Structural composites with encapsulated micro-LED task lighting and molded optics

Abstract

Structural composites with encapsulated micro LED task lighting and molded optics. A composite structure includes a structural composite including a plurality of reinforcing fibers encapsulated in a first polymer resin. M trace sets are arranged on the structural composite. N sets of micro-LEDs are arranged on the structural composite and connected to the M sets of traces, respectively, wherein M and N are integers greater than zero. One or more cables are connected to the M trace sets. A portion of the structural composite, the M trace sets, the N micro LED sets, the one or more cables are encapsulated in a second polymer resin. The second polymer resin includes an integrated lens adjacent to the N sets of micro-LEDs.

Description

[0001] introduction

[0002] The information provided in this section is for the purpose of generally presenting the context of the present disclosure. The work of the presently named inventors is not admitted, either explicitly or implicitly, as prior art against the present disclosure to the extent it is described in this section, nor are aspects of this description that may otherwise not qualify as prior art at the time of filing. Technical Field

[0003] The present disclosure relates to structural composites, and more particularly, to a structural composite having concealed and encapsulated microLED (microLED) task lighting and molded optics. Background Art

[0004] Structural components include reinforcing fibers encapsulated in a resin. They have been used to replace other structural components, such as the roof of a vehicle, to reduce weight. Because the reinforcing fibers do not need to be positioned throughout the structural component, the resin can be transparent to allow light to pass through the structural component. Summary of the Invention

[0005] A composite structure includes a structural composite comprising a plurality of reinforcing fibers encapsulated in a first polymer resin. M trace assemblies are disposed on the structural composite. N micro-LED assemblies are disposed on the structural composite and are connected to the M trace assemblies, respectively, where M and N are integers greater than zero. One or more cables are connected to the M trace assemblies. The structural composite, the M trace assemblies, the N micro-LED assemblies, and a portion of the one or more cables are encapsulated in a second polymer resin. The second polymer resin includes an integrated lens adjacent to the N micro-LED assemblies.

[0006] Among other features, N thermally conductive stacks are in thermal contact with N micro-LED sets and are encapsulated in a second polymer resin. An integrated lens is selected from the group consisting of a Fresnel lens, a groove lens, a concave lens, a convex lens, a pincushion optical lens, and a microlens. The N micro-LED sets are arranged in an array comprising rows and columns.

[0007] In other features, the structural composite includes a polymer substrate, and the reinforcing fibers are attached to the polymer substrate by wires.

[0008] In other features, the structural composite includes a transparent region and an opaque region, and the M trace sets and the N micro-LED sets are arranged at least partially adjacent to the opaque region. The structural composite includes a transparent region and an opaque region, and the M trace sets and the N micro-LED sets are arranged adjacent to the opaque region. The N thermally conductive stack sets include a thermally conductive layer.

[0009] In other features, the N thermally conductive stacks include a first interface layer, a first polymer layer, and a second interface layer. The second polymer resin is transparent. The reinforcing fibers serve as a heat sink for the N micro-LEDs.

[0010] A method for manufacturing a composite structure includes: providing a structural composite comprising a plurality of reinforcing fibers encapsulated in a first polymer resin; arranging M trace sets on the structural composite, where M and N are integers greater than one; arranging N microLED sets on the structural composite and connecting them to the M trace sets respectively; connecting one or more cables to the M trace sets; encapsulating the structural composite, the M trace sets, the N microLED sets, and a portion of the one or more cables in a second polymer resin; and forming an integrated lens adjacent to the N microLED sets using the second polymer resin.

[0011] Among other features, the method includes arranging N thermally conductive stacks in thermal contact with N micro-LED sets. An integrated lens is selected from the group consisting of a Fresnel lens, a groove lens, a concave lens, a convex lens, a pincushion optical lens, and a microlens. The N micro-LED sets are arranged in an array comprising rows and columns. The method includes attaching a plurality of reinforcing fibers to a polymer substrate using leads; and encapsulating the polymer substrate, the plurality of reinforcing fibers, and the leads.

[0012] In other features, the structural composite includes a transparent region and an opaque region, and the M trace sets and the N micro-LED sets are arranged at least partially adjacent to the opaque region. The N thermally conductive stack sets include a thermally conductive layer, a first interface layer, a first polymer layer, and a second interface layer. The second polymer resin is transparent. The reinforcing fibers serve as a heat sink for the N micro-LEDs.

[0013] The present invention includes the following solutions:

[0014] Solution 1. A composite structure comprising:

[0015] a structural composite comprising a plurality of reinforcing fibers encapsulated in a first polymer resin;

[0016] M trace sets arranged on the structural complex;

[0017] N sets of micro-LEDs arranged on the structural complex and respectively connected to the M sets of traces, where M and N are integers greater than zero; and

[0018] one or more cables connected to the M trace sets;

[0019] wherein the structural composite, the M sets of traces, the N sets of micro-LEDs, and a portion of the one or more cables are encapsulated in a second polymer resin, and

[0020] The second polymer resin includes an integrated lens adjacent to the N micro-LED sets.

[0021] Option 2. The composite structure according to Option 1 further comprises N thermally conductive stacks in thermal contact with the N micro LEDs and encapsulated in the second polymer resin.

[0022] Option 3. A composite structure according to Option 1, wherein the integrated lens is selected from the group consisting of: a Fresnel lens, a groove lens, a concave lens, a convex lens, a pillow optical lens and a microlens.

[0023] Option 4. The composite structure of Option 1, wherein the N micro-LED sets are arranged in an array comprising rows and columns.

[0024] Option 5. The composite structure of Option 1, wherein:

[0025] The structural composite comprises a polymer substrate, and

[0026] The reinforcing fibers are attached to the polymer substrate by wire leads.

[0027] Option 6. The composite structure of Option 1, wherein:

[0028] The structural composite comprises a transparent region and an opaque region, and

[0029] The M sets of traces and the N sets of micro LEDs are arranged at least partially adjacent to an opaque region.

[0030] Option 7. The composite structure of Option 1, wherein:

[0031] The structural composite comprises a transparent region and an opaque region, and

[0032] The M sets of traces and the N sets of micro LEDs are arranged adjacent to an opaque region.

[0033] Embodiment 8. The composite structure of embodiment 1, wherein the N thermally conductive stack sets comprise thermally conductive layers.

[0034] Option 9. The composite structure of Option 1, wherein the N thermally conductive stack sets comprise:

[0035] first interface layer;

[0036] a first polymer layer; and

[0037] Second interface layer.

[0038] Item 10. The composite structure of Item 1, wherein the second polymer resin is transparent.

[0039] Option 11. A composite structure according to Option 1, wherein the reinforcing fiber acts as a heat sink for the N micro LEDs.

[0040] Solution 12. A method for manufacturing a composite structure, comprising:

[0041] providing a structural composite comprising a plurality of reinforcing fibers encapsulated in a first polymer resin;

[0042] Arranging M sets of traces on the structural complex, where M and N are integers greater than one;

[0043] Arranging N sets of micro-LEDs on the structural complex and connecting them to the M sets of traces respectively;

[0044] connecting one or more cables to the M trace sets;

[0045] encapsulating the structural composite, the M sets of traces, the N sets of micro-LEDs, and a portion of the one or more cables in a second polymer resin; and

[0046] An integrated lens is formed adjacent to the set of N micro LEDs using the second polymer resin.

[0047] Option 13. The method according to Option 12 further comprises arranging N thermally conductive stacks in heat-collecting contact with the N micro-LEDs.

[0048] Option 14. The method according to Option 12, wherein the integrated lens is selected from the group consisting of: a Fresnel lens, a groove lens, a concave lens, a convex lens, a pillow optical lens, and a microlens.

[0049] Option 15. The method of Option 12, wherein the N micro-LED sets are arranged in an array comprising rows and columns.

[0050] Option 16. The method according to Option 12, further comprising:

[0051] attaching the plurality of reinforcing fibers to a polymer substrate using wires; and

[0052] The polymer substrate, the plurality of reinforcing fibers, and the leads are encapsulated.

[0053] Item 17. The method according to item 12, wherein:

[0054] The structural composite comprises a transparent region and an opaque region, and

[0055] The M sets of traces and the N sets of micro LEDs are arranged at least partially adjacent to an opaque region.

[0056] Option 18. The method of Option 12, wherein the N thermally conductive stack sets include a thermally conductive layer, a first interface layer, a first polymer layer, and a second interface layer.

[0057] Item 19. The method of Item 12, wherein the second polymer resin is transparent.

[0058] Option 20. The method of Option 12, wherein the reinforcing fiber acts as a heat sink for the N micro LEDs.

[0059] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and accompanying drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The present disclosure will become more fully understood from the detailed description and accompanying drawings, in which:

[0061] Figure 1 is a perspective view illustration of an example of reinforcement fibers according to the present disclosure arranged in predetermined positions on a consolidation substrate and attached by wires;

[0062] Figure 2 is a plan view of an example of a structural component including reinforcing fibers, transparent regions, and opaque regions according to the present disclosure;

[0063] Figure 3A is a plan view of an example of a structural component including traces and a micro-LED array according to the present disclosure;

[0064] Figures 3B to 3D is an enlarged plan view of an example of a micro-LED array and traces according to the present disclosure;

[0065] Figure 4 is a side cross-section illustrating an example of a stack according to the present disclosure, the stack including a structural composite, a micro-LED panel, and a thermally conductive stack;

[0066] Figure 5 is a side cross-section illustrating an example of a thermally conductive stack according to the present disclosure;

[0067] Figure 6 is a side cross-section of an example of a stack according to the present disclosure, the stack being consolidated in resin in a molding tool including a lens molding portion;

[0068] Figure 7 is a side cross-section of an example of a controller according to the present disclosure coupled to a micro-LED array of a structural complex;

[0069] Figure 8 and 9A is a side cross-section of an example of a lens according to the present disclosure;

[0070] Figure 9B and 9C yes Figure 9A a bottom view of an example of a middle lens; and

[0071] Figures 10 to 12 is a side cross-section of an example of a lens according to the present disclosure.

[0072] In the drawings, reference numerals may be repeated to identify similar and / or identical elements. DETAILED DESCRIPTION

[0073] Although the structural composite is described below in the context of a roof for a vehicle, the structural composite may be used in other vehicular or non-vehicular applications.

[0074] Conventional task lighting systems for interior applications in vehicles typically include a light source, a housing, and a lens. The housing and lens are used to control the light output by the light source. When a portion of the vehicle roof or another interior structure is replaced with a partially transparent structural composite, there is a mismatch between the transparent portion of the structural composite and the styling of the task lighting system components. In other words, the task lighting system components are visible and may be visually unappealing.

[0075] The present disclosure relates to a partially transparent structural composite, such as a roof panel, that includes an encapsulated micro-LED array and a molded lens to improve task lighting systems. The structural composite includes a transparent portion and an opaque portion. Some of the opaque portions include reinforcing fibers. In some examples, the micro-LEDs and wiring are partially or fully concealed by the reinforcing fibers in the opaque portion of the structural composite, such that they are hidden and / or do not obscure the transparent portion. In other examples, the micro-LEDs and wiring can be located in the transparent portion and at least partially visible.

[0076] The structural composite is manufactured using one or more injection molding or compression molding steps. In some examples, the structural composite includes a polymer substrate. The reinforcing fibers are arranged on the polymer substrate in a predetermined pattern. In some examples, a custom fiber placement (TFP) is used to place and sew the reinforcing fibers to the polymer substrate in a predetermined pattern. The reinforcing fibers are then consolidated with the polymer layers in the polymer resin to form the structural composite.

[0077] After consolidation of the structural composite, traces are formed on the first structural composite and the microLED array is attached to the traces. In some examples, the microLED array and / or traces are attached to opaque portions of the first structural composite (such as those adjacent to the reinforcing fibers). Cables are attached to the traces to provide external connections to the microLED array. In some examples, the cables are arranged at least partially along the opaque portions of the first structural composite. In some examples, the consolidation step is optionally performed before adding a thermally conductive stack adjacent to the microLED array. In other examples, the thermally conductive stack is consolidated with the structural composite, traces, and microLED array.

[0078] The first structural composite, micro-LEDs, and thermally conductive stack are arranged in an injection molding or compression tool. The injection molding or compression tool includes a molded portion that defines one or more integrated optical surfaces (e.g., one or more lenses) in one or more predetermined positions. In some examples, the first structural composite, micro-LEDs, and thermally conductive stack are consolidated using a transparent resin to form a second composite structure including one or more molded lenses. Typically, micro-LEDs produce a Lambertian lighting pattern that may not be suitable for task lighting applications. The one or more lenses use the light output by the micro-LED array to create the desired lighting pattern.

[0079] It is also possible that the micro LED light source is hidden by an opaque structural material during the unlit state to provide a hidden-until-lit feature. In some examples, the thermally conductive stack includes multiple thermally conductive layers to protect the micro LED light source from high temperatures during the molding process.

[0080] Now refer to Figure 1 and 2 , shows reinforcing fibers 56 being sewn to a polymer substrate 38 in a predetermined pattern. The reinforcing fibers 56 are attached to the polymer substrate 38 by leads 60. The reinforcing fibers 56 pass through guides 54 that move relative to the polymer substrate 38 to define the pattern. In some examples, customized fiber placement (TFP) is used, and the guides 54 are guided by a robot. In some examples, the reinforcing fibers 56 are attached in future locations of traces and / or micro-LED arrays and / or other locations. After the reinforcing fibers 56 are attached, the reinforcing fibers 56 and the polymer substrate 38 can be consolidated in a polymer resin to create a composite structure 70. In some examples, the reinforcing fibers 56 are made of a conductive material such as carbon, and the reinforcing fibers act as a heat sink.

[0081] exist Figure 2, an example of a composite structure 70 is shown as a pattern including reinforcement fibers 56, an opaque portion 72 (including the reinforcement fibers 56), and a transparent portion 78. As will be described further below, the micro-LED array and traces are positioned entirely or at least partially adjacent to the opaque portion and / or positioned below the reinforcement fibers 56 such that the micro-LEDs and traces are hidden from view until illuminated.

[0082] Now refer to Figure 3A and 3B For illustration purposes, the composite structure 70 is shown as transparent. However, the composite structure 70 will typically include both transparent and opaque portions, such as Figure 2 As shown in . The set of traces 82 is formed on the composite structure 70 in a predetermined pattern. In some examples, the predetermined pattern of traces 82 completely or partially overlaps the predetermined pattern of the reinforcing fibers. The micro-LED array 84 is arranged on the composite structure 70 and is connected to the traces 82 and / or is connected to the traces 82. For example, the set of traces 82 extends from an edge of the composite structure 70 to a corresponding one of the micro-LED arrays 84. Figure 3A In the example shown in FIG, four of the micro LED arrays 84 are connected by four sets of traces 82. As can be appreciated, the micro LED arrays 84 can be located in other positions, and fewer or additional micro LED arrays can be used.

[0083] In some examples, traces 82 are applied to composite structure 70 using conductive ink in one or more predetermined patterns. Micro-LED array 84 is attached to traces 82. Additional details and other examples are shown and described in commonly assigned U.S. patent application Ser. No. 17 / 699,696, filed on Mar. 21, 2022, which is hereby incorporated by reference herein in its entirety.

[0084] exist Figure 3B , an example of one of the micro-LED arrays 84 is shown to include a plurality of micro-LEDs 88 arranged in rows and columns and connected to traces 82. In some examples, traces 82 include power, ground, row control signals, and column control signals, although other control arrangements can be used. In some examples, the traces and / or the plurality of micro-LEDs 88 are at least partially placed in locations corresponding to opaque portions (e.g., locations with reinforcing fibers 56).

[0085] Now refer to Figure 3C and 3D , shows other example configurations. Figure 3C In FIG, micro LED array 84 is connected to connector 85 by trace 82. Connector 85 is connected to driver 89 by cable 87. Figure 3D, the micro LED array 84 is connected to the driver 87 by traces. The driver 87 is packaged and connected to the cable 87 and the controller 89 by the connector 85.

[0086] exist Figure 4 In the embodiment of the present invention, one or more cables 118 are used to provide external connections for the micro LED array 84. For example, the cables 118 are connected to the micro LED array 84 by the traces 82 to provide power, ground, and / or control signals. After the traces 82 are formed / deposited and the micro LED array 84 is placed, the composite structure 70, the traces 82, the cables 118, and the micro LED array 84 can be optionally consolidated with the polymer resin 90 to form the composite structure 96.

[0087] A thermally conductive stack 122 is disposed adjacent to the micro LED array 114 (either before or after consolidation) to provide thermal management. In some examples, the thickness of the thermally conductive stack 122 ranges from 0.5 mm to 5.0 mm, although other thicknesses may be used.

[0088] Now refer to Figure 5 , an example of a thermally conductive stack 122 is shown to include a thermally conductive layer 124, a first interface polymer layer 126, a polymer layer 128, and a second interface polymer layer 130. In some examples, the thermally conductive layer 124 includes a graphene layer (k ~ 3000 W / mK), a single layer of hexagonal boron nitride (h-BN) (k ~ 550 W / mK), Al2O3 (k ~ 10 W / mK), sapphire (k ~ 1000 W / mK), and / or indium tin oxide (k ~ 2 W / mK), although other materials may be used.

[0089] In some embodiments, first interface polymer layer 126 includes a first polymer A and a second polymer B. In some embodiments, first polymer A is made of the same material that encapsulates the micro-LED array. In some embodiments, second polymer B is made of the same polymer material as polymer layer 128. In some examples, polymer layer 128 includes a transparent polymer suitable for overmolding.

[0090] In some embodiments, polymer layer 128 is made of a transparent polymer that is different from the material encapsulating the micro-LED array. In some embodiments, second interface polymer layer 130 includes a second polymer B and a transition material of the same type as the overmold polymer C. Additional details regarding thermally conductive stack 122 can be found in commonly assigned U.S. patent application Ser. No. 18 / 462,769, filed on September 7, 2023, which is hereby incorporated by reference herein in its entirety.

[0091] Now refer to Figure 6 and 7, the stack 108 is arranged in a cavity of an injection molding tool 132. The stack 108 is consolidated in a polymer resin 140 using injection molding or compression molding to form a composite structure 150. The inner surface 134 of the injection molding tool 132 includes a patterned area 136, such as a cavity having a predetermined surface profile, which is designed to form a lens 138 on the composite structure 150. The lens 138 is positioned to receive and modulate light from one of the micro LED arrays. In some examples, the width of the micro LED array 114 is equal to d1, and the width of the lens 138 is equal to d2, where d2>d1. The injection molding tool 132 injection molds the polymer resin 140 into the cavity to encapsulate the stack 108. In some examples, a portion of the cable 118 extends from the polymer resin 140 to allow external connections.

[0092] exist Figure 7 , the composite structure 150 is removed from the injection molding tool 132. The cable 118 is connected to the LED controller 218 by the connector 210 and the cable 214 or directly to the LED controller 218.

[0093] Now refer to Figures 8 to 12 , shows a non-limiting example of lens 138. Figure 8 In FIG, lens 138 includes a patterned surface 310 that defines a Fresnel lens. Figure 9A In FIG, lens 138 includes a patterned surface 312 that defines an array of lenses 314. Figure 9B In FIG, patterned surface 312 defines a pillow-shaped optical lens having an array of lenses 314 having a dimension d3 in the range from 1 mm to 3 mm. Figure 9C In FIG. 3 , patterned surface 312 defines a microlens array having lenses 314 having a dimension d3 in the range from 0.1 mm to less than 1 mm.

[0094] exist Figure 10 In FIG, lens 138 includes a pattern of cavities 330 defining a groove lens. Figure 11 In FIG, lens 138 comprises a convex lens. Figure 12 , lens 138 comprises a concave lens. Although specific examples of lenses are shown, other lenses may also be used.

[0095] In some examples, transparent and / or opaque polymer resins are used. Examples of transparent polymer resins include epoxy resins, polyurethane (PUR), polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyacrylate (acrylic acid), polyamide (PA), co-transparent layers thereof, and combinations thereof.

[0096] In some examples, the reinforcing fibers are selected from the group consisting of glass fibers, carbon fibers, basalt fibers, aramid fibers, polyethylene fibers, polypropylene fibers, natural fibers, or any combination thereof. In some examples, dry fibers are used. In other examples, the reinforcing fibers are impregnated with a resin or polymer fiber. For example, carbon fibers (e.g., carbon black, carbon nanotubes, talc, fibers derived from polyacrylonitrile and / or pitch precursors), glass fibers (e.g., glass fibers, quartz), basalt fibers, aramid fibers (e.g., polybenzoxazole (PBO)), polyethylene fibers (e.g., high-strength ultra-high molecular weight (UHMW) polyethylene), polypropylene fibers (e.g., high-strength polypropylene), natural fibers (e.g., cotton, flax, cellulose, spider silk), and combinations thereof.

[0097] The foregoing description is merely illustrative in nature and is in no way intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in a variety of forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited, because other modifications will become apparent when studying the drawings, description and appended claims. It should be understood that one or more steps within the method can be performed in a different order (or simultaneously) without changing the principles of the present disclosure. In addition, although each of the embodiments is described above as having specific features, any one or more of those features described with respect to any embodiment of the present disclosure can be implemented in the features of any one of the other embodiments and / or combined with the features of any one of the other embodiments, even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and the permutation of one or more embodiments with each other is still within the scope of the present disclosure.

[0098] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including "connected," "engaged," "coupled," "adjacent," "adjacent," "on top of," "above," "below," and "deployed." Unless explicitly described as "direct," when describing a relationship between a first element and a second element in the above disclosure, the relationship can be a direct relationship in which there are no other intervening elements between the first element and the second element, but can also be an indirect relationship in which there are one or more intervening elements (spatially or functionally) between the first element and the second element. As used herein, the expression at least one of A, B, and C should be interpreted to mean a logical (A or B or C) using a non-exclusive logical OR, and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."

Claims

1. A composite structure comprising: a structural composite comprising a plurality of reinforcing fibers encapsulated in a first polymer resin; M trace sets arranged on the structural complex; N sets of micro-LEDs arranged on the structural complex and respectively connected to the M sets of traces, where M and N are integers greater than zero; and one or more cables connected to the M trace sets; wherein the structural composite, the M sets of traces, the N sets of micro-LEDs, and a portion of the one or more cables are encapsulated in a second polymer resin, and The second polymer resin includes an integrated lens adjacent to the N micro-LED sets. 2 . The composite structure of claim 1 , further comprising N thermally conductive stacks in heat-collecting contact with the N micro LEDs and encapsulated in the second polymer resin.

3. The composite structure of claim 1, wherein the integrated lens is selected from the group consisting of a Fresnel lens, a groove lens, a concave lens, a convex lens, a pincushion optical lens, and a microlens.

4. The composite structure of claim 1 , wherein the N sets of micro-LEDs are arranged in an array comprising rows and columns.

5. The composite structure of claim 1 , wherein: The structural composite comprises a polymer substrate, and The reinforcing fibers are attached to the polymer substrate by wire leads.

6. The composite structure of claim 1 , wherein: The structural composite comprises a transparent region and an opaque region, and The M sets of traces and the N sets of micro LEDs are arranged at least partially adjacent to an opaque region.

7. The composite structure of claim 1 , wherein: The structural composite comprises a transparent region and an opaque region, and The M sets of traces and the N sets of micro LEDs are arranged adjacent to an opaque region. The composite structure of claim 1 , wherein the N thermally conductive stack sets comprise thermally conductive layers.

9. The composite structure of claim 1 , wherein the N thermally conductive stack sets comprise: first interface layer; a first polymer layer; and Second interface layer.

10. The composite structure of claim 1, wherein the second polymeric resin is transparent.

Images