Light Emitting Diode Package Structure and Manufacturing Method Thereof

• US 20120080702A1
• Filed: 05/27/2011
• Published: 04/05/2012
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: Everlight Electronics Company Limited
• Original Assignee: Everlight Electronics Company Limited, Poly-Flow Engineering, LLC
• Inventors: LIN, Hsien Chia
• Granted Patent: US 8,772,807 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• 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 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

In one aspect, an LED package structure comprises a fluorescent substrate, a first electrically conductive pattern, a second electrically conductive pattern, at least one electrically conductive element, and an LED chip. The fluorescent substrate has a first surface and a second surface opposite the first surface. The fluorescent substrate comprises a mixture of a fluorescent material and a glass material. The first electrically conductive pattern is disposed on the first surface. The second electrically conductive pattern is disposed on the second surface. The electrically conductive element passes through the fluorescent substrate and connects the first and second electrically conductive patterns. The LED chip is disposed on the second surface and has a light extraction surface that connects the second electrically conductive pattern. The LED chip is electrically coupled to the first electrically conductive pattern via the electrically conductive element.

Claims

1. A light emitting diode (LED) package structure, comprising:

a fluorescent substrate having a first surface and a second surface opposite the first surface, the fluorescent substrate comprising a fluorescent material and a glass material;

a first electrically conductive pattern disposed on the first surface of the fluorescent substrate;

a second electrically conductive pattern disposed on the second surface of the fluorescent substrate;

at least one electrically conductive component connecting the first electrically conductive pattern and the second electrically conductive pattern; and

an LED chip disposed on the second surface of the fluorescent substrate, the LED chip having a light extraction surface coupled to the second electrically conductive pattern such that the LED chip is electrically coupled to the first electrically conductive pattern via the at least one electrically conductive component.

2. The LED package structure of claim 1, wherein a thickness of the fluorescent substrate is approximately constant throughout the fluorescent substrate.

3. The LED package structure of claim 1, wherein the fluorescent material comprises yellow phosphor.

4. The LED package structure of claim 1, wherein the fluorescent material comprises phosphors of at least two different wavelengths.

5. The LED package structure of claim 4, wherein the phosphors comprise at least two of yellow phosphor, red phosphor, and green phosphor.

6. The LED package structure of claim 1, further comprising an underfill disposed between the light extraction surface of the LED chip and the second surface of the fluorescent substrate, the underfill covering at least partially the light extraction surface of the LED chip.

7. The LED package structure of claim 6, wherein the underfill covers a plurality of side surfaces of the LED chip.

8. The LED package structure of claim 7, wherein the LED chip comprises a sapphire substrate.

9. The LED package structure of claim 1, further comprising a circuit line substrate, a back surface of the LED chip opposite the light extraction surface disposed on the circuit line substrate.

10. The LED package structure of claim 9, further comprising at least one bonding wire that electrically couples the circuit line substrate and the first electrically conductive pattern.

11. A manufacturing method of a light emitting diode (LED) package structure, the method comprising:

providing a fluorescent substrate having a first surface and a second surface opposite the first surface, the fluorescent substrate containing therein a plurality of electrically conductive components that connect the first surface and the second surface, the fluorescent substrate comprising a mixture of at least one fluorescent material and a glass material;

forming a first electrically conductive pattern on the first surface and a second electrically conductive pattern on the second surface, at least some of the electrically conductive components connecting the first electrically conductive pattern and the second electrically conductive pattern; and

bonding a plurality of LED chips on the second surface of the fluorescent substrate, each of the LED chips having a respective light extraction surface coupled to the second electrically conductive pattern, each of the LED chips electrically coupled to the first electrically conductive pattern via a corresponding one of the electrically conductive components.

12. The method of claim 11, wherein the plurality of electrically conductive components are formed by:

forming a plurality of through holes in the fluorescent substrate, the through holes connecting the first surface and the second surface;

galvanizing the through holes to form a plurality of electrically conductive pillars protruding out of the first surface of the fluorescent substrate;

milling the electrically conductive pillars to provide the electrically conductive components that are flush with the first surface of the fluorescent substrate.

13. The method of claim 12, wherein the milling comprises cutting the fluorescent substrate with a cutting device to reduce a thickness of the fluorescent substrate and to expose the electrically conductive components.

14. The method of claim 11, wherein the plurality of electrically conductive components are formed by:

forming a plurality of electrically conductive bumps in a recess of a carrier base;

filling the recess of the carrier base with the at least one fluorescent material and the glass material, the at least one fluorescent material and the glass material covering the electrically conductive bumps;

heating the electrically conductive bumps, the at least one fluorescent material, and the glass material together to form the fluorescent substrate with the electrically conductive bumps buried therein; and

milling the fluorescent substrate and the electrically conductive bumps to form the electrically conductive components that are flush with the first surface of the fluorescent substrate.

15. The method of claim 11, further comprising:

forming a plurality of circuit lines on the second surface after forming the second electrically conductive pattern, the circuit lines connecting the second electrically conductive pattern.

16. The method of claim 11, further comprising:

forming an underfill between the light extraction surface of the LED chips and the second surface of the fluorescent substrate after bonding the LED chips on the second surface of the fluorescent substrate, the underfill covering at least partially the light extraction surface of the LED chips.

17. The method of claim 16, further comprising:

after forming the underfill, carrying out a cutting process to form a plurality of LED package structures.

18. The method of claim 16, wherein the underfill covers at least partially a plurality of side surfaces of the LED chips.

19. The method of claim 18, further comprising:

after forming the underfill, carrying out a cutting process to form a plurality of LED package structures.