METHOD OF MAKING LIGHT EMITTING DEVICE HAVING A MOLDED ENCAPSULANT

• US 20070092636A1
• Filed: 10/20/2006
• Published: 04/26/2007
• Est. Priority Date: 10/24/2005
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Thompson, D., Ouderkirk, Andrew, Leatherdale, Catherine, Boardman, Larry, Kecman, Fedja
• Application Number:
  US11/551,309
• Publication Number:
  US 20070092636A1
• Time in Patent Office: Days
• US Class Current: 427/66
• CPC Class Codes: C08G 77/12 containing silicon bound to hydrogen C08G77/045 takes precedence
• CPC Class Codes: C08G 77/20 containing silicon bound to unsaturated aliphatic groups C08G77/045 takes precedence
• CPC Class Codes: C08J 2383/04 Polysiloxanes
• CPC Class Codes: C08J 3/243 Two or more independent types of crosslinking for one or more polymers
• CPC Class Codes: C08L 83/00 Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 83/04 Polysiloxanes
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• 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 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/01063 Europium [Eu]
• CPC Class Codes: H01L 2924/01067 Holmium [Ho]
• CPC Class Codes: H01L 2924/01077 Iridium [Ir]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/1815 Shape
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/54 : having a particular shape
• 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

Disclosed herein is a method of making a light emitting device comprising an LED and a molded silicon-containing encapsulant. The method includes contacting the LED with a photopolymerizable composition containing a silicon-containing resin having silicon-bonded hydrogen and aliphatic unsaturation and a metal-containing catalyst that may be activated by actinic radiation. Photopolymerization of the photopolymerizable composition is then carried out to form the encapsulant. At some point before polymerization is complete, a mold is used to impart a predetermined shape to the encapsulant.

Claims

1. A method of making a light emitting device, the method comprising:

providing a light emitting diode;

contacting the light emitting diode with a photopolymerizable composition comprising;

a silicon-containing resin comprising silicon-bonded hydrogen and aliphatic unsaturation, and

a metal-containing catalyst that may be activated by actinic radiation; and

contacting the photopolymerizable composition with a mold.

2. The method of claim 1, further comprising:

applying actinic radiation to the photopolymerizable composition after contacting it with the mold,

wherein the actinic radiation is at a wavelength of 700 nm or less and initiates hydrosilylation within the silicon-containing resin, the hydrosilylation comprising reaction between the silicon-bonded hydrogen and the aliphatic unsaturation.

3. The method of claim 2,

wherein applying the actinic radiation comprises forming a partially polymerized composition, and

the method further comprising heating the partially polymerized composition to further initiate hydrosilylation within the silicon-containing resin.

4. The method of claim 1, further comprising:

heating the photopolymerizable composition to a temperature of less than about 150°

C. before contacting it with the mold.

9. The method of claim 1 or 5, wherein the mold is transparent to the actinic radiation.

10. The method as in any one of claims 2, 5 and 6, wherein applying actinic radiation comprises activating the light emitting diode.

11. The method of claim 1, the mold comprising a mold material and being shaped to impart a positive or negative lens on a substantial portion of the surface of the photopolymerizable composition.

12. The method of claim 1, the mold comprising a mold material and being shaped to impart macrostructures, each macrostructure having a dimension of from 10 um to 1 mm.

13. The method of claim 1, the mold comprising a mold material and being shaped to impart microstructures, each microstructure having a dimension of from 100 nm to less than 10 um.

5. A method of making a light emitting device, the method comprising:

providing a light emitting diode;

contacting the light emitting diode with a photopolymerizable composition comprising;

a silicon-containing resin comprising silicon-bonded hydrogen and aliphatic unsaturation, and

a metal-containing catalyst that may be activated by actinic radiation;

applying actinic radiation to the photopolymerizable composition, wherein the actinic radiation is at a wavelength of 700 nm or less and initiates hydrosilylation within the silicon-containing resin, thereby forming a partially polymerized composition, the hydrosilylation comprising reaction between the silicon-bonded hydrogen and the aliphatic unsaturation; and

contacting the partially polymerized composition with a mold.

6. The method of claim 5, further comprising:

applying actinic radiation to the partially polymerized composition after contacting it with the mold, wherein the actinic radiation applied to the partially polymerized composition is at a wavelength of 700 nm or less and further initiates hydrosilylation within the silicon-containing resin.

7. The method of claim 6,

wherein the applying actinic radiation to the partially polymerized composition comprises forming a second partially polymerized composition, and

the method further comprising heating the second partially polymerized composition to further initiate hydrosilylation within the silicon-containing resin.

8. The method of claim 5, further comprising:

heating the partially polymerized composition to a temperature of less than about 150°

C. after contacting it with the mold,

wherein heating further initiates hydrosilylation within the silicon-containing resin.

14. A method of making a light emitting device, the method comprising:

providing a light emitting diode;

contacting the light emitting diode with a photopolymerizable composition comprising;

a silicon-containing resin comprising silicon-bonded hydrogen and aliphatic unsaturation, and

a metal-containing catalyst that may be activated by actinic radiation;

shaping a surface of the photopolymerizable composition by contacting it with a mold;

applying actinic radiation having a wavelength of 700 nm or less to initiate hydrosilylation within the silicon-containing resin, thereby forming a photopolymerized composition, wherein hydrosilylation comprises reaction between the silicon-bonded hydrogen and the aliphatic unsaturation; and

separating the mold from the photopolymerized composition.

15. A light emitting device prepared according to the method of claim 14.

16. A light emitting device comprising:

a light emitting diode;

a photopolymerizable composition comprising;

a silicon-containing resin comprising silicon-bonded hydrogen and aliphatic unsaturation, and

a metal-containing catalyst that may be activated by actinic radiation; and

a mold.

17. The light emitting device of claim 16, wherein the photopolymerizable composition is partially polymerized.

18. A light emitting device comprising:

a light emitting diode;

a photopolymerized composition in contact with the light emitting diode and formed from a photopolymerizable composition comprising;

a silicon-containing resin comprising silicon-bonded hydrogen and aliphatic unsaturation, and

a metal-containing catalyst that may be activated by actinic radiation,

wherein a surface of the photopolymerized composition is shaped as a positive or negative lens on a substantial portion thereof.

19. A light emitting device comprising:

a light emitting diode;

a photopolymerized composition in contact with the light emitting diode and formed from a photopolymerizable composition comprising;

a silicon-containing resin comprising silicon-bonded hydrogen and aliphatic unsaturation, and

a metal-containing catalyst that may be activated by actinic radiation, wherein a surface of the photopolymerized composition is shaped with macrostructures, each macrostructure having a dimension of from 10 um to 1 mm.

20. A light emitting device comprising:

a light emitting diode;

a photopolymerized composition in contact with the light emitting diode and formed from a photopolymerizable composition comprising;

a silicon-containing resin comprising silicon-bonded hydrogen and aliphatic unsaturation, and

a metal-containing catalyst that may be activated by actinic radiation,

wherein a surface of the photopolymerized composition is shaped with microstructures, each microstructure having a dimension of from 100 nm to less than 10 um.