Method of packaging a semiconductor light emitting device
View Patent ↗A semiconductor light emitting device is packaged by forming a sealed compartment enclosing the device, at least one of the walls of the sealed compartment being formed of an elastomeric material. The elastomeric material is then penetrated with a needle and a quantity of softer material is injected through the needle into the sealed compartment. In some embodiments, a coaxial needle or two needles are used, one needle to inject the softer material and one needle to vent air from the compartment.
1. A method of packaging a semiconductor light emitting device, the method comprising:
forming a sealed compartment enclosing a semiconductor light emitting device, the sealed compartment comprising a frame and a cover disposed over the frame, the cover comprising a top section connected to a sidewall section, the top section and sidewall section being formed of a first material comprising an elastomeric material;
penetrating the elastomeric material with a needle; and
injecting a quantity of a second material through the needle into the compartment.
2. The method of claim 1 wherein the first material comprises a material having a hardness of at least ShoreA 20.
3. The method of claim 1 wherein the first material has a hardness between about ShoreA 20 and about ShoreA 80.
4. The method of claim 1 wherein the first material comprises silicone.
5. The method of claim 1 wherein the second material is solid material that is softer than the first material.
6. The method of claim 1 wherein the second material is a gel.
7. The method of claim 1 wherein the second material comprises silicone.
8. The method of claim 1 wherein the second material is a liquid.
9. The method of claim 1 further comprising reacting the second material to form an elastomer.
10. The method of claim 9 wherein reacting the second material comprises exposing the second material to light, exposing the second material to heat, or exposing the second material to a catalyst.
11. The method of claim 1 further comprising venting air from the compartment.
12. The method of claim 1 wherein the needle comprises a coaxial needle having a first chamber and a second chamber, the method further comprising:
injecting the second material through the first chamber; and
venting air from the compartment through the second chamber.
13. The method of claim 1 wherein the needle is a first needle, the method further comprising:
penetrating the elastomeric material with a second needle;
injecting the second material through the first needle; and
venting air from the compartment through the second needle.
14. The method of claim 1 further comprising selecting the elastomeric material such that the elastomeric material seals a hole left by the needle once the needle is removed from the elastomeric material.
15. The method of claim 1 wherein forming a sealed compartment further comprises:
mounting the semiconductor light emitting device on a lead frame;
electrically connecting the semiconductor light emitting device to leads on the lead frame; and
scaling a lens formed from the elastomeric material over the lead frame.
16. The method of claim 1 wherein the second material completely fills the sealed compartment.
17. The method of claim 1 wherein:
the semiconductor light emitting device comprises a surface through which light is extracted;
an index of refraction of the second material is less than or equal to an index of refraction of the surface; and
an index of refraction of the first material is less than or equal to the index of refraction of the second material.
18. The method of claim 17 wherein the index of refraction of the first material is greater than an index of refraction of air.
19. The method of claim 1 wherein the needle pierces the elastomeric material.
20. The method of claim 1 wherein the sealed compartment is formed prior to penetrating the elastomeric material with a needle.
21. The method of claim 1 wherein the top section is substantially perpendicular to the sidewall section.
22. The method of claim 1 wherein the cover has a dome shape.
23. The method of claim 1 wherein the top section and the sidewall section are integrated in a single piece of material of substantially uniform composition.