Optical sensor module

Abstract

The utility model relates to an optical sensor module. An optical sensor module is provided. An exemplary optical sensor module includes: a substrate including a first conductive pad; a module cap assembled on the substrate; a connection flexure incorporated in the module cap, the connection flexure adapted to electrically couple at least one of the first conductive pads to at least one component mounted on and / or within the module cap; the connection flexure includes at least one metal layer that is covered by or encapsulated in at least one dielectric layer.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to French patent application No. 2311581 entitled “Module de Capteur Optique”, filed on October 25, 2023, which is incorporated herein by reference to the fullest extent permitted by law. Technical Field

[0003] This disclosure generally relates to optical sensors, and more particularly to optical sensor modules. Background Technology

[0004] Optical sensors, such as proximity sensors, can be used to detect the presence of nearby objects. Optical sensors do this without physical contact with the object. Certain types of optical sensors, such as those used in optical rangefinders or flight sensors, can be used to determine the actual distance to such nearby objects. Optical sensors can be used in a variety of electronic devices, such as cameras, mobile phones (including smartphones), smartwatches, tablets, vehicles, machinery, and other devices, to detect the presence of nearby objects and / or the distance to them. Upon detecting the presence of a nearby object, the electronic device can be configured to perform functions, such as moving a mechanical feature to a safe position, sending an alarm signal, coupling or decoupling electrical communications, or any other desired function.

[0005] Optical sensors typically include components such as a light-emitting device, a light-receiving sensor (or image sensor), and processing means typically used to process the signal received from the light-receiving sensor. The components of an optical sensor can be formed on a substrate, and a cap can be attached to the substrate over the components, for example, to protect them from damage, thus forming an optical sensor module (also known as an optical sensor package). The cap is typically formed with a first opening over the light-emitting device and a second opening over the light-receiving sensor.

[0006] Generally, the light-emitting device emits a light signal or beam through a first opening. If an object is outside the optical sensor module and sufficiently close, the light signal can be emitted by the object through a second opening towards the light-receiving sensor. The light-receiving sensor can then generate an electrical signal indicating the received light signal, which can be transmitted to a processing device to process the received light signal, for example, to determine the presence of an approaching object and / or the distance to it.

[0007] The light-emitting device used to generate the light beam is typically covered by glass to protect it from dust; this glass is relatively transparent to the wavelength of light used. The first opening located above the light-emitting device may also be covered by glass.

[0008] There is a need to improve the optical sensor module, particularly to improve the electrical coupling between the substrate and components mounted in and / or on the cap, such as the electrical coupling between conductive elements (e.g., conductive traces) in the substrate and glass. Utility Model Content

[0009] One embodiment addresses all or some of the drawbacks of known optical sensor modules.

[0010] One embodiment provides an optical sensor module, including:

[0011] - Substrate, including a first conductive pad;

[0012] - Module cap, assembled on the base plate;

[0013] - A connecting flexible element, incorporated in the module cap, the connecting flexible element being adapted to electrically couple at least one of the first conductive pads to at least one component mounted on and / or within the module cap;

[0014] The connecting flexible element includes at least one metal layer, which is covered by or encapsulated within at least one dielectric layer.

[0015] In one embodiment:

[0016] - The connecting flexible element is overmolded in the module cap; and / or

[0017] - The module cap is a conductive molded cap, for example, formed of a molding material comprising conductive particles dispersed therein.

[0018] In one embodiment:

[0019] - The at least one metal layer of the connecting flexible element includes a plurality of second conductive pads, for example terminating in one of the plurality of second conductive pads, the second conductive pads being adapted to couple with a plurality of first conductive pads of the substrate; and

[0020] - The at least one dielectric layer of the connecting flexible element includes a plurality of insulating elements, for example, terminating in a plurality of insulating elements, with each second conductive pad inserted between two insulating elements.

[0021] In one embodiment, the optical sensor module further includes a light-emitting device, the module cap at least partially covering the light-emitting device and including a first opening above the light-emitting device, the light-emitting device being, for example, one of the at least one component.

[0022] In one embodiment, the optical sensor module further includes glass located in 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 includes conductive traces corresponding to a first component of the at least one component, and the connecting flexible member is electrically coupled to the conductive traces, for example, through conductive lines formed by conductive wire bonding.

[0023] In one embodiment, the second component of the at least one component is located on the connecting flexibility. For example, the second component includes at least a portion of the light-emitting device.

[0024] In one embodiment, the connecting flexibility includes at least a recess adapted to receive the second component.

[0025] In one embodiment, the flexible connection element includes:

[0026] - At least one end portion is configured to be connected to a substrate, and a second conductive pad and an insulating element are defined in at least one end portion.

[0027] - Upper portion, the upper portion at least partially contacts the inner surface of the module cap, the recess being defined in the upper portion.

[0028] In one embodiment, the connecting flexibility includes two end portions and two interconnecting portions, wherein each end portion is connected to an upper portion via one of the interconnecting portions, and each interconnecting portion is disposed substantially perpendicular to the upper portion.

[0029] In one embodiment, the connecting flexibility includes:

[0030] - A first metal layer electrically coupled to a second element, for example through a conductive line, the first metal layer being covered by a first dielectric layer in the at least one dielectric layer;

[0031] - A second metal layer configured to be connected to ground, the second metal layer being covered by a second dielectric layer in the at least one dielectric layer;

[0032] - A third metal layer, located in the recess and electrically isolated from the first metal layer, and a second component connected to the third metal layer, for example, located on the third metal layer;

[0033] - A dielectric core, inserted between the first and second metal layers; and

[0034] - At least one connection via is defined in the dielectric core and electrically couples the third metal layer to the second metal layer. Preferably, the first metal layer, the second metal layer, and / or the third metal layer are some of the at least one metal layer of the connecting flexibility.

[0035] In one embodiment, the recess extends through the entire thickness of the first dielectric layer and the first metal layer to the dielectric core.

[0036] In one embodiment, the connection flexibility includes a plurality of bonding pads defined on the upper portion of the connection flexibility, each bonding pad being configured to be electrically coupled to the second component, for example, via a conductive line.

[0037] In one embodiment, the bonding pad extends through the entire thickness of the first dielectric layer down to the first metal layer. Attached Figure Description

[0038] The above-described features and advantages, as well as other features and advantages, will be detailed in the following description of specific embodiments given in an illustrative rather than restrictive manner with reference to the accompanying drawings, in which:

[0039] Figure 1 This is a 3D view of an example of an optical sensor module;

[0040] Figure 2A , Figure 2B and Figure 2C This is a three-dimensional view of an optical sensor module according to one embodiment;

[0041] Figure 3A yes Figure 2B and 2C A schematic cross-sectional view of the connecting flexible element;

[0042] Figure 3B This is a schematic cross-sectional view of the connecting flexible element of an optical sensor module according to another embodiment;

[0043] Figure 4A , Figure 4B , Figure 4C , Figure 4D , Figure 4E , Figure 4F , Figure 4G and Figure 4H It is shown in Figure 2A Top view and three-dimensional view of the method of assembling the connecting flexible element to the module cap in the optical sensor module;

[0044] Figure 5A This is a three-dimensional cross-sectional view of an optical sensor module according to another embodiment;

[0045] Figure 5B yes Figure 5A Top view of the optical sensor module;

[0046] Figure 5C It is shown Figure 5A and 5BA top view showing details of the flexible connector for the optical sensor module; and

[0047] Figure 5D It is shown Figure 5C A cutaway 3D view of the details of the connecting flexible component. Detailed Implementation

[0048] The same or similar features in the various figures are designated by the same or similar reference numerals. In particular, common structural and / or functional features in various embodiments may have the same reference numerals and may have the same structure, dimensions, and material properties.

[0049] For clarity, only operations and elements useful for understanding the embodiments described herein have been shown and described in detail. In particular, not all components of the optical sensor are described in detail, and the described embodiments are compatible with conventional optical sensors. For example, light-emitting devices, light-receiving sensors, and other components of the optical sensor, such as processing devices, are not described in detail. Similarly, not all components of the optical sensor module are described in detail, and the described embodiments are compatible with conventional optical sensor modules.

[0050] Unless otherwise stated, when referring to two elements connected together, it means that there is no direct connection between them except for the conductor; when referring to two elements coupled together, it means that the two elements can be connected or they can be coupled through one or more other elements.

[0051] In the following disclosure, unless otherwise stated, when referring to absolute position qualifiers, such as the terms “front,” “back,” “top,” “bottom,” “left,” “right,” etc., or relative position qualifiers, such as the terms “up,” “down,” “high,” “low,” etc., or direction qualifiers, such as “horizontal,” “vertical,” etc., reference is made to the direction shown in the accompanying drawings, or to the optical sensor module oriented in normal use.

[0052] Unless otherwise stated, the expressions “about,” “approximately,” “basically,” and “about” indicate within 10%, preferably within 5%.

[0053] In the following disclosure, unless otherwise stated, when referring to glass, it includes elements made of a material that is relatively transparent to light of the wavelength used, for example, having a transmittance of 90% or more for those wavelengths. This includes, but is not limited to, glass materials or plastic materials. Glass can be formed from a single solid material or by assembling multiple materials, in which case a portion of the glass may be within a transparent material. The glass may include (or constitute) glass windows, lenses or multiple lenses and / or optical filters (more generally, optical components).

[0054] In the following disclosure, unless otherwise stated, when referring to a filter, it means an optical filter.

[0055] In the following disclosure, unless otherwise stated, when referring to conductive elements, such as conductive traces, pads, strips, or leads, it means conductive elements.

[0056] In the following disclosure, when reference is made to a connecting flexible element or “flex”, it means a strip suitable for electrically coupling or connecting two elements, which is both flexible, such as allowing it to bend according to a given curvature, and mechanically rigid, such as maintaining that curvature once bent.

[0057] The embodiments involve a variety of optical sensor modules.

[0058] The term "optical sensor module" includes, but is not limited to, proximity sensor modules, time-of-flight (ToF) modules, ambient light sensor (ALS) modules, 3D LiDAR modules, and / or camera modules. The term "optical sensor module" also includes optical sensor modules with combined functions, such as a combination of at least two of the modules described above, or other functions, such as a combination of a proximity detector module with a floodlight and / or a dot projector.

[0059] Optical sensors typically include a light-emitting device and a light-receiving sensor. They also typically include processing means for processing the signal received from the light-receiving sensor. The light-emitting device and the light-receiving sensor can be formed on a substrate, and a cap can be attached to the substrate over the light-emitting device and the light-receiving sensor to form an optical sensor module (also known as an optical sensor package). The cap typically has a first opening over the light-emitting device and a second opening over the light-receiving sensor.

[0060] As explained in the background section above, light-emitting devices are typically covered by glass to protect them, for example, from dust. The glass is relatively transparent to the wavelength of light used. The glass may cover the first opening. The glass can also act as a diffuser, suitable for reducing the intensity of the emitted light beam to some extent, for example, for safety reasons, such as protecting the user.

[0061] Figure 1 This is a 3D view of an example of an optical sensor module.

[0062] The optical sensor module 100 includes a light-emitting device 110, such as a light-emitting diode (LED) (e.g., an infrared LED) and / or a laser (e.g., a vertical-cavity surface-emitting laser (VCSEL)), and a light-receiving sensor 120 (e.g., an image sensor), such as a photodiode or multiple photodiodes, such as one or more SPADs. The light-emitting device 110 and the light-receiving sensor 120 are mounted on a substrate 102.

[0063] The substrate 102 can be a printed circuit board (PCB).

[0064] The light-emitting device 110 is configured to emit light signals or light beams at a specific frequency or frequency range, and the light-receiving sensor 120 is adapted to detect the returned emitted light signals, such as light signals 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 returned IR light signals, such as those reflected by an object.

[0065] Figure 1 The light-emitting device 110 includes first and second light sources 111 and 112 respectively mounted on a first insert 141 and a second insert 142, which are mounted on the top surface 102A of the substrate 102. The first and second light sources 111 and 112 are, for example, first and second VCSELs. In a variant, the light sources may be mounted on the substrate without inserts.

[0066] In one variant, the light-emitting device may consist of only one light source, such as a VCSEL, which may be mounted on a substrate via an insert, or may not even require an insert.

[0067] The light-emitting device 110 can be electrically coupled to the light-receiving sensor 120, for example, via the substrate 102.

[0068] The upper surface 102A of the substrate 102 includes a conductive pad 106 (first conductive pad), which is located, for example, at or near the edge of the substrate.

[0069] 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 is not limiting, and other configurations may be considered by those skilled in the art.

[0070] The optical sensor module 100 may include processing circuitry (not included in...) Figure 1 (As shown in the figure), it can be configured to process light signals emitted by the light-emitting device 110 and received by the light-receiving sensor 120. The processing circuit can be mounted on the top surface 102A of the substrate 102.

[0071] The optical sensor module 100 includes other circuitry or electronic components, such as a surface mount technology (SMT) component 145, which is also mounted on the top surface 102A of the substrate 102. The SMT component 145 may include resistors. Other SMT components may include capacitors.

[0072] The light receiving sensor 120 can be coupled to the substrate 102 using a conductive connector (e.g., a conductive wire), and / or can be fixed to the substrate 102, such as by an adhesive material or solder. The adhesive material can be any material suitable for fixing the light receiving sensor 120 to the substrate, such as tape, paste, or glue.

[0073] A module cap 130, having a first opening 131 and a second opening 132, is attached or joined to a substrate 102 and is adapted to at least partially surround or cover components mounted on the substrate 102, including at least the light-emitting device 110, the light-receiving sensor 120, the inserts 141 and 142, the laser driver 144, and the SMT assembly 145. "At least partially" means that not all components may be covered; for example, the first and second openings may not cover components located below the openings. The module cap 130 may be substantially opaque to the wavelength of light used.

[0074] The first and second openings are located on the top surface 130A of the module cap 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 shown, the first opening 131 is rectangular and the second opening 132 is circular, but this is not limiting, and other forms are possible.

[0075] The module cap 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 isolator to substantially prevent the propagation of a light beam within the module cap 130 between the light-emitting device 110 and the light-receiving sensor 120. For example, the separating wall 133 defines a first cavity and second cavities 136, 137, the first cavity 136 including a first opening 131 above the light-emitting device 110, and the second cavity 137 including a second opening 132 above the light-receiving sensor 120. As described above, the laser driver 144 may be located in the first cavity 136 together with the light-emitting device 110.

[0076] The module cap 130 can be a plastic cap and / or a molded cap formed of a molding material, such as resin, liquid crystal polymer (LCP), nylon, or other engineering plastics. The module cap 130 can be formed using an injection molding method. In some examples, the module cap can be conductive.

[0077] The optical sensor module 100 also includes:

[0078] - Glass 150, located in the first opening 131, or between the first opening 131 and the light-emitting device 110, is adapted to transmit light signals emitted by the light-emitting device; and

[0079] - Filter 160, located in the second opening 132, or between the second opening 132 and the light receiving sensor 120, is adapted to transmit light signals reflected to the light receiving sensor.

[0080] Glass 150 preferably covers the first opening 131. Glass 150 is preferably attached to the module cap 130. For example, glass 150 is situated on a mounting 139 formed within the first opening 131 and is mounted on the exterior of the module cap 130. In one variation, glass may be mounted inside the module cap.

[0081] Similarly, filter 160 preferably covers the second opening 132. Filter 160 is preferably attached to module cap 130. For example, filter 160 is located inside module cap 130. In a variation, filter may be mounted on the outside of module cap.

[0082] Glass 150 may include two optical surfaces, which may be two beamshapers 151A and 151B, with the first beamshaper 151A located above the first light source 111 and the second beamshaper 151B located above the second light source 112. Glass 150 may be a lens or a lens pad.

[0083] The optical sensor module 100 may further include a second lens 162 located between the filter 160 and the light receiving sensor 120.

[0084] Glass 150 may include conductive traces 152 that may be embedded in the glass. Glass 150 may further include conductive pads 154 (third conductive pads) coupled to the conductive traces 152, such as two third conductive pads, each located at the end of the conductive trace.

[0085] In the following disclosures, conductive traces may be referred to as "traces". Conductive pads may be referred to as "pads" in the following disclosures.

[0086] The conductive trace can be one or more of the following materials: copper (Cu), aluminum (Al), tungsten (W), titanium (Ti), gold (Au), indium tin oxide (ITO), or other metals or metal alloys.

[0087] The conductive trace 152 can be a fine and / or thin trace, for example, having a width of less than 1 micrometer and / or a thickness of less than 100 nanometers, but is not limited to these values. The width and thickness of the conductive trace can be a trade-off between its function and the light transmittance of the glass. For example, where the trace is unlikely to restrict light transmission, the conductive trace can be wider and / or thicker, while where the trace may restrict light transmission, the conductive trace can be finer and / or thinner.

[0088] Typically, the conductive trace 152 is configured to be coupled to a conductive rail configured to be at a fixed voltage (e.g., ground), and the conductive rail is typically connected to or included in the substrate 102.

[0089] The conductive trace 152 can serve as protection against electromagnetic interference (EMI) through the first opening 131 of the module cap 130, for example, by providing EMI reflection within the 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, smartphone, smartwatch, tablet, vehicle, machine, or other device that can be used to detect the presence and / or distance to a nearby object. The pitch and pattern of the conductive trace can be determined based on the frequency of the EMI to be managed. For example, the higher the frequency, the lower the pitch can be.

[0090] The conductive trace 152 can also be used to manage safety issues related to the light-emitting device 110, namely, to detect whether the glass 150 has been removed or otherwise separated from the module cap 130. If the glass 150 is removed or separated, it can no longer be used as a diffuser suitable for reducing the intensity of the emitted beam, nor can it protect the user. When the glass 150 is in place, the conductive leads 134, conductive lines 155, and conductive trace 152 form a conductive loop, for example, through conductive paths in the substrate 102. However, if the glass 150 becomes separated, the circuit in the conductive loop can be opened, the detection circuit can detect the open circuit, and the light-emitting device 110 can be deactivated, for example.

[0091] In a variant (not shown), filter 160 may also include a second conductive trace.

[0092] Examples of conductive traces are described in more detail in French patent application 2311561 (law firm number B22689) entitled “Module de Capteur Optique”, filed on October 25, 2023, under the name of STMicroelectronics International NV, which is incorporated herein by reference to the fullest extent permitted by law.

[0093] The optical sensor module 100 also includes two conductive leads 134 assembled to the module cap 130, for example, overmolded in the module cap. The conductive leads 134 are configured and positioned to electrically couple the conductive traces 152 of the glass 150 to the substrate 102. The conductive leads 134 are typically rigid, such as lead frames.

[0094] Each conductive lead 134 can be a single conductive sheet, such as a single metal sheet.

[0095] Each conductive lead 134 includes a first end 134A coupled (e.g., connected) to the substrate 102 via one of the first conductive pads 106, and a second end 134B coupled (e.g., connected) to the conductive trace 152 via one of the third conductive pads 154. The first end 134A of each conductive lead 134 may be coupled to one of the first conductive pads 106 by a conductive adhesive, such as a conductive tape, paste, or glue, or conductive solder. The second end 134B of each conductive lead 134 may be coupled to the third conductive pad 154 by a conductive wire 155 (which is formed by wire bonding, and may be referred to as a "wire bonding member") or by a conductive adhesive or conductive solder.

[0096] Examples of conductive lines are described in more detail in French patent application 2311572 (law firm number B22688), filed on October 25, 2023, entitled “Module de Capteur Optique”, under the name of STMicroelectronics International NV, which is incorporated herein by reference to the fullest extent permitted by law.

[0097] However, conductive leads, especially lead frames, have some drawbacks.

[0098] Leadframes are typically rigid and have low tolerance for relative movement of the components they connect to and / or dimensional variations between these components and the leadframe, which can lead to delamination.

[0099] Furthermore, there may be interest in having multiple pads at the first end 134A of the conductive lead 134. However, due to the common methods of manufacturing conductive leads (such as lead frames), it may be difficult to have small pitches between the pads, and therefore difficult to have such multiple pads. In fact, lead frames are usually manufactured by stamping, and in order to maintain the shape of the lead frames, for example, to avoid contact with each other during the molding process, each lead frame should be made wide and thick enough to maintain strength, and as a result, the pad pitch may be quite large, typically at least 0.4 mm.

[0100] Assembling the conductive leads 134 to the substrate 102, for example using conductive adhesive or solder, may also require creating trenches 104 around each first conductive pad 106 to separate the conductive adhesive or solder from other components (e.g., from other components in the substrate), which may require a large space in the substrate to assemble the conductive leads.

[0101] Furthermore, for example, if the module cap 130 is conductive, it may be necessary to isolate the conductive leads from the module cap. However, it may be difficult to isolate the conductive leads from the conductive module cap.

[0102] The inventors have proposed an optical sensor module that overcomes all or part of the above-mentioned drawbacks, particularly improving the electrical coupling between the substrate and conductive components within the component or module cap, such as the electrical coupling between the substrate and conductive traces within the glass.

[0103] Embodiments of the optical sensor module will now be described. These embodiments are not limiting, and those skilled in the art will recognize various variations based on the indications in this description.

[0104] In the following disclosure, unless otherwise stated, when referring to a component, it means an electronic component, and this includes conductive elements, such as conductive traces.

[0105] Figure 2A , Figure 2B and Figure 2C This is a three-dimensional view of an optical sensor module 200 according to one embodiment. Figure 2B The connecting flexible element of the optical sensor module is shown in more detail. Figure 2C A cross-sectional view corresponding to one of the connecting flexible members 230.

[0106] Figure 2A , 2B And 2C optical sensor module 200 and Figure 1 The main difference between the optical sensor module 100 and the optical sensor module 200 is that, instead of conductive leads (e.g., lead frames) assembled to the module cap 130, the optical sensor module 200 includes two connecting flexible members 230 assembled to the module cap 130. Other components of the optical sensor module 200 can be... Figure 1 Similar to the optical sensor module 100: these elements have the same Figure 1 The same reference numerals are used in the accompanying drawings, and will not be described again.

[0107] Each flexible connector 230 includes at least one metal layer covered or encapsulated within at least one dielectric layer to electrically isolate the flexible connector from other conductive elements of the optical sensor module 200, except for portions of the flexible connector where the at least one dielectric layer is opened to access the at least one metal layer for electrical connection. Therefore, at open portions (e.g., end portions) of the flexible connector 230, the at least one metal layer is adapted to be electrically coupled to components of the optical sensor module 200.

[0108] exist Figure 2B and 2C In the example, each connection flexibility 230 includes two metal layers, a first metal layer 232A and a second metal layer 232B, which are electrically isolated from each other by a dielectric core 231.

[0109] For example, a first metal layer 232A and a second metal layer 232B are embedded in a dielectric core 231, with the first metal layer 232A flush with the first surface 231A of the dielectric core and the second metal layer 232B flush with the second surface 231B of the dielectric core.

[0110] For example, the first and second metal layers 232A and 232B have a width smaller than that of the dielectric core 231 and are substantially centered relative to the dielectric core, such that the first and second metal layers 232A and 232B do not reach the edge of the connecting flexible member 230. Therefore, the edge of the connecting flexible member 230 is electrically isolated.

[0111] For example, the first and second metal layers 232A and 232B form metal strips within the dielectric core 231.

[0112] Each connecting flexible element 230 also includes two dielectric layers 233A and 233B: a first dielectric layer 233A covering a first metal layer 232A and a second dielectric layer 233B covering a second metal layer 232B. The first dielectric layer covers the side of the first metal layer that is not isolated by the dielectric core, and similarly, the second dielectric layer covers the side of the second metal layer that is not isolated by the dielectric core.

[0113] The first and second dielectric layers 233A and 233B may also at least partially cover the first and second surfaces of the dielectric core 231, such as... Figure 2B and 2C As shown, the first and second metal layers 232A and 232B are embedded in the dielectric core 231 and have a width smaller than the width of the dielectric core 231.

[0114] like Figure 2B and 2CAs shown, the first and second metal layers 232A and 232B can be coupled to each other at the first end 230A of the flexible member 230 via a metal component 234, such as a metal button with a hole 235. The metal component 234 is preferably not covered by the first and second dielectric layers 233A and 233B, or at least not partially covered by them. The metal component 234 forms a conductive pad (second conductive pad) connecting the flexible member 230.

[0115] Metal component 234 (i.e., second conductive pad) can be coupled to one of the first conductive pads 106 of substrate 102 by means of conductive adhesive, such as conductive glue or conductive solder.

[0116] At the second end 230B of the connecting flexible member 230, the first dielectric layer 233A is opened to allow electrical connection to the first metal layer 232A, such that the first metal layer 232A can be connected to the conductive trace 152, for example, via one of the third conductive pads 154. For example, the first metal layer 232A terminates in a fourth conductive pad 237, which is coupled to the third conductive pad 154, for example, via a conductive line 155 formed by wire bonding. The conductive trace 152 corresponds to an assembly (first assembly) coupled to the substrate 102 via the connecting flexible member 230.

[0117] In one variant, each connecting flexible element 230 may be coupled to the conductive trace 152 of the glass 150 using a conductive adhesive or conductive solder.

[0118] The second dielectric layer 233B can also be opened to allow access to the second metal layer 232B for electrical connection. For example, the second metal layer 232B can also terminate in a conductive pad or in a fourth conductive pad 237.

[0119] The dielectric material for the dielectric core and / or dielectric layer is, for example, polyimide. Polyimide has the advantages of being both thermosetting and thermoplastic, exhibiting high thermal stability, excellent dielectric properties, and an inherently low coefficient of thermal expansion. Furthermore, polyimide can withstand high temperatures, such as those encountered during reflow, for example, 500°C or higher.

[0120] The metal of the metal layer and / or the metal component connecting the flexible element is, for example, copper.

[0121] In one variant, the two metal layers 232A and 232B may be uncoupled from each other. For example, one of the two metal layers may be coupled to ground, while the other metal layer may be dedicated to conducting electrical signals, such as... Figures 5A to 5D As shown in the example.

[0122] In another variant, the connecting flexible element may consist of only one metal layer, as described below. Figure 3B As shown.

[0123] In another variant, the connecting flexible element may include two or more metal layers, with two adjacent metal layers preferably isolated from each other by a dielectric material.

[0124] In one variant, instead of having two dielectric layers at each face of the connecting flexible member, the connecting flexible member may include dielectric layers arranged to wrap or encapsulate the connecting flexible member.

[0125] Glass 150 may include, or may be present in, a glass window, a lens or multiple lenses, and / or a filter.

[0126] Each connecting flexible element 230 can be overmolded in the module cap 130.

[0127] and Figure 1 Similar to the optical sensor module 100, the module cap 130 of the optical sensor module 200 can be a plastic cap and / or a molded cap formed of a molding material, such as resin, liquid crystal polymer (LCP), polyamide, nylon, or other engineering plastics. The module cap 130 can be formed using an injection molding method. In one variation, the module cap 130 can be conductive, for example, a molded cap formed of a molding material (e.g., one of the aforementioned molding materials) filled with conductive particles dispersed therein. When the module cap is conductive, it is advantageous to use a connecting flexible element because the metal layer of the connecting flexible element can be isolated from the conductive module cap by a dielectric layer and / or a dielectric core.

[0128] Examples of conductive module caps are described in more detail in French patent application 2311561 (law firm number B22689), filed on October 25, 2023, entitled “Module de Capteur Optique”, by STMICROELECTRONICS INTERNATIONAL NV, which is incorporated herein by reference to the fullest extent permitted by law.

[0129] Figure 2A and 2B Other features of the optical sensor module 200 may be similar to Figure 1 Other features of the optical sensor module 100.

[0130] In one variant, the optical sensor module may not include conductive traces, but may include one or more other components located on or under the glass and coupled to one or more connecting flexible elements.

[0131] In one variant, the optical sensor module may not include glass, but may include one or more components that are not located on or under the glass and are coupled to one or more connecting flexible elements.

[0132] In one variant that can be combined with previous variants, one or more components may be located on the connecting flexible element. Examples are illustrated below. Figures 5A to 5D As shown.

[0133] exist Figure 2A and 2B The symbol represents two connecting flexible elements. This is not limiting, and an optical sensor module may include one connecting flexible element. An optical sensor module may also include more than two connecting flexible elements.

[0134] Figure 3A yes Figure 2B and 2C A schematic cross-sectional view of the connecting flexible element. Figure 3A The different layers of the connecting flexible member 230 are schematically shown, as well as the metal button 234 protruding from the rest of the connecting flexible member. Figure 3A The first adhesive layer 236A between the first metal layer 232A and the first dielectric layer 233A is further shown, as well as the second adhesive layer 236B between the second metal layer 232B and the second dielectric layer 233B.

[0135] The thickness of the layer can vary. The thickness range is shown in Table 1 below, which is a non-limiting range.

[0136] [Table 1]

[0137] layer Thickness range (μm) 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]

[0138] Figure 3B This is a schematic cross-sectional view of the connecting flexible member 330 of an optical sensor module according to another embodiment. The connecting flexible member 330 and... Figure 3A The main difference of the connecting flexible element 230 is that it contains only a single metal layer 232A and does not contain a dielectric core. The metal layer 232A protrudes from the rest of the connecting flexible element 330, for example, by being electrically coupled to a substrate.

[0139] The thickness of the layer can vary. The thickness range is shown in Table 2 below as a non-limiting range.

[0140] [Table 2]

[0141] layer Thickness range (μm) 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]

[0142] Figure 4A , Figure 4B , Figure 4C , Figure 4D , Figure 4E , Figure 4F , Figure 4G and Figure 4H It is shown in Figure 2A Top view and three-dimensional view of the method of assembling the connecting flexible element to the module cap in the optical sensor module.

[0143] Figure 4A This is a top view of the initial structure including the 2D connecting flexible element 430. In each 2D connecting flexible element, a metal component 234 or a second conductive pad, a hole 235 in the metal component 234, and a fourth conductive pad 237 are visible. Furthermore, each 2D connecting flexible element has a tab 432 extending the 2D connecting flexible element 430 beyond the metal component 234 to facilitate assembly methods, particularly to facilitate holding the connecting flexible element in the molding tool described below.

[0144] Figure 4B It is a three-dimensional view of the structure obtained by bending the 2D connecting flexible member 430 into the desired 3D shape required for subsequent molding, thereby forming the connecting flexible member 230.

[0145] Figure 4C This is a three-dimensional view of the structure obtained by placing the connecting flexible elements 230 into the core 401 of the molding tool 400, which is adapted to position these connecting flexible elements relative to a future module cap, and by bringing the mold cavity 402 of the molding tool 400 closer together. The mold cavity 402 includes a retaining insert 403 adapted to hold the connecting flexible elements 230 in place during subsequent molding processes.

[0146] Figure 4D This is a three-dimensional view of the structure obtained when the mold cavity 402 and mold core 401 are closed, wherein the retaining insert 403 holds the connecting flexible member 230 in its predetermined position. The connecting flexible member 230 is inserted into the hole 431 of the connecting flexible member (e.g., Figure 4B The retaining insert 403 (as shown) is held in place for subsequent molding.

[0147] Figure 4E This is a three-dimensional view of the structure obtained after the injection molding step, in which molding material is injected into the mold cavity 402 to form a module cap 130 made of the molding material. After the injection molding step, the connecting flexible member 230 is over-molded in the module cap.

[0148] Figure 4F This is a three-dimensional view of the structure obtained after the molding tool 400 is opened, that is, after the mold core 401 and the mold cavity 402 are separated from each other. When the molding tool is opened, the module cap 130 is ejected from the molding tool 400.

[0149] Figure 4GThis is a top view of the structure obtained by cutting each connecting flexible member 230 to remove the tabs 432.

[0150] Figure 4H This is a three-dimensional view of the connecting flexible member 230, which is assembled into the module cap 130 and overmolded into the module cap 130.

[0151] Then, the module cap 130, which is equipped with the connecting flexible member 230, can be assembled onto the substrate.

[0152] Figure 5A This is a cut-out three-dimensional view of an optical sensor module 500 according to another embodiment. Figure 5B for Figure 5A Top view of the optical sensor module 500. Figure 5C It shows Figure 5A and 5B A top view showing details of the connecting flexible element 530 of the optical sensor module 500. Figure 5D It is a cut-out 3D view, showing Figure 5C Details of the connecting flexible element 530. Figure 5A Only indicates in Figure 5B The optical sensor module 500 is shown as half of the BB direction cut.

[0153] and Figures 2A to 2C The optical sensor module 200 is similar. Figures 5A to 5D The optical sensor module 500 includes a module cap 130 and a glass 150 seated on a mounting base 139 formed within a first opening 131 in the module cap 130. The glass 150 includes conductive traces 152 and third conductive pads 154 coupled to each end of the conductive traces.

[0154] Figures 5A to 5D The optical sensor module 500 includes a connecting flexible element 530.

[0155] The connecting flexible member 530 is adapted to receive one or more components 503, 504 (second components) on itself, located below the glass 150. The at least one second component may be a light source 503 (such as a VCSEL), and optionally a photodiode 504, which may be used to monitor the light source 503. The at least one second component may be part of a light-emitting device. This is not limiting; other components may be positioned within the recesses of the connecting flexible member. Figure 5D Details of the light source 503, represented by VCSEL, are shown, as well as details of the connecting flexible member 530 on which the VCSEL 503 is mounted and coupled.

[0156] In the example shown, the connecting flexible member 530 includes a recess 538 adapted to receive components 503, 504 under the glass 150.

[0157] The connecting flexible element 530 includes a plurality of second conductive pads 534 adapted to connect with a plurality of first conductive pads on the substrate 102. Figures 5A to 5D (not shown in the image) coupling.

[0158] The connecting flexible element 530 also includes a plurality of fourth conductive pads 537 adapted to be coupled to the conductive trace 152 via the third conductive pad 154.

[0159] like Figure 5D As shown, the connecting flexible element 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, which is connected to... Figure 2C and 3A Similar to the flexible connection, except that the first and second metal layers are not coupled to each other.

[0160] The recess 538 receiving the VCSEL 503 extends through the entire thickness of the first dielectric layer 533A and the first metal layer 532A, down to the dielectric core 531.

[0161] The first metal layer 532A is dedicated to the conduction of electrical signals.

[0162] The first metal layer 532A terminates at each end 530A of the flexible member 530, which has a second conductive pad 534. For example, openings in the first and second dielectric layers 533A and 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 pad of the substrate 102 through the second conductive pad 534.

[0163] At each end 530A of the connecting flexible member 530, the first and second dielectric layers 533A, 533B of the connecting flexible member 530 may include, for example, terminate at, a plurality of isolation elements 535, and each second conductive pad 534 may be inserted between a pair of isolation elements 535. The isolation elements may be finger-shaped.

[0164] The fourth conductive pad 537 may correspond to an opening in the first dielectric layer 533A in the top portion 530B of the connecting flexible member 530 to access the first metal layer 532A.

[0165] The first metal layer 532A can be divided into multiple metal traces electrically isolated from each other by a dielectric material, and each metal trace can be coupled to a dedicated second conductive pad 534. Therefore, different metal traces and second conductive pads can conduct different electrical signals. For example, at least the first metal trace of the first metal layer 532A is dedicated to conducting electrical signals for the VCSEL 503.

[0166] The second metal layer 532B is suitable for coupling with ground.

[0167] The flexible connector 530 further includes a bonding conductive pad 539 adapted to electrically couple components 503, 504 to the flexible connector 530, for example, via a conductive line 505 (wire bonding). Preferably, the bonding conductive pad 539 is in electrical contact with or terminates the first metal layer 532A, for example, through an opening in the first dielectric layer 533A in the top portion 530B of the flexible connector 530, such that components 503, 504 can be coupled to the first metal layer 532A, as shown below. Figure 5D As shown. For example, using some of the conductive lines 505, the VCSEL 503 is electrically coupled to the connecting flexible element 530, and in particular to the first metal layer 532A, by bonding one of the conductive pads 539.

[0168] VCSEL 503 is located on a third metal layer 506 within a recess 538. The third metal layer 506 is electrically isolated from the first metal layer 532A and electrically coupled to a second metal layer 532B via at least one via 507 (e.g., multiple vias), and is therefore adapted to be coupled to ground. The third metal layer 506 is preferably coplanar with the first metal layer 532A.

[0169] It should be understood that the recess 538 receiving the photodiode 504 can be similar to the recess 538 receiving the VCSEL 503, and the connection between the photodiode 504 and the connecting flexible member 530 can also be similar to the connection between the VCSEL and the connecting flexible member.

[0170] The connecting flexible element 530 includes:

[0171] - Two ends 530A (end portions) are configured to be connected to the substrate 102, and a second conductive pad 534 and an isolation element 535 are defined in each of these end portions;

[0172] - An upper portion 530B, which at least partially contacts the inner surface 130B of the module cap 130, a recess 538 defined in the upper portion, and a fourth conductive pad 537 and a bonding conductive pad 539; and

[0173] - Two interconnecting portions 530C, each end portion 530A is connected to the upper portion 530B through one of the interconnecting portions 530C, each interconnecting portion being arranged substantially perpendicular to the upper portion.

[0174] Therefore, the connecting flexible element 530 has a curved shape.

[0175] The flexible connector 530 allows for multiple second conductive pads 534 adjacent to each other and isolated from each other by an isolation element 535. Because the metal traces in the flexible connector 530 are isolated from each other by a dielectric material, and the second conductive pads 534 are also isolated, the risk of short circuits is low even if the flexible connector deforms during molding. The pitch between the second conductive pads 534 can reach one hundred micrometers.

[0176] Positioning components on a connecting flexible element allows them to be closer to the glass compared to mounting them on a substrate. In one example, glass 150 is a lens, component 503 is a light source such as a VCSEL, and the light from this light source can be divergent, for example, it can be conical. The greater the distance between the light source and the lens, the larger the lens size can be to cover the light cone, and vice versa. This also allows for precise positioning of each component relative to the glass. In the example where glass 150 is a lens and component 503 is a light source such as a VCSEL, positioning the component on the connecting flexible element allows the lens to be well aligned with the VCSEL in three spatial directions.

[0177] Figure 5D This illustrates the advantages of connecting flexible components. In practice, it can be observed that the distance d between the signal layer (first metal layer) and the ground layer (second metal layer) can be essentially constant, allowing for characteristic impedance and very good signal integrity. Furthermore, the signal layer can be very close to the ground layer, and the current loop (indicated by the dashed arrow) can be small, which allows for better electrical performance, such as better EMI performance.

[0178] The connecting flexible element according to the embodiment also has other advantages, such as:

[0179] - The possibility of having high-density metal traces in the metal layer;

[0180] - The metal layers and metal traces in the connecting flexible components can be insulated from the module cap, which is advantageous if the module cap is conductive;

[0181] - Flexible connection design; adjustable parameters such as: number of metal layers, each layer including one or more metal traces; size, thickness and material of different layers; shape of dielectric layer; whether to use dielectric core; size and thickness of connection flexibility; whether to form recesses for receiving components, etc.

[0182] One application of the embodiment is to manage the aforementioned electromagnetic interference (EMI) through the first opening of the module cap by utilizing conductive traces in the first opening and / or in the glass covering the first opening, for example by providing EMI reflection in the first opening. In this application, a connection flexibility may suffice, for example, coupling the conductive traces to ground.

[0183] Another application of this embodiment is for managing the aforementioned safety issues related to light-emitting devices, specifically by using conductive traces in the glass to detect whether the glass has been removed or otherwise separated from the module cap. When the glass is in place, the connecting flexible elements, conductive wires, and conductive traces form a conductive loop, for example, through a conductive path in the substrate. However, if the glass becomes separated, the circuit in the conductive loop is opened, and the detection circuit can detect this open circuit and, for example, deactivate the light-emitting device. In this application, typically two connecting flexible elements are required to form the conductive loop.

[0184] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these embodiments can be combined, and other variations will readily conceive of by those skilled in the art.

[0185] Finally, the actual implementation of the embodiments and variations described herein is based on the functional descriptions provided herein and is within the capabilities of those skilled in the art.

Claims

1. An optical sensor module, characterized in that, include: The substrate includes a first conductive pad; Module cap, assembled on the base plate; A connecting flexible element is incorporated in the module cap, the connecting flexible element being adapted to electrically couple at least one of the first conductive pads to at least one component mounted on and / or within the module cap; and The connecting flexible element includes at least one metal layer, which is covered by or encapsulated within at least one dielectric layer.

2. The optical sensor module as described in claim 1, characterized in that, in: The connecting flexible element is overmolded into the module cap; and / or The module cap is a conductive molded cap, for example, formed of a molding material comprising conductive particles dispersed therein.

3. The optical sensor module as described in claim 1, characterized in that, The at least one metal layer of the connecting flexible element includes a plurality of second conductive pads, for example terminating in a plurality of second conductive pads, the plurality of second conductive pads being adapted to couple with a plurality of first conductive pads of the substrate; and The at least one dielectric layer of the connecting flexible element includes a plurality of insulating elements, for example, terminating in a plurality of insulating elements, with each second conductive pad inserted between two insulating elements.

4. The optical sensor module as described in claim 1, characterized in that, The module cap further includes a light-emitting device, which at least partially covers the light-emitting device and includes a first opening located above the light-emitting device, such as one of the at least one component.

5. The optical sensor module as described in claim 4, characterized in that, The device further includes glass located in 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 includes conductive traces corresponding to a first component of the at least one component, and the connecting flexible member is electrically coupled to the conductive traces, for example, by conductive lines formed by wire bonding.

6. The optical sensor module as described in claim 1, characterized in that, The second component of the at least one component is located on the connecting flexible element.

7. The optical sensor module as described in claim 6, characterized in that, The connecting flexible member includes at least a recess adapted to receive the second component.

8. The optical sensor module as described in claim 7, characterized in that, The connecting flexible element includes: At least one end portion is configured to be connected to a substrate, and a plurality of second conductive pads and a plurality of insulating elements are defined in the at least one end portion. The upper portion, which at least partially contacts the inner surface of the module cap, has the recess defined in the upper portion.

9. The optical sensor module as described in claim 8, characterized in that, The connecting flexible member includes two end portions and two interconnecting portions, wherein each end portion is connected to the upper portion through one of the interconnecting portions, and each interconnecting portion is disposed substantially perpendicular to the upper portion.

10. The optical sensor module as described in claim 8, characterized in that, The connecting flexible element includes: A first metal layer is electrically coupled to a second element, for example, via a conductive line, and the first metal layer is covered by a first dielectric layer in the at least one dielectric layer. A second metal layer is configured to be connected to ground, and the second metal layer is covered by a second dielectric layer in the at least one dielectric layer; A third metal layer is located in the recess and electrically isolated from the first metal layer, and the second component is connected to the third metal layer, for example, located on the third metal layer; Dielectric core, inserted between the first metal layer and the second metal layer; and At least one connection via is defined in the dielectric core and electrically couples the third metal layer to the second metal layer.

11. The optical sensor module as described in claim 10, characterized in that, The recess extends through the entire thickness of the first dielectric layer and the first metal layer to the dielectric core.

12. The optical sensor module as described in claim 8, characterized in that, The connection flexibility includes a plurality of bonding pads defined on the upper portion of the connection flexibility, each bonding pad being configured to be electrically coupled to the second component, for example, via a conductive line.

13. The optical sensor module as described in claim 12, characterized in that, The plurality of bonding pads extend through the entire thickness of the first dielectric layer up to the first metal layer.

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