Led light source with lens and corresponding production method

• US 20020057057A1
• Filed: 10/22/2001
• Published: 05/16/2002
• Est. Priority Date: 04/22/1999
• Status: Active Grant

• Current Assignee: OSRAM GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Sorg, Jorg-Erich
• Granted Patent: US 6,759,803 B2
• Time in Patent Office: Days
• US Class Current: 313/512
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

The light source has an LED, preferably produced for the surface-mounting technique, embedded in a transparent material filling. A converter substance is integrated in the filling for the at least partial wavelength conversion of the light emitted by the LED. A lens is glued onto the transparent material filling. The material filling has a convex surface and the lens has a concave underside entering into a form fit with the convex surface of the material filling.

Claims

1. An LED light source, comprising:

a basic body formed with recess;

an LED disposed in said recess;

a filling of a transparent material embedding said LED and a converter substance in said transparent material for at least partially converting a wavelength of light emitted by said LED;

a lens in contact with said filling, said lens being prefabricated and having a definitively preformed concave underside and being placed on said material filling prior to a final curing of said material filling, whereby an upper side of said material filling enters into a form fit with said concave underside of said lens and has a convex surface formed by said underside of said lens.

2. The LED light source according to claim 1, wherein a volume of said filling is less than a free volume of said recess with said LED disposed therein.

3. The LED light source according to claim 1, wherein said convex surface of said filling and said underside of said lens are formed to have a substantially constant distance from said LED.

4. The LED light source according to claim 1, wherein said LED has an active radiating area and said convex surface of said filling and said underside of said lens are formed at a substantially constant distance from a geometrical center point of said active radiating area of said LED.

5. The LED light source according to claim 1, wherein said LED is a blue light-emitting LED based on GaN and said converter substance is configured to convert light radiation in a blue spectral range into light radiation in a yellow spectral range.

6. The LED light source according to claim 1, wherein said LED is a UV-emitting LED and said converter substance converts UV light into a visible spectral range.

7. The LED light source according to claim 1, wherein a distance of said convex surface from said LED is set such that a degree of conversion along an optical path length of the light radiation is substantially 50%.

8. The LED light source according to claim 1, wherein said LED has an active radiating area and a distance of said convex surface from a geometrical center point of said active radiating area is set such that a degree of conversion along an optical path length of the light radiation is substantially 50%.

9. The LED light source according to claim 1, wherein said LED is a surface-mounted component.

10. The LED light source according to claim 1, wherein said filling contains a resin material.

11. The LED light source according to claim 10, wherein said filling contains an epoxy resin.

12. The LED light source according to claim 1, wherein said basic body contains a thermoplastic material.

13. The LED light source according to claim 1, which further comprises:

a first leadframe carrying said LED at a first electrical contact area thereof;

a second leadframe connected to a second electrical contact area of said LED by a bond wire; and

wherein said basic body is produced by injection molding around said leadframes.

14. The LED light source according to claim 1, wherein said recess is defined by sloping and reflective side walls.

16. The method according to claim 15, wherein the filling step comprises filling the recess with a resin material.

15. A method of producing an LED light source, which comprises the following steps:

forming a recess with a planar bottom face in a basic body;

mounting an LED on the bottom face;

filling the recess with a defined amount of a transparent material containing converter material;

providing a lens with a concave underside;

inserting the lens with the concave underside into the still liquid transparent material; and

curing the transparent material.

17. An LED light source, comprising:

a basic body formed with recess;

an LED disposed in said recess;

a filling of a transparent material embedding said LED and a converter substance in said transparent material for at least partially converting a wavelength of light traveling through said filling, said filling having a convex upper surface defined by substantially equidistant points from said LED; and

a lens in contact with said filling and having a concave underside substantially complementary to said convex upper surface of said filling.