resources of input-output devices 12.

[0027] Input-output devices 12 may include one or more displays, such as display 14. Display 14 may be a touch screen display including a touch sensor for acquiring touch input from a user, or display 14 may be insensitive to touch. The touch sensor of display 14 may be based on an array of capacitive touch sensor electrodes, an acoustic touch sensor structure, a resistive touch assembly, a force-based touch sensor structure, a light-based touch sensor, or other suitable touch sensor arrangements.

[0028] The input-output device 12 may also include a sensor 18. The sensor 18 may include a capacitive sensor, a light-based proximity sensor, a magnetic sensor, an accelerometer, a force sensor, a touch sensor, a temperature sensor, a pressure sensor, a compass, a microphone, a radio frequency sensor, a three-dimensional image sensor, a camera, a light-based position sensor (e.g., a lidar sensor), and other sensors. The sensor 18 may also include one or more light detectors (referred to herein as ambient light sensors) configured to detect ambient light. The sensor 18 may, for example, include one or more monochrome ambient light sensors and one or more color ambient light sensors that are configured to measure ambient light from the environment in which the device 10 operates. A monochrome ambient light sensor may be used to measure ambient light intensity. A color ambient light sensor may be used to measure the color (color spectrum, color temperature, color coordinates, etc.) of the ambient light, and may be used to measure ambient light intensity.

[0029] To perform color measurements, the color ambient light sensor in device 10 may have a photodetector such as a photodiode overlapped by a tunable wavelength filter and / or may have multiple channels, each of which has a photodetector such as a photodiode overlapped by a filter that passes different colors of light (e.g., different wavelength bands) to the photodetector. Photodetectors such as photodiodes may be formed in a semiconductor die. By processing the readings from each of the multiple channels, the relative intensity of each of the different colors of light may be determined. Using data from different channels in the color ambient light sensor, control circuit 16 may therefore generate ambient light color temperature measurements and other color measurements (e.g., colors represented in color coordinates, etc.). Ambient light color information may be used to control display 14 and / or take other actions in device 10. For example, the color cast of an image displayed on display 14 may be adjusted based on the ambient light color measurements (e.g., to make the image on display 14 more yellow under warm ambient lighting conditions and to make the image on display 14 more blue under cool ambient lighting conditions). If desired, control circuitry 16 may automatically increase display brightness in response to detecting bright ambient light conditions, and may automatically decrease display brightness in response to detecting dim ambient light conditions. Adjusting the brightness of an image on display 14 based on ambient light sensor measurements from an ambient light sensor in device 10 in this way may help enhance user comfort when viewing the image.

[0030] Electronic device 10 may include one or more ambient light sensors. Illustrative arrangements in which device 10 includes a single ambient light sensor are sometimes described herein as examples. In some configurations, the ambient light sensor may be located directly below or nearly below display 14 (e.g., below the active display area or below an inactive border of the display, in an inactive notch formed along an edge of the active display area, in an inactive island forming a window area within the active display area, etc.). Alternatively, the ambient light sensor may be located in an inactive area of ​​display 14 (e.g., adjacent to a peripheral area of ​​display 14 that does not include any pixels) or on another portion of device 10.

[0031] The display 14 may be an organic light emitting diode display, a liquid crystal display, a micro-LED display, or other display. In some configurations, the organic light emitting diode pixel light emission or the backlight unit light emission in a backlit liquid crystal display may be temporarily dimmed to help prevent backlight leakage that may generate stray light. This may help reduce noise during ambient light measurements. Ambient light measurements may also be collected when the display backlight is active. To help reduce crosstalk when the backlight is active, the ambient light sensor module may be provided with an optical attenuator. The optical attenuator may attenuate stray light to help reduce stray light noise. The optical attenuator may also help provide the ambient light sensor module with a dark appearance that matches the surrounding opaque masking material used in the inactive area of ​​the display. Light-transmitting holes may be formed in the opaque masking layer to allow ambient light to reach the ambient light sensor module.

[0032] Figure 2 A perspective view of an illustrative electronic device of the type that may include an ambient light sensor is shown. Figure 2 In the example of , device 10 includes a display, such as display 14 mounted in housing 22. Display 14 can be a liquid crystal display, a light emitting diode display such as an organic light emitting diode display, or a display formed by a crystalline semiconductor light emitting diode die, or other suitable display. Display 14 can have a pixel array 26 that extends across some or all of the front face F of device 10 and / or other external device surfaces. The pixel array can be rectangular or can have other suitable shapes. Display 14 can be protected using a display cover layer (e.g., a transparent front housing layer) such as a layer of transparent glass or light-transmitting plastic, sapphire, or other light-transmitting layer. The display cover layer can overlap pixel array 26.

[0033] The housing 22, which may sometimes be referred to as a package or housing, is formed of plastic, glass, ceramic, fiber composite material, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or any combination of two or more of these materials. The housing 22 and the display 14 may separate an internal area within the device 10 from an external area surrounding the device 10. The housing 22 may be formed using an integral configuration, in which a portion or all of the housing 22 is machined or molded into a single structure, or may be formed using multiple structures (e.g., an internal frame structure, one or more structures forming an external housing surface, etc.). If desired, a wristband or other strap may be coupled to the main portion of the housing 22 (e.g., in a configuration where the device 10 is a watch). Internal electronic components 28 (e.g., integrated circuits, discrete components, etc.) for forming the control circuit 16 and the input-output device 12 may be mounted in the interior of the housing 22. In some configurations, the components 28 may be attached to the display 14 (e.g., a display driver circuit may be mounted to the inner surface of the display 14).

[0034] Pixels 26 may cover the entirety of front face F of device 10, or display 14 may have an inactive area (e.g., a notch, a rectangular island, or other area) that is devoid of pixels 26. The inactive area may be used to accommodate openings for speakers and windows for optical components such as image sensors, ambient light sensors, optical proximity sensors, three-dimensional image sensors (such as structured light three-dimensional image sensors), camera flashes, etc. The ambient light sensor may be formed below the window opening in housing 22 (e.g., the sensor may be mounted below a hole in a metal housing wall), may be formed below an active area of ​​display 14, or may be formed below an inactive display area. For example, the ambient light sensor may be formed on front face F along one of the edges of device 10, such as Figure 2 An exemplary ambient light sensor area 30 is shown.

[0035] Figure 2 The device 10 may be a cellular phone, a tablet computer, a wristwatch or other portable device (as an example). If desired, an ambient light sensor may be provided in other electronic equipment. Figure 3 In the example shown in FIG. 1 , the electronic device 10 is a laptop computer. Figure 3 The housing 22 of device 10 includes an upper housing portion 22-1 and a lower housing portion 22-2, which are connected by a hinge to allow the portions to rotate relative to each other. Display 14 can be mounted in upper housing portion 22-1. Keyboard 32 and trackpad 34 can be mounted in lower housing portion 22-2. An ambient light sensor can be mounted on housing 22 facing the exterior of device 10. For example, an ambient light sensor module can be mounted below an active area of ​​display 14 configured to display an image or an inactive area of ​​display 14 (see, e.g., illustrative ambient light sensor area 30).

[0036] To help hide the internal components of the interior of housing 22 from being seen, the inactive area of ​​display 14 may be provided with an opaque masking layer. The opaque masking layer may be any suitable color (e.g., black, gray, white, a non-neutral color such as blue, etc.). In the illustrative example, display 14 has an inactive area with an opaque masking layer formed of black ink. Other opaque materials may be used if desired.

[0037] To allow light to reach the ambient light sensor in region 30, an opening (e.g., a light-transmitting hole, sometimes referred to as an ambient light sensor window or ambient light sensor opening) may be formed in the opaque masking layer in region 30. The shape of region 30 (e.g., the outline of the opaque masking layer opening when viewed from the outside of device 10) may be circular, rectangular, or may have other suitable shapes. The opening may be completely free of opaque masking material (e.g., the opening may be a circular hole, etc.), thereby allowing nearly 100% of ambient light to pass through the opening (e.g., at least 95% or other suitable amount of light). Inside device 10, an ambient light sensor module may be aligned with the ambient light sensor hole in the opaque masking layer. To enhance the uniform appearance of the inactive area of ​​display 14 and to prevent the ambient light sensor opening from being too noticeable to a user of device 10, the ambient light sensor module mounted below the opening may be provided with a light attenuator (e.g., a visible light absorbing structure having a light transmission of about 2% to 16%, at least 3%, 5% to 10%, 8%, at least 4%, at least 6%, less than 20%, less than 10%, or other suitable light transmission value). The dark appearance of the light attenuator in the ambient light sensor module can help absorb ambient light and reduce ambient light reflections so that the ambient light sensor module visually blends with adjacent portions of the opaque masking layer.

[0038] Figure 4 is a side view of an illustrative display with an ambient light sensor. Figure 4 The display 14 has an active area AA that displays an image and an inactive area IA that is covered with an opaque masking material and does not display an image.

[0039] exist Figure 4 In the example of FIG. 1 , display 14 has a transparent display cover layer, such as display cover layer 36. Display cover layer 36 may be formed of glass, a polymer, sapphire or other crystalline material and / or other transparent material. In active area AA, display 14 has an array of pixels P for displaying an image. Pixels P may, for example, form a light emitting diode display panel, such as a thin film organic light emitting diode display panel or a display panel having an array of pixels formed from crystalline semiconductor light emitting diode dies (as examples). Configurations in which display 14 is a liquid crystal display may also be used. As shown in FIG. 1 , display 14 may be a liquid crystal display. Figure 4As shown, pixels P do not exist in inactive area IA of display 14. Opaque masking layer 38 may be formed on the underside (inner surface) of display cover layer 36 in inactive area IA to hide internal components in interior area 48 from being viewed by a user in the external environment surrounding device 10 (external area 46).

[0040] Ambient light sensor module 40 (also referred to herein as optical module 40) may be mounted in alignment with the opening in opaque masking layer 38 in ambient light sensor area 30. This allows ambient light sensor module 40 to receive and measure ambient light 44 that passes through the opening in display cover layer 36 and layer 38 within ambient light sensor area 30. If desired, a transparent adhesive layer such as adhesive layer 42 may be used to attach ambient light sensor module 40 to the interior of display cover layer 38 over the opening in layer 38. Other mounting arrangements may be used if desired.

[0041] although Figure 4 Ambient light sensor module 40 is shown in inactive area IA of display 14, but this is merely illustrative. In some embodiments, ambient light sensor module 40 may be in active area AA of display 14. Alternatively, ambient light sensor module 40 may be formed in another area of ​​device 10, such as on a sidewall or back of a housing of device 10.

[0042] Regardless of where the ambient light sensor module 40 is included in the electronic device, it may be desirable to form the ambient light sensor module 40 with a small volume to reduce the space it occupies in the electronic device. Figure 5 An illustrative example of a process that can be used to form an ambient light sensor module is shown in FIG.

[0043] like Figure 5 As shown, filter 60 and diffuser 62 may be stacked on silicon wafer 52 (also referred to herein as silicon 52 and silicon substrate 52) to form stack 50. Silicon substrate 52 may include photosensor 54, which may include a photosensitive element, such as a photodiode, that generates a charge / signal in response to incident light. Silicon substrate 52 may also include through silicon vias (TSVs) 56 and solder bumps 58 that couple photosensor 54 to circuitry within an electronic device (such as device 10) (e.g., when the resulting ambient light sensor module is installed in the electronic device). Silicon substrate 52, filter 60, diffuser 62, and solder bumps 58 may together form stack 50. Stack 50 may include an array of ambient light sensor photosensors 54 and therefore an array of ambient light sensor modules.

[0044] Silicon substrate 52 may have a thickness of approximately 100 microns, at least 40 microns, between 40 microns and 250 microns, or other suitable thickness. By having a thin silicon substrate 52 , TSVs 56 may be more easily etched through substrate 52 .

[0045] The filter 60 can be a spectral filter, such as a thin film interference filter. Specifically, the filter 60 may include a dielectric layer having alternating high and low refractive indices (e.g., alternating first and second refractive indices, wherein the first refractive index is higher than the second refractive index), which provides destructive interference and filters out light of undesirable wavelengths. Alternatively, the filter 60 can be an absorption-based filter, which includes materials such as metallic materials (e.g., silver) or metal-organic hybrid materials or organic dyes that absorb light of desired wavelengths. Regardless of the type of filter 60 used, the filter 60 can ensure that light of a specific wavelength passes through to the photoelectric sensor 54. For example, the filter 60 can filter out infrared light by blocking or reflecting infrared light. Alternatively or additionally, the filter 60 can filter out ultraviolet light or can filter out visible light of one or more wavelengths that are not desired to be detected by the photoelectric sensor 54 below. In other words, the filter 60 is used to control which wavelengths of light are measured / detected by the photoelectric sensor 54.

[0046] Diffuser 62 may be a surface diffuser or a volume diffuser. In other words, diffuser 62 may have surface textures or features to diffuse light passing through diffuser 62, or diffuser 62 may have embedded scattering centers that diffuse light, respectively. In an illustrative example, diffuser 62 may include a transparent substrate having a surface texture, such as a glass layer, a sapphire layer, a polycarbonate layer, a polymer layer, or other suitable transparent layer. For example, a diffuse coating (e.g., a coating having a texture) may be applied to the surface of the transparent substrate. In general, however, any suitable type of diffuser may be used.

[0047] The diffuser 62 may have a thickness of 30 microns, at least 200 microns, at least 150 microns, between 150 and 250 microns, between 15 and 300 microns, at least 20 microns, at least 50 microns, about 100 microns, 200 microns, or other suitable thicknesses. In some embodiments, for example, the diffuser 62 may be formed by a glass substrate (or substrate of other transparent material) and a diffuser coating on the transparent substrate. The glass substrate may have a thickness of 100 microns, at least 50 microns, at least 25 microns, at least 100 microns, or other suitable thicknesses. The diffuser coating may have a thickness of 30 microns, at least 15 microns, between 15 and 40 microns, or other suitable thicknesses.

[0048] Once stack 50 is formed by stacking silicon substrate 52 , filter 60 , and diffuser 62 , stack 50 may be cut along cut lines 64 , such as between each ambient light sensor module of an array of ambient light sensor modules formed by stack 50 .

[0049] Opaque material 66 may then be used to backfill the openings between cut lines 64 and coat the edges of stack 50. In other words, opaque material 66 may fill the area between each of the ambient light sensor modules in stack 50. Opaque material 66 may be a black molding material such as a polymer, an epoxy such as black epoxy, a carbon layer, black ink, a light absorbing ink of another color, or other opaque material.

[0050] After adding the opaque material 66, the stack 50 may be cut again within the opaque material 66 to form the ambient light sensor modules 40. Each ambient light sensor module 40 may include a silicon substrate 52, a photosensor 54, a TSV 56, solder bumps 58, an optical filter 60, a diffuser 62, and opaque sidewalls 66. Figure 5 Two opaque side walls are shown on each ambient light sensor module 40, but each optical module 40 may also have two opaque side walls perpendicular to the ambient light sensor module 40. Figure 5 4. The sidewalls shown in FIG. 4 have opaque sidewalls on both sides. In general, each optical module 40 may have opaque material 66 on any suitable number of sidewalls.

[0051] In this manner, a plurality of ambient light sensor modules 40 may be formed from a single stack 50, such as a single stack formed on a single wafer 52. In some implementations, at least 2 ambient light sensor modules 40, at least 10 ambient light sensor modules 40, at least 100 ambient light sensor modules 40, at least 1000 ambient light sensor modules 40, at least 2000 ambient light sensor modules 40, at least 3000 ambient light sensor modules 40, at least 5000 ambient light sensor modules, at least 10000 ambient light sensor modules 40, or other desired number of ambient light sensor modules 40 may be formed on a single wafer.

[0052] In operation, incident light may pass through diffuser 62 of a single ambient light sensor module 40, where the light may be diffused. The diffused light may pass through filter 60, which may filter out light of undesired wavelengths. The remaining light may reach photosensor 54, which may generate a charge / signal in response to the light. Ambient light sensor module 40 may be coupled to circuitry (such as control circuitry) within device 10 via solder bumps 58 and TSVs 56, and measurements from photosensor 54 may be read out to circuitry within device 10 as ambient light sensor measurements. Opaque sidewalls 66 may block off-axis light, which may reduce ambient light sensor measurements of stray light.

[0053] By forming ambient light sensor module 40 using a wafer-level process (e.g., a process that forms multiple ambient light sensor modules using a single silicon wafer), ambient light sensor module 40 may have a smaller footprint and / or overall volume than ambient light sensor modules made from separate components, such as approximately a 65% volume reduction, at least a 50% volume reduction, at least a 40% volume reduction, or other volume reductions compared to separately formed sensor modules.

[0054] although Figure 5 Opaque material 66 is shown only on the sides of ambient light sensor module 40, but this is merely exemplary. In some embodiments, it may be desirable to include opaque material on other portions of ambient light sensor module 40, such as the bottom surface of ambient light sensor module 40. Figure 6 An illustrative example of an ambient light sensor module having opaque material on the side and bottom surfaces is shown in FIG.

[0055] like Figure 6 As shown, ambient light sensor module 40 may include opaque material 68 on the bottom surface of silicon substrate 52. Thus, ambient light sensor module may have opaque material 66 on the sidewalls of the module and opaque material 68 on the bottom surface of the module. By including opaque material 68 at the bottom surface of module 40, additional light may be blocked. Additionally, sensitive components, such as components in silicon substrate 52, may be protected when module 40 is mounted within an electronic device.

[0056] The opaque material 68 may be under-molded onto the silicon substrate 52 (simultaneously with the opaque material 66 on the sidewalls, if desired). Alternatively, the opaque material 68 may be sprayed or spin-coated onto the bottom surface of the substrate 52. For example, the silicon substrate 52 may have a cavity on the bottom surface, and the opaque material 68 may be applied by filling the cavity or may leave a void in the cavity. In this way, the bottom surface of the module 40 may be coated with an opaque material 68 that may block additional stray light and improve the performance of the ambient light sensor.

[0057] The opaque material 68 may be a black molding material (e.g., a polymer), an epoxy (e.g., black epoxy), a carbon layer, a black ink, a light-absorbing ink of another color, or other opaque material. In some embodiments, the opaque material 68 may be a solder mask that allows the solder bumps 58 to be formed in desired locations on the bottom surface of the module 40. Alternatively or additionally, the opaque material 68 may include a material that blocks infrared light. For example, the opaque material 68 may include a metal (e.g., silver or other suitable metal) between the TSVs 56 and the solder bumps 58. The metal may block infrared light, thereby reducing interference from ambient infrared light or infrared light from other components within the electronic device.

[0058] although Figure 6 The opaque material 68 on the lowermost surface of the module 40 is shown, but this is merely exemplary. In some embodiments, the opaque material can be incorporated into the silicon wafer 52. For example, the surface of the silicon wafer 52 can be filled with metal, and then the photosensor 54 can be mounted to the silicon wafer 52. In this way, the metal can block light from reaching the photosensor 54 from below the module 40.

[0059] exist Figure 5 and Figure 6 In the example of FIG. 4 , diffuser 62 is shown as a single layer (with a coating on its surface if desired). However, this is merely exemplary. In general, any suitable diffuser may be used in ambient light sensor module 40 . Figure 7 An illustrative example of an ambient light sensor module having a diffuser coating applied directly to a silicon substrate is shown in FIG.

[0060] like Figure 7 5. As shown, diffuser 70 may be a diffuser coating applied directly to the top surface of silicon substrate 52. For example, diffuser 70 may be formed of an epoxy, resin, polymer, or other suitable material having embedded scattering centers 72. Embedded scattering centers 72 may be formed of a metal, a metal oxide (e.g., titanium dioxide), a polymer (e.g., a polymer having a different refractive index than the bulk substrate of diffuser 70), or other suitable material to diffuse light passing through diffuser 70. Diffuser 70 may be applied to filter 60 (and / or silicon substrate 52) using a one-time (or multiple-time) process, or may be applied as a spin-on. Regardless of the process used to form diffuser 70 in module 40, a glass diffuser substrate (such as a 3D-type diffuser) may be omitted. Figures 4 to 5 The diffuser 62 of FIG. 4 is shown in FIG. 1 , and a thinner diffuser coating can be used on the ambient light sensor module 40. This can reduce the height of the ambient light sensor module 40.

[0061] Despite Figure 7 Not shown, but if desired, such as Figure 5 and Figure 6 A filter such as filter 60 may be incorporated into ambient light sensor module 40 between diffuser 70 and photosensor 54. Alternatively, diffuser 70 may be formed of or include a filtering layer that filters light incident on module 40 before the light reaches photosensor 54.

[0062] As another example of a diffuser that may be incorporated into an ambient light sensor module, Figure 8 An exemplary arrangement of a diffuser having a recessed portion forming an air gap is shown. Figure 8 As shown, the diffuser 74 may include a recessed portion that forms an air gap 76 above the photosensor 54. The recessed portion that forms the air gap 76 may be etched into the diffuser 74, such as using photolithography (e.g., if the diffuser 74 is formed of glass or sapphire), or the diffuser 74 may be formed with the recessed portion, such as by molding the diffuser 74 with the recessed portion (e.g., if the diffuser 74 is formed of a polymer). The area of ​​the diffuser 74 adjacent to the recessed portion that forms the air gap 76 may be directly coupled to the filter 60.

[0063] The air gap 76 may allow for greater flexibility in designing the filter 60. Specifically, the air gap 76 may allow light passing through the module 40 to be refracted (e.g., at the interface between the diffuser 74 and the air gap 76) before reaching the filter 60. For example, this may allow the filter 60 to be formed of a pure dielectric layer (e.g., a thin film dielectric layer having alternating refractive indices). Alternatively or additionally, the air gap 76 may allow a robust coating material to be disposed within the module 40 (e.g., on either side of the air gap 76).

[0064] Although air gap 76 is described as being formed by a recess in diffuser 74, this is exemplary only. In some embodiments, the air gap may be formed by adding additional material between the diffuser and the silicon wafer. Fig. 9 Shown in.

[0065] like Fig. 9 As shown, spacer 78 may be disposed between diffuser 62 and filter 60 to form air gap 80. Spacer 78 may be formed of epoxy, photoimageable resist, silicon dioxide, optically clear adhesive, or other suitable material. Air gap 80 may provide a Figure 8 The air gap 76 has the same function.

[0066] If desired, masking material may be provided on either side of the air gap 80. For example, Fig.10In the exemplary embodiment shown in FIG. 5 , an opaque masking layer 82 can be disposed between the spacer 78 and the filter 60. The opaque masking layer 82 can be formed of a black molding material (e.g., a polymer), an epoxy (e.g., a black epoxy), a carbon layer, a black ink, a light-absorbing ink of another color, or other opaque material. Generally speaking, the opaque masking layer 82 can prevent stray light from reaching the photosensor 54 and can therefore improve the ambient light sensor measurements produced by the ambient light sensor module 40.

[0067] Although module 40 is described as an ambient light sensor module, this is merely exemplary. Generally, a wafer-level process (e.g., Figure 5 Specifically, the photoelectric sensor 54 can be replaced by a sensor sensitive to light of other wavelengths (such as infrared light, ultraviolet light, etc.).

[0068] exist Figures 5 to 10 In the example of FIG. 5 , optical module 40 includes a silicon substrate 52. In some embodiments, it may be desirable to form an optical module using a combination substrate that uses multiple layers of different materials. Fig.11 An illustrative example of a process that can be used to form an ambient light sensor module having a combined substrate is shown in FIG.

[0069] like Fig.11 As shown, filter 60, substrate 92, and diffuser 62 may be stacked on silicon wafer 52 (also referred to herein as silicon 52 and silicon substrate 52) to form stack 90. ​​Silicon substrate 52 may include photosensor 54, which may include a photosensitive element, such as a photodiode, that generates a charge / signal in response to incident light. Silicon substrate 52 may also include through silicon vias (TSVs) 56 and solder bumps 58 that couple photosensor 54 to circuitry within an electronic device, such as device 10 (e.g., when the resulting ambient light sensor module is mounted in an electronic device).

[0070] Substrate 92 may be a glass substrate, a ceramic substrate, a sapphire substrate, and / or any other suitable substrate. Substrate 52 and substrate 92 may together form a combined substrate 93 in which filter 60 is embedded (e.g., filter 60 may be between substrate 52 and substrate 92). Silicon substrate 52 may have a height H1 of at least 50 microns, at least 75 microns, at least 100 microns, between 75 microns and 125 microns, less than 200 microns, or another suitable height. Substrate 92 may have a height H2 of at least 50 microns, at least 75 microns, at least 100 microns, between 75 microns and 125 microns, less than 200 microns, or another suitable height. By including substrate 92, silicon substrate 52 may be thinner, and TSV 56 may be more easily etched through substrate 52.

[0071] although Fig.11 Not shown, but if desired, one or more additional layers may be embedded in combined substrate 93, such as a bonding layer between substrate 52, filter 60, diffuser 62, and / or substrate 92.

[0072] Silicon substrate 52, filter 60, substrate 92, diffuser 62, and solder bumps 58 may together form a stack 90. ​​Stack 90 may include an array of ambient light sensor photosensors 54 and thus an array of ambient light sensor modules. Fig.11 In the example of , diffuser 62 is shown as a single layer diffuser, but if desired, diffuser 62 can be formed of multiple layers. For example, diffuser 62 can be formed of a diffuser material mounted on a substrate (e.g., a polymer, glass, ceramic, or polycarbonate substrate), which in turn is attached to substrate 92.

[0073] Once stack 90 is formed by stacking silicon substrate 52 , filter 60 , substrate 92 , and diffuser 62 , stack 90 may be cut along cut lines 64 , such as between each ambient light sensor module of an array of ambient light sensor modules formed by stack 90 .

[0074] Opaque material 66 may then be used to backfill the openings between cut lines 64 and coat the edges of the stack to form stack 94. In other words, opaque material 66 may fill the area between each of the ambient light sensor modules in stack 94. Opaque material 66 may be a black molding material such as a polymer, an epoxy such as black epoxy, a carbon layer, black ink, a light absorbing ink of another color, or other opaque material.

[0075] After adding opaque material 66, stack 94 may be cut again within opaque material 66 to form ambient light sensor modules 96. Each ambient light sensor module 96 may include silicon substrate 52, photosensors 54, TSVs 56, solder bumps 58, filters 60, substrate 92, diffusers 62, and opaque sidewalls 66. Fig.11 Two opaque sidewalls are shown on each ambient light sensor module 96 (also referred to herein as an optical module 96), but each optical module 96 may also have two opaque sidewalls perpendicular to the ambient light sensor module 96. Fig.11 9 has opaque sidewalls on both sides of the sidewalls shown in FIG. In general, each optical module 96 may have opaque material 66 on any suitable number of sidewalls.

[0076] In this manner, a plurality of ambient light sensor modules 96 may be formed from a single stack 90, such as a single stack formed on a single combined substrate 93. In some implementations, at least 2 ambient light sensor modules 96, at least 10 ambient light sensor modules 96, at least 100 ambient light sensor modules 96, at least 1000 ambient light sensor modules 96, at least 2000 ambient light sensor modules 96, at least 3000 ambient light sensor modules 96, at least 5000 ambient light sensor modules 96, at least 10000 ambient light sensor modules 96, or other desired number of ambient light sensors 96 may be formed on a single wafer.

[0077] In operation, incident light may pass through diffuser 62 of a single ambient light sensor module 96, where the light may be diffused. The diffused light may pass through filter 60, which may filter out light of undesired wavelengths. The remaining light may reach photosensor 54, which may generate a charge / signal in response to the light. Ambient light sensor module 96 may be coupled to circuitry (such as control circuitry) within device 10 via solder bumps 58 and TSVs 56, and measurements from photosensor 54 may be read out to circuitry within device 10 as ambient light sensor measurements. Opaque sidewalls 66 may block off-axis light, which may reduce ambient light sensor measurements of stray light.

[0078] By forming ambient light sensor module 96 using a wafer-level process (e.g., a process that forms multiple ambient light sensor modules using a single silicon wafer), ambient light sensor module 96 may have a smaller footprint and / or overall volume than ambient light sensor modules made from separate components, such as approximately a 65% volume reduction, at least a 50% volume reduction, at least a 40% volume reduction, or other volume reductions compared to separately formed sensor modules.

[0079] although Fig.11 The substrate 92 is shown between the filter 60 and the diffuser 62, but this is merely exemplary. In some embodiments, the diffuser 62 can be placed on top of the filter 60, with the substrate 92 on top of the diffuser 62. In other words, the diffuser 62 can be interposed between the filter 60 and the substrate 92. Fig.12 An illustrative example is shown in .

[0080] like Fig.12 As shown, ambient light sensor module 98 may include diffuser 62 on filter 60 (e.g., directly on the filter) and substrate 92 on diffuser 62 (e.g., directly on the diffuser). Substrate 52, substrate 92 may together form a combined substrate 95 in which filter 60 and diffuser 62 are embedded. Fig.12Not shown, but if desired, one or more additional layers may be embedded in combined substrate 95, such as a bonding layer between substrate 52, filter 60, diffuser 62, and / or substrate 92.

[0081] exist Fig.12 In an arrangement of FIG. 1 , substrate 92 may be exposed to the exterior of ambient light sensor module 98 (or may be interposed between the exterior of ambient light sensor module 98 and diffuser 62). Because substrate 92 may be formed of glass or other suitable material having higher scratch resistance and / or other high durability than diffuser 62, substrate 92 may protect diffuser 62.

[0082] although Fig.11 and Fig.12 93 and / or the ambient light sensor module 98 having the combined substrate 95 may have an opaque material (e.g., Figure 6 ), may have a diffuser coating applied directly to the combined substrate 93 (e.g., as shown Figure 7 ), may have a diffuser with a recessed portion forming an air gap (e.g., as Figure 8 ), may have multiple diffusers separated by air gaps (e.g. Fig. 9 ), and / or may include an opaque masking layer and a spacer (e.g., as shown) between the combined substrate 93 and the diffuser Fig.10 ). In this way, an ambient light sensor module can be formed together with the combined substrate.

[0083] As described above, one aspect of the present invention technology is to collect and use information such as sensor information. The present disclosure contemplates that, in some cases, data including personal information data may be collected that uniquely identifies or can be used to contact or locate a specific person. Such personal information data may include demographic data, location-based data, phone numbers, email addresses, twitter IDs, home addresses, data or records related to the user's health or fitness level (e.g., vital sign measurements, medication information, exercise information), date of birth, user name, password, biometric information, or any other identification or personal information.

[0084] The present disclosure recognizes that the use of such personal information in the present technology can be used to benefit users. For example, the personal information data can be used to deliver targeted content that users are more interested in. Therefore, the use of such personal information data enables users to have control over the delivered content. In addition, the present disclosure also anticipates other uses of personal information data that benefit users. For example, health and fitness data can be used to provide insights into the user's overall health status, or can be used as positive feedback to individuals who use technology to pursue health goals.

[0085] The disclosure expects that entities responsible for collecting, analyzing, disclosing, transmitting, storing or otherwise using such personal information data will comply with established privacy policies and / or privacy practices. Specifically, such entities should implement and adhere to the use of privacy policies and practices that are recognized as meeting or exceeding the industry or government requirements for maintaining the privacy and security of personal information data. Such policies should be easily accessible to users and should be updated as the collection and / or use of data changes. Personal information from users should be collected for the legal and reasonable purposes of the entity and not shared or sold outside these legal uses. In addition, such collection / sharing should be performed after receiving the user's informed consent. Additionally, such entities should consider taking any necessary steps to protect and safeguard access to such personal information data, and ensure that other entities with access to personal information data comply with their privacy policies and procedures. In addition, such entities can subject themselves to third-party assessments to prove that they comply with widely accepted privacy policies and practices. In addition, policies and practices should be adjusted to collect and / or access specific types of personal information data, and apply to applicable laws and standards including specific considerations of jurisdiction. For example, in the United States, the collection or access of certain health data may be governed by federal and / or state laws such as the Health Insurance Portability and Accountability Act (HIPAA), while health data in other countries may be subject to other regulations and policies and should be handled accordingly. Therefore, different privacy practices should be maintained for different types of personal data in each country.

[0086] Regardless of the foregoing, the present disclosure also contemplates implementation schemes in which users selectively block the use or access of personal information data. That is, the present disclosure contemplates that hardware elements and / or software elements may be provided to prevent or block access to such personal information data. For example, the technology of the present invention may be configured to allow a user to choose to "opt in" or "opt out" of collecting personal information data at any time during or after registration for a service. For another example, a user may choose not to provide certain types of user data. For another example, a user may choose to limit the length of time that user-specific data is retained. In addition to providing "opt-in" and "opt-out" options, the present disclosure also contemplates providing notifications related to access or use of personal information. For example, a user may be notified that their personal information data will be accessed when downloading an application ("app"), and then be reminded again before the personal information data is accessed by the app.

[0087] Furthermore, it is the intent of the present disclosure that personal information data should be managed and processed in a manner that minimizes the risk of unintentional or unauthorized access or use. Once the data is no longer needed, the risk can be minimized by limiting the collection of data and deleting the data. In addition, and when applicable, including in certain health-related applications, data de-identification can be used to protect the privacy of users. Where appropriate, de-identification can be facilitated by removing specific identifiers (e.g., date of birth, etc.), controlling the amount or characteristics of stored data (e.g., collecting location data at a city level rather than an address level), controlling how data is stored (e.g., aggregating data across users), and / or other methods.

[0088] Thus, while the present disclosure broadly encompasses the use of information that may include personal information data to implement one or more of the various disclosed embodiments, the present disclosure also contemplates that various embodiments may be implemented without requiring access to personal information data. That is, various embodiments of the present technology will not fail to function properly due to the lack of all or a portion of such personal information data.

[0089] According to one embodiment, an ambient light sensor module is provided, comprising: a silicon substrate including a photosensor, the silicon substrate having opposing first and second surfaces; a filter coupled to the first surface of the silicon substrate; and a diffuser coupled to the filter.

[0090] According to another embodiment, an ambient light sensor module includes a through silicon via that passes through a silicon substrate from a first surface to a second surface, and a solder bump that is coupled to the second surface.

[0091] According to another embodiment, a diffuser includes a transparent substrate and a diffusing coating on the transparent substrate.

[0092] According to another embodiment, the transparent substrate includes a recessed portion, and the recessed portion overlaps the photosensor to form an air gap between the photosensor and the diffuser.

[0093] The ambient light sensor module includes a spacer interposed between the optical filter and the diffuser, the spacer forming an air gap between the optical filter and the diffuser.

[0094] According to another embodiment, the ambient light sensor module includes an opaque masking material interposed between the spacer and the filter.

[0095] According to another embodiment, at least a portion of the transparent substrate is separated from the filter by an air gap, the portion overlapping the photosensor, and the filter includes a plurality of thin film dielectric layers having alternating first and second refractive indices, and the first refractive index is higher than the second refractive index.

[0096] According to another embodiment, the silicon substrate has a side surface extending between a first surface and a second surface, and the ambient light sensor module includes an opaque material located on the side surface.

[0097] According to another embodiment, the opaque material is also coupled to the side surfaces of the filter and the diffuser.

[0098] According to another embodiment, the ambient light sensor module includes an additional opaque material located on the second surface of the silicon substrate.

[0099] According to another embodiment, the additional opaque material includes a solder mask surrounding the solder bumps.

[0100] According to another embodiment, the additional opaque material is configured to block infrared light.

[0101] According to another embodiment, the additional opaque material comprises metal.

[0102] According to another embodiment, the diffuser includes a volume diffuser coating on the filter, and the volume diffuser coating includes a plurality of scattering centers in the substrate.

[0103] According to another embodiment, an ambient light sensor module includes a glass substrate that together with a silicon substrate forms a combined substrate.

[0104] According to another embodiment, a glass substrate is interposed between the silicon substrate and the diffuser.

[0105] According to another embodiment, the diffuser is interposed between the silicon substrate and the glass substrate.

[0106] According to one embodiment, a method of forming an ambient light sensor module is provided, the method comprising: stacking filters and diffusers on a silicon wafer including a plurality of photosensors to form an ambient light sensor module array; cutting the ambient light sensor module array; filling an area between each of the ambient light sensor modules with an opaque material; and cutting the ambient light sensor module array within the opaque material to form individual ambient light sensor modules.

[0107] According to another embodiment, the method includes depositing additional opaque material on the back surface of the silicon wafer.

[0108] According to another embodiment, stacking the optical filter and the diffuser on the silicon wafer includes stacking the diffuser on the optical filter with an air gap between a portion of the diffuser and a portion of the optical filter.

[0109] According to another embodiment, stacking the diffuser on the filter with an air gap includes stacking the diffuser on the filter with an intervening spacer.

[0110] According to another embodiment, stacking filters and diffusers on a silicon wafer to form an array of ambient light sensor modules includes forming an array having at least 10 ambient light sensor modules.

[0111] According to another embodiment, the method includes stacking a glass substrate on a silicon wafer, wherein the optical filter is located between the silicon wafer and the glass substrate.

[0112] According to another embodiment, an ambient light sensor module is provided, comprising: a silicon substrate having a first opposing surface and a second opposing surface, a through silicon via extending from the first surface to the second surface, and a photosensor located at the first surface; a solder bump located on the second surface; a filter coupled to the first surface of the silicon substrate; and a diffuser coupled to the filter with an air gap between the diffuser and the filter.

[0113] According to another embodiment, the diffuser includes a transparent substrate having a recess and a portion surrounding the recess, the recess overlaps the photosensor, and the portion of the transparent substrate surrounding the recess is directly coupled to the filter.

[0114] According to another embodiment, the ambient light sensor module includes a spacer interposed between the diffuser and the filter, the spacer forming an air gap.

[0115] According to another embodiment, an ambient light sensor module includes a glass substrate, the glass substrate and a silicon substrate forming a combined substrate, and a filter is located between the glass substrate and the silicon substrate.

[0116] The foregoing is merely illustrative and various modifications may be made to the embodiments described. The foregoing embodiments may be implemented independently or in any combination.

Claims

1. An ambient light sensor module, the ambient light sensor module comprising: a silicon substrate including a photosensor, wherein the silicon substrate has a first surface and a second surface opposite to each other; an optical filter coupled to the first surface of the silicon substrate; and A diffuser is coupled to the filter.

2. The ambient light sensor module according to claim 1, further comprising: a through silicon via, the through silicon via passing through the silicon substrate from the first surface to the second surface; and A solder bump is coupled to the second surface, wherein the diffuser includes a transparent substrate and a diffusing coating on the transparent substrate. 3 . The ambient light sensor module of claim 2 , wherein the transparent substrate includes a recessed portion, and wherein the recessed portion overlaps the photosensor to form an air gap between the photosensor and the diffuser.

4. The ambient light sensor module according to claim 2, further comprising: a spacer interposed between the filter and the diffuser, wherein the spacer forms an air gap between the filter and the diffuser; and An opaque masking material is interposed between the spacer and the filter.

5. The ambient light sensor module of claim 2 , wherein at least a portion of the transparent substrate is separated from the optical filter by an air gap, the portion overlapping the photosensor, the optical filter comprising a plurality of thin film dielectric layers having alternating first and second refractive indices, and the first refractive index is higher than the second refractive index.

6. The ambient light sensor module of claim 2, wherein the silicon substrate has a side surface extending between the first surface and the second surface, the ambient light sensor module further comprising: an opaque material on the side surface, wherein the opaque material is also coupled to the side surfaces of the filter and the diffuser; and An additional opaque material is disposed on the second surface of the silicon substrate.

7. The ambient light sensor module of claim 6, wherein the additional opaque material comprises a solder mask surrounding the solder bumps.

8. The ambient light sensor module of claim 6, wherein the additional opaque material is configured to block infrared light, and wherein the additional opaque material comprises metal.

9. The ambient light sensor module of claim 1, wherein the diffuser comprises a volume diffuser coating on the filter, and wherein the volume diffuser coating comprises a plurality of scattering centers in a substrate.

10. The ambient light sensor module according to claim 1, further comprising: A glass substrate, wherein the glass substrate and the silicon substrate together form a combined substrate.

11. The ambient light sensor module of claim 10, wherein the glass substrate is interposed between the silicon substrate and the diffuser.

12. The ambient light sensor module of claim 10, wherein the diffuser is interposed between the silicon substrate and the glass substrate.

13. A method of forming an ambient light sensor module, the method comprising: stacking filters and diffusers on a silicon wafer including a plurality of photosensors to form an array of ambient light sensor modules; cutting the ambient light sensor module array; filling an area between each of the ambient light sensor modules with an opaque material; as well as The array of ambient light sensor modules is cut within the opaque material to form individual ambient light sensor modules.

14. The method according to claim 13, further comprising: Additional opaque material is deposited on the rear surface of the silicon wafer.

15. The method of claim 13, wherein stacking the filter and the diffuser on the silicon wafer comprises stacking the diffuser on the filter with an air gap between a portion of the diffuser and a portion of the filter, and wherein stacking the diffuser on the filter with the air gap comprises stacking the diffuser on the filter with an intervening spacer.

16. The method of claim 13, wherein stacking the filter and the diffuser on the silicon wafer to form an array of ambient light sensor modules comprises forming an array having at least 10 ambient light sensor modules.

17. An ambient light sensor module, the ambient light sensor module comprising: a silicon substrate having a first opposing surface and a second opposing surface, a through silicon via extending from the first surface to the second surface, and a photosensor located at the first surface; a solder bump, the solder bump being located on the second surface; an optical filter coupled to the first surface of the silicon substrate; and A diffuser is coupled to the filter with an air gap between the diffuser and the filter.

18. The ambient light sensor module of claim 17, wherein the diffuser comprises a transparent substrate having a recess and a portion surrounding the recess, the recess overlapping the photosensor, and the portion of the transparent substrate surrounding the recess is directly coupled to the filter.

19. The ambient light sensor module of claim 17, further comprising: A spacer is interposed between the diffuser and the filter, the spacer forming the air gap.

20. The ambient light sensor module of claim 17, further comprising: A glass substrate, wherein the glass substrate and the silicon substrate form a combined substrate, and wherein the optical filter is located between the glass substrate and the silicon substrate.

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