Light-emitting diode including a plurality of luminescent regions

Abstract

Various embodiments may relate to A light-emitting diode, including an LED chip having at least one emitter surface for emitting primary light, and a plurality of luminescent regions, which are connected optically downstream from the at least one emitter surface. At least one harder one of the luminescent regions is embedded in another, softer one of the luminescent regions.

Claims

1. A light-emitting diode, comprising: an LED chip comprising at least one emitter surface for emitting primary light; and a plurality of luminescent regions, which are connected optically downstream from the at least one emitter surface, wherein a first luminescent region consists of a ceramic material, and a second luminescent region comprises a plastic matrix material having at least one phosphor embedded thereon and/or therein; and wherein the second region is embedded in the first region; and wherein the first luminescent region and the second luminescent region contact a front side of the LED.

2. A light-emitting diode, comprising: an LED chip comprising at least one emitter surface for emitting primary light, and a plurality of luminescent regions, which are connected optically downstream from the at least one emitter surface, wherein at least one harder luminescent region of the luminescent regions is embedded in another, softer luminescent region of the luminescent regions; wherein the at least one harder one of the luminescent regions consists of ceramic and wherein the at least one harder luminescent region and the softer luminescent region contact a front side of the LED.

3. The light-emitting diode as claimed claim 2, wherein the softer one of the luminescent regions comprises a matrix material made of plastic, which is admixed with at least one phosphor as a filler material.

4. The light-emitting diode as claimed in claim 2, wherein the luminescent regions are arranged adjacent to one another in a light path of the primary light.

5. The light-emitting diode as claimed in claim 4, wherein the luminescent regions represent regions of a luminescent lamina and cover an emitter surface of the LED chip.

6. The light-emitting diode as claimed in claim 5, wherein the at least one harder one of the luminescent regions is laterally enclosed by the other, softer one of the luminescent regions.

7. The light-emitting diode as claimed in claim 2, wherein the harder one of the luminescent regions has the basic form of a circular disk.

8. The light-emitting diode as claimed in claim 2, wherein the primary light is blue light, the harder one of the luminescent regions converts the blue primary light at least partially into green to yellow light and the softer one of the luminescent regions converts the blue primary light at least partially into red light.

9. The light-emitting diode as claimed in claim 2, wherein the softer one of the luminescent regions has been produced by a printing method.

10. The light-emitting diode according to claim 2, wherein the softer one of the luminescent regions has been produced by a casting method.

11. The light-emitting diode according to claim 2, wherein the at least one harder luminescent region is disposed on a middle of the front side of the LED.

12. The light-emitting diode according to claim 11, wherein the softer luminescent region is laterally disposed around the at least one harder luminescent region.

13. The light-emitting diode according to claim 12, wherein the at least one harder luminescent region is substantially circular.

14. The light-emitting diode according to claim 2, wherein the at least one harder luminescent region and the softer luminescent region are substantially the same height.

15. The light-emitting diode according to claim 2, wherein the at least one harder luminescent region contacts the softer luminescent region.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the disclosed embodiments. In the following description, various embodiments described with reference to the following drawings, in which:

(2) FIG. 1 shows a sectional illustration in a side view of a light-emitting diode according to various embodiments;

(3) FIG. 2 shows the light-emitting diode according to various embodiments in a top view; and

(4) FIGS. 3A-3B show a sequence of a first method for producing a luminescent lamina of the light-emitting diode according to various embodiments; and

(5) FIG. 4 shows a sequence of a second method for producing a luminescent lamina of the light-emitting diode according to various embodiments.

DETAILED DESCRIPTION

(6) The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and aspects of this disclosure in which the invention may be practiced.

(7) FIG. 1 shows a sectional illustration in a side view of a light-emitting diode 11 having an LED chip 12, which has a rear support surface 13 and a front side 14 having an emitter surface 15, which emits primary light forward or upward (top LED). The LED chip 12 thus emits into a front half-space. The primary light may be blue light, for example.

(8) A luminescent lamina 16, which completely covers the emitter surface 15, rests on the front side 14. As is also apparent in a top view from FIG. 2, the luminescent lamina 16 has two luminescent regions, namely a circular first luminescent region 17 made of ceramic phosphor and a second luminescent region 18 made of plastic matrix material, in particular silicone, filled with phosphor powder. The two luminescent regions 17 and 18 have an at least essentially equal height. The first (harder) luminescent region 17 is arranged in the middle in relation to a longitudinal axis L of the light-emitting diode 11, while the second (softer) luminescent region 18 laterally encloses the first luminescent region 17. The first luminescent region 17 is therefore laterally embedded in the second luminescent region 18.

(9) In operation of the LED chip 12, primary light emitted from the emitter surface 15 is radiated both into the first luminescent region 17 and converted therein, for example, at least partially into green light and also radiated into the second luminescent region 18 and converted therein, for example, at least partially into red light. The luminescent regions 17, 18 are thus connected optically downstream from the emitter surface 15 and arranged adjacent to one another in a light path of the primary light. A red-green-blue or warm white mixed light is thus emitted overall at high efficiency from the luminescent lamina 16. Due to the lateral separation of the luminescent regions 17, 18, the mutual influence thereof is kept low.

(10) FIG. 3A shows a step of a first method for producing the luminescent lamina 16 by a printing method. In this step, a plurality of prefinished first luminescent regions 17 in the form of luminescent ceramic laminae in the shape of circular disks are placed in a mask 19.

(11) In a following step, the mask 19 having the first luminescent regions 17 located therein is printed, specifically using the still viscous material of the second luminescent region 18. The material of the second luminescent region 18 is thus filled in the free lateral intermediate spaces between the mask 19 and the first luminescent regions 17.

(12) After curing of the material of the second luminescent region 18, the mask 19 is removed, whereby the finished luminescent laminae 16 are isolated, as shown in FIG. 3B.

(13) The luminescent laminae 16 can thereafter be applied to the LED chip 12, for example, glued on.

(14) FIG. 4 shows a step of a second method for producing the luminescent lamina 16, specifically by a casting method.

(15) During the casting method, the first luminescent region 17 is placed in a casting mold 19 and then embedded using the material of the second luminescent region 18, here: up to an upper edge of the first luminescent region 17, but not covering the emitter surface 15.

(16) While the disclosed embodiments have been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosed embodiments as defined by the appended claims. The scope of the disclosed embodiments is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.

LIST OF REFERENCE SIGNS

(17) 11 light-emitting diode 12 LED chip 13 rear support surface 14 front side 15 emitter surface 16 luminescent lamina 17 first luminescent region 18 second luminescent region 19 mask 20 casting mold L longitudinal axis