Optical sensor module

Abstract

Optical Sensor Module This description relates to an optical sensor module (200) comprising: - a substrate (102) including first conductive pads (106); - a module cover (130) assembled on the substrate; - a connecting hose (230) incorporated in the module cover, the connecting hose being adapted to electrically couple at least one of the first conductive pads (106) to at least one component (152) mounted on and / or inside the module cover; the connecting hose comprising at least one metallic layer covered by, or encapsulated in, at least one dielectric layer. Figure for the abstract: Fig. 2A

Description

Title of the invention: Optical sensor module Technical field

[0001] The present description relates generally to optical sensors, in particular optical sensor modules. Prior art

[0002] Optical sensors, such as proximity sensors, can be used to detect the presence of nearby objects. Optical sensors are able to do this without physically touching the object. Some types of optical sensors, such as those used in optical ranging devices or time-of-flight sensors, can be used to determine the actual distance of these nearby objects. Optical sensors can be used in various electronic devices, such as cameras, phones, including smart phones or smartphones, smart watches or 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 may be configured to perform a function, such as moving a mechanical element into a safe position, transmitting an alarm signal, connecting or disconnecting 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, in general, a processing device for processing signals received from the light-receiving sensor. The optical sensor components may be formed on a substrate, and a cover may be bonded to the substrate above the components, for example to protect them from damage, thereby forming an optical sensor module, also called an optical sensor housing. The cover is generally formed with a first opening located above the light-emitting device and with 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 outside and sufficiently close to the optical sensor module, the light signal may be reflected by the object to the light receiving sensor through the second aperture. The light receiving sensor may then generate an electrical signal indicative of the received light signal, which may be transmitted to the processing device for processing said received light signal, for example to determine the presence of the nearby object and / or the distance that separates it.

[0005] The light emitting device used to generate the light beam is generally covered with glass to protect the device 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.

[0006] There is a need to improve optical sensor modules, in particular to improve the electrical coupling between the substrate and the components mounted inside and / or on the cover, for example between the substrate and a conductive element inside the glass, such as a conductive trace. Summary of the invention

[0007] One embodiment overcomes all or part of the drawbacks of known optical sensor modules.

[0008] One embodiment provides an optical sensor module comprising: - a substrate comprising first conductive pads; - a module cover assembled on the substrate; - a flexible connection incorporated in the module cover, the flexible connection being adapted to electrically couple at least one of the first conductive pads to at least one component mounted on and / or inside the module cover; the flexible connection comprising at least one metallic layer covered by, or encapsulated in, at least one dielectric layer.

[0009] According to one embodiment: - the connection hose is overmolded in the module cover; and / or - the module cover is a conductive molded cover, for example made of a molding material comprising electrically conductive particles dispersed in said molding material.

[0010] According to one embodiment: - the at least one metallic layer of the flexible connection comprises, for example terminates in, a plurality of second conductive pads which are adapted to be coupled to a plurality of first conductive pads of the substrate; and - the at least one dielectric layer of the flexible connection comprises, for example ends with, a plurality of insulating elements, each second conductive pad being interposed between two insulating elements.

[0011] According to one embodiment, the optical sensor module further comprises a light emitting device, the module cover at least partially covering the light emitting device and comprising a first opening located above above said light emitting device, the light emitting device being for example one of the at least one component.

[0012] According to one embodiment, the optical sensor module further comprises a glass 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 light signals emitted by the light emitting device, the glass including a conductive trace which corresponds to a first component among the at least one component, the connection hose being electrically coupled to the conductive trace, for example via a conductive wire formed by wire welding.

[0013] According to one embodiment, a second component among the at least one component is positioned on the connecting hose. For example, the second component comprises at least a portion of the light emitting device.

[0014] According to one embodiment, the connection hose comprises at least one recess adapted to receive the second component.

[0015] According to one embodiment, the connection hose comprises: - at least one end portion configured to be connected to the substrate, the second conductive pads and the insulating elements being defined in said at least one end portion, and - an upper portion, said upper portion being at least partly in contact with an internal surface of the module cover, the recess being defined in said upper portion.

[0016] According to one embodiment, the flexible connection hose comprises two end portions and two interconnection portions, each end portion being connected to the upper portion by means of one of the interconnection portions, each interconnection portion being arranged substantially perpendicular to the upper portion.

[0017] According to one embodiment, the connection hose comprises: - a first metal layer electrically coupled to the second component, for example by means of a conductive wire, the first metal layer being covered by a first dielectric layer among the at least one dielectric layer; - a second metal layer configured to be connected to ground, the second metal layer being covered by a second dielectric layer among the at least one dielectric layer; - a third metal layer positioned in the recess and electrically insulated from the first metal layer, the second component being connected to said third metal layer, for example positioned on said third metal layer; - a dielectric core interposed between the first metal layer and the second metal layer; - at least one connection via defined in said dielectric core and electrically coupling the third metal layer to the second metal layer. Preferably, the first, second and / or third metal layer are part of the at least one metal layer of the connection hose.

[0018] According to one embodiment, the recess passes through the entire thickness of the first dielectric layer and the first metal layer to the dielectric core.

[0019] According to one embodiment, the connection hose comprises a plurality of connection pads, said connection pads being defined on the upper portion of the connection hose, each connection pad being configured to be electrically coupled to the second component, for example by means of a conductive wire.

[0020] According to one embodiment, the bonding pads pass through the entire thickness of the first dielectric layer up to the first metal layer. Brief description of the drawings

[0021] These characteristics and advantages, as well as others, will be explained in detail in the following description of particular embodiments given without limitation in relation to the attached figures among which:

[0022] [Fig.l] is a three-dimensional view of an exemplary optical sensor module;

[0023] Figures 2A, 2B and 2C are three-dimensional views of an optical sensor module according to one embodiment;

[0024] [Fig.3A] is a schematic cross-sectional view of the connecting hose of Figs. 2B and 2C;

[0025] [Fig.3B] is a schematic cross-sectional view of a connection hose of an optical sensor module according to another embodiment;

[0026] Figures 4A, 4B, 4C, 4D, 4E, 4F, 4G and 4H are top and three-dimensional views illustrating a method of assembling the connection hose to the module cover in the optical sensor module of [Fig.2A];

[0027] [Fig.5A] is a three-dimensional sectional view of an optical sensor module according to another embodiment;

[0028] [Fig.5B] is a top view of the optical sensor module of [Fig.5A];

[0029] [Fig.5C] is a top view illustrating a detail of the connection hose of the optical sensor module of Figures 5A and 5B; and

[0030] [Fig.5D] is a three-dimensional sectional view illustrating a detail of the connecting hose of [Fig.5C]. Description of the embodiments

[0031] The same elements have been designated by the same references in the different figures. In particular, the structural and / or functional elements common to the different embodiments may have the same references and may have identical structural, dimensional and material properties.

[0032] For the sake of clarity, only the steps and elements useful for understanding the described embodiments have been shown and are detailed. In particular, not all the components of an optical sensor have been detailed, the described embodiments being compatible with usual 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 the components of an optical sensor module have been detailed, the described embodiments being compatible with usual optical sensor modules.

[0033] Unless otherwise specified, when referring to two elements connected to each other, 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 be connected by means of one or more other elements.

[0034] 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", "upper", "lower", 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 position of use.

[0035] Unless otherwise indicated, the expressions "about", "approximately", "substantially" and "in the order of" mean to within 10%, and preferably to within 5%.

[0036] In the following description, unless otherwise specified, when reference is made to a glass, it is an element made of a material relatively transparent to light at the wavelengths used, for example having a transmission rate of 90% or more for these wavelengths. It may be, inter alia, a glass or plastic material. The glass may be formed from a single solid material or may be formed by assembling several materials, in which case only a portion of the glass may be of a transparent material. The glass may comprise or consist of a glass window, a lens or a plurality of lenses, and / or an optical filter, more generally an optic.

[0037] In the following description, unless otherwise specified, when reference is made to a filter, reference is made to an optical filter.

[0038] In the following description, unless otherwise specified, when reference is made to a conductive element, for example a trace, a pad, a strip or a conductive cable, reference is made to an electrically conductive element.

[0039] In the following description, when reference is made to a flexible connection hose, or "flexible", reference is made to a strip intended to electrically couple or connect two elements, the strip being both flexible, for example to be able to be bent according to a given curvature, and mechanically rigid, for example to maintain this curvature once bent.

[0040] The embodiments relate to optical sensor modules.

[0041] 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 projector and / or a point projector.

[0042] An optical sensor generally comprises a light-emitting device and a light-receiving sensor. An optical sensor generally also comprises a device for processing signals received from the light-receiving sensor. The light-emitting device and the light-receiving sensor may be formed on a substrate, and a cover may be bonded to the substrate above the light-emitting device and the light-receiving sensor, thereby forming an optical sensor module, also referred to as an optical sensor package. The cover is generally formed with a first opening located above the light-emitting device and with a second opening located above the light-receiving sensor.

[0043] As explained in the prior art section above, the light emitting device 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 opening. The glass may also serve as a diffuser to reduce to some extent the intensity of the emitted light beam, for example for safety reasons, e.g. to protect the user.

[0044] [Fig.l] is a three-dimensional view of an exemplary optical sensor module.

[0045] The optical sensor module 100 comprises a light emitting device 110, comprising for example a light emitting diode (LED) such as an infrared LED, and / or a laser such as a vertical cavity surface emitting laser (VCSEL), and a light receiving sensor 120 (image sensor), comprising for example a photodiode or a plurality of photodiodes, such as one or more SPAD. The light emitting device 110 and the light receiving sensor 120 are mounted on a substrate 102.

[0046] The substrate 102 may be a printed circuit board (PCB).

[0047] The light emitting device 110 is configured to emit a light signal, or a light beam, at a particular frequency or frequency range, and the light receiving sensor 120 is adapted to detect the returned emitted light signal, for example reflected by an object. In one embodiment, the light emitting device 110 is configured to emit an infrared (IR) light signal, and the light receiving sensor 120 is adapted to detect the returned IR light signal, for example reflected by an object.

[0048] The light emitting device 110 of [Fig.l] 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. Alternatively, the light sources may be mounted on the substrate without an interposer.

[0049] In a variant, the light emitting device may comprise a single light source, for example a VCSEL, for example mounted on the substrate via an interposer, or even without an interposer.

[0050] The light emitting device 110 may be electrically coupled to the light receiving sensor 120, for example through the substrate 102.

[0051] The upper surface 102A of the substrate 102 comprises conductive pads 106 (first conductive pads) which are located for example on edges of the substrate or close to them.

[0052] The optical sensor module 100 comprises 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 the person skilled in the art may envisage other configurations.

[0053] The optical sensor module 100 may include processing circuitry (not shown in [Fig.l]) that may be configured to process the light signals emitted by the light emitting device 110 and received by the light receiving sensor 120. The processing circuitry may be mounted on the upper surface 102A of the substrate 102.

[0054] The optical sensor module 100 includes other electrical circuits or electronic components, such as surface mount technology (SMT) components 145 that are also mounted on the upper surface 102A of the substrate 102. SMT components 145 may include resistors. Other SMT components may include capacitors.

[0055] The light receiving sensor 120 may be coupled to the substrate 102 using conductive connectors, for example, conductive wires, and / or may be attached to the substrate 102, for example, using an adhesive material or solder. The adhesive material may be any material suitable for attaching the light receiving sensor 120 to the substrate, such as adhesive tape, paste, glue.

[0056] A module cover 130 having a first opening 131 and a second opening 132 is attached, or bonded, 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 all the components may not be covered, for example the first and second openings do not cover the components that are located under said openings. The module cover 130 may be substantially opaque to light at the wavelengths used.

[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 example illustrated, 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 cover 130 may include a partition wall 133 between the light emitting device 110 and the light receiving sensor 120. The partition wall 133 may form an optical isolator to substantially prevent internal propagation of light beams between the light emitting device 110 and the light receiving sensor 120 within the module cover 130. For example, the partition wall 133 defines the first and second cavities 136, 137, the first cavity 136 including the first opening 131 above the light emitting device 110, and the second cavity 137 including the second opening 132 above the light receiving sensor 120. The laser driver 144 may be located in the first cavity 136, along with the light emitting device 110, as discussed above.

[0059] The module cover 130 may be a plastic cover and / or a molded cover made of a molding material, such as a resin, a liquid crystal polymer (LCP), nylon, or another engineering plastic. The module cover 130 may be formed using an injection molding process. In some examples, the module cover may be electrically conductive.

[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 filter 160, positioned in the second opening 132, or between the second opening 132 and the light reception sensor 120, and adapted to transmit the reflected light signals to the light reception sensor.

[0061] The glass 150 preferably covers the first opening 131. The glass 150 is preferably attached to the module cover 130. For example, the glass 150 rests on a support 139 formed within the first opening 131 and mounted outside the module cover 130. Alternatively, the glass may be mounted inside the module cover.

[0062] Similarly, the filter 160 preferably covers the second opening 132. The filter 160 is preferably attached to the module cover 130. For example, the filter 160 is positioned inside the module cover 130. Alternatively, the filter may be mounted outside the module cover.

[0063] The glass 150 may comprise two optical surfaces which may be two beam shaping devices 151A, 151B, a first beam shaping device 151A located above the first light source 111, and a second beam shaping device 151B 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 may include a conductive trace 152, which may be integrated into this glass. The glass 150 may also include conductive pads 154 (third conductive pads) coupled to the conductive trace 152, for example two third conductive pads, each at one end of the conductive trace.

[0066] The conductive trace may be referred to as "trace" in the following description. The conductive pads may be referred to as "pads" in the following description.

[0067] The material of the conductive trace may be one or more of the following materials: copper (Cu), aluminum (Al), tungsten (W), titanium (Ti), gold (Au), indium tin oxide (ITO) or another metal or metal alloy.

[0068] The conductive trace 152 may be a fine and / or thin trace, for example with a width of less than 1 micrometer and / or a thickness of less than 100 nanometers, without being limited to these values. The width and thickness of the conductive trace may be a compromise between its function and the optical transmission of the glass. For example, the conductive trace may be wider and / or thicker when it is not likely to limit light transmission, and it may be thinner and / or thinner when it may limit light transmission.

[0069] Generally, the conductive trace 152 is configured to be coupled to a conductive rail configured to be at a fixed voltage, e.g., ground, the conductive rail generally being connected to or included in the substrate 102.

[0070] The conductive trace 152 may be used as protection against electromagnetic interference (EMI) through the first opening 131 of the module cover 130, for example by providing reflection of the EMI in said first opening. For example, when the optical sensor module 100 is included in an electronic device, electromagnetic interference may occur between the optical sensor module and the electronic device. The electronic device may be a camera, a smartphone, a smartwatch, a tablet, a vehicle, a machine, or any other device for which it may be useful to detect the presence and / or distance of nearby objects. The pitch and pattern of the conductive trace may be determined based on the frequencies of the EMI to be managed. For example, the higher the frequency, the lower the pitch may be.

[0071] The conductive trace 152 may also be used to manage a safety issue related to the light emitting device 110, i.e., to detect whether the glass 150 is removed or detached from the module cover 130. If the glass 150 is removed or detached, it can no longer be used as a diffuser to reduce the intensity of the emitted light beam and can no longer protect the user. When the glass 150 is in place, the conductive cables 134, the conductive wires 155, and the conductive trace 152 form a conductive loop, for example, through conductive paths in the substrate 102. However, if the glass 150 becomes detached, the circuit of the conductive loop may be opened, a detection circuit may detect the open circuit, and, for example, disable the light emitting device 110.

[0072] In a variant not illustrated, the filter 160 may also comprise a second conductive trace.

[0073] Examples of conductive traces are described in more detail in French patent application number 2311561, filed on October 25, 2023 in the name of STMICROE-LECTRONICS INTERNATIONAL NV (firm reference B22689), entitled "Optical sensor module", which is hereby incorporated by reference to the fullest extent permitted by law.

[0074] The optical sensor module 100 further comprises two conductive leads 134, assembled to the module cover 130, for example overmolded in the module cover. 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 generally rigid, and are by example of lead frames.

[0075] Each conductive cable 134 may be a single conductive part, for example a single metal part.

[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 three conductive pads 154. The first end 134A of each conductive cable 134 may be coupled to one of the first conductive pads 106 by a conductive adhesive, for example a conductive tape, paste or glue, or a conductive solder. The second end 134B of each conductive cable 134 may be coupled to the three conductive pads 154 by a conductive wire 155 formed by wire bonding, a conductive wire that may be called a "wire bond" in English, or by a conductive adhesive or a conductive solder.

[0077] Examples of conductive wires are described in more detail in French patent application number 2311572, filed on October 25, 2023 in the name of STMICROE-LECTRONICS INTERNATIONAL NV (firm reference B22688) entitled "Optical sensor module", which is hereby incorporated by reference to the fullest extent permitted by law.

[0078] However, conductive cables, particularly lead frames, have certain disadvantages.

[0079] Lead frames are generally rigid and less tolerant of relative movements of the elements to which they are connected, and / or dimensional variations between these elements and the lead frames, which could lead to delamination.

[0080] Furthermore, it may be advantageous to have several pads at the first end 134A of the conductive cable 134. However, it may be difficult to have such multiple pads because it may be difficult to have a small pitch between the pads, due to the common method of manufacturing conductive cables such as lead frames. Indeed, lead frames are generally manufactured by stamping and, in order to keep the shape of the lead frame intact, for example to avoid any contact between them during overmolding, each lead frame must be sufficiently wide and thick to maintain its strength and, therefore, the pitch between the pads can be quite large, generally at least 0.4 mm.

[0081] The assembly of the conductive cables 134 on the substrate 102, for example using a conductive adhesive or solder, may also require a trench 104 around each first conductive pad 106 in order to separate the conductive adhesive or solder from other elements, for example other components of the substrate, which may require more space in the substrate to assemble the conductive cables.

[0082] Furthermore, for example if the module cover 130 is electrically conductive, it may be necessary for the conductive cables to be insulated from the module cover. However, it may be difficult to electrically insulate the conductive cables from a conductive module cover.

[0083] The inventors propose an optical sensor module making it possible to overcome all or part of the aforementioned drawbacks, in particular to improve the electrical coupling between the substrate and the conductive components or elements inside the module cover, for example between the substrate and the conductive trace inside the glass.

[0084] 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 of this description.

[0085] In the following description, unless otherwise specified, when reference is made to a component, reference is made to an electronic component, including a conductive element such as a conductive trace.

[0086] Figures 2A, 2B and 2C are three-dimensional views of an optical sensor module 200 according to one embodiment. [Fig. 2B] shows in more detail the connection hoses of the optical sensor module. [Fig. 2C] corresponds to a cross-sectional view AA of one of the connection hoses 230.

[0087] The optical sensor module 200 of Figures 2A, 2B and 2C differs from the optical sensor module 100 of [Fig.l] mainly in that, instead of having conductive cables, for example lead frames, assembled to the module cover 130, the optical sensor module 200 includes two connecting hoses 230 assembled to the module cover 130. The other elements of the optical sensor module 200 may be similar to those of the optical sensor module 100 of [Fig.l]: these elements bear the same reference numerals as in [Fig.l] and are not described again.

[0088] Each connection cable 230 comprises at least one metal layer covered by, or encapsulated in, at least one dielectric layer in order to electrically insulate the connection cable from the other conductive elements of the optical sensor module 200, except in the parts of said connection cable in which the at least one dielectric layer is open, in order to access the at least one metal layer for electrical connection. Therefore, in the open parts, for example the ends, of the connection cable 230, the at least one metal layer is adapted to be electrically coupled to components of the optical sensor module 200.

[0089] In the example of Figures 2B and 2C, each connection hose 230 comprises two metal layers, a first metal layer 232A and a second metal layer 232B, electrically insulated from each other by a dielectric core 231.

[0090] For example, the first and second metal layers 232A, 232B are encapsulated in the dielectric core 231, the first metal layer 232A being flush with a first face 231A of the dielectric core, and the second metal layer 232B being flush with a second face 231B of the dielectric core.

[0091] For example, the first and second metal layers 232A, 232B have a width less than the width of the dielectric core 231, and are substantially centered relative to the dielectric core, such that the first and second metal layers 232A, 232B do not reach the edges of the connecting hose 230. Therefore, the edges of the connecting hose 230 are electrically insulated.

[0092] For example, the first and second metal layers 232A, 232B form metal strips within the dielectric core 231.

[0093] Each flexible connection 230 further comprises two dielectric layers 233A, 233B: a first dielectric layer 233A covering the first metal layer 232A, and a second dielectric layer 233B covering the second metal layer 232B. The first dielectric layer covers the face of the first metal layer that is not insulated by the dielectric core, and similarly, the second dielectric layer covers the face of the second metal layer that is not insulated by the dielectric core.

[0094] The first and second dielectric layers 233A, 233B may also at least partially cover the first and second faces of the dielectric core 231, as illustrated in FIGS. 2B and 2C in which the first and second metal layers 232A, 232B are embedded in the dielectric core 231 and have a width less than the width of the dielectric core 231.

[0095] The first and second metal layers 232A, 232B may be coupled to each other at a first end 230A of the connection hose 230 by a metal portion 234, for example a metal button having a hole 235, as illustrated in FIGS. 2B and 2C. The metal portion 234 is preferably not covered, or at least partially not covered, by the first and second dielectric layers 233A, 233B. The metal portion 234 forms a conductive pad (second conductive pad) of the connection hose 230.

[0096] The metal part 234, i.e. the second conductive pad, may be coupled to one of the first conductive pads 106 of the substrate 102 by a conductive adhesive, for example a conductive glue or a conductive solder.

[0097] At a second end 230B of the flexible connection 230, the first dielectric layer 233A is open in order to access the first metal layer 232A for an electrical connection, so that the first metal layer 232A can be connected to the conductive trace 152, for example by means of one of the third conductive pads 154. For example, the first metal layer 232A terminates with a fourth conductive pad 237 which is coupled to the third conductive pad 154, for example by means of a conductive wire 155 formed by wire bonding. The conductive trace 152 corresponds to a component (first component) which is coupled to the substrate 102 by means of the connection hose 230.

[0098] In a variant, each connection hose 230 can be coupled to the conductive trace 152 of the glass 150 using a conductive adhesive or a conductive solder.

[0099] The second dielectric layer 233B may also be opened to access the second metal layer 232B for electrical connection. For example, the second metal layer 232B may also terminate with a conductive pad, or with the fourth conductive pad 237.

[0100] The dielectric material of the dielectric core and / or dielectric layers is, for example, a polyimide. The advantages of polyimide are that it can be thermosetting or thermoplastic, that it has very high thermal stability and that it also has excellent dielectric properties and an inherently low coefficient of thermal expansion. In addition, polyimide can withstand high temperatures such as those encountered during reflow, for example 500°C or more.

[0101] The metal of the metal layers and / or of the metal part of the flexible connection is, for example, copper.

[0102] In one variant, the two metal layers 232A, 232B may not be coupled to each other. For example, one of the two metal layers may be coupled to ground, and the other of the two metal layers may be dedicated to conducting an electrical signal, as illustrated in the example of FIGS. 5A to 5D.

[0103] In another variant, the flexible connection may comprise only a single metal layer, as illustrated in [Fig.3B] described below.

[0104] In another variant, the flexible connection may comprise more than two metal layers, two adjacent metal layers preferably being insulated from each other by a dielectric material.

[0105] In one variation, instead of having two dielectric layers on each side of the connecting hose, the connecting hose may include a dielectric layer arranged to envelop or encapsulate the connecting hose.

[0106] The glass 150 may comprise or consist of a glass window, a lens or a plurality of lenses, and / or an optical filter.

[0107] Each connection hose 230 can be topped in the module cover 130.

[0108] As for the optical sensor module 100 of [Fig.l], the module cover 130 of the optical sensor module 200 may be a plastic cover, and / or a molded cover made of a molding material, such as a resin, a liquid crystal polymer (LCP), a polyamide, nylon, or another engineering plastic. The module cover 130 may be formed using an injection molding process. Alternatively, the module cover 130 may be electrically conductive, for example a molded cover made of a molding material, for example one of the aforementioned molding materials, filled with electrically conductive particles dispersed in this material. When the module cover is conductive, the use of a connection hose is advantageous because the metal layer(s) of the connection hose may be insulated from the conductive module cover by the dielectric layer(s) and / or the dielectric core.

[0109] Exemptions from conductive module covers are described in more detail in French patent application number 2311561, filed on October 25, 2023 in the name of STMICROELECTRONICS INTERNATIONAL NV (firm reference B22689), entitled "Optical Sensor Module", which is incorporated herein by reference to the fullest extent permitted by law.

[0110] Other features of the optical sensor module 200 of Figures 2A and 2B may be similar to those of the optical sensor module 100 of [Fig.l].

[0111] In one variation, the optical sensor module may not include a conductive trace, but may include one or more other components positioned on or under the glass and coupled to one or more flexible connectors.

[0112] In one variation, the optical sensor module may not include glass, but may include one or more components that are not placed on or under glass and that are coupled to one or more connecting hoses.

[0113] In one embodiment that may be combined with previous embodiments, one or more components may be positioned on a connecting hose. An embodiment is illustrated in Figures 5A to 5D described below.

[0114] In Figures 2A and 2B, two connection hoses have been shown. This representation is not limiting and the optical sensor module may comprise a single connection hose. The optical sensor module may also comprise more than two connection hoses.

[0115] [Fig. 3A] is a schematic cross-sectional view of the connecting hose of Figures 2B and 2C. [Fig. 3A] schematically illustrates the different layers of the connecting hose 230, as well as the metal button 234 which protrudes from the rest of the connecting hose. [Fig. 3A] also illustrates a first adhesive layer 236A between the first metal layer 232A and the first dielectric layer. 233A, and a second adhesive layer 236B between the second metal layer 232B and the second dielectric layer 233B.

[0116] The thickness of the layers can vary. Table 1 below gives non-limiting thickness ranges.

[0117] [Tableauxl] Layer Thickness ranges (pm) 233A [10-100] or [20-50] 236A [10-100] or [20-50] 232A [10-50] or [15-35] 231 [10-100] or [20-50] 232B [10-50] or [15-35] 236B [10-100] or [20-50] 233B [10-100] or [20-50]

[0118] [Fig. 3B] is a schematic cross-sectional view of a connection hose 330 of an optical sensor module according to another embodiment. The connection hose 330 differs from the connection hose 230 of [Fig. 3A] primarily in that it comprises only a single metal layer 232A and in that it does not comprise a dielectric core. The metal layer 232A protrudes from the remainder of the connection hose 330, for example to be electrically coupled to the substrate.

[0119] The thickness of the layers can vary. Table 2 below gives non-limiting thickness ranges.

[0120] [Tables2] Layer Thickness ranges (pm) 233A [10-100] or [20-50] 236A [10-100] or [20-50] 232A [10-50] or [15-35] 236B [10-100] or [20-50] 233B [10-100] or [20-50]

[0121] Figures 4A, 4B, 4C, 4D, 4E, 4F, 4G and 4H are top and three-dimensional views illustrating a method of assembling the connection hose to the module cover in the optical sensor module of [Fig.2A].

[0122] [Fig.4A] is a top view of a starting structure comprising flexible hoses 2D connection hose 430. In each 2D connection hose, the metal portion 234, or the second conductive pad, the hole 235 in the metal portion 234, and the fourth conductive pad 237 can be seen. In addition, each 2D connection hose has tabs 432 extending the 2D connection hose 430 beyond the metal portion 234, in order to facilitate the assembly process, in particular to facilitate the holding of the connection hose in the molding tool described below.

[0123] [Fig.4B] is a three-dimensional view of a structure obtained by bending the 2D connecting hoses 430 to a desired 3D shape, required for subsequent molding, thereby forming the connecting hoses 230.

[0124] [Fig.4C] is a three-dimensional view of a structure obtained by placing the connection hoses 230 in a mold core 401 of a molding tool 400 adapted to position these connection hoses relative to the future module cover, and by approaching a mold cavity 402 of the molding tool 400. The mold cavity 402 comprises holding inserts 403 which are adapted to hold the connection hoses 230 in place during subsequent molding.

[0125] [Fig.4D] is a three-dimensional view of a structure obtained when the mold cavity 402 and the mold core 401 are closed, with the holding inserts 403 securing the connecting hoses 230 in their intended positions. The connecting hoses 230 are held in place for the next molding by means of the holding inserts 403 which are inserted into holes 431 of the connecting hoses (illustrated in [Fig.4B]).

[0126] [Fig.4E] is a three-dimensional view of a structure obtained after an injection molding step during which a molding material is injected into the mold cavity 402, forming the module cover 130 made of the molding material. After the injection molding step, the connection hoses 230 are overmolded in the module cover.

[0127] [Fig.4F] is a three-dimensional view of a structure obtained after opening the molding tool 400, i.e. after moving the mold core 401 and the mold cavity 402 away from each other. The module cover 130 is ejected from the molding tool 400 when this molding tool is opened.

[0128] [Fig.4G] is a top view of a structure obtained by cutting each connecting hose 230 in order to remove the tabs 432.

[0129] [Fig.4H] ​​is a three-dimensional view of the connection hoses 230 assembled and overmolded in the module cover 130.

[0130] Then, the module cover 130 assembled with the connection hoses 230 can be assembled to the substrate.

[0131] [Fig.5A] is a three-dimensional cross-sectional view of an optical sensor module 500 according to another embodiment. [Fig.5B] is a top view of the module of optical sensor 500 of [Fig.5A]. [Fig.5C] is a top view illustrating a detail of the connection hose 530 of the optical sensor module 500 of FIGS. 5A and 5B. [Fig.5D] is a three-dimensional sectional view illustrating a detail of the connection hose 530 of [Fig.5C]. [Fig.5A] represents only one half of the optical sensor module 500 cut along the direction BB illustrated in [Fig.5B].

[0132] Similar to the optical sensor module 200 of Figures 2A-2C, the optical sensor module 500 of Figures 5A-5D includes a module cover 130 and a glass 150 resting on a support 139 formed within a first opening 131 of the module cover 130. The glass 150 includes a conductive trace 152 and third conductive pads 154 coupled to each end of the conductive trace.

[0133] The optical sensor module 500 of Figures 5A to 5D includes a connection hose 530.

[0134] The connection hose 530 is adapted to receive one or more components 503, 504 (second component(s)) on itself, under the glass 150. The at least one second component may be a light source 503 such as a VCSEL, and possibly a photodiode 504 which may be dedicated to monitoring the light source 503. The at least one second component may be part of a light emitting device. This is not limiting and other components may be positioned in recesses of the connection hose. [Fig.5D] shows a detail of the light source 503, shown as a VCSEL, and the connection hose 530 on which the VCSEL 503 is mounted and to which the VCSEL 503 is coupled.

[0135] In the illustrated example, the connection hose 530 comprises recesses 538, adapted to receive the components 503, 504 under the glass 150.

[0136] The connection hose 530 comprises a plurality of second conductive pads 534, adapted to be coupled to a plurality of first conductive pads of the substrate 102 (not shown in FIGS. 5A to 5D).

[0137] The connection hose 530 further comprises a plurality of fourth conductive pads 537 which are adapted to be coupled to the conductive trace 152 via the third conductive pads 154.

[0138] As illustrated in [Fig.5D], the connecting flex 530 includes a dielectric core 531, a first metal layer 532A on a first side of the dielectric core, a first dielectric layer 533A partially covering the first metal layer, a second metal layer 532B on a second side of the dielectric core, and a second dielectric layer 533B covering the second metal layer, similarly to the connecting flex of Figures 2C and 3A, except that the first and second metal layers are not coupled to each other.

[0139] The cavity 538 which receives the VCSEL 503 passes through the entire thickness of the first dielectric layer 533A and the first metal layer 532A up to the dielectric core 531.

[0140] The first metal layer 532A is dedicated to the conduction of electrical signals.

[0141] The first metal layer 532A terminates at each end 530A of the connecting hose 530 by the second conductive pads 534. For example, openings in the first and second dielectric layers 533A, 533B, the dielectric core 531 and the second metal layer 532B may allow the first metal layer 532A to be coupled to the first conductive pads of the substrate 102 by means of the second conductive pads 534.

[0142] The first and second dielectric layers 533A, 533B of the connecting hose 530 may comprise, for example terminate in, a plurality of insulating elements 535 at each end 530A of the connecting hose 530, and each second conductive pad 534 may be interposed between a pair of insulating elements 535. The insulating elements may be finger-shaped.

[0143] The fourth conductive pads 537 may correspond to openings in the first dielectric layer 533A to access the first metal layer 532A, in an upper portion 530B of the flexible connection 530.

[0144] The first metal layer 532A may be divided into a plurality of metal traces electrically insulated from each other by the dielectric material, and each metal trace may be coupled to a dedicated second conductive pad 534. Therefore, different electrical signals may be conducted by different metal traces and second conductive pads. For example, at least one first metal trace of the first metal layer 532A is dedicated to conducting the electrical signals of the VCSEL 503.

[0145] The second metal layer 532B is adapted to be coupled to ground.

[0146] The connection hose 530 further comprises conductive bonding pads 539 adapted to electrically couple the components 503, 504 to the connection hose 530, for example via conductive wires 505 (wire bonding). Preferably, the conductive bonding pads 539 are in electrical contact with the first metal layer 532A, for example through openings in the first dielectric layer 533A in the upper portion 530B of the connection hose 530, so that the components 503, 504 can be coupled to the first metal layer 532A, as illustrated in [Fig.5D]. For example, the VCSEL 503 is electrically coupled to the connection flex 530, in particular to the first metal layer 532A, by means of one of the bonding conductive pads 539 using some of the conductive wires 505.

[0147] The VCSEL 503 is positioned on a third metal layer 506 positioned in the recess 538. The third metal layer 506 is electrically isolated from the first metal layer 532A and is electrically coupled to the second metal layer 532B by at least one connection via 507, for example a plurality of connection vias, and is therefore adapted to be coupled to ground. The third metal layer 506 is preferably coplanar with the first metal layer 532A.

[0148] It should be considered that the recess 538 which receives the photodiode 504 may be similar to the recess 538 which receives the VCSEL 503, and that the connections of the photodiode 504 with the connection hose 530 may also be similar to those of the VCSEL with the connection hose.

[0149] The connection hose 530 comprises: - the two ends 530A (end portions) configured to be connected to the substrate 102, the second conductive pads 534 and the insulating elements 535 being defined in each of these end portions; - the upper portion 530B, this upper portion being at least partly in contact with an internal surface 130B of the module cover 130, the recesses 538 being defined in this upper portion, as well as the fourth conductive pads 537 and the connecting conductive pads 539; and - two interconnection portions 530C, each end portion 530A being connected to the upper portion 530B via one of the interconnection portions 530C, each interconnection portion being arranged substantially perpendicular to the upper portion.

[0150] Therefore, the connecting hose 530 has a curved shape.

[0151] The connection hose 530 allows for several second conductive pads 534 adjacent to each other and insulated from each other by the insulating elements 535. Since the metal traces in the connection hose 530 are insulated from each other by the dielectric material, as well as the second conductive pads 534, the risk of short circuit is reduced, even if the connection hose is deformed during molding. The pitch between the second conductive pads 534 can be about a hundred micrometers.

[0152] Positioning the components on the connecting flex allows the components to be closer to the glass than those mounted on the substrate. In one example, the glass 150 is a lens and the component 503 is a light source such as a VCSEL, and the light from the light source may be divergent, e.g., have a conical shape. The greater the distance between the light source and the lens, the larger the size of the lens can be increased to cover the cone of light, and conversely, the smaller the distance, the larger the size of the The lens can be reduced to cover the light cone. This also allows each component to be precisely positioned relative to the glass. In the example where the glass 150 is a lens and the component 503 is a light source such as a VCSEL, positioning the component on the connecting hose allows the lens to be properly aligned in all three spatial directions relative to the VCSEL.

[0153] [Fig.5D] illustrates an advantage of the flexible connection. Indeed, it can be observed that the distance d between the signal layer (first metal layer) and the ground layer (second metal layer) can be substantially stable, which allows for a characteristic impedance, and very good signal integrity. In addition, the signal layer can be very close to the ground layer and the current loop, illustrated by the dotted arrows, can be small, which can allow for better electrical performance, for example better EMI performance.

[0154] The connection hose according to the embodiments has other advantages such as: - the possibility of having a high density of metallic traces in the metallic layer(s); - the metal layer(s), and the metal traces, in the connection hose can be isolated from the module cover, which is advantageous if the module cover is electrically conductive; - the design of the connection hose is flexible; the parameters that can be adapted are for example: the number of metal layers each comprising one or more metal traces; the dimensions, thicknesses and materials of the different layers; the shape of the dielectric layer(s); the use or not of a dielectric core; the dimensions and thickness of the connection hose; the formation or not of a cavity to receive a component...

[0155] One application of the embodiments is to manage the aforementioned electromagnetic interference (EMI) through the first opening of the module cover, by using a conductive trace in a glass in the first opening and / or by covering the first opening, for example by providing EMI reflection in said first opening. In this application, a single connection hose may be sufficient, for example to connect the conductive trace to ground.

[0156] Another application of the embodiments is to address the aforementioned safety issue related to the light emitting device, i.e., to detect whether the glass is removed or detaches from the module cover, using a conductive trace in the glass. When the glass is in place, the connecting hoses, the conductive wires and the conductive trace form a conductive loop, for example via conductive paths in the substrate. If, however, the glass detaches, the circuit of the conductive loop can be opened, a detection circuit can detect the open circuit and, for example, deactivate the light-emitting device. In this application, it is usually necessary to have two connecting hoses to form a conductive loop.

[0157] 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 occur to those skilled in the art.

[0158] Finally, the practical implementation of the embodiments and variants described is within the reach of those skilled in the art from the functional indications given above.

Claims

Claims

1. An optical sensor module (200; 500) comprising: - a substrate (102) comprising first conductive pads (106); - a module cover (130) assembled on the substrate; - a connection hose (230; 330; 530) incorporated in the module cover, the connection hose being adapted to electrically couple at least one of the first conductive pads (106) to at least one component (152; 503, 504) mounted on and / or inside the module cover; the connection hose (230; 330; 530) comprising at least one metal layer (232A, 232B; 532A, 532B) covered by, or encapsulated in, at least one dielectric layer (233A, 233B; 533A, 533B).

2. Optical sensor module (200; 500) according to claim 1, wherein: - the connection hose (230; 530) is overmolded in the module cover (130); and / or - the module cover (130) is a conductive molded cover, for example made of a molding material comprising electrically conductive particles dispersed in said molding material.

3. An optical sensor module (500) according to claim 1 or 2, wherein: - the at least one metal layer (532A, 532B) of the flexible connection (530) comprises, for example terminates in, a plurality of second conductive pads (534) which are adapted to be coupled to a plurality of first conductive pads (106) of the substrate (102); and - the at least one dielectric layer (533A, 533B) of the flexible connection (530) comprises, for example terminates in, a plurality of insulating elements (535), each second conductive pad (534) being interposed between two insulating elements (532).

4. An optical sensor module (200; 500) according to any one of claims 1 to 3, further comprising a light emitting device (110; 503, 504), the module cover (130) at least partially covering the light emitting device and comprising a first opening (131) located above said light emitting device, the light emitting device being for example one of the at least one component.

5. An optical sensor module (200; 500) according to claim 4, further comprising 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 light signals emitted by the light emitting device (110; 503), the glass comprising a conductive trace (152) which corresponds to a first component among the at least one component, the connection hose (230; 530) being electrically coupled to the conductive trace, for example via a conductive wire (155) formed by wire soldering.

6. An optical sensor module (500) according to any one of claims 1 to 5, wherein a second component (503, 504) among the at least one component is positioned on the connection hose (530).

7. Optical sensor module (500) according to claim 6, wherein the connection hose (530) comprises at least one recess (538) adapted to receive the second component (503, 504).

8. An optical sensor module (500) according to claim 7 in combination with claim 3, wherein the flexible connection (530) comprises: - at least one end portion (530A) configured to be connected to the substrate (102), the second conductive pads (534) and the insulating elements (535) being defined in said at least one end portion, and - an upper portion (530B), said upper portion being at least partly in contact with an internal surface (130B) of the module cover (130), the recess (538) being defined in said upper portion.

9. The optical sensor module (500) of claim 8, wherein the connecting hose (530) comprises two end portions (530A) and two interconnecting portions (530C), wherein each end portion is connected to the upper portion (530B) by means of one of the interconnecting portions, each interconnecting portion being arranged substantially perpendicular to the upper portion.

10. Optical sensor module (500) according to claim 8 or 9, wherein the connection hose (530) comprises: - a first metal layer (532A) electrically coupled to the second component (503), for example by means of a conductive wire (505), the first metal layer being covered by a first dielectric layer (533A) among the at least one dielectric layer; - a second metal layer (532B) configured to be connected to ground, the second metal layer being covered by a second dielectric layer (533B) among the at least one dielectric layer; - a third metal layer (506) positioned in the recess (538) and electrically insulated from the first metal layer, the second component (503) being connected to said third metal layer, for example positioned on said third metal layer; - a dielectric core (531) interposed between the first metal layer (532A) and the second metal layer (532B); - at least one connection via (507) defined in said dielectric core (531) and electrically coupling the third metal layer (506) to the second metal layer (532B).

11. The optical sensor module (500) of claim 10, wherein the recess (538) extends through the entire thickness of the first dielectric layer (533A) and the first metal layer (532A) to the dielectric core (531).

12. An optical sensor module according to any one of claims 8 to 11, wherein the connection hose (530) comprises a plurality of bonding pads (539), said bonding pads being defined on the upper portion (530B) of the connection hose, each bonding pad (539) being configured to be electrically coupled to the second component (503, 504), for example by means of a conductive wire (505).

13. An optical sensor module according to claim 12 in combination with claim 10 or 11, wherein the bonding pads (539) extend through the entire thickness of the first dielectric layer (533A) to the first metal layer (532A).

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