Optical communication device using a conformal coating layer as an optical waveguide

Abstract

An optical communication device according to an embodiment disclosed in this document includes a first optical element, a second optical element capable of performing optical communication with the first optical element, a printed circuit board (PCB) on which the first optical element and the second optical element are disposed, and a first conformal coating layer made of a polymer material coated on at least a part of the surface of the PCB, and the optical communication is characterized in that it is performed using the first conformal coating layer as an optical waveguide.

Description

Technical Field

[0001] The present invention claims the benefit of priority based on Korean Patent Application No. 10-2022-0117485 filed on September 16, 2022, and all the contents disclosed in the document of the Korean patent application are incorporated herein by reference in their entirety.

[0002] The embodiments disclosed in this document relate to an optical communication device using a conformal coating layer as an optical waveguide.

Background Art

[0003] In recent years, with the advancement of autonomous driving and advanced driver assistance systems (ADAS), not only an increase in the bandwidth and consistency of data are required, but also the problems of data consistency and electromagnetic compatibility (EMC) are faced. Therefore, optical communication technologies replacing the standards such as LIN (local interconnect network), CAN (controller area network), CAN FD (controller area network flexible data-rate), and FlexRay, which have been conventionally used for automotive communication, are being introduced.

[0004] Optical communication technology is a means for high-speed signal transmission between components constituting an electronic device. When optical communication technology is applied in an electronic device, not only can signal transmission be performed at a higher speed, but also drawbacks of conventional signal transmission methods such as high resistance, high heat generation, and parasitic capacitance phenomena can be alleviated.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Conventionally, optical cables have been used as optical waveguides for optical communication. However, optical cables are expensive components, and due to the flexibility of the cables, it is not possible to freely ensure the LOS (line of sight) of the components for transmitting and receiving optical communication signals, and there are limitations in using them for short-distance communication inside automobiles.

[0006] One object of the embodiments disclosed in this document is to provide an optical communication device that uses a conformal coating layer of a PCB (printed circuit board) on which optical elements are arranged as an optical waveguide for optical communication.

[0007] The technical problems of the embodiments disclosed in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the following description.

Means for Solving the Problems

[0008] An optical communication device according to an embodiment disclosed in this document includes a first optical element, a second optical element capable of performing optical communication with the first optical element, a PCB (printed circuit board) on which the first optical element and the second optical element are arranged, and a first conformal coating layer of a polymer material coated on at least a part of the surface of the PCB, and the optical communication is characterized in that it is performed using the first conformal coating layer as an optical waveguide.

[0009] In the optical communication device according to an embodiment disclosed in this document, the first conformal coating layer can be configured to be in contact with the optical signal input / output part of the first optical element and the optical signal input / output part of the second optical element. In the optical communication device according to an embodiment disclosed in this document, the optical signal input / output part of the first optical element includes a first input unit and a first output unit, the optical signal input / output part of the second optical element includes a second input unit and a second output unit, the first optical signal can be transmitted from the first output unit to the second input unit, and the second optical signal can be transmitted from the second output unit to the first input unit. In the optical communication device according to an embodiment disclosed in this document, the optical signal input / output part of the first optical element and the optical signal input / output part of the second optical element can be within the line of sight (LOS) of each other. In the optical communication device according to an embodiment disclosed in this document, the first optical signal and the second optical signal can be transmitted through the first part and the second part of the first conformal coating layer. In the optical communication device according to an embodiment disclosed in this document, the first part and the second part of the first conformal coating layer can be separated by a predetermined distance. In the optical communication device according to an embodiment disclosed in this document, the first part and the second part of the first conformal coating layer can be in the same layer. In the optical communication device according to an embodiment disclosed in this document, the optical signal input / output part of the first optical element and the optical signal input / output part of the second optical element do not have to be within the line of sight (LOS) of each other. In the optical communication device according to an embodiment disclosed in this document, the third optical element can be positioned within the line of sight (LOS) between the optical signal input / output part of the first optical element and the optical signal input / output part of the second optical element. In the optical communication device according to an embodiment disclosed in this document, it further includes a second conformal coating layer on the first conformal coating layer and the third optical element, and a part of the second conformal coating layer can be positioned between the first conformal coating layer and the third optical element. In the optical communication device according to an embodiment disclosed in this document, the first conformal coating layer can include a plurality of corner parts. In the optical communication device according to an embodiment disclosed in this document, the first optical signal and the second optical signal can be reflected at the plurality of corner parts.

[0010] In the optical communication device according to an embodiment disclosed in this document, the first conformal coating layer can be configured not to contact optical elements other than the first optical element and the second optical element among the plurality of optical elements arranged on the PCB.

[0011] In the optical communication device according to an embodiment disclosed in this document, the first conformal coating layer can be made of a material in which an optical signal traveling inside the first conformal coating layer is totally reflected at the surface of the first conformal coating layer.

[0012] In the optical communication device according to an embodiment disclosed in this document, the refractive index of the first conformal coating layer may be greater than the refractive index of the PCB.

[0013] The optical communication device according to an embodiment disclosed in this document can include a second conformal coating layer made of a polymer material that is coated on at least a part of a second surface that is distinguished from a first surface that contacts the PCB among the surfaces of the first conformal coating layer.

[0014] In the optical communication device according to an embodiment disclosed in this document, the second surface can include a third surface where the first conformal coating layer contacts the first optical element, a fourth surface where the first conformal coating layer contacts the second optical element, and a fifth surface excluding the third surface and the fourth surface.

[0015] In the optical communication device according to an embodiment disclosed in this document, the second conformal coating layer can be configured to contact the entire fifth surface.

[0016] In the optical communication device according to an embodiment disclosed in this document, the refractive index of the first conformal coating layer may be greater than the refractive index of the PCB and the refractive index of the second conformal coating layer. In the optical communication device according to an embodiment disclosed in this document, the PCB is in contact with the first surface of the first conformal coating layer, and the second conformal coating layer can be in contact with the second surface of the first conformal coating layer.

Advantages of the Invention

[0017] According to the embodiment disclosed in this document, optical communication between optical elements can be performed using the conformal coating layer of the PCB as an optical waveguide without adding another configuration (for example, an optical cable, a connector).

[0018] According to the embodiment disclosed in this document, it enables optical communication between optical elements where line of sight (LOS) is not ensured. In addition, various effects that can be directly or indirectly understood are provided by this document.

Brief Description of the Drawings

[0019]

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Embodiments for Carrying Out the Invention

[0020] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include various modifications, equivalents, and / or alternatives of the embodiments of the present invention.

[0021] The various embodiments of this document and the terms used therein are not intended to limit the technical features described in this document to specific embodiments, but should be understood to include various modifications, equivalents, or alternatives of such embodiments. In connection with the description of the drawings, similar or related components may be denoted by similar reference numerals. The singular form of a noun corresponding to an item may include one or more of the said item unless the context clearly indicates otherwise.

[0022] In this document, phrases such as "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" each may include any one of the items listed together in the corresponding phrase, or all possible combinations of these. Terms such as "first", "second", "the first", "the second", "A", "B", "(a)", or "(b)" may be used merely to distinguish the component from other components, and do not limit the component in other aspects (e.g., importance or order) unless otherwise stated.

[0023] In this document, when a certain (e.g., first) component is referred to as being "coupled", "connected", or "joined" to another (e.g., second) component, with or without the terms "functionally" or "communicatively", or when referred to as "coupled" or "connected", this means that the certain component may be directly (e.g., wired), wirelessly, or via a third component, coupled to the other component.

[0024] According to one embodiment, the methods according to the various embodiments disclosed in this document may be provided included in a computer program product. The computer program product may be traded as a commodity between a seller and a purchaser. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) via an application store or directly between two user devices. In the case of online distribution, at least a part of the computer program product may be at least temporarily stored in a machine-readable storage medium such as the memory of a manufacturing company's server, an application store's server, or a relay server, or may be temporarily generated.

[0025] According to various embodiments, each of the components (e.g., elements or programs) of the described components may include a single or multiple individuals, and some of the multiple individuals may be separately arranged from other components. According to various embodiments, one or more of the aforementioned components or operations may be omitted, or one or more other components or operations may be added. Alternatively or additionally, multiple components (e.g., elements or programs) may be integrated into one component. In this case, the integrated component may perform one or more functions of each of the multiple components in the same or similar manner as those performed by the component among the multiple components before the integration. According to various embodiments, the operations performed by an element, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0026] FIG. 1 is a block diagram showing the configuration of an optical communication device according to one embodiment. Referring to FIG. 1, the optical communication device 100 can include a printed circuit board (PCB) 110, a first optical element 120, a second optical element 130, and an optical waveguide 140.

[0027] The PCB 110 can mount components of the optical communication device 100 (for example, the first optical element 120 and / or the second optical element 130). According to one embodiment, the PCB 110 may be a metal-core PCB (MPCB) based on a metal with good thermal conductivity. According to another embodiment, the PCB 110 can be based on an insulating substrate material. However, it is not limited thereto, and the PCB 110 can be realized in various types and structures.

[0028] The first optical element 120 (or the second optical element 130) can perform optical communication with the second optical element 130 (or the first optical element 120). According to one embodiment, the first optical element 120 and the second optical element 130 can transmit and receive optical signals to and from each other using the optical waveguide 140. The first optical element 120 (or the second optical element 130) can transmit an optical signal to the second optical element 130 (or the first optical element 120) using the optical waveguide 140, or receive an optical signal from the second optical element 130 (or the first optical element 120).

[0029] The optical waveguide 140 can transmit the optical signal output from the first optical element 120 (or the second optical element 130) to the second optical element 130 (or the first optical element 120). According to one embodiment, the optical waveguide 140 can transmit an optical signal using the total internal reflection characteristic of light. For this purpose, the optical waveguide 140 can be composed of a material in which the optical signal traveling inside the optical waveguide 140 is totally reflected from the surface of the optical waveguide 140. For example, the refractive index of the material in contact with the surface of the optical waveguide 140 is Large It can be composed of a substance having a refractive index. According to one embodiment, the optical waveguide 140 can be realized by using a conformal coating layer of a polymer material that is coated on at least a part of the surface of the PCB 110.

[0030] FIG. 2 is a diagram for explaining a method of transmitting an optical signal by using the total internal reflection characteristic of light in the optical waveguide. FIG. 2 can be explained by using the configuration of FIG. 1. Referring to FIG. 2, the optical waveguide module 200 can include a core layer 210, a lower cladding layer 220, and an upper cladding layer 230. According to one embodiment, the core layer 210 can be in contact with the lower cladding layer 220 and the upper cladding layer 230.

[0031] According to one embodiment, the optical waveguide module 200 can transmit an optical signal by using the characteristic that the optical signal incident on the core layer 210 operating as an optical waveguide (for example, the optical waveguide 140 in FIG. 1) is totally reflected on the surface of the core layer 210. For this purpose, the core layer 210 can be composed of a substance having a refractive index (n1) higher than the refractive index (n2) of the lower cladding layer 220 and the refractive index (n3) of the upper cladding layer 230. Large It can be composed of a substance having a refractive index.

[0032] According to one embodiment, the core layer 210 can be realized by using a conformal coating layer of a polymer material that is coated on at least a part of the surface of the PCB 110. In this case, although it is fixed that the lower cladding layer 220 is realized by the PCB 110, the upper cladding layer 230 can be realized by air or a conformal coating layer of a material different from that of the core layer 210.

[0033] For example, when the surface of the PCB 110 is conformally coated with a single substance, only the core layer 210 that operates as an optical waveguide is realized by the conformal coating layer, and the upper cladding layer 230 can be realized with air. In this case, the conformal coating layer can be composed of a substance having a refractive index (n1) higher than the refractive index (n2) of the PCB 110 and the refractive index (n3) of air. Large than the refractive index (n1).

[0034] As another example, when the surface of the PCB 110 is conformally coated with a dual substance, the core layer 210 that operates as an optical waveguide is realized by the first conformal coating layer, and the upper cladding layer 230 can be realized by a second conformal coating layer composed of a substance different from the first conformal coating layer. In this case, the first conformal coating layer can be composed of a substance having a refractive index (n1) higher than the refractive index (n2) of the PCB 110 and the refractive index (n3) of the second conformal coating layer. Large than the refractive index (n1).

[0035] FIG. 3 is a plan view and a cross-sectional view showing the arrangement states of the PCB, the first optical element, the second optical element, and the conformal coating layer of the optical communication device according to an embodiment.

[0036] Referring to FIG. 3, the optical communication device 100 can include a PCB 110, a first optical element 120, a second optical element 130, and a conformal coating layer 300.

[0037] The first optical element 120 (or the second optical element 130) can include an optical signal input / output unit (121 or 131). According to an embodiment, the optical signal input / output unit (121 or 131) can include an optical signal output unit (TX) that outputs an optical signal and an optical signal input unit (RX) that receives an optical signal. According to an embodiment, the first optical element 120 (or the second optical element 130) can output an optical signal via the optical signal output unit (TX) and receive an optical signal from the outside via the optical signal input unit (RX).

[0038] The conformal coating layer 300 can be coated on at least a part of the surface of the PCB 110. Here, the conformal coating layer 300 can be composed of a polymer material.

[0039] According to an embodiment, the conformal coating layer 300 can be used as an optical waveguide in optical communication between the first optical element 120 and the second optical element 130. According to an embodiment, the conformal coating layer 300 can transmit an optical signal output from the first optical element 120 (or the second optical element 130) to the second optical element 130 (or the first optical element 120). For this purpose, the conformal coating layer 300 can be in contact with the optical signal input / output parts (121 and 131) of the first optical element 120 and the second optical element 130. For example, the conformal coating layer 300 includes a first coating layer in contact with the optical signal output part (TX) of the first optical element 120 and the optical signal input part (RX) of the second optical element 130, and a second coating layer in contact with the optical signal input part (RX) of the first optical element 120 and the optical signal output part (TX) of the second optical element 130 and not in contact with the first coating layer. As another example, the conformal coating layer 300 can include one coating layer in contact with the optical signal input / output part 121 of the first optical element 120 and the optical signal input / output part 131 of the second optical element 130.

[0040] According to an embodiment, the conformal coating layer 300 can transmit an optical signal by using the total reflection characteristic of light. For this purpose, the conformal coating layer 300 can be composed of a material in which an optical signal traveling inside is totally reflected at the surface. For example, the conformal coating layer 300 can have a refractive index Large higher than that of the material in contact with the surface.

[0041] Figures 4a and 4b are a plan view and a cross-sectional view showing the arrangement states of the PCB, the first optical element, the second optical element, and the conformal coating layer of an optical communication device according to an embodiment. In particular, FIG. 4b is a cross-sectional view obtained by cutting the plan view of FIG. 4a along the line A1-A2.

[0042] Referring to FIGS. 4a and 4b, the optical communication device 100 can include a PCB 110, a first optical element 120, a second optical element 130, and a conformal coating layer 400.

[0043] The first optical element 120 (or the second optical element 130) can include an optical signal input / output unit (121 or 131). According to an embodiment, the optical signal input / output unit (121 or 131) can include an optical signal output unit (TX) that outputs an optical signal and an optical signal input unit (RX) that receives an optical signal. According to an embodiment, the first optical element 120 (or the second optical element 130) can output an optical signal via the optical signal output unit (TX) and receive an optical signal from the outside via the optical signal input unit (RX).

[0044] The conformal coating layer 400 can be coated on at least a part of the surface of the PCB 110 and on the entire surface of the first optical element 120 and the second optical element 130 that does not contact the PCB 110. Here, the conformal coating layer 400 can be made of a polymer material.

[0045] According to an embodiment, the conformal coating layer 400 can be used as an optical waveguide in the optical communication between the first optical element 120 and the second optical element 130. According to an embodiment, the conformal coating layer 400 can transmit the optical signal output from the first optical element 120 (or the second optical element 130) to the second optical element 130 (or the first optical element 120). For this purpose, the conformal coating layer 400 can be in contact with the optical signal input / output units (121 and 131) of the first optical element 120 and the second optical element 130.

[0046] According to one embodiment, the conformal coating layer 400 can transmit an optical signal by using the total internal reflection characteristic of light. For this purpose, the conformal coating layer 400 can be composed of a material in which the optical signal traveling inside is totally reflected at the surface. For example, the conformal coating layer 400 can have a refractive index higher than that of the material in contact with the surface. Large It can be composed of a material having a refractive index.

[0047] FIG. 5 is a plan view showing the arrangement state of the PCB, the first optical element, the second optical element, the third optical element, and the conformal coating layer according to one embodiment.

[0048] Referring to FIG. 5, the optical communication device 100 can include a PCB 110, a first optical element 120, a second optical element 130, a third optical element 520, and a conformal coating layer 510.

[0049] The first optical element 120 (or the second optical element 130) can include an optical signal input / output section (121 or 131). According to one embodiment, the optical signal input / output section (121 or 131) can include an optical signal output section (TX) that outputs an optical signal and an optical signal input section (RX) that receives an optical signal. According to one embodiment, the first optical element 120 (or the second optical element 130) can output an optical signal via the optical signal output section (TX) and receive an optical signal from the outside via the optical signal input section (RX).

[0050] The conformal coating layer 510 can be coated on at least a part of the surface of the PCB 110. Here, the conformal coating layer 300 can be composed of a polymer material. According to one embodiment, the conformal coating layer 510 can be configured not to contact the third optical element 520 so that the optical signal traveling inside is not input to the third optical element 520.

[0051] According to one embodiment, the conformal coating layer 510 can be used as an optical waveguide in optical communication between the first optical element 120 and the second optical element 130. According to one embodiment, the conformal coating layer 510 can transmit an optical signal output from the first optical element 120 (or the second optical element 130) to the second optical element 130 (or the first optical element 120). For this purpose, the conformal coating layer 510 can be in contact with the optical signal input / output portions (121 and 131) of the first optical element 120 and the second optical element 130.

[0052] According to one embodiment, the conformal coating layer 510 can transmit an optical signal by using the total internal reflection characteristic of light. For this purpose, the conformal coating layer 510 can be composed of a material in which an optical signal traveling inside is totally reflected at the surface. For example, the conformal coating layer 510 can be composed of a material having a refractive index Large higher than the refractive index of the material in contact with the surface.

[0053] According to one embodiment, the edge portion of the conformal coating layer 510 can be configured to have a specified curvature so that an optical signal incident from the first optical element 120 (or the second optical element 130) is totally reflected and travels to the second optical element 130 (or the first optical element 120).

[0054] According to FIG. 5, optical communication via the conformal coating layer 510 used as an optical waveguide can be enabled even if a LOS (line of sight) is not secured between the optical signal input / output portions of the first optical element 120 and the second optical element 130 that transmit and receive optical signals via optical communication with each other.

[0055] FIG. 6 is a plan view showing the arrangement state of a PCB, a first optical element, a second optical element, and a conformal coating layer of an optical communication device according to one embodiment. Referring to FIG. 6, the optical communication device 100 can include a PCB 110, a first optical element 120, a second optical element 130, and a conformal coating layer 600.

[0056] The first optical element 120 (or the second optical element 130) can include an optical signal input / output section (121 or 131). According to one embodiment, the optical signal input / output section (121 or 131) can include an optical signal output section (TX) that outputs an optical signal, and an optical signal input section (RX) that receives an optical signal. According to one embodiment, the first optical element 120 (or the second optical element 130) can output an optical signal via the optical signal output section (TX) and receive an optical signal from the outside via the optical signal input section (RX).

[0057] The conformal coating layer 600 can be coated on at least a part of the surface of the PCB 110. Here, the conformal coating layer 600 can be made of a polymer material.

[0058] According to one embodiment, the conformal coating layer 600 can be used as an optical waveguide in the optical communication between the first optical element 120 and the second optical element 130. According to one embodiment, the conformal coating layer 600 can transmit the optical signal output from the first optical element 120 (or the second optical element 130) to the second optical element 130 (or the first optical element 120). For this purpose, the conformal coating layer 600 can be in contact with the optical signal input / output sections (121 and 131) of the first optical element 120 and the second optical element 130.

[0059] According to one embodiment, the conformal coating layer 600 can transmit an optical signal by using the total internal reflection characteristic of light. For this purpose, the conformal coating layer 600 can be made of a substance in which the optical signal traveling inside is totally reflected at the surface. For example, the conformal coating layer 600 can have a refractive index higher than that of the substance in contact with the surface. Large It can be made of a substance having a refractive index.

[0060] According to one embodiment, the edge portion of the conformal coating layer 600 can be configured to have a specified curvature such that an optical signal incident from the first optical element 120 (or the second optical element 130) is totally reflected and travels to the second optical element 130 (or the first optical element 120).

[0061] According to FIG. 6, optical communication can be enabled via the conformal coating layer 600 used as an optical waveguide even if a line of sight (LOS) is not secured between the optical signal input / output portions of the first optical element 120 and the second optical element 130 that transmit and receive optical signals via optical communication with each other.

[0062] FIGS. 7a and 7b are a plan view and a cross-sectional view showing the arrangement states of the PCB, the first optical element, the second optical element, the first conformal coating layer, and the second conformal coating layer of an optical communication device according to one embodiment. In particular, FIG. 7b is a cross-sectional view obtained by cutting the plan view of FIG. 7a along line B1 - B2.

[0063] Referring to FIGS. 7a and 7b, the optical communication device 100 can include a PCB 110, a first optical element 120, a second optical element 130, a first conformal coating layer 710, and a second conformal coating layer 720.

[0064] The first optical element 120 (or the second optical element 130) can include an optical signal input / output portion (121 or 131). According to one embodiment, the optical signal input / output portion (121 or 131) can include an optical signal output portion (TX) that outputs an optical signal and an optical signal input portion (RX) that receives an optical signal. According to one embodiment, the first optical element 120 (or the second optical element 130) can output an optical signal via the optical signal output portion (TX) and receive an optical signal from the outside via the optical signal input portion (RX).

[0065] The first conformal coating layer 710 can be coated on at least a part of the surface of the PCB 110. Here, the first conformal coating layer 710 can be composed of a polymer material.

[0066] According to one embodiment, the first conformal coating layer 710 can be used as an optical waveguide in optical communication between the first optical element 120 and the second optical element 130. According to one embodiment, the first conformal coating layer 710 can transmit an optical signal output from the first optical element 120 (or the second optical element 130) to the second optical element 130 (or the first optical element 120). For this purpose, the first conformal coating layer 710 can be in contact with the optical signal input / output portions (121 and 131) of the first optical element 120 and the second optical element 130.

[0067] According to one embodiment, the first conformal coating layer 710 can transmit an optical signal by using the total reflection characteristic of light. For this purpose, the first conformal coating layer 710 can be composed of a substance in which an optical signal traveling inside is totally reflected at the surface. For example, the first conformal coating layer 710 can have a refractive index Large higher than that of the substance in contact with the surface.

[0068] According to one embodiment, the second conformal coating layer 720 can be coated on at least a part of the second surface of the first conformal coating layer 710, which is separated from the first surface in contact with the PCB 110. Here, the second conformal coating layer 720 can be composed of a polymer material.

[0069] According to FIGS. 7a and 7b, the second surface of the first conformal coating layer 710 can include a third surface in contact with the first optical element 120, a fourth surface in contact with the second optical element 130, and a fifth surface excluding the third and fourth surfaces. According to one embodiment, the second conformal coating layer 720 can be coated over the entire fifth surface of the second surface of the first conformal coating layer 710. In this case, the first conformal coating layer 710 has a refractive index Large that can be composed of a substance having a refractive index higher than that of the PCB 110 in contact with the surface and the second conformal coating layer 720.

[0070] FIGS. 8a and 8b are a plan view and a cross-sectional view showing the arrangement states of the PCB, the first optical element, the second optical element, the third optical element, the first conformal coating layer, and the second conformal coating layer of an optical communication device according to one embodiment. In particular, FIG. 8b is a cross-sectional view obtained by cutting the plan view of FIG. 8a along the line C1-C2.

[0071] Referring to FIGS. 8a and 8b, the optical communication device 100 can include a PCB 110, a first optical element 120, a second optical element 130, a third optical element 830, a first conformal coating layer 810, and a second conformal coating layer 820.

[0072] The first optical element 120 (or the second optical element 130) can include an optical signal input / output part (121 or 131). According to one embodiment, the optical signal input / output part (121 or 131) can include an optical signal output part (TX) that outputs an optical signal and an optical signal input part (RX) that receives an optical signal. According to one embodiment, the first optical element 120 (or the second optical element 130) can output an optical signal via the optical signal output part (TX) and receive an optical signal from the outside via the optical signal input part (RX).

[0073] The first conformal coating layer 810 can be coated on at least a part of the surface of the PCB 110. Here, the first conformal coating layer 810 can be composed of a polymer material. According to an embodiment, the first conformal coating layer 810 can be configured not to contact the third optical element 830 so that an optical signal traveling inside is not input to the third optical element 830.

[0074] According to an embodiment, the first conformal coating layer 810 can be used as an optical waveguide in optical communication between the first optical element 120 and the second optical element 130. According to an embodiment, the first conformal coating layer 810 can transmit an optical signal output from the first optical element 120 (or the second optical element 130) to the second optical element 130 (or the first optical element 120). For this purpose, the first conformal coating layer 810 can contact the optical signal input / output portions (121 and 131) of the first optical element 120 and the second optical element 130.

[0075] According to an embodiment, the first conformal coating layer 810 can transmit an optical signal by using the total reflection characteristic of light. For this purpose, the first conformal coating layer 810 can be composed of a material in which an optical signal traveling inside is totally reflected at the surface. For example, the first conformal coating layer 810 can have a refractive index Large higher than that of the material in contact with the surface.

[0076] According to an embodiment, the edge portion of the first conformal coating layer 810 can be configured to have a specified curvature so that an optical signal incident from the first optical element 120 (or the second optical element 130) is totally reflected and travels to the second optical element 130 (or the first optical element 120).

[0077] According to one embodiment, the second conformal coating layer 820 can be coated on at least a part of the second surface of the surface of the first conformal coating layer 810, which is separated from the first surface in contact with the PCB 110. Here, the second conformal coating layer 820 can be made of a polymer material.

[0078] According to FIGS. 8a and 8b, the second surface of the first conformal coating layer 810 can include a third surface in contact with the first optical element 120, a fourth surface in contact with the second optical element 130, and a fifth surface excluding the third and fourth surfaces. According to one embodiment, the second conformal coating layer 820 can be coated on the entire fifth surface of the second surface of the first conformal coating layer 810. In this case, the first conformal coating layer 810 can be made of a material having a refractive index Large higher than the refractive indices of the PCB 110 and the second conformal coating layer 820 in contact with the surface.

[0079] According to FIGS. 8a and 8b, optical communication can be enabled via the first conformal coating layer 810 used as an optical waveguide even if a LOS is not ensured between the optical signal input / output portions of the first optical element 120 and the second optical element 130 that transmit and receive optical signals via optical communication with each other.

[0080] Terms such as "including", "comprising", or "having" described above shall be construed to mean that the component can be inherent therein, and not to exclude other components, and may further include other components, unless otherwise stated to the contrary. All terms, including technical or scientific terms, shall have the same meaning as generally understood by a person having ordinary knowledge in the technical field to which the embodiments disclosed in this document belong, unless otherwise defined. Commonly used terms such as those defined in a dictionary shall be construed to be consistent with the meaning in the context of the related art, and shall not be construed in an ideal or overly formal sense unless clearly defined in this document.

Claims

1. An optical communication device, comprising: a first optical element; a second optical element capable of performing optical communication with the first optical element; a PCB (printed circuit board) on which the first optical element and the second optical element are disposed; a first conformal coating layer made of a polymer material coated on at least a part of the surface of the PCB; and the optical communication is performed using the first conformal coating layer as an optical waveguide. The optical communication device is characterized in that.

2. The optical communication device according to claim 1, wherein the first conformal coating layer is configured to be in contact with an optical signal input / output portion of the first optical element and an optical signal input / output portion of the second optical element.

3. The optical communication device according to claim 1, wherein the first conformal coating layer is configured not to be in contact with optical elements other than the first optical element and the second optical element among a plurality of optical elements disposed on the PCB.

4. The optical communication device according to claim 1, wherein the first conformal coating layer is made of a material in which an optical signal traveling inside the first conformal coating layer is totally reflected on the surface of the first conformal coating layer.

5. The optical communication device according to claim 4, wherein the refractive index of the first conformal coating layer is greater than the refractive index of the PCB.

6. The optical communication device according to claim 1, further comprising a second conformal coating layer made of a polymer material coated on at least a part of a second surface of the first conformal coating layer, the second surface being distinct from a first surface in contact with the PCB.

7. The optical communication device according to claim 6, wherein the second surface includes a third surface in contact with the first optical element by the first conformal coating layer, a fourth surface in contact with the second optical element, and a fifth surface excluding the third surface and the fourth surface.

8. The optical communication device according to claim 7, wherein the second conformal coating layer is configured to be in contact with the entire fifth surface.

9. The optical communication device according to claim 6, wherein the refractive index of the first conformal coating layer is greater than the refractive index of the PCB and the refractive index of the second conformal coating layer.

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