Substrate assembly for optical sensor module and optical sensor module

Abstract

The utility model relates to a substrate assembly for an optical sensor module and the optical sensor module. An example substrate assembly for an optical sensor module includes: a light emitting device mounted on a first region of a substrate; a metal shield assembly including a first metal shield assembled to the substrate over the first region; and wherein the first metal shield comprises a first opening providing an optical path for light emitted by the light emitting device, the first opening being dimensioned such that the light emitting device can be inserted inside the first metal shield through the first opening.

Description

Technical Field

[0001] This disclosure generally relates to optical sensors, and more particularly to optical sensor modules. Background Technology

[0002] Optical sensors, such as proximity sensors, can be used to detect the presence of nearby objects. Optical sensors can do this without physical contact with the object. Some types of optical sensors, such as those used in optical rangefinders or time-of-flight sensors, can be used to determine the actual distance to such a nearby object. Optical sensors can be used in a variety of electronic devices, such as cameras, telephones (including smartphones), smartwatches, tablets, vehicles, machinery, and other devices used to detect the presence of nearby objects and / or the distance to them. After detecting the presence of a nearby object, the electronic device can be configured to perform functions such as moving mechanical features to a safe position, transmitting alarm signals, coupling or decoupling electrical communications, or any other desired function.

[0003] Optical sensors typically include components such as light emitting devices, light receiving sensors, and processing devices generally used to process signals received from the light receiving sensors. The components of an optical sensor can be formed on a substrate, and a cap can be bonded to the substrate above the components, for example, to protect them from damage, thus forming an optical sensor module, also known as an optical sensor package. The cap typically has a first cap opening above the light emitting device and a second cap opening above the light receiving sensor.

[0004] Generally, a light-emitting device emits a light signal, for example, through a first cap opening. If an object is outside the optical sensor module and sufficiently close to it, the light signal can be reflected by the object toward a light-receiving sensor, for example, through a second cap opening. The light-receiving sensor can then generate an electrical signal indicating the received light signal, which can be transmitted to a processing device to process the received light signal, for example, to determine the presence of a nearby object and / or the distance to the nearby object.

[0005] There is a need to improve optical sensor modules, particularly to address electromagnetic interference (EMI) issues between the optical sensor module and another electronic device (e.g., an electronic device incorporating the optical sensor module), which can be designated as the host device, especially for optical sensors used in consumer electronics. For example, the host device could be a camera, smartphone, smartwatch, tablet, or another device that can be useful for detecting the presence of nearby objects and / or the distance to those objects. Utility Model Content

[0006] One objective of this invention is to overcome all or some of the shortcomings of known optical sensor modules.

[0007] According to one aspect of this disclosure, a substrate assembly for an optical sensor module is provided, the substrate assembly comprising:

[0008] - A light-emitting device mounted on the first region of the substrate;

[0009] - A metal shielding assembly, including a first metal shielding member assembled onto a substrate over a first region;

[0010] The first metal shield includes a first opening that provides an optical path for light emitted by the light emitting device. The first opening is sized such that the light emitting device can be inserted into the first metal shield through the first opening.

[0011] In one embodiment, a first metal shield is designed to enclose and at least partially cover the light emitting device, the first metal shield including, for example, sidewalls joined by a top wall, the top wall including a first opening.

[0012] In one embodiment, the optical emitting device includes:

[0013] - At least one light source, wherein the first opening provides an optical path for light emitted by the at least one light source and is sized such that the at least one light source can be inserted through the first opening into the interior of the first metal shield and mounted onto the substrate; and, optionally,

[0014] - A photodiode, configured as a monitoring light emitting device, has a first opening that also provides an optical path for light transmitted to the photodiode, and is sized such that the photodiode can be inserted through the first opening into a first metal shield and mounted on a substrate.

[0015] In one embodiment, the substrate assembly further includes a driver mounted on a first region of the substrate, the driver being configured to control a light emitting device.

[0016] In one embodiment, the first opening extends over the drive.

[0017] In one embodiment, the first metal shield is electrically coupled to the substrate, for example, electrically coupled to a ground trace on the substrate.

[0018] In one embodiment, the metal shielding assembly further includes a second metal shielding member assembled to the first metal shielding member and at least partially covering the first opening. The second metal shielding member includes at least a second opening that allows light emitted by and / or transmitted to the light emitting device to pass through. The second metal shielding member is, for example, electrically coupled to or in contact with the first metal shielding member.

[0019] In one embodiment, the second metal shield includes a recessed portion extending into the interior of the metal shield assembly.

[0020] In one embodiment, a second metal shield seals the first opening.

[0021] In one embodiment, the second metal shield at least partially closes the first metal shield.

[0022] In one embodiment, the metal shielding assembly includes an absorbent layer positioned on the inner surface of the metal shielding assembly facing the light emitting device, for example, positioned on the inner surface of the first metal shield facing the light emitting device.

[0023] In one embodiment, the substrate assembly further includes glass assembled to the first metal shield over the first opening, the glass including electrically conductive traces, such as those electrically coupled to or in contact with the first metal shield, or ground traces coupled to the substrate through the first metal shield.

[0024] In one embodiment, the metal of the metal shielding component is selected to reflect and / or absorb electromagnetic waves, for example, the metal is copper, copper alloy, stainless steel, or any conductive material that also has a relative permeability greater than 1.

[0025] According to one aspect of this disclosure, an optical sensor module is provided, comprising: a substrate assembly, such as the substrate assembly described above; and a module cap assembled to the substrate and adapted to at least partially cover a metal shielding assembly and components mounted on the substrate.

[0026] According to one aspect of this disclosure, a method for manufacturing a substrate assembly for an optical sensor module is provided, the method comprising:

[0027] - Assembling a first metal shield onto a first region of a substrate, the first metal shield including a first opening providing an optical path for light emitted by a light-emitting device to be mounted on the first region; and

[0028] - Install the light emitting device into the first area through the first opening.

[0029] In one embodiment, the method further includes, after the installation step, assembling a glass comprising an electrically conductive trace over a first opening to a first metal shield, the conductive trace being electrically coupled to or in contact with the first metal shield, for example.

[0030] In one embodiment, the method further includes, after the installation step, assembling a second metal shield to a first metal shield to at least partially cover the first opening, the second metal shield including at least a second opening that allows light emitted by and / or transmitted to the light emitting device to pass through, the second metal shield being, for example, electrically coupled to or in contact with the first metal shield. Attached Figure Description

[0031] The foregoing features and advantages, as well as other features and advantages, will be described in detail below with reference to the accompanying drawings, in which specific embodiments are given in an illustrative rather than limiting manner, wherein:

[0032] Figure 1A This is a three-dimensional view of the substrate assembly of the optical sensor module according to an embodiment;

[0033] Figure 1B yes Figure 1A A cross-sectional view of the substrate assembly;

[0034] Figure 2A , Figure 2B , Figure 2C and Figure 2D This is an example of manufacturing. Figure 1A and Figure 1B Top-view and 3D views of an example of a method for assembling a substrate;

[0035] Figure 3A This is a three-dimensional view of the substrate assembly of an optical sensor module according to another embodiment;

[0036] Figure 3B It is shown Figure 3A A detailed cross-sectional three-dimensional view of the substrate assembly;

[0037] Figure 4 This is an example used in manufacturing Figure 3A and Figure 3B substrate components Figures 2A to 2D A 3D view of a variant of the method;

[0038] Figure 5A This is a three-dimensional view of the substrate assembly of an optical sensor module according to another embodiment;

[0039] Figure 5B It is shown Figure 5A A detailed cross-sectional three-dimensional view of the substrate assembly;

[0040] Figure 5C yes Figure 5A A 3D view of a variant of the substrate assembly;

[0041] Figure 6A and Figure 6BThis is an example used in manufacturing Figures 5A to 5C substrate components Figures 2A to 2D The method includes variations of top-view and 3D views;

[0042] Figure 7 This is a three-dimensional view of the substrate assembly of an optical sensor module according to another embodiment; and

[0043] Figure 8A and Figure 8B This is an example used in manufacturing Figure 7 substrate components Figures 2A to 2D The method includes variations of top-view and 3D views. Detailed Implementation

[0044] Cross-references to (one or more) related applications

[0045] This application claims priority to French patent application No. 2311593 entitled “Module de Capteur Optique”, filed on October 25, 2023, which is incorporated herein by reference to the fullest extent permitted by law.

[0046] Similar features in the various figures are indicated by similar reference numerals. In particular, common structural and / or functional features in the various embodiments may have the same reference numerals and may have the same structure, dimensions, and material properties.

[0047] For clarity, only operations and elements useful for understanding the embodiments described herein are illustrated and described in detail. In particular, not all components of the substrate assembly are described in detail, and the embodiments are compatible with common substrate assemblies in optical sensor modules. For example, light emitting devices, light receiving sensors, and other components of optical sensors (such as processing devices or circuitry) are not described in detail. Similarly, not all components of the optical sensor module are described in detail, and the embodiments are compatible with common optical sensor modules.

[0048] Unless otherwise stated, when referring to two elements connected together, it means a direct connection without any intermediate elements other than the conductor; when referring to two elements coupled together, it means that the two elements can be connected or they can be coupled via one or more other elements.

[0049] In the following disclosure, unless otherwise stated, when referring to absolute position qualifiers (such as the terms "front", "back", "top", "bottom", "left", "right", etc.) or relative position qualifiers (such as the terms "above", "below", "higher", "lower", etc.) or orientation qualifiers (such as "horizontal", "vertical", etc.), the orientation shown in the accompanying drawings shall be used, or the orientation of the substrate assembly or optical sensor module during normal use shall be used.

[0050] Unless otherwise stated, the expressions “approximately,” “around,” “substantially,” and “around” indicate within 10%, preferably within 5%.

[0051] In the following disclosure, unless otherwise stated, when referring to glass, this includes elements made of materials that are relatively transparent to light at the wavelengths used (e.g., have a transmittance of 90% or higher for these wavelengths). This includes, but is not limited to, glass materials or plastic materials. Glass can be formed from a single solid material or by combining multiple materials, in which case only a portion of the glass may be a transparent material. Glass may include, or consist of, lenses or multiple lenses and / or optical filters.

[0052] In the following disclosure, unless otherwise stated, when referring to a conductive element, it refers to a part that conducts electricity.

[0053] In this disclosure, unless otherwise stated, when referring to a component, reference is made to an electronic component.

[0054] The term "optical sensor module" includes, but is not limited to, proximity sensor modules, time-of-flight (ToF) modules, ambient light sensor (ALS) modules, 3D LiDAR modules, and / or camera modules. The term "optical sensor module" also includes optical sensor modules with combined functions (e.g., a combination of at least two of the modules mentioned above) or other functions (e.g., a combination of a proximity detector module with a floodlight and / or a dot projector).

[0055] The embodiments relate to optical sensor modules. Optical sensors typically include light-emitting devices, such as light-emitting diodes (LEDs) or lasers such as vertical-cavity surface-emitting lasers (VCSELs), and light-receiving sensors, such as photodiodes or multiple photodiodes. Optical sensors generally also include processing devices or circuitry for processing signals received from the light-receiving sensor. The light-emitting device and the light-receiving sensor can be formed on a substrate, and a module cap can be assembled onto the substrate on top of the light-emitting device and the light-receiving sensor to form an optical sensor module, also known as an optical sensor package. The light-emitting device may include multiple light sources, such as multiple VCSELs.

[0056] The term "substrate assembly" corresponds to a sub-component of an optical sensor module. A substrate assembly generally includes a substrate and components mounted on the substrate, such as light emitting devices and light receiving sensors. The module cap of an optical sensor module is typically assembled onto the substrate on top of the components mounted on the substrate.

[0057] Optical sensor modules may be affected by electromagnetic interference (EMI) from another electronic device.

[0058] For example, when an optical sensor module is included in an electronic device (host device), electromagnetic interference (EMI) may occur between the optical sensor module and the host device. The host device may be a camera, a telephone (e.g., a smartphone), a smartwatch, a tablet, a vehicle, or another device that can be useful for detecting the presence of nearby objects and / or the distance to nearby objects.

[0059] Electromagnetic interference between the optical sensor module and the host device can include:

[0060] - Electromagnetic waves emitted by components of the optical sensor module that may affect components of the host device; and / or

[0061] - Electromagnetic waves emitted by the host device that may affect the performance of the optical sensor module.

[0062] For example, potential sources of electromagnetic waves emitted by an optical sensor module can be light emitting devices (e.g., light sources from light emitting devices such as VCSELs), drivers (such as laser drivers), inductors, or even conductive lines (wire bonding).

[0063] In addition, environments with large electromagnetic waves (such as data centers) can also interfere with the components of optical sensor modules and affect their performance.

[0064] In some applications, controlling the effects of EMI is important, such as protecting electronic components and circuits from EMI.

[0065] One solution to the electromagnetic interference problem is to add a single metal shield over the electromagnetically sensitive component.

[0066] However, a single metal shield has several drawbacks. A single metal shield may require a large opening in the optical path. Depending on the methods used, the fabrication of the metal shield may introduce numerous steps, such as assembly steps, leading to high costs and potentially altering or affecting the operation of some components of the optical sensor module. Fabrication may also introduce slots or gaps in the metal shield, such as for the assembly or cleaning of surface mount technology (SMT) components, which allows electromagnetic waves to pass through, potentially becoming a source of EMI leakage. The optical path may also be affected by a single metal shield, resulting in an increased or uncontrolled level of external crosstalk in the optical sensor module.

[0067] The inventors have proposed an optical sensor module that enables the use of efficient and simple EMI protection that reduces EMI leakage and / or increases EMI shielding to overcome all or some of the aforementioned drawbacks, particularly addressing electromagnetic interference issues. This avoids altering the operation of some components of the optical sensor module and preferably avoids increasing the footprint of the optical sensor module and complicating the manufacturing process.

[0068] It can also be expected that the optical sensor module can manage electromagnetic interference through EMI-protected openings.

[0069] Embodiments of a substrate assembly for an optical sensor module will now be described. These embodiments are not limiting, and various variations will occur to those skilled in the art based on the instructions in this description.

[0070] Figure 1A This is a three-dimensional view of the substrate assembly 100 of the optical sensor module according to an embodiment. Figure 1B yes Figure 1A A cross-sectional view of the substrate assembly 100. Figure 1B The cross-sectional view shows along Figure 1A The substrate assembly 100 shown is cut in the AA direction.

[0071] The substrate assembly 100 includes a plurality of components mounted on the top surface 101A of the substrate 101.

[0072] The substrate assembly 100 includes a light emitting device 110, such as an LED (e.g., an infrared LED) and / or a laser (e.g., a VCSEL or an edge-emitting laser (EEL)), and a light receiving sensor 120, such as a photodiode or multiple photodiodes (e.g., one or more SPADs). The light emitting device 110 and the light receiving sensor 120 are mounted on the top surface 101A of the substrate 101. The light emitting device 110 may include multiple light sources.

[0073] The substrate 101 may be a printed circuit board (PCB).

[0074] The light emitting device 110 is configured to emit a light signal at a specific frequency or frequency range, while the light receiving sensor 120 is adapted to detect the returned emitted light signal, such as a light signal reflected by an object. In one embodiment, the light emitting device 110 is configured to emit an infrared (IR) light signal, while the light receiving sensor 120 is adapted to detect the returned IR light signal, such as an IR light signal reflected by an object.

[0075] For example, the light emitting device 110 may include a first light source 111 and a second light source 112, each of which is mounted on the top surface 101A of the substrate 101, as described below. Figure 2D What we see in the video. Figure 1A and Figure 1B Only the second light source 112 is shown. The first light source 111 and the second light source 112 are, for example, a first VCSEL and a second VCSEL. The light emitting device 110 may also include a photodiode 113 mounted on the top surface 101A of the substrate 101. The photodiode 113 may be dedicated to monitoring the light source.

[0076] In one variant, the light emitting device may include only one light source. In another variant, the light emitting device may include more than two light sources.

[0077] In one variation, the light-emitting device may not include a photodiode and / or may include another component that monitors one or more light sources. In another variation, the light-emitting device may include more than one photodiode.

[0078] The light emitting device 110 can be electrically coupled to the light receiving sensor 120, for example, via the substrate 101.

[0079] The substrate assembly 100 may include a driver 103, such as a laser driver, configured to control the light emitting device 110, and a processing circuit 104 for processing the optical signals emitted by the light emitting device 110 and received by the light receiving sensor 120. The driver 103 and the processing circuit 104 may be mounted on the top surface 101A of the substrate 101. The driver 103 may be mounted on the substrate 101, for example, using a ball grid array (BGA) technique.

[0080] The substrate assembly 100 may include other electrical circuitry or components, such as an inductor 105 or other surface mount technology (SMT) components 106 also mounted on the top surface 101A of the substrate 101. Other SMT components 106 may include resistors. Additional SMT components may include capacitors.

[0081] A light emitting device 110, including light sources 111, 112 and photodiode 113, driver 103, inductor 105 and some other SMT components 106, is mounted on a first region 101R of substrate 101.

[0082] The substrate assembly 100 also includes a first metal shield 130 mounted on a first region 101R of the substrate 101. The shape and size of the first metal shield 130 are preferably configured to surround and at least partially cover the components mounted on the first region 101R (at least the light emitting device 110, the driver 103, and the inductor 105). Thus, the first metal shield 130 advantageously surrounds potential sources of electromagnetic waves emitted by the components of the substrate assembly.

[0083] The first metal shield 130 has a sidewall 130B that is joined to the top wall 130A.

[0084] The first metal shield 130 may be referred to as a metal shielding assembly, or may be included in a metal shielding assembly.

[0085] The first metal shield 130 is electrically coupled to the substrate 101, preferably to the ground trace or ground rail of the substrate 101, to further improve the effectiveness of EMI protection, for example, for effective absorption of electromagnetic waves.

[0086] The first metal shield 130 includes a first opening 131 formed in the top wall 130A, which provides an optical path for light emitted by and optionally transmitted to the light emitting device 110, i.e., allows light emitted by and optionally transmitted to the light emitting device to pass through.

[0087] The shape and size of the first opening 131 are also designed to allow the light emitting device 110 (i.e., one or more light sources) and optionally a photodiode to be vertically inserted into the first metal shield 130 through this first opening for mounting onto the substrate 101. The size of the first opening 131 may include sufficient clearance to allow these components to be mounted onto the substrate 101 through this first opening, depending on the surface mounting method used.

[0088] For example, as shown in the figure, in a first plane parallel to the plane of substrate 101, the area of ​​the first opening 131 can be at least equal to the area of ​​one or more light sources and optionally photodiodes in the first plane, for example, the area of ​​one or more light sources and optionally photodiodes adjusted to be the area of ​​one or more light sources and optionally photodiodes. This allows the area of ​​the first opening to be limited to the area strictly necessary for mounting to avoid increasing EMI leakage.

[0089] The area of ​​the first opening 131 can be a trade-off between EMI protection and mounting (one or more) light sources and optionally photodiodes onto the substrate 101 through this first opening.

[0090] The first opening 131 is configured to mount one or more light sources and optionally photodiodes on the substrate 101 after the first metal shield 130 is assembled onto the substrate 101, for example, to prevent the light emitting device 110 from being affected or altered during the assembly of the first metal shield 130 onto the substrate 101. For example, this can prevent contamination of the light emitting device 110 during assembly steps such as a reflow step.

[0091] In the variant, instead of a single first opening, there can be multiple first openings, which do not necessarily join together.

[0092] The metal of the first metal shield 130 is preferably selected to reflect and / or absorb electromagnetic waves generated by components mounted on the first region 101R, to prevent electromagnetic waves from leaving the substrate assembly 100 and the optical sensor module, and, for example, to prevent interference with the host device. The metal of the first metal shield 130 may also be selected to reflect and / or absorb electromagnetic waves generated by another electronic device (such as the host device) or from the environment, to prevent electromagnetic waves from affecting the performance of components of the optical sensor module mounted on the first region. The metal of the first metal shield is, for example, copper or a copper alloy, stainless steel, or any conductive material also having a relative permeability greater than 1.

[0093] The first metal shield 130 also includes an absorber layer 132, or EMI absorber layer, located on the inner surface of the top wall 130A of the first metal shield. The absorber layer 132 faces the light emitting device 110. The absorber layer comprises a material suitable for absorbing electromagnetic waves, such as CHO-MUTE from Parker Chomerics. TM Commercially available EMI absorber materials, such as those from DoosungCorp under the names IDSOB and IDCIM, or those from Laird. The absorber layer 132 has an opening facing the first opening 131, and its area is preferably equal to or greater than the area of ​​the first opening.

[0094] Although Figure 1A and Figure 1BNot shown, but an optical sensor module generally includes a module cap assembled to a substrate assembly 100 and adapted to at least partially enclose or cover components (at least a light emitting device and a light receiving sensor) mounted on the substrate. The module cap also covers a metal shielding assembly. "At least partially" means that not all components may be covered. For example, the module cap generally includes a first cap opening above the light emitting device and a second cap opening above the light receiving sensor. The first cap opening preferably faces a first opening of a first metal shielding member and has an area preferably equal to or greater than the area of ​​this first opening. The module cap may be substantially opaque to light at the wavelength used. The module cap can be mounted on... Figure 1A The opaque adhesive 140 shown is attached to the substrate 101. The module cap may include a partition wall between the light emitting device and the light receiving sensor to form an optical isolator for substantially preventing the propagation of a light beam within the light emitting device and the light receiving sensor.

[0095] Figure 2A , Figure 2B , Figure 2C and Figure 2D This is an example of manufacturing. Figure 1A and Figure 1B Top view and three-dimensional view of an example of a method for using substrate assembly 100.

[0096] Figure 2A This is a top view of the initial structure including substrate 101. Inductor 105 and other SMT components 106 are mounted on a first region 101R of substrate 101. Driver 103 can also be mounted on the first region 101R using surface mount assembly techniques such as ball grid array technology.

[0097] The first region 101R includes a first conductive pad 102A adapted to receive and connect light sources 111, 112 and photodiode 113, and a second conductive pad 102B corresponding to or connected to the ground trace of substrate 101.

[0098] Figure 2B This is a top view of the structure obtained by assembling a first metal shield 130, including an absorbent layer 132, on a substrate 101.

[0099] The first metal shield 130 can be assembled onto the substrate 101 using surface mount technology, for example, by forming solder paste dots on the second conductive pad 102B and bringing the first metal shield 130 into contact with the solder joint, followed by reflowing the solder paste to form a solder joint 133. Other soldering techniques can be used. Alternatively, conductive adhesives or other electrical coupling means between the first metal shield and the ground trace on the substrate can be used for assembly.

[0100] At the end of this assembly step, the first metal shield 130 is attached to the substrate 101 and makes electrical contact with the second conductive pad 102B, thereby making electrical contact with the ground trace.

[0101] Figure 2C This is a three-dimensional view of the structure during the insertion of the first light source 111, the second light source 112, and the photodiode 113 into the first metal shield 130 through the first opening 131.

[0102] Then, the first light source 111, the second light source 112, and the photodiode 113 are mounted on the substrate 101, for example, using a die-attachment process.

[0103] Figure 2D This is a top view of the structure obtained, for example, after each of the first light source 111 and the second light source 112, and possibly a photodiode 113, has been electrically connected to the substrate 101 through the first opening 131 using wire bonding technology. As an example, such as... Figure 2D As shown, conductive line 114 connects each light source to the third conductive pad 102C of substrate 101, but other techniques can also be used to connect the light source to the substrate.

[0104] In some embodiments, such as Figure 2D As shown in the plan view, the first conductive pad 102A, on which one or more light sources and optionally photodiodes are positioned, is fully visible through the first opening 131. In other words, the vertical projection of the first opening 131 onto the substrate 101 completely encompasses the area occupied by the first conductive pad 102A on the substrate 101. This means that, advantageously, the light source(s) and optionally photodiodes can be directly and vertically lowered through the first opening 131 to reach their final positions on the substrate 101 and can be wire-bonded to these first conductive pads.

[0105] The light receiving sensor 120 and other components (such as the processing circuit 104) can then be mounted on the substrate 101.

[0106] Therefore, components of the substrate assembly 100 that can act as electromagnetic sources (such as the light emitting device 110, driver 103, inductor 105, or even conductive line 114) are at least partially surrounded or contained within the first metal shield 130. The first metal shield 130 allows for the absorption and reflection of electromagnetic waves emitted by these components. The first metal shield 130 also allows for the protection of these components from electromagnetic waves supplied from outside the first metal shield or even from outside the optical sensor module. Furthermore, the absorbent layer 132 of the first metal shield 130 allows for better absorption of electromagnetic waves emitted by electromagnetic sources, such as those emitted by the light emitting device 110, driver 103, inductor 105, and / or conductive line 114, thereby reducing the EMI power intensity within this first metal shield and thus reducing EMI leakage. Therefore, the first metal shield 130, including the absorbent layer 132, allows for reduced EMI leakage (e.g., leakage from through the first opening 131), thereby providing efficient EMI protection.

[0107] Figure 3A This is a three-dimensional view of the substrate assembly 300 of an optical sensor module according to another embodiment. Figure 3B It is shown Figure 3A A detailed cross-sectional three-dimensional view of the substrate assembly 300. Figure 3B The three-dimensional view of the cross section shows that Figure 3A The details of the substrate assembly 300 cut in the BB direction are shown, which is slightly less than half its width, and make it easier to see the different parts of the substrate assembly located below the first metal shield.

[0108] Figure 3A and Figure 3B substrate assembly 300 and Figure 1A and Figure 1B The main difference in the substrate assembly is that the first opening 131 of the first metal shield 130 is covered by glass 350 including conductive traces 351. The conductive traces 351 in the glass 350 allow EMI in the first opening 131 to be managed, for example by providing EMI reflection in the first opening, thereby limiting EMI leakage and providing efficient EMI protection even if the first opening is large.

[0109] The first metal shield 130 may be referred to as a metal shielding assembly, or may be included in a metal shielding assembly.

[0110] The conductive trace material can be one or more of the following materials: copper (Cu), aluminum (Al), indium tin oxide (ITO), tungsten (W), titanium (Ti), and gold (Au).

[0111] Figure 3A and Figure 3BThe conductive traces 351 shown form a grid or grating having multiple first linear portions 351A that are substantially parallel in a first direction of the glass plane and multiple second linear portions 351B that are substantially parallel in a second direction of the glass plane. The first and second directions are, for example, substantially perpendicular to each other. Two adjacent first linear portions are separated by a first distance or a first pitch in the first direction, while two adjacent second linear portions are separated by a second distance or a second pitch in the second direction. Each of the first and second distances is, for example, less than or equal to a small fraction of the wavelength λ as defined above.

[0112] Each linear portion of the conductive trace 351 can be a thin portion, for example, having a thickness of less than 100 nanometers. The first pitch between the first linear portions 351A and the second pitch between the second linear portions 351B can be determined according to the frequency of the EMI to be managed. For example, the higher the frequency, the smaller the pitch can be.

[0113] Each pitch is, for example, smaller than the wavelength λ of the electromagnetic signal to be attenuated, and is, for example, a fraction of the wavelength λ, where λ is equal to:

[0114] λ=v / f

[0115] Where v is the speed of light, and f is the frequency of the electromagnetic wave to be attenuated.

[0116] The thickness and pitch of the conductive trace 351 can be a trade-off between EMI protection and the light transmittance of the glass 350. For example, when the conductive trace is unlikely to affect the desired quality of light transmission, the conductive trace can be thicker and / or the pitch can be lower; alternatively, when the conductive trace may affect the desired quality of light transmission, the conductive trace can be thinner and / or the pitch can be higher.

[0117] A grid is an example of a pattern that can be used to form conductive traces. Those skilled in the art can envision different patterns for conductive traces. For example, conductive traces may include portions that are not perpendicular to each other, such as a zigzag pattern, thereby allowing for minimal distance between patterns.

[0118] Advantageously, the conductive trace 351 is grounded to provide additional EMI protection. For example, the conductive trace 351 is electrically coupled to, for example, in contact with, the first metal shield 130, and coupled through the first metal shield 130 to the ground trace of the substrate 101.

[0119] An example of a conductive trace is described in more detail in French patent application No. 2311561 (law firm reference number B22689), filed on October 25, 2023, in the name of STMICROELECTRONICS INTERNATIONAL NV, which is incorporated herein by reference to the fullest extent permitted by law.

[0120] Figure 3A and Figure 3B Other features of the substrate assembly 300 can be combined with Figure 1A and Figure 1B The features are similar to those of the substrate assembly 100. And... Figure 1A and Figure 1B The variants of the substrate assembly 100 described herein may also be applied. Figure 3A and Figure 3B The substrate assembly 300. With Figure 1A and Figure 1B Similarly, the optical sensor module, Figure 3A and Figure 3B The optical sensor module typically includes a module cap assembled onto the substrate assembly 300.

[0121] Figure 3B An EMI absorber layer 132 is shown on the inner surface of the top wall 130A of the first metal shield 130. In a variant, Figure 3A and Figure 3B The substrate assembly 300 may not include an EMI absorber layer.

[0122] Figure 3A and Figure 3B The first opening 131 shown has a similar Figure 1A and Figure 1B The first opening has a roughly the same area, but this is not restrictive.

[0123] Figure 4 This is an example used in manufacturing Figure 3A and Figure 3B 300 substrate components Figures 2A to 2D A variant of the method for creating a 3D view.

[0124] from Figure 2D The construction begins by positioning a glass 350 with conductive traces 351 on the top wall 130A of the first metal shield 130 to cover the first opening 131 and allow the conductive traces 351 to contact the first metal shield 130. The conductive traces 351 are then assembled to the top wall 130A, for example, using a conductive adhesive (such as conductive epoxy resin). Preferably, this assembly ensures electrical connection between the conductive traces 351 and the first metal shield 130.

[0125] The light receiving sensor 120 and other components (such as the processing circuit 104) can then be mounted on the substrate 101.

[0126] Figure 5A This is a three-dimensional view of the substrate assembly 500 of an optical sensor module according to another embodiment. Figure 5B It is shown Figure 5A A detailed cross-sectional three-dimensional view of the substrate assembly 500. Figure 5C yes Figure 5A A 3D view of a variant of the substrate assembly. Figure 5B The three-dimensional view of the cross section shows that Figure 5A The details of the substrate assembly 500, cut in the CC direction to approximately one-third of its width, are shown, making it easier to see the different components of the substrate assembly located beneath the first and second metal shields.

[0127] Figures 5A to 5C substrate assembly 500 and Figure 1A and Figure 1B The main difference in the substrate assembly is that the first opening 531 of the first metal shield 530 does not need to be adjusted to the dimensions of the light source(s) and optionally the photodiode(s) on the substrate 101, including mounting gaps. In other words, there is no need to find a trade-off between EMI protection and mounting through the first opening 531, and the first opening 531 can have a large area. Furthermore, the substrate assembly 500 includes a second metal shield 534 adapted to be assembled onto the first metal shield 530 over the first opening 531 once the light emitting device 110 is mounted and electrically connected to the substrate 101. The shape and size of the second metal shield 534 are preferably adapted to cover the first opening 531. For example, the second metal shield 534 is adapted to seal the first opening 531.

[0128] The first metal shield 530 and the second metal shield 534 form a metal shielding assembly.

[0129] The metal of the second metal shield 534 is preferably selected to reflect and / or absorb:

[0130] - Electromagnetic waves generated by components mounted on the first region 101R, to prevent electromagnetic waves from leaving the substrate assembly 100 and also to prevent electromagnetic waves from leaving the optical sensor module, and to prevent, for example, from affecting the host device.

[0131] - Electromagnetic waves generated by another electronic device (such as a host device) or electromagnetic waves from the environment, to prevent electromagnetic waves from affecting the performance of components of the optical sensor module mounted on the first area.

[0132] The metal of the second metal shield can be the same as the metal of the first metal shield.

[0133] Metal shielding components advantageously surround potential sources of electromagnetic waves emitted by components of the substrate assembly 500 mounted on the first region 101R of the substrate 101, such as the light emitting device 110 and the driver 103 (described below). Figure 6A (See in the middle).

[0134] For example, such as Figure 5B As shown, the second metal shield 534 is larger than the first opening 531 and is positioned overhanging on either side of the first opening. Solder or conductive adhesive 536, positioned on the top wall 530A of the first metal shield 530 and the edge of the second metal shield 534, seals the metal shield assembly. The use of solder or conductive adhesive allows the second metal shield to be electrically connected to the first metal shield, for example, by coupling the second metal shield to ground through the first metal shield. This assembly technique is a non-limiting example, and other assembly techniques can be envisioned by those skilled in the art. For example, the second metal shield may be assembled below the first opening and / or the shape and size of the second metal shield may be adjusted to fit the first opening.

[0135] The first and second metal shields can be coupled or joined to each other by welding (such as laser welding).

[0136] The second metal shield 534 includes at least a second opening that provides an optical path for light emitted by and optionally transmitted to the light emitting device 110. Figures 5A to 5C The second metal shield 534 shown includes a plurality of second openings: two second openings 535A and 535B provide optical paths 501 and 502 for light emitted by the first light source 111 and the second light source 112, respectively, while another second opening 535C allows light transmitted to the photodiode 113 to pass through. The size of each second opening is designed (e.g., adjusted) for the optical path to be provided.

[0137] like Figure 5B As shown, in some embodiments, when viewed vertically through the second opening, one or more light sources and optionally photodiodes will at least partially conceal the first conductive pads 102A positioned thereon from the second metal shield 534. In other words, the vertical projection of the second opening onto the substrate 101 does not fully encompass the area occupied by these first conductive pads on the substrate 101.

[0138] Figures 5A to 5CThe metal shielding assembly allows for easier mounting and electrical connection of the light emitting device 110 (e.g., one or more light sources and optionally photodiodes) to the substrate 101 before the second metal shield 534 is assembled to the first metal shield 530. Simultaneously, once the second metal shield 534 is assembled, it limits the area of ​​the opening in the metal shielding assembly, which is preferably primarily dedicated to one or more optical paths, thereby limiting EMI leakage and providing efficient EMI protection. Furthermore, the first opening 531 can be larger than... Figure 1A and Figure 1B The first opening, 131, is easier to machine.

[0139] The second metal shielding element 534 can be substantially flat, such as... Figure 5C As shown, or it could be concave, such as Figure 5A and Figure 5B As shown in the image. Figure 5A and Figure 5B The recessed design allows for limiting the size of the second openings 535A, 535B, and 535C, as it allows these second openings to be positioned closer to the light sources 111 and 112 and / or the light-receiving photodiode 113 of the light emitting device 110, thereby providing better EMI shielding.

[0140] Figures 5A to 5C The first metal shield 530 does not include an EMI absorber layer. In the variant, Figures 5A to 5C The first metal shield 530 and / or the second metal shield 534 may include an EMI absorber layer.

[0141] Figures 5A to 5C Other features of the substrate assembly 500 can be combined with Figure 1A and Figure 1B The features are similar to those of the substrate assembly 100. And... Figure 1A and Figure 1B The variants of the substrate assembly 100 described herein may also be applied. Figures 5A to 5C The substrate assembly 500. With Figure 1A and Figure 1B Similarly, the optical sensor module, Figures 5A to 5C The optical sensor module typically includes a module cap assembled onto the substrate assembly 500.

[0142] Figures 5A to 5C The embodiments can be advantageously combined with Figure 3A and Figure 3B The embodiment combination is a glass assembly including conductive traces that at least partially covers the second opening of the second metal shield. The conductive traces are preferably electrically coupled to the second metal shield, for example, in contact with the second metal shield, and can be coupled to ground through the second metal shield.

[0143] Figure 6A and Figure 6B This is an example used in manufacturing Figures 5A to 5C 500 substrate components Figures 2A to 2D The method includes variations of top-view and 3D views.

[0144] Figure 6A This is a top view of the initial structure. Except that the first metal shield 530 has a larger first opening 531 and this first opening has a simpler shape, the structure is similar to... Figure 2D The structure of the light emitting device 110 is as follows: the first light source 111, the second light source 112, and the photodiode 113 are mounted and electrically connected to the substrate 101 through this larger first opening 531.

[0145] Figure 6B This is a three-dimensional view of the structure obtained, for example, after assembling the second metal shield 534 to the first metal shield 530 to cover the first opening 531 using solder or conductive adhesive 536.

[0146] Figure 7 This is a three-dimensional view of the substrate assembly 700 of an optical sensor module according to another embodiment.

[0147] Figure 7 The substrate assembly 700 and Figure 1A and Figure 1B The main difference in the substrate assembly is that the first opening 731 of the first metal shield 730 (described below) Figure 8A As can be seen, it is not necessary to adjust the dimensions of the light source(s) and optional photodiode(s) to accommodate mounting of the light source(s) and optional photodiode(s) onto the substrate 101, including the mounting gap, similar to... Figures 5A to 5C In other words, there is no need to find a trade-off between EMI protection and mounting of the first opening, and the first opening 731 can have a large area. In addition, the substrate assembly 700 also includes a second metal shield 734, which is adapted to be assembled onto the first metal shield over the first opening 731 once the light emitting device 110 is mounted and electrically connected to the substrate 101.

[0148] Figure 7 The substrate assembly 700 and Figures 5A to 5C The main difference in the substrate assembly is that the second metal shield 734 not only covers the first opening 731, but also covers the top wall 730A of the first metal shield 730 (top wall 730A is described below). Figure 8A (See in the middle).

[0149] The first metal shield 730 and the second metal shield 734 form a metal shielding assembly. For example, the first metal shield 730 forms a metal frame, while the second metal shield 734 forms a metal cover.

[0150] The metal shielding assembly advantageously surrounds potential sources of electromagnetic waves emitted by components of the optical sensor module mounted on the first region 101R of the substrate 101, such as the light emitting device 110, the driver 103, and the inductor 105 (described below). Figure 8A (See in the middle).

[0151] exist Figure 7 In this configuration, the second metal shield 734 is substantially flat. This is not limiting, and those skilled in the art can envision other shapes. For example, in variations, the second metal shield may be recessed, or may have recessed portions, such as on a light-emitting device, as... Figure 5A and Figure 5B The second metal shield 534.

[0152] For example, such as Figure 7 As shown, the second metal shield 734 can be assembled to the sidewall 730B of the first metal shield 730. More specifically, the second metal shield 734 has a top wall 734A with edges 734B that are substantially orthogonally curved and extend relative to the top wall. These edges are conformally oriented to seal the upper edges of at least some of the sidewalls 730B of the first metal shield 730. The second metal shield 734 also includes a retaining tab 736 adapted to cooperate with a groove 733 positioned in the top wall 730A of the first metal shield 730.

[0153] This assembly technique ensures electrical connection between the second metal shield 734 and the first metal shield 730 without the need for conductive adhesives or solders. Therefore, the second metal shield 734 can be coupled to ground through the first metal shield 730. Figure 7 The assembly of the second metal shield 734 can be compared to Figures 5A to 5C Assembling the second metal shield 534 is easier. This assembly technique is a non-limiting example, and those skilled in the art can encompass other assembly techniques by using or not using conductive adhesives or solder. For example, the second metal shield may include clips adapted to clamp onto the sidewalls of the first metal shield, or may be inserted into the interior of the first metal shield and in contact with the sidewalls of the first metal shield, or the second metal shield may be assembled to the top wall of the first metal shield.

[0154] The top wall 734A of the second metal shield 734 includes at least a second opening that provides an optical path for light emitted by the light emitting device 110 and optionally transmitted to the light emitting device 110. Figure 7 The second metal shield 734 shown includes a plurality of second openings: two second openings 735A and 735B provide optical paths for light emitted by the first light source 111 and the second light source 112, respectively, and another second opening 735C allows light transmitted to the photodiode 113 to pass through. The size of each second opening is designed (e.g., adjusted) for the optical path to be provided.

[0155] The top wall 734A of the second metal shield 734 may also include a third opening 737, which is adapted to approach the fixing tab 736 to clamp it, and / or to position the second metal shield 734 relative to the first metal shield 730.

[0156] The top wall 730A of the first metal shield 730 may also include a fourth opening 732 located above the inductor 105, as described below. Figure 8A As shown, for visual inspection.

[0157] exist Figure 7 In the first metal shield 730 and the second metal shield 734, neither includes an EMI absorber layer. In the variant, Figure 7 The first metal shield 730 and / or the second metal shield 734 may include an EMI absorber layer on their inner top surface.

[0158] Figure 7 The embodiments can be related to Figure 3A and Figure 3B The embodiment combination is a combination of glass including conductive traces that at least partially covers a second opening and / or a third opening of the second metal shield. The conductive traces are preferably electrically coupled to the second metal shield, for example, in contact with the second metal shield, and can be coupled to ground through the second metal shield.

[0159] Figure 7 Other features of the substrate assembly 700 can be combined with Figure 1A and Figure 1B The features of the substrate assembly 100 are similar. And... Figure 1A and Figure 1B The variants of the substrate assembly 100 described herein may also be applied. Figure 7 The substrate assembly 700. With Figure 1A and Figure 1B Similarly, the optical sensor module, Figure 7 The optical sensor module typically includes a module cap assembled onto the substrate assembly 700.

[0160] In some embodiments, when viewed vertically through the second opening, the first conductive pads 102A on which one or more light sources and optionally photodiodes are positioned are at least partially hidden by the second metal shield 734. In other words, the vertical projection of the second opening onto the substrate 101 does not fully encompass the area occupied by these first conductive pads on the substrate 101.

[0161] Figure 7 The metal shielding assembly allows for easier mounting and electrical connection of the light emitting device 110 (e.g., one or more light sources and optionally photodiodes) to the substrate 101, and allows for inspection of the surface-mount components before assembling the second metal shield 734 to the first metal shield 730. Once the second metal shield 734 is assembled, it limits the area of ​​the opening in the metal shielding assembly. The second opening is preferably dedicated primarily to one or more optical paths, thereby limiting EMI leakage and providing efficient EMI protection.

[0162] Figure 8A and Figure 8B This is an example used in manufacturing Figure 7 700 substrate components Figures 2A to 2D The method includes variations of top-view and 3D views.

[0163] Figure 8A This is a top view of the initial structure, except that the first metal shield 130 is... Figure 7 In addition to replacing the first metal shield 730, this initial structure is consistent with... Figure 2D The structures are similar. The first light source 111 and the second light source 112 of the light emitting device 110, as well as the photodiode 113, have been mounted and electrically connected to the substrate 101 through the large first opening 731. The inductor 105 and other SMT components 106 are mounted on the substrate 101 and contained within the first metal shield 730.

[0164] Figure 8A A fourth opening 732 of the first metal shield 730 above the inductor 105 is shown, as well as a slot 733 adapted to cooperate with a retaining tab 736 of the second metal shield 734. Figure 8A As shown, the first opening 731 can extend over the driver 103 and also over some of the other SMT components 106, for example, for visual inspection.

[0165] Figure 8B This is a three-dimensional view of the structure obtained after assembling (e.g., clipping) the second metal shield 734 to the first metal shield 730, the assembly being, for example, by sealing the curved edge 734B of the second metal shield around the upper edge of the sidewall 730B of the first metal shield and by inserting the retaining tab 736 into the slot 733.

[0166] Various embodiments and variations have been described. It will be understood by those skilled in the art that certain features of these embodiments can be combined, and other variations will be readily apparent to them.

[0167] Finally, based on the functional descriptions provided above, the actual implementation of the embodiments and variations described herein is within the capabilities of those skilled in the art.

Claims

1. A substrate assembly for an optical sensor module, characterized in that, The substrate assembly includes: A light-emitting device mounted on a first region of a substrate; The metal shielding assembly includes a first metal shielding member assembled onto a substrate over a first region; and The first metal shield includes a first opening, which provides an optical path for light emitted by the light emitting device. The first opening is sized so that the light emitting device can be inserted into the first metal shield through the first opening.

2. The substrate assembly as described in claim 1, characterized in that, A first metal shield is designed to enclose and at least partially cover a light-emitting device. The first metal shield includes sidewalls joined by a top wall, the top wall including a first opening.

3. The substrate assembly as described in claim 1, characterized in that, The optical emitting equipment includes: At least one light source, wherein a first opening provides an optical path for light emitted by the at least one light source and is sized such that the at least one light source can be inserted through the first opening into the interior of a first metal shield and mounted onto a substrate; and A photodiode is configured as a monitoring light emitting device. The first opening also provides an optical path for the light transmitted to the photodiode, and is further sized so that the photodiode can be inserted through the first opening into the interior of the first metal shield and mounted on the substrate.

4. The substrate assembly as claimed in claim 1, characterized in that, It also includes a driver mounted on a first region of the substrate, the driver being configured to control a light emitting device.

5. The substrate assembly as described in claim 4, characterized in that, The first opening extends onto the drive.

6. The substrate assembly as claimed in claim 1, characterized in that, The first metal shield is electrically coupled to the substrate, including a ground trace electrically coupled to the substrate.

7. The substrate assembly as claimed in claim 1, characterized in that, The metal shielding assembly further includes a second metal shielding member assembled to the first metal shielding member and at least partially covering the first opening, the second metal shielding member including at least a second opening that allows light emitted by or transmitted to the light emitting device to pass through, the second metal shielding member being electrically coupled to or in contact with the first metal shielding member.

8. The substrate assembly as claimed in claim 7, characterized in that, The second metal shield includes a recessed portion extending into the interior of the metal shield assembly.

9. The substrate assembly as claimed in claim 7, characterized in that, The second metal shield seals the first opening.

10. The substrate assembly as claimed in claim 7, characterized in that, The second metal shield at least partially closes the first metal shield.

11. The substrate assembly as claimed in claim 1, characterized in that, The metal shielding assembly includes an absorbent layer positioned on the inner surface of the metal shielding assembly facing the light emitting device, including positioning on the inner surface of the first metal shield facing the light emitting device.

12. The substrate assembly as claimed in claim 1, characterized in that, It also includes glass assembled to a first metal shield over a first opening, the glass including electrically conductive traces electrically coupled to or in contact with the first metal shield, including ground traces coupled to a substrate through the first metal shield.

13. The substrate assembly as claimed in claim 1, characterized in that, The metal in a metal shielding assembly is selected to reflect or absorb electromagnetic waves, wherein the metal is copper, copper alloy, stainless steel, or any conductive material that also has a relative permeability greater than 1.

14. An optical sensor module, characterized in that, include: The substrate assembly as described in claim 1; as well as A module cap, assembled to a substrate and adapted to at least partially cover a metal shielding assembly and components mounted on the substrate.

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