Optical sensor module

Abstract

Optical Sensor Module This description relates to an optical sensor module (100) comprising: - a light-emitting device (110); - a module cover (130) adapted to at least partially cover the light-emitting device, the module cover (130) comprising a first opening (131) located above the light-emitting device; - at least one conductive strip (134) assembled with, or included in, the module cover; - a lens (150) positioned in and / or covering the first opening, and adapted to transmit the light signals emitted by the light-emitting device, the lens comprising a conductive trace (152); and - at least one conductive wire (155) formed by wiring, the at least one conductive wire electrically connecting the conductive trace to the at least one conductive strip. Figure for the abbreviation: Fig. 1

Description

Title of the invention: Optical sensor module technical field

[0001] This description relates generally to optical sensors, in particular optical sensor modules. Previous technique

[0002] Optical sensors, such as proximity sensors, can be used to detect the presence of nearby objects. Optical sensors are capable of doing this without physically touching the object. Certain types of optical sensors, such as those used in optical rangefinder devices or time-of-flight sensors, can be used to determine the actual distance to these nearby objects. Optical sensors can be used in various electronic devices, such as cameras, telephones (including smartphones), smartwatches, tablets, vehicles, machines, and other devices to detect the presence of nearby objects and / or the distance between them.After detecting the presence of a nearby object, the electronic device can be configured to perform a function, for example, moving a mechanical element to a safe position, transmitting an alarm signal, activating or deactivating electrical communication, or any other desired function.

[0003] Optical sensors generally comprise components such as a light-emitting device, a light-receiving sensor (or image sensor), and, typically, a device for processing the signals received from the light-receiving sensor. The optical sensor components can be formed on a substrate, and a cover can be bonded to the substrate over the components, for example, to protect them from damage, thus forming an optical sensor module, also called an optical sensor housing. The cover generally consists of a first opening located above the light-emitting device and a second opening located above the light-receiving sensor.

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

[0005] The light-emitting device used to generate the light beam is generally covered with glass to protect it from dust, the glass being relatively transparent to light at the wavelengths used. The first opening, located above the light-emitting device, may be covered by the glass. The glass may also act as a diffuser, reducing the intensity of the emitted light beam to some extent, for example, for safety reasons, such as protecting a user. However, if the glass is detached, broken, or otherwise removed from the surface of the light-emitting device, the intensity of the light emitting device may be such that it could cause damage, for example, to the user's eyes.

[0006] It is necessary to improve the optical sensor modules, in particular to address the aforementioned safety problem related to the light-emitting device.

[0007] It may also be necessary to manage electromagnetic interference (EMI) between an optical sensor module and another electronic device, particularly through hood openings. Summary of the invention

[0008] One embodiment overcomes all or part of the drawbacks of known optical sensor modules.

[0009] One embodiment provides an optical sensor module comprising: - a light-emitting device; - a module cover adapted to at least partially cover the light-emitting device, the module cover including a first opening located above the light-emitting device; - at least one conductive strip assembled with, or included in, the module cover; - a lens positioned in the first opening or between the first opening and the light-emitting device, and / or covering the first opening, and adapted to transmit the light signals emitted by the light-emitting device, the lens including a conductive trace; and - at least one conductive wire formed by welding wire, at least one conductive wire electrically connecting the conductive trace to at least one conductive strip.

[0010] In one embodiment, the material of each conducting wire comprises one or more of the following materials: gold, copper, aluminum, silver or a tin alloy.

[0011] In one embodiment, at least one conductive wire is configured to have a flexibility to absorb dimensional changes between the glass, the module cover and at least one conductive strip.

[0012] In one embodiment, at least one conducting wire has a thickness less or equal to 40 pm, for example less than or greater than 20 pm, and / or a length less than or equal to 2 mm.

[0013] In one embodiment, the module further comprises a substrate with which the module cover is assembled, the at least one conductive strip being coupled to at least one first conductive pad of the substrate, for example using a conductive adhesive material.

[0014] In one embodiment, the substrate includes a conductive rail configured to be at a fixed voltage, for example to ground, the conductive rail being coupled to one of at least one first conductive pad.

[0015] In one embodiment, the glass further includes at least one second conductive pad coupled to the conductive trace, for example at least one second conductive pad is connected to one end of the conductive trace, at least one conductive strip being coupled to at least one second conductive pad using at least one conductive wire.

[0016] In one embodiment, at least one conductive wire and / or the connection of said at least one conductive wire is designed to break if the glass detaches from the module cover.

[0017] In one embodiment, the module further includes a detection circuit adapted to detect the break of a conductive loop formed by at least one conductive strip, at least one conductive wire and the conductive trace, the detection circuit being configured to deactivate the light-emitting device if it detects an open circuit in the conductive loop.

[0018] In one embodiment, the conductive trace provides shielding against electromagnetic interference.

[0019] In one embodiment, at least one conductive strip is inserted into at least one channel of the module hood.

[0020] In one embodiment, at least one conductive strip is at least one conductive cable, for example at least one connecting grid.

[0021] In one embodiment, at least one conductive strip is at least one flexible connection overmolded into the module hood.

[0022] In one embodiment, the glass is a lens or a lens support, the glass comprising for example at least one beam shaping device.

[0023] In one embodiment, the module cover: - is an injection-molded hood, the molding material being, for example, a resin; and / or - is a plastic module cover; and / or - includes a suitable material to provide shielding against electromagnetic interference.

[0024] In one embodiment, the module further comprises: - a light-receiving sensor at least partially covered by the module cover, the module cover including a second opening located above the light-receiving sensor; and - a filter in the second aperture, or covering the second aperture, and adapted to transmit reflected light signals to the light receiving sensor; the filter including for example a second conductive trace providing shielding against electromagnetic interference. Brief description of the drawings

[0025] These features and advantages, as well as others, will be described in detail in the following description of particular embodiments, given by way of non-limiting example, in relation to the accompanying figures, among which:

[0026] Fig. 1 is a three-dimensional view of an optical sensor module according to one embodiment;

[0027] Figures 2A and 2B are three-dimensional views of the optical sensor module cover of [Fig. 1]; and

[0028] Figures 3A, 3B, 3C and 3D are three-dimensional and top views illustrating a method of forming the optical sensor module of [Fig.1]. Description of the implementation methods

[0029] The same elements have been designated by the same reference numerals in the different figures. In particular, structural and / or functional elements common to the different embodiments may have the same reference numerals and may have identical structural, dimensional and material properties.

[0030] For the sake of clarity, only the steps and elements necessary for understanding the described embodiments have been shown and are detailed. In particular, not all components of an optical sensor have been detailed, as the described embodiments are compatible with conventional optical sensors. For example, the light-emitting device, the light-receiving sensor, and other components of an optical sensor, such as a processing device, have not been detailed. Similarly, not all components of an optical sensor module have been detailed, as the described embodiments are compatible with conventional optical sensor modules.

[0031] Unless otherwise specified, when referring to two elements connected between them, this means directly connected without intermediate elements other than conductors, and when referring to two elements connected (in English "coupled") to each other, this means that these two elements can be connected or linked via one or more other elements.

[0032] In the following description, when reference is made 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", "superior", "inferior", etc., or to orientation qualifiers, such as the terms "horizontal", "vertical", etc., reference is made, unless otherwise specified, to the orientation of the figures or to an optical sensor module in a normal operating position.

[0033] Unless otherwise specified, the expressions "approximately", "roughly", and "in the order of" mean within 10%, preferably within 5%.

[0034] In the following description, unless otherwise specified, references to a lens are made of a material that is relatively transparent to light at the wavelengths used, for example, having a transmission rate of 90% or more for those wavelengths. This material may be, among others, glass or plastic. The lens may be made of a single solid material or may be formed by combining several materials, in which case only a portion of the lens may be made of a transparent material. The lens may comprise or consist of a lens or a plurality of lenses, and / or an optical filter.

[0035] In the following description, unless otherwise specified, when a filter is referred to, an optical filter is referred to.

[0036] In the following description, unless otherwise specified, when reference is made to a conductive element, for example a trace, a stud, a strip or a conductive cable, reference is made to an electrically conductive element.

[0037] The term "optical sensor module" includes, but is not limited to, a proximity sensor module, a time-of-flight (ToF) module, an ambient light sensor (ALS) module, a 3D Lidar module, and / or a camera module. The term "optical sensor module" also includes an optical sensor module with combined functions, for example, a combination of at least two of the aforementioned modules, or other functions, for example, a combination of a proximity sensor module with a spotlight and / or a dot projector.

[0038] The embodiments relate to optical sensor modules. An optical sensor generally comprises a light-emitting device, including, for example, a light-emitting diode (LED) and / or a laser such as a vertical-cavity surface-emitting laser (VCSEL), and a light-receiving sensor, including, for example, a photodiode or a plurality of photodiodes. An optical sensor also generally includes a device for processing the signals received from the light-receiving sensor. The light-emitting device and the light-receiving sensor can be formed on a substrate, and a cover can be bonded to the substrate over the light-emitting device and the light-receiving sensor, thus forming an optical sensor module, also called a sensor housing. optical sensor. The hood is generally formed with a first opening located above the light-emitting device and with a second opening located above the light-receiving sensor.

[0039] As explained in the previous section on prior art, the light-emitting device used to generate the light beam is generally covered with glass to protect the device, for example, from dust, the glass being relatively transparent to light at the wavelengths used. The glass may cover the first aperture. The glass may also act as a diffuser to reduce the intensity of the emitted light beam to some extent, for example, for safety reasons, particularly to protect the user. However, if the glass is detached, broken, or otherwise removed from the light-emitting device, the latter is no longer covered, and the user is exposed to the full intensity of the light beam.

[0040] To overcome these safety issues related to the light-emitting device, the glass may include a conductive trace above the light-emitting device. Generally, the conductive trace is designed to be coupled to a conductive rail configured to operate at a fixed voltage, the conductive rail being typically connected to or embedded within the substrate. This can be achieved by means of one or more conductive elements in the hood, for example, by means of one or more lead frames. In this case, coupling between the conductive trace and the conductive element(s) of the hood is provided. One solution is to use a conductive adhesive between the conductive trace and the conductive element(s).However, coupling using a conductive adhesive can be subject to dimensional changes between the glass and the hood, which may be due to different coefficients of thermal expansion (CTE), and there is a risk of breakage.

[0041] The inventors propose an optical sensor module that overcomes all or part of the aforementioned drawbacks, in particular by improving the coupling between a conductive trace in glass and a substrate, for example, the coupling between the conductive trace and the conductive element(s) of a cover bonded to the substrate. It may be desirable for the solution to be adapted to address the safety issue related to the light-emitting device.

[0042] Examples of embodiments of optical sensor modules are described below. These embodiments are not limiting, and various variations will become apparent to those skilled in the art from the indications in this description.

[0043] Fig. 1 is a three-dimensional view of an optical sensor module according to one embodiment.

[0044] The optical sensor module 100 includes a light-emitting device 110, comprising, for example, an LED such as an infrared LED and / or a laser such as a VCSEL, and a light receiving sensor 120, or image sensor, comprising for example a photodiode or a plurality of photodiodes, such as one or more SPADs. The light emitting device 110 and the light receiving sensor 120 are mounted on a substrate 102.

[0045] The substrate 102 can be a printed circuit board (PCB).

[0046] The light-emitting device 110 is configured to emit light signals at a particular frequency or frequency range, and the light-receiving sensor 120 is adapted to detect the returning light signals, for example, those reflected by an object. In one embodiment, the light-emitting device 110 is configured to emit infrared (IR) light signals, and the light-receiving sensor 120 is adapted to detect the returning IR light signals, for example, those reflected by an object.

[0047] The light-emitting device 110 of [Fig. 1] comprises first and second light sources 111, 112, each mounted on a first interposer 141 and a second interposer 142, the first and second interposers 141, 142 being mounted on an upper surface 102A of the substrate 102. The first and second light sources 111, 112 are, for example, first and second VCSELs. In an alternative embodiment, the light sources may be mounted on the substrate without an interposer.

[0048] In one variant, the light-emitting device may comprise a single light source, for example a VCSEL, for example mounted on an interposer.

[0049] The light-emitting device 110 can be electrically coupled to the light-receiving sensor 120, for example by means of the substrate 102.

[0050] The upper surface 102A of the substrate 102 includes first conductive pads 106 which are located for example on the edges of the substrate or near them (not shown in [Fig.1], but shown in [Fig.3A]).

[0051] The optical sensor module 100 includes a laser driver 144, configured to control the first and second light sources 111, 112. The laser driver 144 may be located in the same cavity as the light-emitting device 110, as described below. This description is not limiting, and those skilled in the art may consider other configurations.

[0052] The optical sensor module 100 may include a processing circuit (not shown in [Fig.1]) which can be configured to process the light signals emitted by the light-emitting device 110 and received by the light-receiving sensor 120. The processing circuit may be mounted on the upper surface 102A of the substrate 102.

[0053] The optical sensor module 100 includes other electrical circuits or components, such as SMT (surface mount technology) components 145 which are also mounted on the top surface 102A of the substrate 102. SMT 145 components may include resistors. Other SMT components may include capacitors.

[0054] The light receiving sensor 120 can be coupled to the substrate 102 using conductive connectors, for example, conductive wires, and / or can be fixed to the substrate 102, for example, using an adhesive material or solder. The adhesive material can be any suitable material for fixing the light receiving sensor 120 to the substrate, such as adhesive tape, paste, or glue.

[0055] A module cover 130 having a first opening 131 and a second opening 132 is fixed, or glued, to the substrate 102 and is adapted to at least partially enclose, or cover, the components that are mounted on the substrate 102, at least the light-emitting device 110, the light-receiving sensor 120, the interposers 141, 142, the laser driver 144, and the SMT components 145. At least partially means that not all components may be covered; for example, the first and second openings may not cover the components located below said openings. The module cover 130 may be substantially opaque to light at the wavelengths used.

[0056] For example, the module cover 130 is mounted on an opaque adhesive 104 which is positioned on the substrate 102.

[0057] The first and second openings are located on the upper face 130A of the module cover 130. The first opening 131 is located above the light-emitting device 110 and the second opening 132 is located above the light-receiving sensor 120. In the illustrated example, the first opening 131 is rectangular and the second opening 132 is circular, but this is not limiting and other shapes are possible.

[0058] The module hood 130 may include a separating wall 133 between the light-emitting device 110 and the light-receiving sensor 120. The separating wall 133 may form an optical insulator to substantially prevent the internal propagation of light beams between the light-emitting device 110 and the light-receiving sensor 120 inside the module hood 130. For example, the separating wall 133 defines first and second cavities 136, 137, the first cavity 136 comprising the first opening 131 above the light-emitting device 110, and the second cavity 137 comprising the second opening 132 above the light-receiving sensor 120. The laser driver 144 may be located in the first cavity 136, with the light-emitting device 110, as shown above.

[0059] The module 130 cover can be a plastic cover and / or a molded cover made of a molding material, such as a resin or a liquid crystal polymer. (LCP), nylon or other engineering plastic. The module 130 cover can be formed using an injection molding process.

[0060] The optical sensor module 100 further comprises: - a glass 150 positioned in the first opening 131, or between the first opening 131 and the light-emitting device 110, and adapted to transmit the light signals emitted by the light-emitting device; and - a 160 filter, positioned in the second aperture 132, or between the second aperture 132 and the light receiving sensor 120, and adapted to transmit the reflected light signals to the light receiving sensor.

[0061] The glass 150 preferably covers the first opening 131. The glass 150 is preferably fixed to the module cover 130. For example, the glass 150 rests on a support 139 formed inside the first opening 131 and mounted outside the module cover 130. In an alternative, the glass can be mounted inside the module cover.

[0062] Similarly, the filter 160 preferably covers the second opening 132. The filter 160 is preferably fixed to the module cover 130. For example, the filter 160 is positioned inside the module cover 130. In an alternative embodiment, the filter can be mounted outside the module cover.

[0063] The glass 150 may include two optical surfaces which may be two beam shaping devices 151 A, 15 IB, a first beam shaping device 151A located above the first light source 111, and a second beam shaping device 15 IB located above the second light source 112. The glass 150 may be a lens or a lens pad.

[0064] The optical sensor module 100 may also include a second lens 162 between the filter 160 and the light receiving sensor 120.

[0065] The glass 150 includes a conductive trace 152, which can be integrated into said glass. The glass 150 further includes second conductive pads 154 coupled to the conductive trace 152, for example two second conductive pads, each at one end of the conductive trace.

[0066] The conductive trace may be referred to as a "trace" in the following description. The conductive studs may be referred to as "studs" in the remainder of this exposition.

[0067] The trace 152 and the second pads 154 of the glass 150 can be produced by the same conductive coating, formed, for example, using a photolithography process. Examples of process sequences for forming the trace 152 and the second pads 154 of the glass 150 are as follows: - a subtractive process, that is to say in the following order: metal deposition, photolithography, etching and pickling; - an additive process, or lift-off, i.e. in the following order: photolithography, metal deposition and pickling; or - micro-molding, that is to say in the following order: metal deposition, photolithography, electrodeposition, pickling and engraving.

[0068] The conductive trace 152 of the glass 150 can be used in a safety function related to the light-emitting device.

[0069] In one variant, the filter 160 may also include a second conductive trace, which may also be used as protection against electromagnetic interference in the second opening 132 of the module hood 130, for example by providing a reflection of EMI in said second opening.

[0070] The conductive material of the trace can be one or more of the following materials: copper (Cu), aluminium (Al), tungsten (W), titanium (Ti), gold (Au), indium tin oxide (ITO) or another metal or alloy of metals.

[0071] The conductive trace may be fine and / or thin, for example, less than 1 micrometer wide and / or less than 100 nanometers thick, but is not limited to these values. The width and thickness of each conductive trace may represent a compromise between the safety function and the optical transmission of the glass. For example, the trace may be wider and / or thicker when it is unlikely to limit light transmission, and finer and / or thinner when it is likely to limit light transmission.

[0072] The optical sensor module 100 further includes two conductive leads 134, assembled to the module cover 130. The conductive leads 134 are configured and positioned so as to electrically couple the conductive trace 152 of the glass 150 to the substrate 102. The conductive leads 134 are, for example, connection grids.

[0073] Each conductor cable 134 can be a single conductive piece, for example a single metal piece.

[0074] Each conductor cable 134 can be inserted into the recesses, or channels, 135 formed in the module cover 130 (illustrated in Figures 2A and 2B).

[0075] In one embodiment, the conductive cables can be overmolded during an injection molding operation to form the module cover. The conductive cables are then overmolded into the module cover.

[0076] Each conductive cable 134 comprises a first end 134A coupled, for example connected, to the substrate 102 by means of one of the first conductive pads 106, and a second end 134B coupled, for example connected, to the conductive trace 152 by means of one of the second conductive pads 154. The first end 134A of each conductive cable 134 can be coupled to one of the first conductive pads 106 by a conductive adhesive material 108, for example a tape, a conductive paste or glue, or a conductive solder (not shown in [Fig.1], but illustrated in [Fig.3A]).

[0077] The second end 134B of each conductor cable 134 is coupled to the second conductor pads 154 by a conductor wire 155 formed by wire bonding, a conductor wire which can be called "wire bond" in English.

[0078] Therefore, the conductive cables 134 are coupled to the conductive trace 152, by means of the second conductive pads 154, using the conductive wires 155.

[0079] The conductive wires 155 are preferably sufficiently flexible, for example, to absorb dimensional changes between the glass 150, the module cover 130, and the conductive cables 134, which may be due to different coefficients of thermal expansion (CTE). Indeed, a key function of the conductive wires 155 is to provide a flexible connection between the conductive cables 134 and the module cover 130, in particular between the conductive cables 134 and the second conductive pads 154 on the glass 150. Now, one of the main parameters impacting flexibility is the diameter of the conductive wire. More precisely, the smaller the diameter, the greater the flexibility.

[0080] For example, the 155 conductor wires have a thickness between 20 and 40 pm or even less than 20 pm.

[0081] The conductive wires 155 may have a length of about 2 mm or less than 2 mm.

[0082] The material of the conducting wires 155 can be one or more of the following materials: gold, copper, aluminum, silver or even a tin alloy.

[0083] The advantages of using conductive wires formed by wire bonding are as follows: - the connection can be mechanically and electrically stable and withstand temperature differences; - Wire welding is a mature technology, easily controllable and which allows for obtaining different shapes and lengths of wires; - Wire welding is a clean technology with a low risk of glass contamination; - the conductive wires formed by wire welding allow the glass, for example the lens or the lens support, to be close to the first opening of the module hood.

[0084] Furthermore, coupling the conductor wires 155 to the conductor cables 134, instead of coupling the conductor wires directly to the substrate 102, allows the conductor wires to be shortened. The advantage of having shorter conductor wires is to avoid short circuits with other components.

[0085] Figure 1 represents two conductive cables and two conductive wires. This representation The description is not exhaustive, and the optical sensor module may include a single conductive cable and a single conductive wire formed by soldering wires and coupling the conductive trace to the conductive cable. The optical sensor module may also include more than two conductive cables and more than two conductive wires.

[0086] In one embodiment, each conductor cable can be replaced by a flexible connecting cable. Examples of flexible connecting cables are described in more detail in the French patent application filed on October 25, 2023, on behalf of STMICROE-LECTRONICS INTERNATIONAL NV (firm reference B22927).

[0087] The conductor cable and the connecting flexible can be called "conductive strip".

[0088] The conductive trace 152 of the glass 150, as well as the conductive wires 155, can be used in a protective mechanism to solve the aforementioned safety problem related to the light-emitting device 110.

[0089] Each conductor wire 155, and / or the connection of each conductor wire 155, can function as a fuse. The connection of the conductor wire corresponds to its connection, when formed by wire soldering, with the conductive trace 152 and / or the conductor cable 134.

[0090] Indeed, the conductor wire 155, and / or the bond of each conductor wire 155, can be designed to break if the glass 150 is removed or otherwise detached from the module cover 130. The term "fuse" is used because the conductor wire, and / or the bond of each conductor wire, can be designed to break an electrical connection in order to provide a protective mechanism. In particular, the fuse is configured to break under mechanical force caused by the detachment of the glass. To this end, the conductor wires may have a diameter or thickness of 25 µm or less, and for example 15 µm or less, which makes them relatively brittle and liable to break if the glass detaches, and / or the bond of the conductor wires may be formed in a relatively brittle manner and liable to break if the glass detaches.

[0091] Figures 2A and 2B are three-dimensional views of the module cover 130 of the optical sensor module 100 of [Fig. 1]. More specifically, Figures 2A and 2B show the assembly of the conductor cables 134 in the channels 135 of the module cover 130. The module cover 130 is shown with its lower face 130B facing upwards and its upper face 130A facing downwards.

[0092] Fig. 2A shows the insertion of the conductor cables 134 into the channels 135 and Fig. 2B shows the final assembly of the conductor cables 134 in the channels 135 of the module cap 130. The first and second ends 134A, 134B of the conductor cables 134 protrude from the module cap 130, for example to be coupled respectively to the substrate 102 and the conductive trace 152.

[0093] The module cover 130 can be painted or plated, for example to provide protection against electromagnetic interference, preferably before the insertion of the conductor cables 134 in order to avoid contaminating them.

[0094] The substrate 102 may include a conductive rail (not shown in [Fig. 1]) configured to be at a fixed voltage, such as ground, so that the conductive trace 152 in the glass 150 can be coupled to the fixed voltage, by means of the conductive cables 134 and the substrate 102, and for example by means of some of the first and second conductive pads.

[0095] By combining the glass 150 with an optical surface, such as a lens and / or a filter, the optical sensor module 100 can further perform any optical function such as filtering, beam shaping and / or imaging, while reducing the total number of elements in the module.

[0096] Figures 3A, 3B, 3C and 3D are three-dimensional and top views illustrating a method of forming the optical sensor module 100 of [Fig.1].

[0097] Fig. 3A shows, in top view, a starting substrate 102, on which components are already mounted, at least the light-emitting device 110, the light-receiving sensor 120, the interposers 141, 142, the laser driver circuit 144 and the SMT components 145. The substrate 102 may be a printed circuit board.

[0098] The upper surface 102A of the substrate 102 includes the first conductive pads 106 which are located on or near the edges of the substrate.

[0099] An adhesive material 104, for example an opaque adhesive material such as an opaque glue, is formed on the upper surface 102A of the substrate 102. An edge portion 104A of the adhesive material 104 is formed on the edges of the upper surface 102A, and a central portion 104B of the adhesive material 104 is formed on a central portion of the upper surface 102A between the light receiving sensor 120 and the laser driver 144 / the light emitting device 110, defining the future first and second cavities 136, 137.

[0100] A conductive material 108, for example a conductive solder or a conductive adhesive, is deposited on the first conductive pads 106.

[0101] Figure 3B shows, in three-dimensional view, the assembly of the module cover 130, with the first opening 131, the second opening 132, and the partition wall 133 (not shown in Figure 3B), on the substrate 102. The filter 160 may already be attached to the module cover 130. The conductor cables 134 are already assembled to the module cover 130, for example, as described in relation to Figures 2A and 2B. Figure 3B mainly shows the second ends 134B of the conductor cables 134, which protrude from the outside of the module cover 130.

[0102] During assembly, the lower surfaces of the side walls of the hood of module 130 are brought into contact with part 104A of the adhesive 104, in order to be glued to the substrate 102, and the separating wall 133 of the module 130 cover is brought into contact with the central part 104B of the adhesive 104, thus forming the first and second cavities 136, 137.

[0103] The assembly of the module cover 130 and the substrate 102 can then be appropriately cured, either by heat, UV light, or another suitable curing technique, in order to fully cure the adhesive materials and secure the assembly. For example, this assembly can be reflow-welded.

[0104] Fig. 3C shows, in three-dimensional view, the assembly of the glass 150 on the support 139 in the first opening 131 of the module hood 130.

[0105] Fig. 3D shows, in top view, the assembly of the conducting wires 155 to the second ends 134B of the conducting cables 134 and to the second conducting pads 154 of the glass 150, using a wire welding technique.

[0106] The optical sensor module 100 may include a detection circuit adapted to detect an open circuit corresponding to a detachment of the glass 150 from the module cover 130.

[0107] The detection circuit can be coupled to the conductive trace 152 and the conductive wires 155 by means of the conductive cables 134. The detection circuit can be implemented on and / or in the substrate 102. When the glass 150 is in place and the conductive wires 155, as well as the connection of the conductive wires 155, are intact, the conductive cables 134, the conductive wires 155 and the conductive trace 152 form a conductive loop, for example by means of conductive paths in the substrate 102. However, if the glass 150 detaches, at least one of the conductive wires 155 and / or the connection of at least one of the conductive wires 155 may be broken, resulting in an open circuit in the conductive loop.

[0108] The detection circuit can be configured to control the light-emitting device 110, for example, to deactivate the light-emitting device 110 if an open circuit is detected in the conductive loop. The detection circuit tests the conductive loop periodically or continuously, for example by passing a current through it, and can deactivate the light-emitting device 110 if an open circuit is detected in the conductive loop.

[0109] Besides the safety issue related to the light-emitting device, the embodiments may have other applications. For example, they may be used to manage electromagnetic interference (EMI) from the optical sensor module with another electronic device.

[0110] For example, when the optical sensor module is included in an electronic device (host device), electromagnetic interference may occur between the optical sensor module and the host device. The electronic device can be a camera, a phone, for example a smartphone, a smartwatch, a tablet, a vehicle, a machine or other device for which it may be useful to detect the presence and / or distance of nearby objects.

[0111] In particular, the conductive trace can be used as protection against electromagnetic interference (EMI) through the first opening of the module hood, for example by providing a reflection of EMI in said first opening.

[0112] The pitch and pattern of the conductive trace can be determined according to the frequencies of the EMI to be managed. For example, the higher the frequency, the smaller the pitch can be.

[0113] The step between the traces is, for example, less than the wavelength X of the signal to be attenuated, and is, for example, a fraction of the wavelength X, where X is equal to:

[0114] X = v / f where v is the speed of light and f is the background electromagnetic frequency to be attenuated.

[0115] Advantageously, the conductive trace can be coupled to a fixed voltage, for example to earth, for example to provide additional protection against EMI.

[0116] Examples of conductive trace are described in more detail in French patent application number 2311561, filed on October 25, 2023 on behalf of STMICROE-LECTRONICS INTERNATIONAL NV (firm reference: B22689).

[0117] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will become apparent to those skilled in the art. For example, instead of being inserted into channels in the module cover, the conductive cables may be conductive layers formed on surfaces of the module cover. The conductive layers may be coated or plated onto the module cover, for example, using a laser direct structuring (LDS) technique.

[0118] Finally, the practical implementation of the embodiments and variants described is within the reach of a person skilled in the art, based on the functional indications given above.

Claims

Claims

1. An optical sensor module (100) comprising: - a light emitting device (110); - a module cover (130) adapted to at least partially cover the light emitting device, the module cover (130) comprising a first opening (131) located above the light emitting device; - at least one conductive strip (134) assembled with, or included in, the module cover; - a glass (150) positioned in the first opening or between the first opening and the light emitting device, and / or covering the first opening, and adapted to transmit the light signals emitted by the light emitting device, the glass including a conductive trace (152); and - at least one conductive wire (155) formed by wire soldering, the at least one conductive wire electrically connecting the conductive trace to the at least one conductive strip.

2. The module (100) of claim 1, wherein the material of each conductive wire (155) comprises one or more of the following materials: gold, copper, aluminum, silver, or a tin alloy.

3. Module (100) according to claim 1 or 2, wherein the at least one conductive wire (155) has a thickness less than or equal to 40 pm, for example less than or greater than 20 pm, and / or a length less than or equal to 2 mm.

4. Module (100) according to any one of claims 1 to 3, further comprising a substrate (102) with which the module cover (130) is assembled, the at least one conductive strip (134) being coupled to at least a first conductive pad (106) of the substrate, for example using a conductive adhesive material (108).

5. The module (100) of claim 4, wherein the substrate (102) comprises a conductive rail configured to be at a fixed voltage, e.g., ground, the conductive rail being coupled to one of the at least one first conductive pad (106).

6. The module (100) of any one of claims 1 to 5, wherein the glass (150) further includes at least one second conductive pad (154) coupled to the conductive trace (152), for example the at least one second conductive pad is connected to one end of the conductive trace, the at least one conductive strip (134) being coupled to the at least one second conductive pad using the at least one conductive wire (155).

7. Module (100) according to any one of claims 1 to 6, wherein the at least one conductive wire (155) and / or the connection of said at least one conductive wire is adapted to be broken if the glass (150) becomes detached from the module cover (130).

8. Module according to claim 7, further comprising a detection circuit adapted to detect the breakage of a conductive loop formed by the at least one conductive strip (134), the at least one conductive wire (155) and the conductive trace (152), the detection circuit being configured to deactivate the light emitting device (110) if it detects an open circuit in the conductive loop.

9. The module (100) of any one of claims 1 to 8, wherein the conductive trace (152) provides shielding against electromagnetic interference.

10. Module (100) according to any one of claims 1 to 9, wherein the at least one conductive strip (134) is inserted into at least one channel (135) of the module cover (130).

11. Module (100) according to any one of claims 1 to 10, wherein the at least one conductive strip (134) is at least one conductive cable, for example at least one connection grid.

12. Module according to any one of claims 1 to 10, in which the at least one conductive strip is at least one flexible connection overmolded in the module cover.

13. Module according to any one of claims 1 to 12, wherein the glass is a lens or a lens support, the glass comprising for example at least one beam shaping device (151A; 151B).

14. Module (100) according to any one of claims 1 to 13, wherein the module cover (130): - is an injection-molded cover, the molding material being for example a resin; and / or - is a plastic module cover; and / or - comprises a material suitable for providing shielding against electromagnetic interference.

15. Module (100) according to any one of claims 1 to 14, further comprising: - a light receiving sensor (120) at least partially covered by the module cover (130), the module cover comprising a second opening (132) located above the light receiving sensor; and - a filter (160) in the second opening (132), or covering the second opening (132), and adapted to transmit the reflected light signals to the light receiving sensor; the filter including for example a second conductive trace providing shielding against electromagnetic interference.

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