Granted Patent B2

US 8,728,835 · App. 12/811,832 · Granted May 20, 2014

Abstract

Claims (19)

1. A method for the manufacture of a light emitting device comprising:

providing a slurry comprising ceramic particles of at least one wavelength converting material and polymeric particles having a diameter of from 2 μm to 10 μm;

forming a ceramic body from said slurry;

removing said polymeric particles from said ceramic body to provide a porous ceramic element having an average pore diameter of from 2 μm to 10 μm; and

arranging said porous ceramic element to receive light from at least one light emitting diode.

2. A method according to claim 1 , wherein said ceramic particles have an average particle size of from 5 μm to 10 μm.

3. A method according to claim 1 , wherein said polymeric particles have an average diameter of from 2 μm to 5 μm.

4. A method according to claim 1 , wherein said polymeric particles comprise polystyrene or polyacrylate.

5. A method according to claim 1 , further comprising subjecting said porous ceramic element to a thermal treatment at a temperature above 1000° C.

6. A method according to claim 1 , wherein removing said polymeric particles from said ceramic body comprises applying a thermal treatment such that the polymeric particles are decomposed or oxidized.

7. A method according to claim 1 , wherein forming a ceramic body from said slurry comprises one of pressing, slip casting, tape casting, roller pressing, extruding, and injection molding.

8. A method according to claim 1 , wherein the porous ceramic element is self-supporting.

9. A method according to claim 1 , wherein the at least one light emitting diode is a blue light emitting LED and the porous ceramic element is adapted to absorb blue light, while emitting yellow light.

10. A method according to claim 2 , wherein said polymeric particles are removed by subjecting said ceramic body to a thermal treatment at a temperature up to 1000° C.

11. A method according to claim 10 , wherein during said thermal treatment, the ceramic body is sintered such that the ceramic particles are fused together.

12. A method for the manufacture of a porous ceramic element comprising:

providing a slurry comprising ceramic particles of at least one wavelength converting material and polymeric particles having a diameter of from 2 μm to 10 μm;

forming a ceramic body from said slurry; and

removing said polymeric particles from said ceramic body to provide a porous ceramic element having an average pore diameter of from 2 μm to 10 μm.

Assignments (8)