COATED LIGHT EMITTING DEVICE AND METHOD FOR COATING THEREOF

• US 20110175117A1
• Filed: 09/21/2009
• Published: 07/21/2011
• Est. Priority Date: 09/25/2008
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Jagt, Hendrik J. B., Kleynen, Christian, Weijers, Aldegonda L.
• Granted Patent: US 8,957,428 B2
• Time in Patent Office: Days
• US Class Current: 257/88
• CPC Class Codes: H01L 2224/0554 External layer
• CPC Class Codes: H01L 2224/0555 Shape
• CPC Class Codes: H01L 2224/0556 Disposition
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• 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

Abstract

The present invention relates to the field of a light emitting device (1), comprising a light emitting diode (2) arranged on a submount (3), said device having a lateral circumference surface (6) and a top surface (8), and an optically active coating layer (7), said coating layer (7):

• • covering along at least a part of said circumference surface (6),
  • extending from the submount (3) to said top surface (8), and
  • essentially not covering the top surface (8). A method for producing the device is also disclosed.

Claims

1. A light emitting device comprising a light emitting diode arranged on a submount, said device having a lateral circumference surface and a top surface, and an optically active coating layer, said coating layer:

covering along at least a part of said circumference surface,

extending from the submount to said top surface, and

essentially not covering the top surface.

2. A light emitting device according to claim 1, wherein said optically active coating layer is selected from the group consisting of:

reflective, diffusing, spectrally filtering, luminescent, and light blocking coating layers, and combinations thereof.

3. A light emitting device according to claim 1, further comprising an optical component arranged on said light emitting diode, selected from the group consisting of:

a phosphor body, a light transmissive body and a reflecting body, and combinations thereof.

4. A light emitting device according to claim 3, wherein said reflecting body is arranged so that the light will escape through at least a part of the lateral circumference surface.

5. A light emitting device according to claim 1 further comprising an optical component arranged on said light emitting device.

6. A light emitting device according to claim 1 wherein said coating layer is solid.

7. A light emitting device according to claim 1, wherein said at least part of said lateral circumference surface is coated by more than one coating layer.

8. An array of light emitting devices according to claim 1.

9. An array of light emitting devices according to claim 8, wherein said light emitting devices are arranged to share said coating layer.

10. A method for applying a coating layer on at least a part of a lateral circumference surface of a light emitting device comprising a light emitting diode, said method comprising:

arranging an optically active coating layer on at least a part of said circumference surface, said coating layer extending from the submount to said top surface, and essentially not covering the top surface.

11. A method according to claim 10, further comprising the steps of;

applying a first liquid coating composition on said submount,

allowing said first coating composition to cover at least part of a first lateral circumference surface of said light emitting device, and

solidifying said first coating composition to obtain a first solid coating layer on said at least part of said first lateral circumference surface.

12. A method according to claim 11, wherein said coating composition by capillary force is allowed to cover at least part of a first lateral circumference surface.

13. A method according to claim 10, wherein said coating composition is applied by a method selected from the group of by needle dispense, nozzle dispense, by printing and by spraying.

14. A method according to claim 11, wherein said liquid coating composition upon solidification forms a solid coating layer selected from the group of reflective, diffusing, spectrally filtering, luminescent, and light blocking coating layers, and combinations thereof.

15. A method according to claim 11, wherein said coating composition comprises a sol-gel derived material or a silicone resin.

16. A method according to claim 11, further comprising pre-treating said lateral circumference surface to become polar, and using a polar coating composition.

17. A method according to claim 11, further comprising pre-treating said lateral circumference surface to become apolar, and using an apolar or polar coating composition.

18. A method according to claim 11, further comprising the steps of;

applying at least a second liquid coating composition on said submount,

allowing said second coating composition to cover at least part of a second lateral circumference surface of said light emitting device, and

solidifying said second coating composition to obtain a second solid coating layer on said at least part of said second lateral circumference surface.

19. A method according to claim 18, wherein said first coating composition is different from said second coating composition.

20. A method according to claim 18, wherein said first lateral circumference surface is different from said second lateral circumference surface.