FRAME BASED PACKAGE FOR FLIP-CHIP LED

• US 20170301841A1
• Filed: 07/01/2017
• Published: 10/19/2017
• Est. Priority Date: 09/13/2013
• Status: Abandoned Application

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Inventors: Stockman, Stephen Andrew, de Samber, Marc Andre, Shchekin, Oleg Borisovich, Sweegers, Norbertus Antonius Maria, Haque, Ashim Shatil, Martynov, Yourii
• Application Number:
  US15/640,482
• Publication Number:
  US 20170301841A1
• Time in Patent Office: Days
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A hollow frame is configured to surround the periphery of a substantially self-supporting flip-chip light emitting device. The frame may be shaped to also contain a wavelength conversion element above the light emitting surface of the light emitting device. The lower surface of the light emitting device, which is exposed through the hollow frame, includes contact pads coupled to the light emitting element for surface mounting the light emitting module on a printed circuit board or other fixture. The flip-chip light emitting device may include a patterned sapphire substrate (PSS) upon which the light emitting element is grown, the patterned surface providing enhanced light extraction from the light emitting element, through the patterned sapphire substrate.

Claims

1. A light emitting device comprising:

a frame with an opening formed therethrough;

a light emitting chip disposed within the opening, the light emitting chip comprising;

a substrate,

a light emitting element in contact with the substrate, the light emitting element comprising an active region between an n-type semiconductor and a p-type semiconductor, and

at least a first contact pad and a second contact pad in contact with a surface of the light emitting element that is opposite the substrate, the first contact pad being coupled to the n-type semiconductor and the second contact being coupled to the p-type semiconductor; and

a pre-formed cap disposed within the opening.

2. The light emitting device of claim 1, wherein the pre-formed cap is shaped to form a lens.

3. The light emitting device of claim 1, wherein the pre-formed cap includes wavelength conversion material.

4. The light emitting device of claim 1, wherein the opening defines one or more inner walls of the frame, and surfaces of the one or more inner walls are reflective.

5. The light emitting device of claim 4, further comprising one of TiO₂ or silicone disposed between the one or more inner walls of the frame and the pre-formed cap.

6. The light emitting device of claim 1, further comprising a removable sheet, a bottom surface of the frame being disposed on the removable sheet, the light emitting chip being disposed within the frame such that at least the first contact and the second contact extend below the bottom surface of the frame or are level with the bottom surface of the frame.

7. The light emitting device of claim 1, wherein the light emitting chip and the pre-formed cap are disposed within the frame such that a surface of the substrate of the light emitting chip is adjacent a surface of the pre-formed cap such that the surface of the substrate that is adjacent the surface of the pre-formed cap is a light emitting surface of the light emitting chip and a surface of the pre-formed cap that is opposite the surface of the pre-formed cap that is adjacent the light emitting surface of the light emitting chip is a light emitting surface of the pre-formed cap.

8. The light emitting device of claim 7, wherein at least one of the light emitting surface of the pre-formed cap and the light emitting surface of the light emitting chip is roughened or patterned.

9. The light emitting device of claim 8, further comprising an interface material disposed between the pre-formed cap and the light emitting chip.

10. The light emitting device of claim 9, wherein the interface material has an index of refraction between an index of refraction of the light emitting chip and an index of refraction of the pre-formed cap.

11. The light emitting device of claim 7, wherein the opening defines one or more inner walls of the frame, and the one or more inner walls of the frame are shaped to include a step on which the pre-formed cap is disposed.

12. The light emitting device of claim 7, wherein the opening defines one or more inner walls of the frame, and each of the one or more inner walls of the frame includes a sloped portion adjacent the pre-formed cap.

13. The light emitting device of claim 1, wherein the opening and the frame have the same shape.

14. The light emitting device of claim 1, wherein the opening has a cylindrical shape.

15. The light emitting device of claim 14, wherein the light emitting chip is rectilinear and the pre-formed cap has a cylindrical shape.

16. The light emitting device of claim 15, wherein a diagonal of the light emitting chip is less than or equal to a diameter of the opening having the cylindrical shape.

17. The light emitting device of claim 16, wherein one or more spaces between the pre-formed cap and inner walls of the frame defined by the opening having the cylindrical shape are filled with a reflective material.

18. The light emitting device of claim 1, wherein the frame is formed from a pliable material, and the opening is sized to provide a friction fit with at least one of the light emitting chip and the pre-formed cap.

19. The light emitting device of claim 1, wherein the opening is larger than the light emitting chip, and an adhesive material is disposed between the light emitting chip and inner walls of the frame defined by the opening.

20. The light emitting device of claim 19, wherein the adhesive is reflective.

21. The light emitting device of claim 1, wherein the frame is formed from a heat-shrink material.