Method of manufacturing light emitting diode packaging lens and light emmiting diode package

• US 20110068356A1
• Filed: 09/21/2009
• Published: 03/24/2011
• Est. Priority Date: 09/21/2009
• Status: Active Grant

• Current Assignee: Walsin Lihwa Corporation
• Original Assignee: Walsin Lihwa Corporation
• Inventors: Ho, Hsien-Lung, Lin, Hung-Yi, Chiang, Chung-I, Lu, Tsan
• Granted Patent: US 8,455,910 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: C23C 28/00 Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
• CPC Class Codes: C23C 28/04 only coatings of inorganic non-metallic material
• CPC Class Codes: C23C 28/322 only coatings of metal elements only
• CPC Class Codes: C23C 28/345 with at least one oxide layer
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A method of manufacturing light emitting diode packaging lens and packages made by using the method are disclosed in the present invention. By using electrophoretic deposition, one or more layers of phosphors are coated onto one surface of a cup which has a curved portion. The cup is used for the packaging lens. Thickness of phosphor layer can be controlled and distribution of phosphor particles is uniform. Therefore, light emitting diode packages with the lens can be a uniform light source.

Claims

1. A method of manufacturing light emitting diode packaging lens, comprising the steps of:

a) providing a cup having a curved portion;

b) forming a transparent conductive coating on one surface of the cup;

c) providing a first solution having a first group of phosphors for electrophoretic deposition and a first curved electrode immersed in the first solution, wherein surface shapes of the cup and the first curved electrode are the same;

d) immersing the cup into the first solution;

e) positioning the cup and the first curved electrode wherein when the first curved electrode and the transparent conductive coating have electric potential difference, equal electric potential contour lines form the same shape as the surface shape between the cup and the first curved electrode;

f) providing a first direct current to the transparent conductive coating and the first curve electrode for electrophoretically depositing the first group of phosphors onto the coated surface of the cup and forming a first phosphor layer;

g) removing the cup from the first solution; and

h) drying the cup.

2. The method according to claim 1, wherein the surface shape is hemispherical.

3. The method according to claim 1, wherein the cup is made of epoxy resin, silicone, polyetherimide, fluorocarbon polymer, polymethyl methacrylate (PMMA), polycarbonate (PC), cyclo olefin copolymer (COC) or glass.

4. The method according to claim 1, wherein the transparent conductive coating comprises indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), zinc oxide, tin dioxide, or a mixture thereof.

5. The method according to claim 1, wherein the first solution further comprises a first solvent and a first binder.

6. The method according to claim 5, wherein the first solvent is isopropyl alcohol (IPA), ethanol, acetone, or water.

7. The method according to claim 5, wherein the first binder is silver nitrate or magnesium nitrate.

8. The method according to claim 1, wherein the cup further has a fixing portion formed on rim of the curved portion.

9. The method according to claim 8, wherein the fixing portion is a cylinder having a thickness as that of the cup.

10. The method according to claim 2, wherein a radius of the curved portion of the cup differs from a radius of the first curved electrode by at least one order.

11. The method according to claim 1, further comprising the steps of:

g1) providing a second solution having a second group of phosphors for electrophoretic deposition and a second curved electrode immersed in the second solution, wherein the surface curve of the second curved electrode is the same as that of the cup;

g2) immersing the cup into the second solution;

g3) locating the cup and the second curved electrode wherein when a direct current applied to the second curved electrode and the transparent conductive coating, equal electric potential forms the same shape as the surface shape between the cup and the first curved electrode;

g4) providing a second direct current to the transparent conductive coating and the second curved electrode for electrophoretically depositing the second group of phosphors onto the first phosphor layer; and

g5) removing the cup from the second solution.

12. The method according to claim 11, wherein the second solution further comprises a second solvent and a second binder.

13. The method according to claim 12, wherein the second solvent is isopropyl alcohol (IPA), ethanol, acetone, or water.

14. The method according to claim 12, wherein the second binder is silver nitrate or magnesium nitrate.

15. A light emitting diode package, comprising:

a substrate;

a reflecting layer formed on a top surface of the substrate;

a one light emitting chip mounted on the reflecting layer; and

a lens including;

a cup having a curved portion enclosing the light emitting diode, fixed on the substrate;

a transparent conductive coating formed on one surface of the cup; and

at least one phosphor layer formed on the transparent conductive coating.

16. The package according to claim 15, wherein the curved portion is hemispherical.

17. The package according to claim 15, wherein the substrate is a silicon substrate, a ceramic substrate, an aluminum plate, a copper plate or a printed circuit board.

18. The package according to claim 15, wherein the reflecting layer is made of a metal.

19. The package according to claim 15, wherein the cup is made of epoxy resin, silicone, polyetherimide, fluorocarbon polymer, polymethyl methacrylate (PMMA), polycarbonate (PC), cyclo olefin copolymer (COC) or glass.

20. The package according to claim 15, wherein the transparent conductive coating comprises indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), zinc oxide, tin dioxide, or a mixture thereof.

21. The package according to claim 15, wherein the cup is fixed on the substrate by gluing.

22. The package according to claim 15, wherein the cup further has a fixing portion formed on rim of the curved portion.

23. The method according to claim 22, wherein the fixing portion is a cylinder having a thickness as that of the cup.