WO2021133369A1

WO2021133369A1 - Led element of a light-emitting array grid

Info

Publication number: WO2021133369A1
Application number: PCT/UA2020/000107
Authority: WO
Inventors: Виктор Григорьевич ПЕТРЕНКО; Сергей Александрович ЯКОВЕНКО
Original assignee: Виктор Григорьевич ПЕТРЕНКО
Priority date: 2019-12-24
Filing date: 2020-12-22
Publication date: 2021-07-01

Abstract

The invention relates to a light-emitting diode element of a light-emitting array grid. The technical result is an LED element that provides effective dissipation of the heat generated by an LED within a light-emitting array grid. This result is achieved in that an LED element (100) comprises a printed circuit board (PCB) (110) configured so that it can be positioned in the intersection between orthogonally arranged rectilinear metal wires (201a, 201b) for supplying energy to the PCB (110). The PCB (110) comprises a substrate (111) having a thermally conductive layer; a solid-state light source (120) in thermal contact with the thermally conductive layer; and terminal contacts (130a, 130b) of an electric power circuit of the solid-state light source (120) for connection to the two wires (201a, 201b), said terminal contacts comprising: a thermally conductive strip (131a, 131b) that is in heat contact with the thermally conductive layer and is configured for continuous contact with its respective wire throughout the length of the PCB (110), thus providing a heat channel from the heat-generating solid-state light source through the thermally conductive layer and the strip (131a, 131b) to said wire (201a, 201b). The possibility of positioning an LED element in the intersection between rectilinear mutually orthogonal metal wires results in an improvement in the thermal performance of such an LED element within a light-emitting array.

Description

LED element of a lattice light-emitting array

Technical field to which the utility model belongs

The present utility model relates to the field of LED lighting devices with a grid or mesh arrangement of electrical wires, and in particular to the light emitting element of a lattice LED array.

State of the art

There are a number of applications in which uniform illumination of a large surface area (from a few to several tens of square meters) is required with a relatively small thickness of the lighting device. These applications include lighting and / or lighting devices for ceilings or wall panels, light boxes, etc. In such lighting devices, it is especially advantageous to use light-emitting diodes (LEDs) in the form of LED elements of an ordered two-dimensional LED array located on forming a grid or a grid of electrical conductors to supply power to these LED elements.

Note - Throughout this document, when referring to a light emitting array, the term "LED element" is used to define a solid state light source as an element of such an array. Solid-state light sources are understood as light sources in which light is created through the recombination of electrons and holes. Examples of LED elements include LEDs, LED arrays, LED assemblies, together with a package or board and components on which they are located, or any other similar solid state light sources.

Particularly effective is the use of such an "optically transparent" LED array as an active feed of a passive reflecting surface, since it makes it possible to reduce the thickness of the device while maintaining the step between the array elements by lengthening the propagation path of the reflected light.

Note - In the context of this document, the term "optically transparent" should be understood as "transmitting at least a portion of the incident light radiation".

A number of patent sources disclose light emitting array designs for use in such lighting devices. Thus, a device for creating light effects is known (application for a utility model DE202005013148), in one of the embodiments of which LEDs are placed in the nodes of an orthogonal lattice,

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SUBSTITUTE SHEET (RULE 26) formed by strings of thin steel wire. The strings, in addition to securing the LEDs, also provide for the transmission of electric current through the LEDs, however, due to their low electrical and thermal conductivity, they significantly limit the power of the LEDs used.

Known is a projection lamp with an LED matrix panel (US patent for invention US6767112) containing an "optically transparent" LED array in the form of a plurality of LEDs on the surface of the panel, representing an orthogonal array of two layers of linear metal electrodes separated by a dielectric, and said electrodes also provide and dissipation of the heat generated by the LED. However, this solution may not be cost effective when used in large format LED arrays.

Also known is the LED array grid and LED component for use in it (LED array grid, method and device for manufacturing said grid and LED component for use in the same, US patent for invention US7942551), representing an "optically transparent" mesh LED an array in the form of a plurality of LED components mounted in the nodes of the wire mesh to power them, these LED components comprising LEDs mounted on printed circuit boards with locations provided for such mounting.

Note - With regard to the spatial structure of the electrical conductors feeding the LED array elements, the terms "mesh" and the term "lattice" as used herein refer to different ways of forming a cell assembly. For example, a pair of bent non-intersecting conductors in the form of two symbols> <forms a "mesh knot", respectively, a pair of straight cross wires in the form of a + symbol forms a "lattice knot".

The said LED components located at the nodes of the said mesh play, in the sense of mechanics, the role of connecting links between adjacent, alternately bent electrically conductive wires (wires) of the mesh, to which the tensile force of the mesh is transmitted. However, this circumstance limits the permissible magnitude of this force by the strength of such LED components. Since these wires acquire a zigzag shape as a result of stretching a set of initially even wires in the mesh, a limitation is imposed on their thickness (as a parameter that affects their rigidity and, accordingly, the amount of force required to bend them). A negative consequence of this circumstance may be ineffective heat dissipation generated by the LED, since the heat dissipation capacity of such a grid may be insufficient due to the limited thickness, and, accordingly, the cross-sectional area of the said wires, which, in turn, can worsen

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SUBSTITUTE SHEET (RULE 26) temperature mode of LED operation or require additional means for cooling the LED.

There are known lighting devices containing a similar LED array grid, in which solutions are applied that partially eliminate the above drawback by complicating the design, for example, improving the mechanical strength and heat dissipation ability of the wired lighting module by giving the LED array a three-dimensional topography and attaching such a three-dimensional structure to a heat sink (patent for invention US9395071), an increase in the LED mesh device for heat removal due to additional heat-conducting elements functioning in the LED-elements of the array as radiators (patent for invention US9841170), however, these designs are known in the art, in order to to carry out heat removal in LED arrays with an area of several units or tens of square meters may not be simple and durable enough, while requiring additional means of ensuring heat exchange.

The essence of the utility model

The task of the claimed utility model is to eliminate, or at least mitigate the disadvantages noted above. In particular, the object is to provide an LED element with improved thermal functionality for a large format light emitting array.

The technical result of the utility model is that an LED element is provided, which in a lattice light-emitting array effectively removes the heat generated by the LED.

The problem is solved by the fact that, in accordance with the utility model, the LED element of the lattice light-emitting array contains a printed circuit board (PCB) made with the possibility of placing between two metal electrically conductive wires (wires) to supply energy to the said PCB, while the said PCB contains:

- a substrate provided with at least one heat-conducting layer, and

- in thermal contact with said heat-conducting layer, a solid-state light source containing one or more LEDs, and

- the first and second terminal contact of the electric power circuit of the said solid-state light source for connection to, respectively, the first and second wires from among the two mentioned wires, and:

- said terminal contact, at least one, contains located in

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SUBSTITUTE SHEET (RULE 26) by thermal contact with said heat-conducting layer, a heat-conducting lamella made with the possibility of contacting the corresponding wire with the corresponding wire so that a heat channel is provided from the heat-generating said solid-state light source through said heat-conducting layer and said lamella to said wire, and

- the mentioned PP is made with the possibility of placement in the crosshair between the orthogonally located rectilinear said wires.

Due to the possibility of placing the PP LED element in the crosshair between rectilinear orthogonally located wires, it is possible to achieve almost complete elimination of the effect of the tensile force of these wires on it, which is absent with straight wires, but increases as their bending angle increases, which is characteristic of the wires of the mesh of the LED array of the known state of the art, and completely eliminate the need for the formation of such bends, and what, in the aggregate, prevent deformations of the LED element caused by bending and tension of the wires and remove the associated restrictions on the tensile force, thickness and cross-sectional area of the wires used (both parameters affecting on their rigidity and, accordingly, on the amount of force required to bend them). In addition, no electrical insulating coating of such wires is required (impairing their heat dissipation capacity and "optical transparency"), since the possibility of placing an LED element in a crosshair between orthogonally located electrically conductive wires allows to achieve reliable interwire insulation using a PP LED element. In general, the specified placement possibility removes the problem of limiting the heat-dissipating ability of the said wires - since, using wires of the proper cross-section in the corresponding lattice LED array, they can provide with their help a sufficient level of removal, transfer and dissipation in space of heat generated by the LED array elements. In addition, with such an arrangement, mechanical fixation of the LED element in the array can be achieved without additional components, only due to the tensile force of the mentioned cross wires. However, from the point of view of functionality, it may be preferable to add a clamping element to the terminal contact for pressing said wire to said lamella in order to ensure fixation of the LED element in the crosshairs of the wires, regardless of their tension, and which, in addition, can further improve their efficiency. thermal joint.

Due to the possibility of the length of the PP of contact contained in at least one terminal contact of the heat-conducting lamella with its counterpart

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SUBSTITUTE SHEET (RULE 26) metal wire (electrically conductive wire, usually copper), it is possible to achieve their effective thermal joint, the heat transfer of which is proportional to the area of the joint, determined, among other things, by the length of such contact, which is difficult to achieve in IDC contacts traditionally used for the LED array grid of the prior art. (Insulation Displacement Contact), characterized by the creation of an electrical connection at the edge of the blades that displaces (cuts through) the insulation of a thin contact. In addition, due to the aforementioned possibility of increasing the thickness of the wire, and, accordingly, increasing the area of the lateral surface, it is possible to additionally obtain an increase in the area of the joint due to the increase in its width. In addition, from the point of view of functionality, it may be preferable to have a groove in the lamella - a guide groove (saddle) for receiving the wire and accurately fixing the LED element, which, in turn, can also provide an increase in the width of the joint.

In general, the claimed utility model is based on the understanding that by using a properly designed heat-conducting lamella in the LED element and the interface between the terminals of the solid-state light source body and the heat-conducting layer, the heat-conducting layer and the heat-conducting lamella and between the heat-conducting lamella and the one used in the lattice LED- Array of heat and electrically conductive wire (wire) of the correct size, you can achieve effective heat dissipation from the heat-generating solid-state light source.

The claimed utility model is feasible for manufacturing, as it can be performed by cost-effective methods of mass production and assembly of printed circuit boards. Thus, the thermally conductive layer can be formed by a foil and / or an insulated metal substrate of the base material of the printed circuit board, in turn, the lamella can be part of such a base material, for example, a printed contact of a conductive pattern or a metal substrate, or a component mounted on a printed circuit board, which can be, for example, stamped from copper or copper alloy. The lamella can be made with a groove - a guiding groove (saddle) for receiving the wire, thereby providing accurate mechanical fixation of the wire and / or an additional reduced thermal resistance of the joint due to the increased surface area of the thermal contact. The clamping element, preferably, can be made in the form of a flat or shaped spring, stamped from a spring, preferably on a copper base, in the form of a sheet material or wire, alloy, and can be made as a component and mounted on a printed circuit board using standard PCB mounting methods , while several places of clamping, to improve its uniformity, can be

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SUBSTITUTE SHEET (RULE 26) created by one such spring or several such springs, or a component containing such a spring or springs.

These and additional tasks, features and advantages of the proposed utility model will be disclosed in detail in the following detailed description, the accompanying claims of the utility model, as well as shown in the drawings.

Brief Description of Drawings

The foregoing, as well as other objectives, features and advantages of the proposed utility model will be better understood due to the following illustrative and non-limiting detailed description of preferred embodiments of this utility model with reference to the accompanying drawings, in which:

1 illustrates a perspective view of a prior art LED array grid;

2a, b are schematic general views of one (some) embodiment of the utility model (views from a and b, respectively);

Fig. 3 schematically illustrates an exemplary application of the LED element shown in Fig. 3 above. 2, many of which are located at the crosshairs between the power wires and form a lattice LED array;

4 is a cross-sectional view of one (some) embodiment of the invention taken along the centerline of the lamella.

Detailed Description of Preferred Embodiments of the Utility Model

On figa, b schematically shows a LED element 100, where the indices -a, -b correspond to its views from opposite sides, containing, according to the first exemplary embodiment, a printed circuit board 110, on which a solid-state light source 120 is located, and, for connection to the wires for its power supply, terminal contacts 130, which contain heat-conducting lamellas 131 with clamping elements 132, and the terminal contacts are located on opposite sides of the board (130a and 1 ZOB, respectively) and are oriented so that their lamellas can be in long contact (131a and 131 b, respectively) with reciprocal straight-line cross wires (201a and 201b, respectively), which are also shown in FIGS. 2a, b (dash-dotted line, for reference).

Note - Here and hereinafter in the text and in the drawings, the same numbers refer to identical parts of the device, in addition, such numbers with indices a and b indicate the location of such parts on the corresponding side of the PCB. For example, both terminal contacts have a digital

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SUBSTITUTE SHEET (RULE 26) designation 130, while the terminal contact located on the side b is designated 1 0b, and if a pair of contacts is meant, then it is designated as 130a-b.

It should be noted that the solid state light source 120 is shown as two LEDs symmetrically positioned with respect to the lamellae, and that the pressure members 132a and 132b are shown as pairs of flat springs oriented centrally symmetrically to the lamellae, however, their design can be provided in many different ways, clear to the person skilled in the art. the field of technology.

Fig. 3 schematically shows an exemplary application of a plurality of such LED elements 100 (designation, for ease of reading of the drawing, is assigned only to one), which are enclosed between straight metal wires for power supply (201a and 20 lb - designations, for ease of reading the drawing, are assigned only one pair), arranged crosswise in two sets (200a and 200b, respectively) with a certain step, and thus formed a lattice LED array. It should be noted that FIG. is a simplified illustration of an example of the application of a plurality of LED elements shown in FIG. 2 and also in FIG. 4 below, and that various structures such as a wire retention and tensioning device, a power supply or a driver for activating the LED elements are not specifically indicated however, such constructions can be provided in many different ways, clear to the person skilled in the art.

In Fig. 4, an LED element 100 (shown above in Figs. 2a, b and Fig. H), in which the solid-state light source 120 consists of two LEDs mounted on a printed circuit board (PGI) 110, is shown in an axial section. a line transverse for lamella 131a, and, accordingly, longitudinal for lamella 13 lb, also installed on this PCB. Terminal contacts 1 30a-b, containing the aforementioned lamellas 131a-b together with the clamping elements 132a-b, are placed, respectively, on opposite sides (a, b) of the PP and are oriented crosswise to each other, which makes it possible to place this PP in a crosshair between two straight metal wires 201a-b for supplying electrical power.

The LED typically includes a light-emitting semiconductor chip 121 housing its body 122 and terminals 123 for electrical contact and heat dissipation. Said PCB 110 comprises a dielectric substrate 111 provided on both sides with sheets of copper (foil) 112. Typically, a conductive PCB pattern is etched from copper foil 112, while the dielectric substrate 111 provides electrical insulation between the conductor paths of the PCB electrical circuits, and the possibility

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SUBSTITUTE SHEET (RULE 26) of such insulation between crossed metal wires, the locations of which are indicated by a dash-and-dot line (201a and 20 lb). Copper foil 112 also forms a heat conductive layer located on both sides of the PCB 110, the area of which can be varied depending on the conductive pattern of the PCB as long as effective thermal contact is maintained between the LED terminals 123 and the lamellas 131a-b. Typical thickness of the heat-conducting copper layer is 35 micrometers, or multiples more, for example, 70 or 105 micrometers. In addition, although the thermally conductive layer in this embodiment of the utility model is formed by copper foil, in other embodiments it can also be formed by an insulated PCB metal substrate.

Leads 123 LED are mounted on the PCB 110 by soldering, and this provides it with electrical and thermal contacts, respectively, with the conductive pattern of the PCB and with the foil section constituting the heat-conducting layer of this PCB. The same is realized with respect to the heat-conducting lamellas 131a-b, which in this embodiment of the utility model are made in the form of stamped components made of copper or copper alloy, while, in order to ensure the possibility of an effective thermal joint with the metal wires 201a-b, they are made extended over the length of the PP ...

Although in the embodiment shown in Fig. 4, said lamellas are mounted on the PCB as components, they can also be made in the PCB itself from its base material, for example, in the form of a printed contact of a conductive pattern or in the form of a thermally conductive insulated metal substrate. provided with such a contact. As can be seen in the cross section, the heat-conducting lamellae 131, in accordance with one of the embodiments of the utility model, are made with a groove - a guide groove (saddle), thereby providing, in addition to simplifying the orientation of the mating wire, the possibility of obtaining a greater width of the said thermal joint, which additionally contributes to heat transfer.

The clamping elements 132 in this embodiment of the utility model are made in the form of = E-shaped springs, stamped from sheet material, typically from a spring alloy on a copper base and mounted on the PCB 110 by soldering, and spaced in pairs along the length of the lamella for a more even distribution of the clamping force the counter wire, thereby providing, in addition to the possibility of additional fixation of the LED element in the crosshairs of the wires, the possibility of improving the efficiency of heat transfer of the said thermal joint. The centrally symmetric orientation of the clamping elements 132a-b, shown above in FIGS. 2a, b and 3 and shown in FIG. 4 in cross-section, allows the replacement of the LED element 110 in the lattice LED array by a small

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SUBSTITUTE SHEET (RULE 26) rotation around the axis perpendicular to the plane PP 110 of the above-mentioned central symmetry, followed by an increase in the gap between the wires 201a-b and the removal of the LED element from the crosshair of the wires.

According to another embodiment of the invention, the clamping element 132 can be made in the form of a single spring having two clamping points spaced along the length of the lamella, and not in the form of a pair of springs shown in Fig. 4. In another embodiment, the pressing member 132 may be part of a PCB-mounted component containing such springs, it should be noted that FIG. contains a simplified illustration of an example of terminal contacts 130, and that various parts of their structure, for example, the connecting portions of the clamping elements 132 are not specifically indicated, however, their designs can be provided in many different ways, clear to the person skilled in the art.

In operation, the heat generated by the LED is conducted from its terminals 123 through the solder metal to the upper heat-conducting layer 112 and further, in the embodiment shown in FIG. 4, is transferred through the heat-conducting lamella 131a to the wire 201a and, to a lesser extent, through the dielectric layer. to the lower heat-conducting layer 112 and through the heat-conducting lamella 13 lb to the 20 lb wire, and then from the wires 201a and 20 lb is dissipated into the environment.

It should be noted that the possibility of replacing the LED element 100 in a lattice LED array, based on the absence of the tensile effect of wires on such an LED element and described above in one (some) embodiment of the utility model, can also be provided with a different design of the clamping elements 132, for example, with a mirror-symmetrical arrangement of the springs, it is possible to replace by two, along the axis of each of the wires 201a-b, displacements of the LED element 100, with a subsequent increase in the gap between the wires 201a-b and removing this LED element from the crosshairs of these wires.

The utility model has been largely described above with reference to several embodiments. These options for implementation should be considered only as non-limiting examples. However, as is readily understood by a person skilled in the art, other embodiments other than those disclosed above are equally possible within the scope of the invention as defined by the appended claims. It should be noted that for the purpose of its application and, in particular, in relation to the attached utility model claims, the word "containing" does not exclude

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SUBSTITUTE SHEET (RULE 26) other constituents, and "one" or "some" does not exclude a plurality, which in itself will be obvious to a person skilled in the art.

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SUBSTITUTE SHEET (RULE 26)

Claims

Utility model formula

1.LED-element of a lattice light-emitting array containing a printed circuit board (PCB) made with the possibility of placing between two metal electrically conductive wires (wires) for supplying energy to said PCB, wherein said PCB contains:

- a substrate provided with at least one heat-conducting layer, and

- the first and the second terminal contact of the electric power circuit of the said solid-state light source for connection to, respectively, the first and second wires from among the mentioned two wires, wherein:

- said terminal contact, at least one, comprises a heat-conducting lamella in thermal contact with said heat-conducting layer, made with the possibility of extending the length of the PP in contact with the corresponding said wire so that a heat channel is provided from the heat-generating said solid-state light source through said a heat-conducting layer and said lamella to said wire, and

2. LED element according to claim 1, characterized in that said lamella is a component made of copper or copper alloy, mounted on said PCB.

3. LED element according to claim 1, characterized in that said lamella comprises a groove (saddle) for receiving a wire.

4. LED element according to claim 1, characterized in that the base material of said PCB is an insulated metal substrate or a foil-clad dielectric.

5. LED element according to claim 4, characterized in that said lamella is part of the base material of said PCB.

6. LED element according to claim 5, characterized in that said lamella is a printed contact of said PCB.

7.LED element according to claim 1, characterized in that said terminal contact, at least one, comprises a pressing element for pressing said wire to said lamella, which is a component mounted on said PCB, or a part of such a component, or consisting of such components.

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SUBSTITUTE SHEET (RULE 26)