Luminaire driver with antenna module

Abstract

The present invention provides a luminaire driver with an antenna module having a multi-layer printed circuit board (PCB) having conductive layers forming an antenna, at least one insulating layer between the conductive layers, and an electrical connection to the antenna, further comprising a top protective layer disposed above the conductive layers of the antenna and a bottom protective layer disposed below the conductive layers of the antenna, the top protective layer, the bottom protective layer, and the at least one insulating layer being made of a dielectric composite material.

Description

[Technical Field]

[0001] The present invention relates to a PCB design for providing an antenna module, in particular a PCB design for an antenna for use in communicating signals to (and optionally from) a driver of a lighting fixture. [Background technology]

[0002] Some designs of drivers for lighting fixtures include a metal outer casing, such as a metal linear driver housing. If an antenna is used to transmit a received radio signal (to control the lighting fixture's light source) to the driver, the metal housing will block the radio signal if the antenna is inside the metal housing. As a result, the antenna can only be placed outside the metal housing. However, because the antenna is treated as a live part, the antenna's bare printed circuit board (PCB) cannot be left exposed.

[0003] It is known to provide an antenna, such as a near field communication (NFC) antenna, as a separate module outside of a metal housing, with the antenna having its own plastic cover that enables the antenna to meet communication and approbation requirements.

[0004] 1 illustrates an antenna covered by a plastic cover 106. The antenna has a printed circuit board formed of conductive layers 102 disposed between insulating layers 104. If the antenna were not covered by the plastic cover 106, the top and bottom conductive layers 102 would be exposed to the environment.

[0005] However, the addition of a plastic cover not only increases the number of manufacturing steps, but also increases the overall cost of the LED driver.

[0006] Other options include the use of plastic shells, such as those used in radio frequency identification (RFID) antennas. Figure 2 illustrates an RFID antenna covered by a plastic shell 206. The conductive layers 202 of the RFID antenna are disposed between insulating layers 204. As with the previous example using a plastic cover, if the antenna were not covered by the plastic shell 206, the top and bottom conductive layers 202 would be exposed to the environment. Summary of the Invention [Problem to be solved by the invention]

[0007] However, adding a plastic shell not only increases the number of manufacturing steps but also increases the overall cost of the LED driver. Therefore, an improved antenna design is needed.

[0008] CN 204834882U discloses a chip-type NFC antenna.

[0009] US 20160205752A1 discloses a lighting device including a communication module including an antenna device.

[0010] EP 3576499A1 discloses a lighting driving device that includes a housing and a driving unit. [Means for solving the problem]

[0011] The invention is defined by the claims.

[0012] According to an example embodiment of the present invention, there is provided an antenna module having a multi-layer printed circuit board (PCB), the multi-layer PCB comprising: a conductive layer forming an antenna; at least one insulating layer between the conductive layers; a top protective layer overlying the conductive layer of the antenna; a bottom protective layer underlying the conductive layer of the antenna; an electrical connection to the antenna; An antenna module is provided in which the top protective layer, the bottom protective layer and the at least one insulating layer are made of a dielectric composite material, and the top protective layer and the bottom protective layer are intended to be exposed to the ambient environment around the antenna module.

[0013] The top and bottom protective layers act as protection for the antenna, not only serving to electrically insulate the antenna traces but also protecting the traces from the environment to which they are exposed.

[0014] Typically, wireless antennas are protected with a plastic cover (or a cover made from other non-metallic materials), however this solution not only increases the cost of the wireless antenna, but also adds an additional manufacturing step.

[0015] Forming the protective layers directly as part of the multi-layer PCB of the antenna module can reduce overall costs and improve manufacturing efficiency while ensuring proper function of the antenna. The top and bottom protective layers can be for protecting the conductive layers from the environment (e.g., moisture, dust, etc.).

[0016] By designing the top and bottom layers for exposure to the ambient environment, the antenna module is not intended to be placed within a device housing or its own housing; rather, the antenna module is intended for placement outside a device housing and is exposed to the ambient environment around the device incorporating the antenna module. In this manner, the cost of a cover for the antenna module is avoided and RF signal attenuation is prevented. The edges of the multilayer PCB of the antenna module are similarly exposed to the ambient environment.

[0017] The top protective layer preferably completely covers the top conductive layer of the antenna, and similarly, the bottom protective layer preferably completely covers the bottom conductive layer of the antenna.

[0018] Two-layer and four-layer radio antenna designs are well known to those skilled in the art. They are formed using two or more conductive layers of a multi-layer PCB separated by an insulating layer. Radio signals for reception or transmission by the antenna can pass through the top protective layer and the bottom protective layer.

[0019] The thickness of both the top protective layer and the bottom protective layer is, for example, greater than 0.05 mm, and therefore the top protective layer and the bottom protective layer are, for example, structural PCB layers (e.g., prepreg layers) rather than solder mask layers.

[0020] Using a dielectric composite material for the insulating layer and the protective layer improves manufacturing efficiency, as the addition of the protective layer can be achieved in the same way as the addition of the insulating layer (i.e., using conventional multilayer PCB manufacturing methods).

[0021] The dielectric composite material is electrically insulating and typically comprises a woven or nonwoven material such as resin-filled paper or fiberglass. The resin may be fully cured in the core / laminate layers or only partially cured in the prepreg layers.

[0022] The multilayer PCB may have an antenna portion that defines at least a portion of the antenna, and a hidden portion that defines the electrical connections.

[0023] The antenna portion of the PCB is intended to be exposed to the environment. This is possible with the addition of the top and bottom protective layers. Traditionally, the outer conductive layers of a PCB are only covered by a thin solder mask layer that does not adequately protect the conductive layers. The protective layers mean that the conductive layers are not exposed in the antenna portion.

[0024] The hidden part is intended to be used as a connector, so that when the antenna module is in use the electrical connections in the hidden part are not exposed to the outside environment, and may be shielded or covered, for example, by the main PCB of a luminaire driver.

[0025] The exposed vias between the conductive layers may be located in the hidden portion, which allows the vias to be hidden when the antenna module is connected to, for example, an LED driver. Multi-layer PCBs have vias between the conductive layers to electrically connect different conductive layers as needed.

[0026] The electrical connections may include a set of exposed conductive pads (eg, two exposed conductive pads).

[0027] The top protective layer, the bottom protective layer and the at least one insulating layer may be made of the same material.

[0028] Both the top and bottom protective layers may be prepreg layers. Prepreg layers are made of insulating materials commonly used as insulating layers between conductive traces in PCB manufacturing. These materials can also serve as protective layers for the conductive portions of the radio antenna, allowing it to still function as intended. These layers are formed as part of PCB manufacturing.

[0029] Four conductive layers may form the antenna, which may be a near field communication (NFC) antenna, and the antenna module may further include a structural support for providing mounting for the antenna module.

[0030] The present invention also provides a luminaire driver comprising a power supply for powering one or more light sources, a metal housing containing the power supply, an antenna module as defined above external to the metal housing, and a driver electrical connection between the antenna of the antenna module and the power supply.

[0031] This allows the power supply to be enclosed in the metal housing while still having access to wireless communication with the radio antenna.

[0032] In particular, conventional PCB materials can be used for the antenna module without the need for any further protection, since the top and bottom protective layers provide the necessary protection, e.g., for indoor use.

[0033] The luminaire driver is for example a linear LED driver.

[0034] The metal housing may include a metal chassis to which the power supply is mounted and a metal cover.

[0035] The present invention also provides a luminaire comprising a luminaire driver as defined above and one or more light sources powered by the power source of the luminaire driver.

[0036] The antenna portion of the antenna module of the luminaire driver is exposed to the ambient environment around the luminaire, and therefore no protective cover is provided on the antenna portion.

[0037] These and other aspects of the invention will be elucidated and elucidated with reference to the following embodiments. [Brief explanation of the drawings]

[0038] For a better understanding of the present invention, and to show more clearly how the same may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which: [Figure 1] 1 shows a prior art antenna covered by a plastic cover. [Figure 2] 1 shows a prior art RFID antenna covered by a plastic shell. [Figure 3] 1 shows a first example cross section of PCB layers within an antenna module. [Figure 4] 1 shows an example of a top view of an antenna module. [Figure 5] 1 shows a second example cross section of PCB layers within an antenna module. [Figure 6] Shows the antenna connected to an external PCB assembly. [Figure 7] 7 illustrates the electrical connection between the antenna of FIG. 6 and an external PCB assembly. [Figure 8] 1 shows a linear driver housing with a metal housing. [Figure 9] A close-up of the antenna in Figure 8 is shown. [Figure 10] FIG. 9 shows a side view of the linear driver housing of FIG. 8. [Figure 11] A close-up of the antenna in Figure 10 is shown. DETAILED DESCRIPTION OF THE INVENTION

[0039] The present invention will be described with reference to the drawings.

[0040] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the devices, systems, and methods, are for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the devices, systems, and methods of the present invention will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the figures to indicate the same or similar parts.

[0041] The present invention provides an antenna module having a multilayer printed circuit board (PCB) having conductive layers forming an antenna, at least one insulating layer between the conductive layers, and an electrical connection to the antenna, further comprising a top protective layer above the conductive layers of the antenna and a bottom protective layer below the conductive layers of the antenna, the top protective layer, the bottom protective layer, and the at least one insulating layer being made of a dielectric composite material.

[0042] Figure 3 shows a first example cross-section of PCB layers within an antenna module. The antenna module is formed with four conductive layers 302, three insulating layers 304 disposed between the conductive layers 302, a top protective layer 306, and a bottom protective layer 308. The conductive layers 302 are connected using through holes and vias that penetrate the insulating layers 304 to form the NFC antenna. Note that Figure 3 is intended to show the order of these layers. In reality, the conductive layers may not be exposed at the edges of the antenna.

[0043] As shown, the antenna module has an antenna portion 301 and a hidden portion 303, separated by a line 312 (which is for representational purposes only). The antenna portion 301 is intended to be exposed to the environment when the antenna module is in use, while the hidden portion 303 is intended to be connected to another PCB (e.g., an LED driver) to electrically connect the antenna module to the other PCB, and such that the hidden portion 303 where the electrical connection between the PCBs is made is not exposed to the outside.

[0044] In the example shown, hidden portion 303 has electrical connections 310 that are exposed to allow connection to another PCB. Once the connection to the other PCB is made, the electrical connections are no longer exposed outward to the surrounding environment.

[0045] The electrical connections 310 can be disposed above the top protective layer 306 and below the bottom protective layer 308. When the antenna module is connected to another PCB, the exposed electrical connections are no longer exposed to the environment. In another example, the protective layers 304 and 306 can be removed in the hidden portion 303 to expose the top and bottom conductive layers 302.

[0046] Of course, instead of exposing both the top and bottom conductive layers 302, it is possible to expose only a single conductive layer 302 above or below the protective layers 304 and 306. Any suitable connection may be used between the other PCB and the antenna PCB that ensures that electrical contact pads are not left exposed outward to the surrounding environment.

[0047] The protective layers 306 and 308 serve to protect the conductive layer 302 in the antenna portion 301. The protective layers 306 and 308 can be made of the same dielectric composite material as the insulating layer 304. Therefore, the protective layers 306 and 308 can be prepreg layers and / or core layers conventionally used in PCBs. This allows the use of existing processes in multilayer PCB manufacturing to add the protective layers 306 and 308, thereby simplifying the manufacturing process.

[0048] A variety of dielectric composite materials can be selected to provide different insulation values ​​depending on the requirements of the PCB. Well-known prepreg materials used in the PCB industry include FR-2 (phenolic cotton paper), FR-3 (cotton paper and epoxy), FR-4 (woven glass and epoxy), FR-5 (woven glass and epoxy), FR-6 (matte glass and polyester), G-10 (woven glass and epoxy), CEM-1 (cotton paper and epoxy), CEM-2 (cotton paper and epoxy), CEM-3 (non-woven glass and epoxy), CEM-4 (woven glass and epoxy), and CEM-5 (woven glass and polyester).

[0049] One or more of these dielectric composite materials may be used for the insulating layer 304 and the protective layers 306 and 308. Of course, other dielectric composite materials may be used depending, for example, on the required thickness, required dielectric constant, and / or required thermal expansion.

[0050] In an example, FR-4 prepreg layers are used for protective layers 306 and 308. Insulation layer 304 may have one or more copper clad cores (also called copper clad laminates) and one or more FR-4 prepreg layers. FR-4 grade materials are commonly used because of their flame retardant and self-extinguishing properties. However, the exact materials and resin proportions chosen may depend on the required dielectric constant and / or layer thickness.

[0051] Conductive layer 302 is conventionally made of copper and has a thickness of about 1 or 2 ounces. Of course, other conductive materials and thicknesses may be used.

[0052] In summary, FIG. 3 shows a six-layer PCB design (i.e., a PCB design with a total of six conductive layers) for an NFC antenna, where four of the conductive layers 302 form the antenna and the top and bottom conductive layers (layers 310) are exposed only in a hidden portion 303 of the six-layer PCB.

[0053] Figure 4 shows an example top-down view of an antenna module. In Figure 4, a portion of an antenna 408 is shown exposed in the antenna portion 402 of the antenna module. Line 403 represents the boundary between the antenna portion 402 and a hidden portion 404. The hidden portion 404 has two pads 410 and 412 (which, in this example, are on the same side of the antenna PCB) that allow the antenna 408 to be electrically connected to a different PCB. All vias 414 used to connect conductive layers within the antenna module PCB are located in the hidden portion 404 so that the vias 414 are hidden when the antenna module is connected to a different PCB.

[0054] The antenna module also has a structural support 406 for providing mounting support for the antenna module, which helps the antenna module remain attached to a different PCB when the antenna module is connected to another PCB (e.g., during manufacturing).

[0055] The other PCB may be a PCB assembly (PCBA) of a lighting fixture driver (e.g., an LED driver), and the antenna module may be attached to the PCBA of the LED driver to enable wireless NFC functionality.

[0056] The antenna module may be mounted so that the antenna is parallel to the LED driver PCBA (e.g., horizontally), or so that the antenna is vertical. For example, there may be a 90-degree angle between the plane of the LED driver PCBA and the plane of the antenna module PCB. For example, the LED driver may be intended for horizontal mounting and the antenna module may be intended for vertical mounting so that the radiation pattern spreads around the horizontal plane.

[0057] 5 shows a second example cross-section of PCB layers within an antenna module. Conductive layer 302 is separated by insulating layer 304. Protective layers 306 and 308 not only protect conductive layer 302 from the environment, but also protect the user from the conductive layer. In this example, sides 502 and 504 of the PCB are shown covered by insulating layer 304 and protective layers 306 and 308. Thus, the conductive layers on the sides of the PCB are protected from the environment, just like the top and bottom sides.

[0058] 6 shows an antenna 604 connected to an external PCB assembly (PCBA) 602. The antenna 604 is mounted at a right angle to the PCBA 602. The antenna portion 402 of the antenna is exposed to the environment, while the hidden portion 404 is embedded within and under the PCBA 602.

[0059] Figure 7 shows the electrical connection between the antenna 604 and the external PCBA 602 of Figure 6. Solder 702 is used to provide the electrical connection between the antenna 604 and the PCBA 602, which is connected to a conductive layer using vias 704.

[0060] Figure 8 shows a linear driver housing with a metal housing. Figure 9 shows a close-up of the antenna of Figure 8.

[0061] The linear driver housing has a PCBA 802 to which the power supply is attached. The PCBA 802 is attached to a metal chassis 806 of the metal housing and is covered by a metal cover 808 of the metal housing. A portion of the PCBA 802 is outside the metal housing. This allows an antenna module 804 to be connected to the PCBA 802 while still providing wireless NFC connectivity.

[0062] The antenna module 804 cannot be mounted inside a metal housing because this would prevent the antenna from communicating wirelessly with other antenna modules outside the metal housing.

[0063] Generally, the presence of an outer conductive layer in the antenna module 804 means that there are live parts exposed on the PCB of the antenna module, so some protection is required for the antenna module 804. In the conventional approach, a plastic cover is used to cover the antenna module 804. However, this increases manufacturing time and costs.

[0064] The inclusion of the aforementioned protective layers (layers 306 and 308 in FIG. 3) allows the bare antenna module PCB to be connected to the luminaire driver PCBA 802 without the need for an additional protective cover.

[0065] The hidden portion of the antenna module 804 may be placed under the PCBA 802 of the luminaire driver or may be plugged into a slot in the PCBA 802, in which case an electrical connection is made between the power source on the PCBA 802 and the antenna module 804.

[0066] For example, the electrical connections (layer 310 in FIG. 3) and all exposed vias in the antenna module 804 may be located in the hidden portion 404 of the antenna module 804 as shown in FIG.

[0067] The hidden portion of the antenna is received through a slot in the main PCBA, as shown in Figure 9. The structural support portions 406 are also received in respective slots in the main PCBA.

[0068] The hidden portion is then inserted through a receiving slot in PCBA 802 so that the electrical connections that need to be made to PCBA 802 are located on the underside of the PCBA.

[0069] The electrical connection between the antenna PCB and the main PCB may for example comprise connection pins (of a connector pin block) on one of the PCBs and connection slots (of a connector slot block) on the other of the PCBs. Any other suitable connection type may be used between the contacts of the antenna module and the contacts of the main PCB, such as a soldered connection or a wired connection or any suitable electrical or mechanical and electrical connector.

[0070] In all cases, the electrical connection between the antenna module and the PCBA is not exposed. The structural support 406 of the antenna module 804 is used to hold the antenna module in place during manufacturing. The antenna portion 402 (unobstructed by metal parts) provides the wireless connection.

[0071] Figure 10 shows a side view of the linear driver housing of Figure 8. Figure 11 shows a close-up of the antenna of Figure 10 with a portion of the chassis 806 cut away. The PCBA 802 can be mounted to the metal chassis 806, and a metal cover 808 covers the driver to form the linear driver housing. The metal cover 808 covers the power supply located on the PCBA 802.

[0072] As can be seen, the antenna module 804 is visible from the side of the linear driver housing and is not covered by metal. Therefore, the antenna module 804 can interact with another external antenna module (e.g., a mobile phone with an NFC antenna) to control the power supply of the linear driver housing. Notably, the antenna portion 402 of the antenna module 804 is not covered by metal parts. The hidden portion 404 is inserted into a slot in the PCBA 802 and protrudes from the bottom of the PCBA. However, this portion of the driver is shielded by the chassis and is therefore essentially protected from the environment.

[0073] The structural support 406 supports the antenna module when it is attached to the PCBA 802 .

[0074] In the example shown, the antenna module is perpendicular to the main PCB, e.g., the main PCB is parallel to the bottom of the housing (i.e., the chassis portion) and the antenna PCB stands perpendicular to the bottom of the housing. For example, the housing is horizontal and the antenna is vertical. However, the main PCB and the antenna PCB may extend in parallel planes, e.g., such that the main PCB overlaps the antenna PCB in the region of the hidden portion of the antenna PCB.

[0075] The antenna module 804 is used, for example, as part of an indoor lighting fixture, and no additional housing is required outside the antenna module.

[0076] Those skilled in the art can understand and effect variations to the disclosed embodiments in practicing the claimed invention, from a study of the drawings, the specification and the appended claims. In the claims, the word "comprises" does not exclude other elements or steps, and the singular does not exclude a plurality.

[0077] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0078] It should be noted that when the term "adapted to" is used in the claims or the specification, the term "adapted to" is intended to be equivalent to the term "configured to." It should be noted that when the term "configuration" is used in the claims or the specification, the term "configuration" is intended to be equivalent to the term "system," and vice versa.

[0079] Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. a power source for powering one or more light sources; a metal housing that houses the power supply; an antenna module located outside the metal housing; and a luminaire driver having a driver electrical connection between an antenna of the antenna module and the power source, The antenna module has a multi-layer PCB, the multi-layer PCB comprising: a conductive layer forming the antenna; at least one insulating layer between said conductive layers; a top protective layer overlying the conductive layer of the antenna; a bottom protective layer underlying the conductive layer of the antenna; and an electrical connection to the antenna; The luminaire driver, wherein the top protective layer, the bottom protective layer, and the at least one insulating layer are made of a dielectric composite material, and the top protective layer and the bottom protective layer are intended to be exposed to an ambient environment around the antenna module.

2. 2. The luminaire driver of claim 1, wherein the multi-layer PCB has an antenna portion that defines at least a portion of the antenna and a hidden portion that defines the electrical connections.

3. The luminaire driver of claim 2 , wherein exposed vias between the conductive layers are located in the hidden portion.

4. 4. A luminaire driver according to any one of claims 1 to 3, wherein the electrical connections comprise a set of exposed conductive pads.

5. 5. A luminaire driver according to any one of the preceding claims, wherein the top protective layer, the bottom protective layer and the at least one insulating layer are made of the same material.

6. 6. A luminaire driver according to any one of claims 1 to 5, wherein both the top protective layer and the bottom protective layer are prepreg layers.

7. 7. A luminaire driver according to any one of the preceding claims, comprising four conductive layers forming the antenna.

8. 8. A luminaire driver according to any one of claims 1 to 7, wherein the antenna is a short-range wireless communication antenna.

9. 9. A luminaire driver according to any preceding claim, further comprising a structural support for providing a mounting for the antenna module.

10. 2. The light fixture driver of claim 1, wherein the metal housing comprises a metal chassis in which the power supply is mounted and a metal cover.

11. A luminaire driver according to any one of claims 1 to 10; and one or more light sources powered by the power source of the luminaire driver.

12. 12. The lighting fixture of claim 11, wherein an antenna portion of the antenna module of the lighting fixture driver is exposed to the ambient environment around the lighting fixture.

13. 11. An antenna module adapted for a luminaire driver according to any one of claims 1 to 10, the antenna module comprising a multi-layer PCB, the multi-layer PCB comprising: a conductive layer forming the antenna; at least one insulating layer between said conductive layers; a top protective layer overlying the conductive layer of the antenna; a bottom protective layer underlying the conductive layer of the antenna; and an electrical connection to the antenna; the top protective layer, the bottom protective layer, and the at least one insulating layer are made of a dielectric composite material, and the top protective layer and the bottom protective layer are intended to be exposed to an ambient environment around the antenna module; the multilayer PCB having an antenna portion defining at least a portion of the antenna and a hidden portion defining the electrical connection; The antenna module wherein the exposed vias between the conductive layers are located in the hidden portion.

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