Electronic LED module and detection device

Abstract

In various aspects, the present invention provides an electronic LED module and a detection device incorporating such an electronic LED module. In illustrative embodiments, an electronic LED module (1) comprises a flexible printed circuit board (2) having at least one cavity (4) formed in a surface of the flexible printed circuit board (2) and at least one LED (8) disposed in at least one cavity (4) of the flexible printed circuit board (2) and attached to the flexible printed circuit board (2). The inner surfaces of at least one cavity (4) are at least partially covered with a conductive component comprising a material (4b), and the at least one LED (8) is encapsulated by a high-refractive-index material (10). (Fig. 2)

Description

Title of the invention: Electronic LED module and detection device

[0001] Scope of disclosure

[0002] The present invention relates to an electronic LED module for a detection device and a detection device equipped with such an electronic LED module.

[0003] Context

[0004] As a general rule, optical sensors are devices that measure the amount of light rays physically present and transform this information into an electrical signal that can be interpreted by a person or an electronic instrument.

[0005] In important applications, optical sensors are used to monitor vital signs that can indicate a general state of well-being. For example, optical sensors form the basis for measuring heart rate or blood oxygen levels. In particular, these optical sensors can be implemented as specialized sensors such as accelerometers, heart rate monitors, or, at a more advanced stage, electrocardiogram (ECG) and blood oxygen saturation (SpO2) monitors.

[0006] Current generation wearable devices accurately record these values ​​over long periods and show changes, where wearable devices represent laptops or body-worn computers, i.e., computing devices worn on a user's body. For example, laptops can be smartphones or even ordinary wristwatches. Heart rate variability (HRV) is a key parameter of overall well-being. HRV indicates whether and to what extent a person is under stress or physical strain and how long the recovery phase lasts. Since applications and gadgets that record and analyze vital signs require a basis in the form of highly accurate measurements, this application area is driving the development of photodiodes and sensing devices for precise biomonitoring systems.

[0007] A conventional optical SpO2 monitoring sensor measures blood oxygen saturation, that is, the proportion of oxygenated hemoglobin relative to total hemoglobin. This oxygen saturation is measured by sending light of different wavelengths through the tissue and analyzing the portions of light that are reflected or transmitted. Such an optical sensor comprises an array of light-emitting diodes (LEDs) configured to emit light in The wavelength regions of red and infrared light are used because light in these two wavelength regions allows for the measurement of the amounts of bound (oxygenated) and unbound (deoxygenated) hemoglobin. The percentage of bound hemoglobin is calculated from the ratio between these two measured amounts.

[0008] Figure 1 shows a polar diagram of the light intensity of an LED array of a conventional SpO2 sensor. The polar diagram shows the light intensity measurements with the LED array oriented in different directions. A polar region P indicates, in different directions, the lateral radiometric flux losses and wavelength losses for a conventional optical sensor with this LED array.

[0009] An object of the present invention is to provide an electronic LED module for a detection device, this electronic LED module having an improved uniform radiometric output flux in a desired polar region of light / radiation emission. Summary of the invention

[0010] The aforementioned problems and objects can be at least partially solved by at least one of the electronic light-emitting diode (LED) modules and a detection device as described below.

[0011] In various aspects, the present invention proposes an electronic LED module and a detection device equipped with such an electronic LED module.

[0012] In a first aspect of the present invention, an electronic LED module for a sensor device is provided. In embodiments illustrative of the first aspect, the electronic LED module comprises a flexible printed circuit board having at least one cavity formed in a surface of the flexible printed circuit board and at least one LED arranged in at least one cavity of the flexible printed circuit board and attached to the flexible printed circuit board. The cavity may partially expose a conductive material disposed inside the flexible printed circuit board. The interior surfaces of at least one cavity are at least partially covered with a material comprising a conductive component.The material containing a conductive component can be a conductive adhesive (for example, at least one of the following materials: silver, nickel, copper, and graphite) or a material containing metal (for example, at least one of the following materials: silver, nickel, copper, gold, etc.). For example, the LED can be mounted inside the cavity, for example, via solder pads inside the cavity and in contact with the plated inner surfaces of the cavity (for example, a lower region of the cavity) and / or by adhesive. An adhesive can be electrically non-conductive. conductive in the case of a solder attachment, while the glue can be an electrically conductive glue in the case of an attachment to the cavity by an electrically conductive chip attachment via an adhesive layer on the bottom of the cavity.

[0013] Furthermore, at least one LED is encapsulated by a high refractive index material. The high refractive index material is provided for light diffracting at the normal to a surface of the high refractive index material opposite the flexible printed circuit board.

[0014] In accordance with the illustrative embodiments of the first aspect, at least one cavity allows the LED and the high refractive index material to be housed so as to configure the electronic LED module to emit a radiometric flux with improved uniformity.

[0015] In certain illustrative embodiments of the first aspect, the fabrication of the electronic LED module can be improved. For example, at least one cavity can allow for better positioning and attachment of at least one LED and better deposition of a high-refractive-index material. Improved positioning of at least one LED and a high-refractive-index material can allow for the emission of a radiometric flux with greater uniformity during the operation of the electronic LED module.

[0016] In the examples given here, the material with a high refractive index can be understood as representing a material having a refractive index of at least 1.2 or at least 1.3 or at least 1.4 or at least 1.43 or at least 1.45 or at least 1.5 such that at least 1.51 or at least 1.53. For example, the high refractive index material may be a silicon material having a refractive index in one of the aforementioned ranges, preferably a silicon material used as an encapsulant for LED devices, such as a high refractive index silicon having a refractive index of at least 1.2 or at least 1.3 or at least 1.4 or at least 1.43 or at least 1.45 or at least 1.5 such as at least 1.51 or at least 1.53. The silicon material may be a thixotropic silicon material that can be deposited and solidify after deposition without further curing.Alternatively, the silicon material may be a sand-cured silicon material allowing for deposition and subsequent curing. In particular examples, the silicon material has high optical transmission, optical transmission being understood as a measure of the proportion of light transmitted through the silicon material, having an optical transmission (according to this definition) of at least 0.5, preferably at least 0.6, 0.7, 0.8, 0.9, or 0.95, and more preferably at least 0.96, 0.97, 0.98, or 0.99. In some particular examples, the silicon material may be chosen as a self-bulging material. relative to the surface of the flexible printed circuit board, for example, a plated surface of the flexible printed circuit board.

[0017] In some illustrative examples of the first aspect, the high-refractive-index material may be a self-bulging material. A self-bulging material is a material having mechanical properties such that it forms a dome after being deposited on the surface of the flexible printed circuit board. In other words, the self-bulging material has a viscosity and surface tension that allow it to neatly position itself in a dome shape on the surface of the flexible printed circuit board.

[0018] According to illustrative examples of the first aspect, a cavity can be provided in a surface of the flexible printed circuit board, for example, the cavity can be formed in a main surface of the flexible printed circuit board.

[0019] In the first examples, an LED may be disposed in the cavity, the LED being configured to emit light in a first wavelength region. In a particular illustrative example, the first wavelength region may include wavelengths between 600 nm and 800 nm. However, the first wavelength region is not limited to this explicit range, and any other suitable wavelength range may be used instead.

[0020] In secondary examples, two LEDs may be arranged in the cavity, one LED being configured to emit light in a first wavelength region and the other LED being configured to emit light in a second wavelength region different from the first. In a particular illustrative example, the first wavelength region may include wavelengths between 600 nm and 700 nm (red light). The second wavelength region may include wavelengths between 700 nm and 1200 nm (near-infrared and infrared light). However, the second wavelength region is not limited to this explicit range, and any other suitable wavelength range may be used instead.

[0021] In tertiary examples, three or more LEDs may be arranged in the cavity, one of the LEDs being configured to emit light of a first wavelength region, another LED being configured to emit light of a second wavelength region different from the first wavelength region, and yet another LED being configured to emit light of a third wavelength region different from both the first and second wavelength regions, and so on. At least two of the three, or more, wavelength regions may correspond to the first and second wavelength regions defined in the secondary examples.

[0022] According to other illustrative examples of the first aspect, two or more cavities may be provided in a surface of the flexible printed circuit board, for example, two or more cavities may be formed in a main surface of the flexible printed circuit board, each cavity accommodating a dedicated LED from among a plurality of LEDs, the LEDs being configured in accordance with the LEDs of the tertiary examples.

[0023] According to illustrative examples of the first aspect, at least one cavity may extend partially into the flexible printed circuit along a thickness direction such that each of the at least one cavity may have a single opening receiving at least one LED and a high refractive index material, each of the at least one LED being attached to a lower surface of its respective cavity within the at least one cavity. The thickness direction is oriented perpendicular to the surface of the flexible printed circuit.

[0024] In certain embodiments illustrating the first aspect, at least one cavity may be at least partially plated with a metallic material, for example, at least one of the following materials: gold, aluminum, copper, silver, etc. For example, the bottom of at least one cavity may be at least partially plated and, optionally, the side walls of the cavity may be at least partially plated. Consequently, the plated cavity may allow contact with the LEDs. In one particular embodiment, the flexible printed circuit board may be a flexible printed circuit board in which the printed circuit is printed on only one of its sides. In these particular examples, it is possible that no additional plating is present inside at least one cavity of the flexible printed circuit board in which the printed circuit is printed on only one of its sides.A flexible printed circuit board (PCB) with the printed circuit printed on only one side may consist of a flexible film made of insulating material, such as a polyimide film, laminated to a thin sheet of metal, such as copper, forming a metallic layer that can be chemically etched to produce a circuit pattern specific to the design requirements. A cover layer, such as a polyimide cover layer, may be added for insulation and to protect the circuit from its environment. The flexible PCB may be double-sided, and at least one cavity may be partially plated. In this case, the double-sided flexible PCB has two conductive layers (such as copper layers), one on each side of a base layer of insulating material, such as polyimide.User-specific tracing patterns can be created on both sides of the base layer and can be interconnected at the desired location by plated holes, so that the plated holes establish connections. electrical connections exist between the two conductive layers. In some examples, the holes may be blind holes.

[0025] In embodiments with at least one partially plated cavity, the plated portions of at least one cavity can increase the luminous efficiency because a plated surface can act as a reflector. The plated surface can allow the high-refractive-index material to form a dome when deposited on the plated surface; that is, the high-refractive-index material can have a viscosity and surface tension such that the deposited high-refractive-index material can form a dome when deposited on the plated surface.

[0026] In embodiments illustrating the first aspect, the cavity can be entirely formed by a recess in the surface of the flexible printed circuit.

[0027] In a first embodiment of the first aspect, the high-refractive-index material may have a first surface in contact with the flexible printed circuit board and a second surface opposite the cavity, the second surface being at least partially curved, for example, a concave or convex curved surface, or generally curved. Consequently, a desired optical effect of the encapsulant provided by the high-refractive-index material encapsulating at least one cavity can be adjusted by appropriately designing the second surface as a concave or convex curved surface, or flat, or generally curved, with a collimation and / or convergence and / or diffusion and / or diffraction effect to implement an optical element acting as at least one of a lens, a diffuser, and others.For example, the second surface can be completely curved, specifically convex or concave, or generally curved to accommodate a plurality of small lenses (e.g., a small lens or microlens array, etc.), a diffraction grating, and so on. In a particular illustrative example, the high-refractive-index material can be dome-shaped so that the second surface is purely convex.

[0028] In a first example of the first embodiment illustrated above, the material with a high refractive index can completely fill the cavity and the curved surface can be completely outside at least one cavity. This makes it possible to obtain an advantageous luminous efficiency.

[0029] In a second illustrative example of the first embodiment above, or as another illustrative example of the first illustrative example above, the second surface of the high-refractive-index material may have a convex shape. As a result, a collimation or convergence effect may be obtained, thereby improving the directivity of the emitted light.

[0030] In a second embodiment illustrating the first aspect, the electronic LED module may further include a dam formed in the surface of the flexible printed circuit board. The dam can completely surround a region of the surface, and the cavity can be entirely formed within that region. Consequently, the dam can advantageously delimit the region of the surface that must be filled with a material having a high refractive index and prevent lateral loss through the dam. The dam can be formed from a thixotropic material that allows the dam to be deposited while still forming a solid dam after deposition.

[0031] In a first example of the second embodiment illustrated above, the dam can define a filling volume bordered by the surface area of ​​the flexible printed circuit board. The filling volume can be at least partially filled by the high-refractive-index material and / or the filling volume can completely cover at least one LED. Consequently, the shaping of the high-refractive-index material can be achieved by the dam and / or ensure the complete encapsulation of at least one LED.

[0032] In a second illustrative example of the second embodiment above, or in another illustrative example of the first illustrative example above, the dam may be formed of a thermosetting material comprising a non-transparent thixotropic thermosetting material, for example, a non-transparent thermoplastic, and / or a non-transparent metallic binder component and / or a non-transparent glass binder component. For example, a non-transparent thermosetting material may be a black thermosetting material, such as a black epoxy material. Consequently, lateral loss can be further avoided and, optionally, the reflectivity of the dam can be adjusted by the inclusion of metallic and / or glass components.

[0033] In a third illustrative example of the second embodiment above, or in another illustrative example of the first or second illustrative example above, the dam may be formed by a single layer of dam material or by a stack of at least two layers of dam material (which may represent a dam structure formed by an arrangement of stacked rings). Consequently, the height of the dam structure relative to the height of at least one LED may be adjusted to ensure the complete encapsulation of at least one LED.

[0034] In a third embodiment of the first aspect, at least one LED may be an LED array, and the high-refractive-index material may be in direct contact with the LED array. As a result, the luminous efficacy can be improved.

[0035] In a second aspect of the present invention, a detection device, such as an optical detection device, is provided. In embodiments illustrative of the second aspect, the detection device comprises the LED module The first aspect of the electronics consists of a photodetector and a housing containing the electronic LED module and the photodetector. The photodetector is arranged and configured to detect the light emitted by the electronic LED module during the operation of the detection device. As a result, it is possible to obtain a detection device with improved efficiency.

[0036] In certain embodiments of the second aspect, the detection device may be an oximetric detection device. This makes it possible to obtain very precise oxygen monitoring.

[0037] The electronic LED module can be manufactured as part of a high-volume production process, offering higher productivity and a more cost-effective solution compared to conventional electronic LED modules. Brief description of the drawings

[0038] Various illustrative embodiments and other advantages of the different aspects of this disclosure will become apparent from the detailed description in the accompanying figures shown below.

[0039] Fig. 1 shows the polar diagram of the light intensity of an LED assembly of a conventional SpO2 sensor.

[0040] Figure 2 schematically shows an electronic LED module in accordance with some examples of how this disclosure could be implemented.

[0041] [Fig.3] schematically represents an electronic LED module in accordance with certain illustrative embodiment examples described with reference to [Fig.2].

[0042] Figure 4 schematically shows an electronic LED module in accordance with other examples of embodiments illustrating this disclosure.

[0043] [Fig.5] schematically represents an electronic LED module conforming to certain illustrative embodiments described with reference to [Fig.4].

[0044] [Fig.6] schematically shows an electronic LED module in accordance with other examples of the illustrative embodiments disclosed in relation to [Fig.4],

[0045] Figure 7 schematically shows an electronic LED module in accordance with other examples of embodiments illustrating this disclosure.

[0046] Figure 8 schematically shows a cross-sectional view of a detection device comprising an electronic LED module in accordance with the illustrative embodiments of this disclosure.

[0047] Figure 9 schematically shows a cross-sectional view of a printed circuit board flexible material intended for use in an electronic LED module in accordance with certain illustrative embodiments of this disclosure.

[0048] Fig. 10 schematically shows a cross-sectional view of another flexible printed circuit board intended for use in an electronic LED module in accordance with other illustrative embodiments in this disclosure.

[0049] The figures accompanying this disclosure are provided only to schematically illustrate certain concepts and aspects of this disclosure without showing all possible details of certain embodiments. The illustrations in the figures are not to scale. Detailed description of preferred embodiments

[0050] With regard to Figures 2 to 10, various illustrative embodiments of an electronic LED module are schematically shown and described below, in addition to the first aspect described above. The features of the various exemplary embodiments of the first aspect described above can be implemented and combined with the exemplary embodiments described below.

[0051] With reference to [Fig. 9], a flexible printed circuit board FPCB-SS, intended for use in an electronic LED module according to certain illustrative embodiments of this disclosure, is shown. The flexible printed circuit board FPCB-SS is a single-sided printed circuit board. As shown in [Fig. 9], the flexible printed circuit board FPCB-SS comprises a metal layer SS-1, for example a thin sheet of metal such as copper, aluminum, etc., laminated onto a substrate SS-3, for example a polyimide substrate such as a polyimide film, via an adhesive layer SS-2 between the metal layer SS-1 and the substrate SS-3. The metal layer SS-1 can be chemically etched to provide a circuit pattern specific to the user's design requirements, according to a patterned metal layer comprising metallic wiring routing.In addition, a layer of SS-4 plating, for example a NiAu plating layer, can be deposited on the SS-1 metal layer to protect it from environmental influences.

[0052] With reference to [Fig. 9], at least one cavity can be formed in the FPCB-SS flexible printed circuit board, for example, the SS-C cavity illustrated in [Fig. 9]. This at least one SS-C cavity can extend through the SS-3 substrate so as to partially expose the SS-1 metal layer. The side walls of the SS-C cavity expose the substrate 3 material, while the bottom of the SS-C cavity partially exposes the SS-1 metal layer, for example, the traces of a metallic wiring routing of the patterned metal layer. The bottom of the SS-C cavity can be covered with an SS-5 plating layer, which can be formed on the layer The exposed metal layer SS-1 is present in the cavity SS-C during the formation of the plating layer SS-4 on the metal layer SS-1, following the deposition of plating layer material SS-4 onto the metal layer SS-1. In this case, the plating layer material SS-4 and the plating layer material SS-5 can be identical. However, this does not impose any limitation, and the plating layers SS-4 and SS-5 can be deposited or formed in separate process steps, and the materials of the plating layers SS-4 and SS-5 can be different.

[0053] By way of illustrative but not limiting examples, the SS-4 plating layer and the SS-5 plating layer may each be a two-layer stack formed from a Ni / Au two-layer stack, with a Ni sublayer of each two-layer stack being covered by an Au sublayer. However, this does not impose any limitation, and a single layer may be formed instead of a two-layer stack, or a multi-layer stack with more than two sublayers may be formed instead. Furthermore, or alternatively, materials other than Ni and Au may be used.

[0054] In some illustrative embodiments, an SS-7 LED chip is inserted into the SS-C cavity and attached using SS-6 conductive adhesive. The SS-6 conductive adhesive partially covers the bottom of the SS-C cavity and is interposed between the SS-7 LED chip and the SS-1 exposed metal layer so as to provide a mechanical and electrical connection between the SS-7 LED chip and the SS-1 metal layer. However, this does not impose any limitations, and a solder attachment of the SS-7 LED chip to the SS-5 plating layer can be applied instead by using a soldering material to attach the SS-7 LED chip to the SS-5 plating layer or, in unillustrated alternatives, directly to the SS-1 exposed metal layer in the SS-C cavity, omitting the SS-5 plating layer in the SS-C cavity.

[0055] Referring to [Fig. 10], a flexible printed circuit board FPCB-DS, intended for use in an electronic LED module according to other illustrative embodiments of this disclosure, is shown. The flexible printed circuit board FPCB-DS is a flexible printed circuit board with both sides printed. As shown in [Fig. 10], the flexible printed circuit board FPCB-DS comprises a metal layer DS-1, for example a thin sheet of metal such as copper, aluminum, etc., laminated onto a substrate DS-3, for example a polyimide substrate such as a polyimide film, via an adhesive layer DS-2 between the metal layer DS-1 and the substrate DS-3. The metal layer DS-1 can be chemically etched to provide a circuit pattern specific to the user's design requirements, according to a patterned metal layer comprising metallic wiring routing.In addition, a layer of . DS-4 plating, for example a NiAu plating layer, can be deposited on the DS-1 metal layer to protect it from environmental influences.

[0056] With reference to [Fig. 10], at least one cavity can be formed in the FPCB-DS flexible printed circuit board, for example, the DS-C cavity illustrated in [Fig. 10]. This at least one DS-C cavity can extend through the DS-3 substrate so as to partially expose the DS-1 metal layer, such that initially, a bottom of the DS-C cavity can partially expose the DS-1 metal layer, for example, the traces of a metal wiring routing of the patterned metal layer, before forming a DS-8 plating layer on the bottom of the DS-C cavity. The DS-8 plating layer is deposited onto the bottom of the DS-C cavity via an adhesive layer. The inner walls of the DS-C cavity can be coated with a DS-7 metal bonding layer. In some illustrative examples, the DS-7 metal bonding layer partially covers an exposed DS-3S surface of the DS-3 substrate.The DS-7 metallic bonding layer can be completely covered by the DS-8 plating layer. In certain specific examples, the DS-8 plating layer may include NiAu, for example, a bilayer stack with a Ni sublayer and an Au sublayer, the Ni sublayer being deposited directly onto the DS-1 metallic layer and the Au sublayer being deposited directly onto the Ni sublayer. However, this does not impose any limitations, and the internal side walls of the DS-C cavity can be covered by a single or multilayer coating (with more than two coating layers) which can be deposited by electrodeposition techniques or, alternatively, by plating techniques that do not use electrodeposition.

[0057] A DS-6 LED chip is inserted into the DS-C cavity and attached by means of a DS-5 conductive adhesive. The DS-5 conductive adhesive partially covers the bottom of the DS-C cavity and is interposed between the DS-6 LED chip and the DS-8 plating layer so as to ensure a mechanical and electrical connection between the DS-6 LED chip and the DS-8 plating layer. For example, the DS-5 conductive adhesive and the adhesive layer used to attach the DS-8 plating layer to the DS-1 metal layer and optionally to the DS-7 metal bonding layer (if present), may be of the same or a similar material.

[0058] With further reference to [Fig. 10], the FPCB-DS flexible printed circuit board provides a circuit comprising two conductive layers via the metal layer DS-1 and the metal bonding layer DS-7, each on either side of the substrate DS-3. Each of the metal layers DS-1 and DS-7 can provide tracing patterns created on both sides of the substrate DS-3 and can be connected, where desired, with holes via at least one DS-C cavity whose internal walls are covered. of an electrically conductive material, for example the DS-7 metallic bonding layer and / or the DS-8 plating layer.

[0059] [Fig.2] shows, in a schematic cross-sectional view, an electronic LED module 1 comprising a flexible printed circuit board 2 having a cavity 4 formed in a surface 2s of the flexible printed circuit board 2. The flexible printed circuit board 2 can be one of the FPCB-SS flexible printed circuit boards with one side printed as described in [Fig.9] and the FPCB-DS flexible printed circuit boards with both sides printed as described in relation to [Fig.10].

[0060] The cavity 4 includes a material 6 formed at least on a bottom 4b of the cavity 4. As shown in [Fig.2], it is possible that only the bottom 4b of the cavity 4 is covered with the material 6. However, this does not impose any limitation and the bottom 4b as well as the inner side walls 4s of the cavity 4 can be covered with the material 6. The material 6 can be a material comprising a conductive component.

[0061] In the case where the flexible printed circuit board 2 is formed according to the flexible printed circuit board FPCB-SS of [Fig. 9], the material 6 corresponds to the conductive adhesive SS-6 of [Fig. 9]. Alternatively, the material 6 may be a metal-compounding material made of at least one metal among gold, silver, copper, and aluminum, or the inner side walls 4s of the cavity 4 may be at least partially plated with the metal-compounding material, in which case the flexible printed circuit board 2 may be formed according to the flexible printed circuit board FPCB-DS of [Fig. 10]. In some illustrative examples, the material 6 may represent the two layers DS-5 and DS-8 together with an adhesive layer interposed therein.In other illustrative examples, cavity 4 can partially expose an electrically conductive routing line in the flexible printed circuit board 2, this electrically conductive line representing the metal-containing material. Thus, the electrically conductive line can also be plated with the metal-containing material. Therefore, it may be possible to apply an electrical potential to the LED 8.

[0062] The LED electronic module 1 further includes an LED 8 (for example, the SS-7 LED chip in the case of the FPCB-SS of [Fig. 9] or the DS-6 LED chip in the case of the FPCB-DS of [Fig. 10]) which is arranged inside the cavity 4. In this case, the cavity 4 is entirely formed by a recess in the surface 2s of the flexible printed circuit board 2.

[0063] The LED 8 is attached to the flexible printed circuit board 2 using conductive adhesive or by bonding to the material 6 as a metal-component material, in which case the LED 8 may be attached to the material 6 by the "flip-chip bonded" technique, as a metal-component material, where a slot (not shown) may be formed in the cavity 4 to separate the contacts of the anode (not shown) and the cathode (not shown) of LED 8 and to LED 8.

[0064] With reference to [Fig. 2], the electronic LED module 1 further comprises a high refractive index material 10, the LED 8 being encapsulated by the high refractive index material 10. The high refractive index material 10 can be formed directly on the LED 8 so that the high refractive index material 10 can be in mechanical contact with a chip or LED array of the LED 8. The high refractive index material 10 completely fills the cavity 4 and completely encapsulates the LED 8. A surface 10s of the high refractive index material 10, opposite the LED 8 and the flexible printed circuit board 2, is convex in shape. [Fig. 2] schematically shows the light rays LR1 indicating the light emitted by the LED 8 during the operation of the electronic LED module 1.The high refractive index material 10 can implement a collimating optical element resulting from a suitable shape of the surface 10s of the high refractive index material 10. The high refractive index material 10 can be a self-bulging material as described in the context of the first aspect of disclosure as described above.

[0065] Although [Fig.2] shows the electronic LED module 1 having only one LED 8 and only one cavity 4, this does not impose any limitation on the present disclosure and the electronic LED module 1 may further include one or more additional cavities (not shown) formed in the surface 2s of the flexible printed circuit board 2. One or more additional cavities (not shown) may be equipped with at least one additional LED (not shown) in a manner similar to cavity 4 equipped with LED 8.

[0066] With reference to [Fig.2], the high refractive index material 10 can cover a region of the surface 2s with a size at least equal to that of the cavity 4. Consequently, shaping of the surface 10s of the high refractive index material 10 can be achieved by direct mechanical contact of the high refractive index material 10 with the material comprising metal 6 and / or by direct contact with the surface 2s of the flexible printed circuit board 2.

[0067] Although [Fig. 2] shows the surface 10s of the high refractive index material 10 having a convex shape, this does not impose any limitation on the present disclosure, and the high refractive index material 10 may have at least one upper surface opposite the LED 8 with at least one shape among at least partially convex, at least partially concave, and at least partially planar. Accordingly, the high refractive index material 10 can be shaped to form an optical component with a desired optical effect, for example, a converging, collimating, dispersing, or diffracting effect, or a combination thereof.

[0068] Figure 3 shows, in a schematic cross-sectional view, an electronic LED module 1' comprising a flexible printed circuit board 2 having a cavity 4 formed in a surface 2s of the flexible printed circuit board 2. The electronic LED module 1' may represent illustrative examples of the electronic LED module 1 described above with respect to Figure 2. Therefore, similar reference numerals may indicate equal or similar technical characteristics. In particular, the flexible printed circuit board 2' may be one of the FPCB-SS flexible printed circuit board with one printed side described in Figure 9 and the FPCB-DS flexible printed circuit board with two printed sides described in Figure 10, similarly to the description in Figure 2 in this respect.

[0069] The cavity 4' is entirely formed by a recess in the surface 2s' of the flexible printed circuit board 2', and a bottom 4b' of the cavity 4' is covered with a material 6'. As shown in [Fig. 3], only the bottom 4b' of the cavity 4' is covered with the material 6'. However, this does not impose any limitation, and both the bottom 4b' and the inner side walls 4s' of the cavity 4' may be covered with the material 6'. In certain specific illustrative examples, the material 6' may be an adhesive material such as a conductive adhesive conforming to SS-6 adhesive or a material comprising a metal composed of at least one of the following elements: gold, silver, copper, and aluminum. However, this does not impose any limitation, and the inner side walls 4s' of the cavity 4' may also be at least partially covered with the material 6'. The material 6' may be a material comprising a conductive component.

[0070] In the case where the flexible printed circuit board 2' is formed according to the flexible printed circuit board FPCB-SS of [Fig. 9], the material 6' corresponds to the conductive adhesive SS-6 of [Fig. 9]. Alternatively, the material 6' is a metal-component material composed of at least one of the following materials: gold, silver, copper, and aluminum, or the inner walls 4s' of the cavity 4' may be at least partially plated with the metal-component material, in the case where the flexible printed circuit board 2' is formed according to the flexible printed circuit board FPCB-DS of [Fig. 10]. In some illustrative examples, the material 6' may represent the DS-5 and DS-8 layers as well as an adhesive layer interposed therein.

[0071] The electronic LED module 1' further includes an LED 8' (for example, the SS-7 LED chip in the case of the FPCB-SS of [Fig. 9] or the DS-6 LED chip in the case of the FPCB-DS of [Fig. 10]) which is arranged inside the cavity 4'. The LED 8' can be attached to the flexible printed circuit board 2' in the same way as the LED 8 in the description of [Fig. 2] above, the description of which is incorporated by reference in its entirety.

[0072] As shown in [Fig. 3], the flexible printed circuit board 2' further comprises a cavity 5' formed in the surface 2s', the cavity 5' being formed is adjacent to the cavity 4' from which it is separated by a portion of surface 2s 1' of the surface 2'. The cavity 5' can be covered with a material 7' by analogy with the cavity 4' comprising the material 6' described above.

[0073] The LED 8' has a contact pad Cl formed on it, the contact pad Cl being connected by a connecting line CL to a contact pad C2. In some illustrative examples, the cavity 5' may partially expose an electrically conductive routing line in the flexible printed circuit board 2', the conductive routing line possibly representing material 7' or possibly being plated with material 7' in the case where material 7' is a metal-containing material or material 7' representing a conductive adhesive by analogy with material 6' as described above. It is thus possible to apply an electrical potential to contact C2.Similarly, the cavity 4' can partially expose another routing conductive line within the flexible printed circuit board 2', this other routing conductive line being either the metal-compounding material 6' or plated with the metal-compounding material 6'. This makes it possible to apply an electrical potential to the contact CL.

[0074] With reference to [Fig. 3], the electronic LED module 1' further comprises a high refractive index material 10', the LED 8' being encapsulated by the high refractive index material 10'. The high refractive index material 10' can be formed directly on the LED 8' so that the high refractive index material 10' can be in mechanical contact with an LED matrix or chip of the LED 8'. The high refractive index material 10' completely fills the cavities 4' and 5', the high refractive index material 10' completely encapsulating the LED 8', the connecting line CL, and the contact C2. A surface 10s' of the high refractive index material 10', opposite the LED 8 and the flexible printed circuit board 2, is convex in shape. As a result, light rays (similar to the LR1 light rays illustrated in [Fig.2] relative to the electronic LED module 1) can be obtained during the operation of the electronic LED module 1'. Consequently, the high refractive index material 10' can form a collimating optical element resulting from a suitable shape of the surface 10s' of the high refractive index material 10'. The high refractive index material 10' can be a self-bulging material as described in the context of the first aspect of disclosure as described above.

[0075] Although [Fig. 3] shows the electronic LED module 1' with a single LED 8', this does not impose any limitation on the present disclosure and the electronic LED module 1' may further include one or more additional LEDs (not shown) as well as additional cavities (not shown) formed in the surface 2s' of the flexible printed circuit board 2' in a manner similar to the cavities 4' and 5'. The additional cavity(ies) (not shown) may be fitted with at least one additional LED (not shown) in a manner similar to cavity 4' fitted with LED 8' and be in contact via an additional connecting line (not shown) making contact with an additional contact (not shown) similar to contact C2.

[0076] With reference to [Fig. 3], the high refractive index material 10' can cover a region of the surface 2s' of at least a size that can cover the cavities 4' and 5'. Consequently, shaping of the surface 10s' of the high refractive index material 10' can be achieved by direct mechanical contact of the high refractive index material 10' with the materials 6', 7' and / or by direct contact with the surface 2s' of the flexible printed circuit board 2'. For example, appropriate dimensioning of the surface portion 2s 1' can fit a shape of the surface 10s' of the high refractive index material 10'.

[0077] Although [Fig. 3] shows the surface 10s' of the high refractive index material 10' having a convex shape, this does not impose any limitation on the present disclosure, and the high refractive index material 10' may have at least one upper surface opposite the LED 8' with at least one shape among at least partially convex, at least partially concave, and at least partially planar. Accordingly, the high refractive index material 10' may be shaped to form an optical component with a desired optical effect, for example, a converging, collimating, dispersing, or diffracting effect, or a combination thereof.

[0078] Figure 4 shows, in a schematic cross-sectional view, an electronic LED module 20. In particular, the flexible printed circuit board 20 can be one of the following: the single-sided printed flexible printed circuit board FPCB-SS described in Figure 9 and the double-sided printed flexible printed circuit board FPCB-DS described in Figure 10, similarly to the description in Figures 2 and 3 in this respect. The above disclosure concerning the single-sided printed flexible printed circuit board FPCB-SS and the double-sided printed flexible printed circuit board FPCB-DS is incorporated herein in its entirety by reference.

[0079] The electronic LED module 20 comprises a flexible printed circuit board 22 having a cavity 24 (see SS-C or DS-C cavity above in the case where the flexible printed circuit board 22 corresponds to one of the flexible printed circuit boards FPCB-SS and FPCB-DS) formed in a surface 22s of the flexible printed circuit board 22, the cavity 24 being delimited on the surface 22s of the flexible printed circuit board 22 by a dam 25. The dam 25 defines a filling volume bounded by a surface region, i.e., the surface region comprising a bottom 24b of the cavity 24, and the side walls 24s of the cavity 24. The walls 24s of the cavity 24 are formed from the internal walls 24s1 of a recess 24r in the flexible printed circuit board 22, and from the internal walls 24s2 of the dam 25. The dam 25 completely surrounds the surface region of the surface 22s, the cavity 24 being entirely formed in the surface region, the dam 25 being formed from a single layer of dam material representing a single dam ring completely surrounding the recess 24r.

[0080] The filling volume defined by the cavity 24 can be at least partially filled by the high refractive index material 30. In some illustrative examples, the barrier 25 can be formed of a non-transparent thermosetting material, for example a non-transparent thermoplastic such as a non-transparent epoxy material comprising a non-transparent thixotropic thermosetting material, for example a non-transparent thixotropic thermoplastic such as a non-transparent thixotropic epoxy material and / or a thixotropic metallic binder component and / or a thixotropic glass binder component.

[0081] The cavity 24 can be partially covered with a material 26. As shown in [Fig. 4], the bottom 24b of the cavity 24 is covered with the material 26. The material 26 can be a material comprising a conductive component. For example, the material 26 can be a conductive adhesive. In other illustrative examples, the material 26 may include at least one of the gold, silver, copper, and aluminum platings on at least the bottom 24b of the cavity 24 and possibly on at least part of the side walls 24s of the cavity 24. However, this does not impose any limitation, and the internal side walls 24s1 of the recess 24r of the cavity 24 may be at least partially plated with the material 26. As a result, light may be reflected by the walls 24s1 of the recess 24r up to a certain level of plating on the walls 24s1 of the recess 24r.

[0082] In some illustrative examples, the cavity 24, i.e. the recess 24r in the flexible printed circuit board 22, may partially expose an electrically conductive routing line in the flexible printed circuit board 22, this routing line representing the metal-compounding material 26. The routing line may also be plated with the metal-compounding material 26. It is thus possible to apply an electrical potential to the LED 28.

[0083] The electronic LED module 20 further includes an LED 28 (similar to the SS-7 or DS-6 LED chip above in the case of the flexible printed circuit board 22 corresponding to one of the FPCB-SS and FPCB-DS flexible printed circuit boards) which is arranged in the cavity 24. The filling volume can completely cover the LED 28 (i.e., a height of the dam 25 is greater than a level of height of LED 28 or that a depth of cavity 24 is greater than a height of LED 28).

[0084] As shown in [Fig.4], the cavity 24 is completely filled with the high refractive index material 30. However, this does not impose any limitation and a filling height may only partially fill the filling volume so that the LED 28 is encapsulated, where a height of the LED 28 is less than a height of the dam 25.

[0085] The LED 28 is attached to the flexible printed circuit board 22 by means of a conductive adhesive, as shown above, or by bonding to the material 26 if the latter is a metal-containing material. In some examples, the LED 28 may be bonded to the metal-containing material 26 using the "flip-flop" technique. In the case of bonding using the "flip-flop" technique, a slot (not shown) may be formed in the cavity 24 to separate the anode (not shown) and cathode (not shown) contacts of and to the LED 28. However, this does not impose any limitations, and any other chip attachment or bonding techniques may be used as described in the context of Figures 2 and 3 above.

[0086] With reference to [Fig.4], the electronic LED module 20 further comprises a high refractive index material 30, the LED 28 being encapsulated by the high refractive index material 30. The high refractive index material 30 can be formed directly on the LED 28 so that the high refractive index material 30 can be in mechanical contact with a matrix or chip of the LED 28.

[0087] As described above, the high refractive index material 30 completely fills the cavity 24 and fully encapsulates the LED 28. With reference to [Fig. 4], the high refractive index material 30 completely fills the cavity 24, and a surface 30s of the high refractive index material 30 opposite the LED 28 and the flexible printed circuit board 22 is convex. [Fig. 4] schematically shows the light rays LR2 indicating the light emitted by the LED 28 during the operation of the electronic LED module 20. The high refractive index material 30 can form a collimating optical element resulting from a suitable shape of the surface 30s of the high refractive index material 30. The high refractive index material 30 can be a self-bulging material as described in the context of the first aspect of disclosure as described above.

[0088] Although [Fig. 4] shows the electronic LED module 20 with a single LED 28 and a single cavity 24, this does not impose any limitation on the present disclosure, and the electronic LED module 20 may further include one or more additional cavities (not shown) formed in the surface 22s of the flexible printed circuit board 22. One or more additional cavities (not shown) may be equipped with at least one additional LED (not shown) in a manner similar to cavity 24 equipped with LED 28.

[0089] With reference to [Fig.4], the high refractive index material 30 can cover a surface area of ​​the surface 22s with a size at least equal to that of the cavity 24. Consequently, shaping of the surface 30s of the high refractive index material 30 can be achieved by direct mechanical contact of the high refractive index material 30 with the metal-compounding material 26 and / or by direct contact with the surface 22s of the flexible printed circuit board 22.

[0090] Although [Fig. 4] shows the surface 30s of the high refractive index material 30 having a convex shape, this does not impose any limitation on the present disclosure, and the high refractive index material 30 may have at least one upper surface opposite the LED 28 that is at least partially convex, at least partially concave, and at least partially flat. Accordingly, the high refractive index material 30 can be shaped to form an optical component with a desired optical effect, for example, a convergence, collimation, dispersion, or diffraction effect, or a combination thereof.

[0091] Figure 5 shows, in a schematic cross-sectional view, an electronic LED module 20'. The electronic LED module 20' may represent illustrative examples of the electronic LED module 20 described above in Figure 4. Therefore, similar reference numbers may indicate equal or similar technical characteristics. In particular, the flexible printed circuit board 20' may be one of the boards among the single-sided printed FPCB-SS flexible printed circuit board described in Figure 9 and the double-sided printed FPCB-DS flexible printed circuit board described in Figure 10, similarly to the description in Figures 2 to 4 in this respect. The above disclosure concerning the single-sided printed FPCB-SS flexible printed circuit board and the double-sided printed FPCB-DS flexible printed circuit board is incorporated herein in its entirety by reference.

[0092] The electronic LED module 20' comprises a flexible printed circuit board 22' having a cavity 24' formed in a surface 22s' of the flexible printed circuit board 22', and an LED 28' which is arranged inside the cavity 24'. The cavity 24' is delimited on the surface 22s' of the flexible printed circuit board 22' by a dam 25'. The dam 25' defines a fill volume bounded by a surface region of the flexible printed circuit board 22'. The fill volume can completely cover the LED 28' (i.e., a height of the dam 25' is greater than a height level of the LED 28' or a depth of the cavity 24' is greater than a height of the LED 28'). The walls 24s' of the cavity 24' are formed by the internal walls 24s 1' of a recess 24rl' of the flexible printed circuit board 22', the inner walls 24s3' of a recess 24r2' in the flexible printed circuit board 22', and the inner walls 24s2' of the dam 25'. The surface region includes a lower portion 24b' of the recess 24rl' and a lower portion 25' of the recess 24r2'. In other words, the dam 25' completely surrounds the surface region of the surface 22s', with the recesses 24rl' and 24r2' being entirely formed within the surface region. The dam 25' is formed from a single layer of dam material representing a single dam ring completely surrounding the recesses 24rl' and 24r2'. The recesses 24rl' and 24r2' are formed adjacent to the recess of the cavity 24rl' from which they are separated by a portion of the surface 22s 1' of the surface 22'.

[0093] The recess 24r1' may be at least partially covered by the material 26' and the recess 24r2' may be at least partially covered by the material 27' (which may be the same as the material 26' or the two materials may be different). For example, only the bottom 25b' of the recess 24r2' may be covered by the material 27'. The material 27' may be a material comprising a conductive component. In some examples, the material 27' may be made of conductive adhesive or at least one of the following materials: gold, silver, copper, and aluminum. However, this does not impose any limitation, and the inner walls 25s' of the recess 24r2' may be at least partially covered by the material 27'. The LED 28' has a contact pad C3, the contact pad C3 being connected by a connecting line CLa to a contact pad C4.

[0094] The recess 24rl' is partially covered with a material 26'. The material 26' may be a material comprising a conductive component. The material 26' may be made of a conductive adhesive or of at least one material from among gold, silver, copper, and aluminum. However, this does not impose any limitation, and the inner walls 24s 1' of the recess 24rl' of the cavity 24' may be at least partially covered with the material 26'. If the material 26' is a metal, light may be reflected by the walls 24s 1' of the recess 24rl' up to a certain level of plating on the walls 24s 1' of the recess 24rl'.

[0095] In some illustrative examples, the recess 24rl' in the flexible printed circuit board 22' may partially expose a routing conductive line within the flexible printed circuit board 22', this routing conductive line representing the metal-containing material 26'. Alternatively, the routing conductive line may also be plated with the metal-containing material 26' or covered with a conductive adhesive. This makes it possible to apply an electrical potential to the LED 28'.

[0096] In some illustrative examples, the recess 24r2' may partially expose a routed routing conductive line in the flexible printed circuit board 22', the routing conductor representing material 27' or being plated with material 27' or being coated with conductive adhesive. It is thus possible to apply an electrical potential to contact C4. Similarly, the recess 24rl' can partially expose another routing conductor within the flexible printed circuit board 22', this other routing conductor representing material 26' or being coated with conductive adhesive or being plated with metal-containing material 26', so that it is possible to apply an electrical potential to contact C3.

[0097] The filling volume defined by the cavity 24' can be at least partially filled by the high refractive index material 30'. In some illustrative examples, the dam 25' can be formed of a thixotropic thermosetting material as described in the aspects and embodiments of the disclosure above, for example a material comprising a non-transparent thixotropic epoxy material, for example a black epoxy material, and / or a metal binder component and / or a glass binder component.

[0098] As shown in [Fig. 5], the cavity 24' is completely filled with the high refractive index material 30'. However, this does not impose any limitations, and a certain filling height may only partially fill the filling volume so that the LED 28' is encapsulated, with the height of the LED 28' being less than the height of the dam 25'. The filling volume may be filled to a certain height level inside the cavity 24' so that the connecting line CLa is completely encapsulated by the high refractive index material 30'.

[0099] The LED 28' is attached to the flexible printed circuit board 22' by the material 26'. For example, the LED 28' can be attached to the material 26' by the "flip-up" technique or attached to the flexible printed circuit board 22' via the conductive adhesive material 26'. In the case of attachment by the "flip-up" technique, a slot (not shown) can be formed in the cavity 24' to separate the anode (not shown) and cathode (not shown) contacts of the LED 28' and to the LED 28'. However, this does not impose any limitations, and any other chip attachment or bonding technique may be used.

[0100] With reference to [Fig. 5], the electronic LED module 20' further comprises a high refractive index material 30', the LED 28' being encapsulated by the high refractive index material 30'. The high refractive index material 30' can be formed directly on the LED 28' so that the high refractive index material 30' can be in mechanical contact with an LED matrix or chip of the LED 28'.

[0101] As described above, the high refractive index material 30' completely fills the cavity 24' and completely encapsulates the LED 28'. With reference to [Fig. 5], the high refractive index material 30' completely fills the cavity 24' and a 30s' surface of the high refractive index material 30' opposite the LED 28' and the flexible printed circuit board 22' is flat.

[0102] Although [Fig. 5] shows the electronic LED module 20' with a single LED 28' and a single cavity 24', this does not impose any limitation on the present disclosure, and the electronic LED module 20' may also include one or more additional cavities (not shown) formed in the surface 22s' of the flexible printed circuit board 22'. One or more additional cavities (not shown) may be fitted with at least one additional LED (not shown) in a manner similar to the cavity 24' fitted with the LED 28'.

[0103] Figure 6 shows, in a schematic cross-sectional view, a 20" electronic LED module. The 20" electronic LED module may represent other illustrative examples of the 20" electronic LED module described above with respect to Figure 4. Therefore, similar reference numbers may indicate equal or similar technical characteristics. In particular, the 20" flexible printed circuit board may be one of the boards among the single-sided printed FPCB-SS flexible printed circuit board described in Figure 9 and the double-sided printed FPCB-DS flexible printed circuit board described in Figure 10, similarly to the description in Figures 2 to 5 in this respect. The above disclosure concerning the single-sided printed FPCB-SS flexible printed circuit board and the double-sided printed FPCB-DS flexible printed circuit board is incorporated herein in its entirety by reference.

[0104] The 20" electronic LED module comprises a 22" flexible printed circuit board having a 24" cavity formed in a 22s" surface of the 22" flexible printed circuit board, and an LED 28" which is arranged inside the 24" cavity. The 24" cavity is delimited on the 22s" surface of the 22" flexible printed circuit board by a 25" dam. The 25" dam defines a fill volume bounded by a region of the 22" flexible printed circuit board surface. The fill volume can completely cover the 28" LED (i.e., a height of the 25" dam is greater than a height level of the 28" LED or a depth of the 24" cavity is greater than a height of the 28" LED). The walls 24s" of the cavity 24" are formed by the internal walls 24s 1" of a recess 24rl" of the flexible printed circuit board 22", the internal walls 24s3" of a recess 24r2" of the flexible printed circuit board 22", and the internal walls 24s2" of the dam 25".The surface region comprises a lower portion 24b" of the indentation 24rl" and a lower portion 25" of the indentation 24r2". In other words, the 25" dam completely surrounds the surface region of the surface 22s", with the indentations 24rl" and 24r2" being entirely formed within the surface region. The 25" dam is formed from a single layer of dam material representing a single dam ring completely surrounding the surface. The recesses 24rl" and 24r2". The recesses 24rl" and 24r2" are adjacent to the cavity recess 24rl" from which they are separated by a portion of the surface 22s 1" of the surface 22".

[0105] The recess 24r1" is covered with a metal-containing material 26" and the recess 24r2" is covered with a metal-containing material 27" (which may be the same as the metal-containing material 26" or the two materials may be different metal-containing materials). For example, only the lower portion 25b" of the recess 24r2" may be covered with the material 27". In some examples, the material 27" may include a conductive adhesive or be formed of at least one of the following metals: gold, silver, copper, and aluminum. However, this does not impose any limitation, and the inner walls 25s" of the recess 24r2" may be at least partially covered by the material 27". The LED 28" has a contact pad C5, the contact pad C5 being connected by a connecting line CLb to a contact pad C6.

[0106] The recess 24rl" is partially covered with a material 26". The material 26" may be a material comprising a conductive component. The material 26" may be formed of a conductive adhesive or of at least one material among gold, silver, copper, and aluminum. However, this does not impose any limitation, and the inner walls 24sl" of the recess 24rl" of the cavity 24" may be at least partially covered with the metal-comprising material 26". If the material 26" is a metal-comprising material used for plating the surfaces of the cavity 24", light may be reflected by the walls 24sl" of the recess 24rl" up to a certain level of plating on the walls 24sl" of the recess 24rl".

[0107] In some illustrative examples, the recess 24rl" in the flexible printed circuit board 22" may partially expose a routing conductive line within the flexible printed circuit board 22", this routing conductive line representing the metal-compounding material 26". The routing conductive line may also be plated with the metal-compounding material 26". It is thus possible to apply an electrical potential to the LED 28".

[0108] In certain illustrative examples, the recess 24r2" may partially expose a routing lead line within the flexible printed circuit board 22", the routing lead line being either the metal-compound material 27" or plated with the metal-compound material 27". An electrical potential can thus be applied to contact C6. Similarly, the recess 24rl" may partially expose another routing lead line within the flexible printed circuit board 22", this other routing lead being either the metal-compound material 26" or plated with the material comprising 26" metal in such a way that it is possible to apply an electrical potential to contact C5.

[0109] The filling volume defined by the cavity 24" can be at least partially filled by the high refractive index material 30". In some illustrative examples, the dam 25" can be formed of a thixotropic and non-transparent thermosetting material, for example an epoxy material comprising a non-transparent epoxy material, for example a black epoxy material, and / or a metallic binder component and / or a glass binder component.

[0110] As shown in [Fig. 6], the 24" cavity is completely filled with the high refractive index material 30". However, this does not impose any limitation, and a fill height may only partially fill the fill volume so that the 28" LED is encapsulated, the height of the 28" LED being less than the height of the dam 25". The fill volume may be filled to a height level inside the 24" cavity so that the CLb connecting line is completely encapsulated by the high refractive index material 30".

[0111] The 28" LED is attached to the 22" flexible printed circuit board by attachment or bonding to the 26" material. For example, the 28" LED may be attached to the 26" material using a conductive adhesive or attached by the "flip-flop" attachment technique to the 26" material. In the case of attachment by the "flip-flop" technique, a slot (not shown) may be formed in the 24" cavity to separate the anode (not shown) and cathode (not shown) contacts of the 28" LED and to the 28" LED. However, this does not impose any limitations, and any other chip attachment or bonding technique may be used.

[0112] With reference to [Fig. 6], the electronic LED module 20" further comprises a high refractive index material 30", the LED 28" being encapsulated by the high refractive index material 30". The high refractive index material 30" can be formed directly on the LED 28" so that the high refractive index material 30" can be in mechanical contact with a chip or LED array of the LED 28".

[0113] As described above, the high refractive index material 30" completely fills the cavity 24" and completely encapsulates the LED 28". With reference to [Fig.6], the high refractive index material 30" completely fills the cavity 24" and a surface 30s" of the high refractive index material 30" opposite the LED 28" and the flexible printed circuit 22" is convex.

[0114] Although [Fig. 6] shows the 20" electronic LED module with a single 28" LED and a single 24" cavity, this does not impose any limitation on the present disclosure, and the 20" electronic LED module may further include one or more additional cavities (not shown) formed in the 22s" surface of the 22" flexible printed circuit board. One or more additional cavities (not shown) can be fitted with at least one additional LED (not shown) in a similar manner to the 24" cavity fitted with the 28" LED.

[0115] Although [Fig. 6] shows the 30s" surface of the 30" high refractive index material having a convex shape, this does not impose any limitation on the present disclosure, and the 30" high refractive index material may have at least one upper surface opposite the 28" LED having at least one shape among at least partially convex, at least partially concave, and at least partially planar. Accordingly, the 30" high refractive index material may be shaped to form an optical component with a desired optical effect, for example, a converging, collimating, dispersing, or diffracting effect, or a combination thereof.

[0116] Fig. 7 shows, in a schematic cross-sectional view, an electronic LED module 40 comprising a flexible printed circuit board 42 having a cavity 44 formed in a surface 42s of the flexible printed circuit board 42, the cavity 44 being delimited on the surface 42s of the flexible printed circuit board 42 by a dam structure 45 formed of at least a first dam 45a and a second dam 45b. The dam structure 45 defines a filling volume bounded by a surface region, i.e. the surface region comprising a bottom 44b of the cavity 44, and the side walls 24s of the cavity 24. The walls 24s of the cavity 24 are formed by the internal walls 24s1 of a recess 44r of the flexible printed circuit board 42, and the internal walls 44s2 and 44s3 of the dam structure 45.The dam structure 45 completely surrounds the surface region 42s, the cavity 44 being completely formed in the surface region, the dam structure 45 being formed by several layers of dam material representing the first dam 45a and the second dam 45b formed in a stacked arrangement like a stacking ring completely surrounding the recess 44r.

[0117] The filling volume defined by the cavity 44 can be at least partially filled by the high refractive index material 50. In some illustrative examples, the barrier structure 45 can be formed of a thixotropic and non-transparent thermosetting material, for example an epoxy material comprising a thixotropic and non-transparent epoxy material, for example a black epoxy material, and / or a metallic binder component and / or a glass binder component.

[0118] The cavity 44 is partially covered with a material 46. The material 46 may be a material comprising a conductive component. As shown in [Fig. 7], the bottom 44b of the cavity 44 is covered with the material 46. The material 46 may be a conductive adhesive or be made of at least one of the following materials: gold, silver, copper, and aluminum. However, this does not impose any limitation, and the inner side walls 44s of the recess 44r of the cavity 44 may be at least partially covered with the material 46. If the material 46' is a material Including metal used for plating the interior surfaces of cavity 44, light can be reflected by the side walls 44s1 of the recess 44r up to a plating level on the side walls 44s1 of the recess 44r.

[0119] In some illustrative examples, cavity 44, i.e., the recess 44r in the flexible printed circuit board 42, may partially expose a routing conductive line within the flexible printed circuit board 42, this routing conductive line representing material 46. The routing conductive line may also be plated with material 46 if the latter is a metal, or material 46 may be a conductive adhesive deposited on the routing conductive line. It is thus possible to apply an electrical potential to the LED 48.

[0120] The electronic LED module 40 further includes an LED 48 arranged in the cavity 44. The filling volume can completely cover the LED 48 (i.e., a height of the dam structure 45 is greater than a height of the LED 48, or a depth of the cavity 44 is greater than the height of the LED 48). The dam structure 45 adjusts a sufficient depth for the cavity 44 such that the depth of the cavity 44 is greater than the height of the LED 48, although the first dam 45a may not have sufficient height to provide a recess of sufficient depth relative to the LED 48. Depending on the desired depth of the cavity 44, the dam structure 45 may include at least one additional dam beyond the first and second dams 45a and 45b.

[0121] As shown in [Fig.7], the cavity 44 is completely filled with the high refractive index material 50. However, this does not impose any limitation and a filling height may only partially fill the filling volume so that the LED 48 is encapsulated, a height of the LED 48 being less than a height of the barrier structure 45.

[0122] The LED 48 is attached to the flexible printed circuit board 42 by attaching or gluing it to the material 46. For example, the LED 48 can be attached using conductive adhesive or the "flip-flop" attachment technique to the material 46. In the case of "flip-flop" bonding, a slot (not shown) can be formed in the cavity 44 to separate the anode (not shown) and cathode (not shown) contacts of the LED 48. However, this does not impose any limitations, and any other chip attachment or bonding technique can be used.

[0123] With reference to [Fig. 7], the electronic LED module 40 further comprises a high refractive index material 50, the LED 48 being encapsulated by the high refractive index material 50. The high refractive index material 50 can be formed directly on the LED 48 so that the high refractive index material 50 can be in mechanical contact with an LED matrix or chip 48.

[0124] As described above, the high refractive index material 50 completely fills the cavity 44 and fully encapsulates the LED 48. With reference to [Fig. 7], the high refractive index material 50 completely fills the cavity 44, and a surface 50s of the high refractive index material 50 opposite the LED 48 and the flexible printed circuit board 42 is convex. The high refractive index material 50 can form a collimating optical element resulting from a suitable shape of the surface 50s of the high refractive index material 50. The high refractive index material 50 can be a self-bulging material as described in the context of the first aspect of disclosure as described above.

[0125] Although [Fig.7] shows the electronic LED module 40 with a single LED 48 and a single cavity 44, this does not impose any limitation on the present disclosure and the electronic LED module 40 may further include one or more additional cavities (not shown) formed in the surface 42s of the flexible printed circuit board 42. One or more additional cavities (not shown) may be equipped with at least one additional LED (not shown) in a manner similar to the cavity 44 equipped with the LED 48.

[0126] With reference to [Fig.7], the high refractive index material 50 can cover a surface area of ​​the surface 42s with a size at least equal to that of the cavity 44. Consequently, shaping of the surface 50s of the high refractive index material 50 can be achieved by direct mechanical contact of the high refractive index material 50 with the material 46 and / or by direct contact with the surface 42s of the flexible printed circuit board 42.

[0127] Although [Fig. 7] shows the surface 50s of the high refractive index material 50 having a convex shape, this does not impose any limitation on the present disclosure, and the high refractive index material 50 may have at least one upper surface opposite the LED 48 having at least a shape that is at least partially convex, at least partially concave, and at least partially planar. Accordingly, the high refractive index material 50 may be shaped to form an optical component with a desired optical effect, for example, a convergence, collimation, dispersion, or diffraction effect, or a combination thereof.

[0128] With reference to [Fig.8], a possible but non-limiting implementation of a detection device conforming to the second aspect described above is represented in a schematic cross-section.

[0129] Figure 8 shows a detection device 60, for example an oximetric detection device. The detection device 60 comprises a housing 62 containing an electronic LED module 64 with light sources L1 and L2, and a Photodetector 66 configured to detect the light emitted by light sources L1 and L2. The electronic LED module 64 can be the electronic LED module described above in the first aspect. In other words, the electronic LED module 64 can be one of the electronic LED modules described above relating to any of Figures 1 to 7.

[0130] The housing 62 can be a metal housing or a flexible bandage configured to accommodate a finger F of a user of the detection device 60. However, the housing 62 can be designed so that another part of the body of a user of the detection device 60 can be arranged inside the housing 62, so that the photodetector 66 is arranged and configured to detect the light emitted by the electronic LED module 64 during the operation of the detection device 60.

Claims

Demands

1. An electronic LED module (1, 1', 20, 20', 20”, 40, 64), comprising: a flexible printed circuit board (2, 2', 22, 22', 22”, 42) having at least one cavity (4, 4', 24, 24', 24”, 44) formed in a surface of the flexible printed circuit board (2, 2', 22, 22', 22”, 42), the interior surfaces of at least one cavity (4, 4', 24, 24', 24”, 44) being at least partially covered with a material comprising a conductive component (6, 6', 26, 26', 27', 26”, 46); and at least one LED (8, 8', 28, 28', 28”, 48) arranged inside at least one cavity (4, 4', 24, 24', 24”, 44) of the flexible printed circuit board (2, 2', 22, 22', 22”, 42) and attached to the flexible printed circuit board (2, 2', 22, 22', 22”, 42), in which at least one LED (8, 8', 28, 28', 28”, 48) is encapsulated by a high refractive index material (10, 10', 30, 30', 30”, 50).

2. The electronic LED module (1, 1', 20, 20', 20”, 40, 64) according to claim 1, wherein the high refractive index material (10, 10', 30, 30', 30”, 50) has a first surface in contact with the flexible printed circuit board (2, 2', 22, 22', 22”, 42) and a second surface (10s, 10s') opposite the cavity (4, 4', 24, 24', 24”, 44), the second surface (10s, 10s') being at least partially a curved surface.

3. The electronic LED module (1, 1', 20, 20', 20”, 40, 64) according to claim 2, wherein the high refractive index material (10, 10', 30, 30', 30”, 50) completely fills the cavity (4, 4', 24, 24', 24”, 44) and the curved surface is completely outside the at least one cavity (4, 4', 24, 24', 24”, 44).

4. The electronic LED module (1, 1', 20, 20', 20”, 40, 64) according to claim 2 or 3, wherein the second surface (10s, 10s') of the high refractive index material (10, 10', 30, 30', 30”, 50) is convex in shape.

5. The electronic LED module (1, 1', 20, 20', 20", 40, 64) according to any one of claims 1 to 4, further comprising a dam (25, 25', 25”, 45) formed in the surface (2s, 2s', 22s, 22s', 22s”, 42s) of the flexible printed circuit board (2, 2', 22, 22', 22”, 42), wherein the dam (25, 25', 25”, 45) completely surrounds a surface region of the surface (2s, 2s', 22s, 22s', 22s”, 42s), the cavity (4, 4', 24, 24', 24”, 44) being completely formed in the surface region.

6. The electronic LED module (1, 1', 20, 20', 20”, 40, 64) according to claim 5, wherein the dam (25, 25', 25”, 45) defines a filling volume bordered by the surface region of the flexible printed circuit board (2, 2', 22, 22', 22”, 42), the filling volume being at least partially filled by the high refractive index material (10, 10', 30, 30', 30”, 50) and / or the filling volume completely covering at least one LED (8, 8', 28, 28', 28”, 48).

7. The electronic LED module (1, 1', 20, 20', 20”, 40, 64) according to claim 5 or 6, wherein the barrier (25, 25', 25”, 45) is formed of a non-transparent thermosetting material and / or a metallic binding component and / or a glass binding component.

8. The electronic LED module (1, 1', 20, 20', 20”, 40, 64) according to any one of claims 5 to 7, wherein the dam (25, 25', 25”, 45) is formed by a single layer of dam material (25, 25', 25”, 45) or by a stack of at least two layers of dam material (25, 25', 25”, 45).

9. The electronic LED module (1, 1', 20, 20', 20”, 40, 64) according to any one of claims 1 to 8, wherein at least one LED (8, 8', 28, 28', 28”, 48) is an LED chip and the high refractive index material (10, 10', 30, 30', 30”, 50) is in direct contact with the LED chip.

10. Detection device (60) comprising: the electronic LED module (1, 1', 20, 20', 20”, 40, 64) according to any one of claims 1 to 9; a photodetector (66); and a housing containing (62) the electronic LED module (1, 1', 20, 20', 20”, 40, 64) and the photodetector (66),

11. in which the photodetector (66) is arranged and configured to detect the light emitted by the electronic LED module (1, 1', 20, 20', 20”, 40, 64) during the operation of the detection device (60). The detection device (60) according to claim 10, wherein the detection device (60) is an oximetric detection device.

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