Light-source module and light-emitting device

Abstract

A light-emitting module (3a-c; 23; 26; 33a-c) comprising a plurality of light-sources (12a-e; 27a-h) arranged in at least a first and a second column (18a-b; 28a-c) arranged side by side and extending along a first direction of extension (X.sub.1) of the light-emitting module (3a-c; 23; 26; 33a-c); and a plurality of connector terminal pairs (13a-b, 14a-b, 15a-b, 16a-b 17a-b), each being electrically connected to a corresponding one of the light-sources (3a-c; 23; 26; 33a-c) for enabling supply of electrical power thereto. Each connector terminal pair (13a-b, 14a-b, 15a-b, 16a-b 17a-b) comprises a first connector terminal (13a, 14a, 15a, 16a 17a) and a second connector terminal (13b, 14b, 15b, 16b 17b) being arranged at opposite sides of the light-emitting module (3a-c; 23; 26; 33a-c). The light-sources (12a-e; 27a-h) are arranged in a predetermined light-source sequence along the first direction of extension (X.sub.1) of the light-emitting module (3a-c; 23; 26; 33a-c), and the connector terminal pairs (13a-b, 14a-b, 15a-b, 16a-b 17a-b) being electrically connected to the corresponding light-sources (12a-e; 27a-h) are arranged in the predetermined light-source sequence along the first direction of extension (X.sub.1) of the light-emitting module.

Claims

1. A light-emitting module, comprising: a substrate having a top and a bottom, and further having a first side extending in a first direction from a first end of the substrate to a second end of the substrate, and a second side opposite the first side also extending in the first direction from the first end of the substrate to the second end of the substrate; a plurality of light-sources arranged on the top of the substrate, including a plurality of first light-sources aligned with each other in a first column and a plurality of second light-sources aligned with each other in a second column, each of which columns extends along the first direction, wherein the first and second columns are side by side, separated and spaced apart from each other in a second direction which is orthogonal to the first direction, the second direction extending from the first side of the substrate to the second side of the substrate; a plurality of connector terminal pairs, each being electrically connected to a corresponding one of said plurality of light-sources for enabling supply of electrical power thereto, each connector terminal pair comprising a first connector terminal disposed immediately adjacent to the first side of the substrate and a second connector terminal disposed immediately adjacent to the second side of the substrate; and at least one bond wire, the bond wire connecting at least one of the light sources to one connector terminal of its corresponding connector terminal pair, wherein none of said first light-sources of the first column is aligned with any of the second light sources of the second column along the second direction, and wherein the connector terminal pairs are arranged to provide for spatially alternating connection of the corresponding light sources to positive and negative voltages along the first direction on each of the first and second sides of the substrate.

2. The light-emitting module of claim 1, wherein each of said plurality of light-sources is individually controllable.

3. The light-emitting module of claim 1, wherein said plurality of light-sources are configured to emit light of mutually different primary colors.

4. The light-emitting module of claim 1, wherein the substrate has a conductor pattern formed thereon, the conductor pattern being configured to interconnect each of said light-sources with at least one of said first connector terminal and said second connector terminal of the connector terminal pair corresponding to the light-source.

5. The light-emitting module of claim 4, wherein a portion of said conductor pattern interconnecting one of said first light-sources arranged in said first column with said first or second connector terminal passes between two mutually adjacent second light-sources arranged in said second column.

6. The light-emitting module of claim 5, wherein the bond wire connects the one of the first light sources arranged in the first column to the first or second connector terminal which is connected to the one of the first light sources by the portion of the conductor pattern which passes between the two mutually adjacent second light-sources arranged in said second column.

7. The light-emitting module of claim 1, wherein said plurality of light-sources are arranged in such a way that there is an unpopulated portion surrounded by at least some of the light-sources for facilitating automated mounting of the light-emitting module.

8. The light-emitting module of claim 7, wherein said unpopulated portion has an area corresponding at least to one half of an area occupied by one of said plurality of light-sources.

9. The light-emitting module of claim 1, wherein a ratio between a luminous area of the light-emitting module and a total surface area of the light-emitting module is greater than 25%.

10. The light-emitting module of claim 1, wherein each of the plurality of light sources is configured to receive the electric power directly from its corresponding terminal pair.

11. A device comprising a plurality of light-emitting modules, wherein each of the light-emitting modules comprises: a plurality of light-sources arranged in at least a plurality of first light-sources aligned with each other in a first column and a plurality of second light-sources aligned with each other in a second column, each of which columns extends along a first direction of the light-emitting module, wherein the first and second columns are side by side, separated and spaced apart from each other in a second direction which is orthogonal to the first direction, wherein the second direction extends from a first side of the light-emitting module to a second side of the light-emitting module; and a plurality of connector terminal pairs, each being electrically connected to a corresponding one of said plurality of light-sources for enabling supply of electrical power thereto, each connector terminal pair comprising a first connector terminal disposed immediately adjacent to the first side of the light-emitting module and a second connector terminal disposed immediately adjacent to the second side of the light-emitting module such that the first and second connector terminals do not overlap each other, wherein the first light-sources of the first column are at least partially offset in the first direction with respect to the second light-sources of the second column, wherein the connector terminal pairs are arranged to provide for connection of the corresponding light sources to positive and negative voltages which spatially alternate with each other along the first direction on each of the first and second sides of the light-emitting module, and wherein the light-emitting modules are electrically connected to each other via said connector terminal pairs.

12. The device of claim 11, further comprising a heat-dissipating structure arranged in thermal connection with said light-emitting modules.

13. The device of claim 12, wherein said heat-dissipating structure is mechanically structured to define the positions of the light-emitting modules relative to each other.

14. The device of claim 11, further comprising: a tubular reflector arranged to receive light emitted by the plurality of light-sources.

15. The device of claim 11, wherein each of the light-emitting modules further comprises at least one bond wire, the bond wire connecting at least one of the plurality of light sources to one connector terminal of its corresponding connector terminal pair.

16. The device of claim 11, wherein the light-emitting modules are electrically connected to each other via bond wires between the connector terminal pairs.

17. A light-emitting module, comprising: a plurality of light-sources each having a top surface and a bottom surface, including a plurality of first light sources arranged in a first column and a plurality of second light sources arranged in a second column, each of which columns extends along a first direction of said light-emitting module; a plurality of connector terminal pairs, each being electrically connected to a corresponding one of the plurality of light-sources and further being configured to receive a supply of electrical power directly from outside of the light-emitting module, each connector terminal pair comprising a first connector terminal and a second connector terminal being disposed at opposite sides of the light-emitting module with respect to each other; and a plurality of bond wires each connecting a top surface of a corresponding one of the plurality of light-sources to the first connector terminal of the corresponding connector terminal pair, wherein the connector terminal pairs are arranged to provide for spatially alternating connection of the corresponding light sources to positive and negative voltages along the first direction on each of the opposite sides of the light-emitting module.

18. The light-emitting module of claim 17, further comprising a substrate on which the plurality of light-sources are arranged, wherein the substrate has a conductor pattern formed thereon, the conductor pattern being configured to interconnect each of said plurality of light-sources with the second connector terminal of the connector terminal pair corresponding to the light-source without including any bond wire, wherein a portion of said conductor pattern interconnecting one of said first light-sources arranged in said first column with said connector terminal passes between two mutually adjacent second light-sources arranged in said second column.

19. The light-emitting module of claim 17, wherein none of said first light-sources of the first column is aligned with any of the second light sources of the second column along the second direction.

20. The light-emitting module of claim 17, wherein the opposite sides of the light-emitting module comprise a first side of the light-emitting module and a second side of the light-emitting module opposite the first side, and wherein the first connector terminal is disposed immediately adjacent to the first side of the light-emitting module and the second connector terminal is disposed immediately adjacent to the second side of the light-emitting module.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing an exemplary embodiment of the invention, wherein:

(2) FIG. 1 is an exploded view of an illumination system according to an embodiment of the present invention;

(3) FIG. 2 is a perspective view of three light-emitting modules according to an embodiment of the present invention being interconnected in a tiled configuration;

(4) FIGS. 3a-b schematically illustrate two further embodiments of the light-emitting module according to the present invention; and

(5) FIG. 4 schematically illustrates positioning of the light-emitting modules using a structured heat-dissipating structure.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

(6) In the following description, the present invention is described with reference to an illumination system comprising light-emitting devices formed by a plurality of light-emitting modules being arranged side-by-side and electrically interconnected using bond wires that interconnect connector terminals in the form of bond pads located on the top side of the light-emitting modules.

(7) It should be noted that this by no means limits the scope of the invention, which is equally applicable to many other light-emitting module configurations and interconnections between light-emitting modules comprised in a light-emitting device. For example, the connector terminals may be provided on the sides of the light-emitting modules or on the bottom side of the light-emitting modules. In particular in the case when the connector terminals are located on the sides of the light-emitting modules, the electrical interconnection between adjacent light-emitting modules may be achieved by forming solder bridges. Such solder bridges may be formed simultaneously with attaching the light-emitting modules to their carrier, which may be a heat-dissipating structure.

(8) FIG. 1 is an exploded view schematically illustrating an illumination device for spot illumination suitable for atmosphere creating lighting, such as scene setting. The illumination device 1 comprises a light-emitting device 2 comprising a plurality of light-emitting modules 3a-c (only a few of the light-emitting modules have been assigned reference numerals for the sake of clarity of drawing), a heat-dissipating structure 4, a tubular reflector 5 and a diffuser 6.

(9) The light-emitting device 2 is a scalable system formed by a plurality of light-emitting modules 3a-c arranged side-by-side and interconnected with non-crossing electrical connections along the sides thereof. Through this configuration, a light-emitting device having a high production yield in combination with a high ratio between luminous area and total area can be achieved.

(10) These and further advantageous properties of the light-emitting device are provided through the light-emitting module 3a-c according to various embodiments of the present invention.

(11) Turning to FIG. 2, the light-emitting modules 3a-c in FIG. 1 are shown in more detail (only the center light-emitting module 3b will be discussed in detail below for the sake of clarity). In the exemplary embodiment that is schematically illustrated in FIG. 2, the light-emitting module 3b comprises a substrate 10, a conductor pattern 11 formed on the substrate 10 and five individually controllable LEDs 12a-e attached to the substrate 10 and electrically connected to the conductor pattern 11. The LEDs 12a-e are configured to emit light of the mutually different primary colors blue (B) (12a), cyan (C) (12b), red (R) (12c), green (G) (12d), and deep red (dR) (12e), and the conductor pattern 11 defines corresponding connector terminal pairs 13a-b, 14a-b, 15a-b, 16a-b and 17a-b. As can be seen in FIG. 2, the LEDs 12a-e are arranged in two columns 18a-b arranged side-by-side and extending along a first direction x.sub.1 of extension of the light-emitting module 3b. The columns 18a-b are offset relative each other in such a way that the LEDs 12a-e are arranged in the light-source sequence 12a/B, 12b/C, 12c/R, 12d/G, and 12e/dR along the first direction x.sub.1 of extension of the light-emitting module, and the corresponding connector terminal pairs 13a-b, 14a-b, 15a-b, 16a-b and 17a-b are arranged in the same sequence.

(12) As can be understood by studying FIG. 2, this arrangement in two columns 18a-b and in sequence of the LEDs 12a-e, and configuration of the conductor pattern 11 to define connector terminal pairs 13a-b, 14a-b, 15a-b, 16a-b and 17a-b in the same sequence results in light-emitting modules 3a-c that are easy to arrange side-by-side and electrically interconnect without crossing connecting conductors. Furthermore, the routing of the conductor pattern 11 is simplified and allows for a high ratio between luminous area and total area for the light-emitting modules 3a-c. Moreover, the connections between the LEDs 12a-e and the connector terminal pairs 13a-b, 14a-b, 15a-b, 16a-b and 17a-b can be achieved using a single conductive pattern arranged on the substrate, which allows for very efficient conduction of heat away from the LEDs 12a-e through the substrate 10 towards the heat-dissipating structure 4 (FIG. 1).

(13) In the presently illustrated example, the substrate is a ceramic substrate and the LEDs are provided as naked dies. Furthermore, the LEDs 11a-e are electrically connected to the conductor pattern 11 through a bottom connector (not visible in FIG. 2) and bond wires, and the light-emitting modules 3a-c are electrically interconnected using bond wires.

(14) It should, however, be noted that the substrate may be any other suitable substrate, such as a substrate made of AlN, AlOx or Si, and that one or several of the LEDs may be packaged.

(15) FIGS. 3a-b schematically illustrate two further embodiments of the light-emitting module according to the present invention.

(16) Turning first to FIG. 3a, the exemplary light-emitting module 23 that is schematically illustrated therein differs from the light-emitting module 3b shown in FIG. 2 in that the LEDs 12a-e have been arranged with their top side connections facing away from the sides of the light-emitting module 23, and in that the conductor pattern 11 has been modified accordingly. Hereby, the bond wire connections are distanced from the connector terminals 13a-b, 14a-b, 15a-b, 16a-b and 17a-b, which facilitates protection of the bond wires using glob top or similar (not shown in FIG. 3a) while still allowing testing of the light-emitting module 23 through probing of the connector terminals 13a-b, 14a-b, 15a-b, 16a-b and 17a-b after as well as before the application of glob-top.

(17) FIG. 3b schematically illustrates another exemplary light-emitting module 26 on which eight LEDs 27a-h are arranged in three columns 28a-c. The LEDs 27a-h are provided in individually controllable sets of LEDs configured to emit light of mutually different primary colors. As is indicated in FIG. 3b, four of the LEDs 27a, 27c, 27f, and 27h are configured to emit green (G) light, two of the LEDs 27b and 27g are configured to emit blue (B) light, one of the LEDs 27d is configured to emit red (R) light and one of the LEDs 27e is configured to emit deep red (dR) light.

(18) As can be seen in FIG. 3b, some of the LEDs that are configured to emit light having the same color are connected to each other and together form an individually controllable set of light-sources. The individually controllable sets of light-sources in the embodiment in FIG. 3b are green (G) LEDs 27a and 27f, red (R) LED 27d, blue (B) LEDs 27b and 27g, deep red (dR) LED 27e and green (G) LEDs 27c and 27h.

(19) Furthermore, the LEDs 27a-h in the exemplary light-emitting module 26 in FIG. 3b are arranged in such a way that there is an unpopulated portion 30 surrounded by LEDs 27a-h for facilitating mounting of the light-emitting module 26. In particular, a pick-and-place tool can pick up the light-emitting module 26 at the unpopulated portion 30.

(20) For optimum quality of the light output by the illumination device 1 in FIG. 1 in respect of such factors as color mixing and uniformity, the light-emitting device(s) 2 comprised therein should be positioned accurately at least in relation to each other and advantageously also in relation to the tubular reflector 5.

(21) FIG. 4 schematically illustrates a light-emitting device according to an embodiment of the present invention, comprising a heat-dissipating structure 32 that is structured so as to define the positions of the light-emitting devices 33a-c, each comprising a plurality of interconnected light-emitting modules, in relation to each other and to the printed circuit board (PCB) 34 used for connecting the light-emitting device 33a-c to external power.

(22) As is schematically indicated in FIG. 4, the heat-dissipating structure 32 is provided with a number of relatively shallow recesses 35a-c for accommodating the light-emitting devices 32a-c and a relatively deep recess 36 for accommodating the PCB 34, which, in the exemplary embodiment that is shown in FIG. 4, is considerably thicker than the light-emitting devices 32a-c. By fitting the light-emitting devices 32a-c and the PCB 34 in the respective recesses 35a-c, 36, the light-sources comprised in the light-emitting devices 32a-c can be positioned accurately and reliably in relation to each other and to the PCB 34.

(23) Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage.