Light emitting diode substrate assembly

• US 20110128731A1
• Filed: 12/01/2009
• Published: 06/02/2011
• Est. Priority Date: 12/01/2009
• Status: Active Grant

• Current Assignee: Shin ZU Shing Company Limited
• Original Assignee: Shin ZU Shing Company Limited
• Inventors: Lin, Shun-Tian, Chung, Chao-Tung
• Granted Patent: US 8,157,412 B2
• Time in Patent Office: Days
• US Class Current: 362/235
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• 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 33/642 characterized by the shape
• CPC Class Codes: H05K 1/021 Components thermally connected to metal substrates or heat-sinks by insert mounting
• CPC Class Codes: H05K 2201/09745 Recess in conductor, e.g. in pad or in metallic substrate
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: H05K 2201/2054 Light-reflecting surface, e.g. conductors, substrates, coatings, dielectrics
• CPC Class Codes: Y10S 362/80 Light emitting diode
• CPC Class Codes: Y10T 29/4935 Heat exchanger or boiler making

Abstract

A light emitting diode substrate assembly has a metal substrate, a circuit board, multiple chip strings, an annular wall and an encapsulant. The circuit board is mounted on the top surface of the substrate and has multiple through holes and multiple current conducting lines. The chip strings are mounted on the substrate and respectively in the through hole in the circuit board. Each chip string has at least one light emitting diode chip connected electrically to two corresponding current conducting lines on the circuit board with bonding wires. Accordingly, the heat generating during the operation of the chips can be efficiently dissipated from the substrate.

Claims

1. A light emitting diode substrate assembly comprising:

a metal substrate having

a top surface; and

multiple reflecting cups formed on the top surface of the substrate and each reflecting cup having

a top; and

a recess defined in the top of the reflecting cup and having an opening defined in the top of the reflecting cup, a bottom opposite to the opening, an inner side wall to form as a reflecting surface and a diameter gradually increasing from the bottom to the opening;

a circuit board mounted on the top surface of the substrate and having

a top;

multiple through holes defined through the circuit board and mounted respectively around the reflecting cups on the substrate; and

multiple current conducting lines formed on the top of the circuit board, wherein each adjacent two of the through holes has one of the current conducting lines mounted between the adjacent through holes and each through hole has at least two of the current conducting lines mounted adjacent to the through hole;

multiple chip strings mounted respectively in the reflecting cups, wherein each reflecting cup has at least one of the chip strings mounted in the reflecting cup and each chip string comprises

at least one light emitting diode chip mounted on the bottom of the recess in a corresponding one of the reflecting cups and connected electrically to two corresponding current conducting lines on the circuit board with bonding wires;

an annular wall mounted on the top of the circuit board around the through holes and having a holding space defined through the annular wall and enclosing the reflecting cups inside; and

an encapsulant with fluorescent powders mounted in the holding space in the annular wall and encapsulating the chip strings.

2. The light emitting diode substrate assembly as claimed in claim 1, wherein the reflecting cups on the substrate are arranged in an array.

3. The light emitting diode substrate assembly as claimed in claim 1, wherein each chip string has multiple light emitting diode chips connected with each other in series.

4. The light emitting diode substrate assembly as claimed in claim 1, wherein the recess of each reflecting cap is truncated cylindrical cone in shape.

5. The light emitting diode substrate assembly as claimed in claim 1, wherein the recess of each reflecting cap is truncated cubic cone in shape.

6. The light emitting diode substrate assembly as claimed in claim 1, wherein the substrate has a bottom surface and multiple fins formed on and protruding from the bottom surface of the substrate.

7. The light emitting diode substrate assembly as claimed in claim 1, wherein the substrate has a flat bottom surface.

8. The light emitting diode substrate assembly as claimed in claim 1, wherein the substrate further has a cavity defined in the top surface of the substrate;

and

the circuit board is mounted in the cavity.

9. The light emitting diode substrate assembly as claimed in claim 1, wherein the reflecting surface is made of a metal having a high reflective index.

10. The light emitting diode substrate assembly as claimed in claim 9, wherein the metal is selected from nickel, aluminum and silver.

29. A method for forming a metal substrate for a light emitting diode substrate assembly as claimed in claim 1 comprising an act of forming the metal substrate by a material selected from copper or alloy of copper.

30. The method as claimed in claim 29, wherein the metal substrate is formed by hot forging, cold forging or metal powder injection molding process.

31. A method for forming a metal substrate for a light emitting diode substrate assembly as claimed in claim 1 comprising an act of forming the metal substrate by a material selected from aluminum or aluminum alloy.

32. The method as claimed in claim 31, wherein the metal substrate is formed by hot forging, cold forging or metal powder injection molding or by extruding or casting process to form a semifinished product and is then applied with a machining process to a final substrate.

11. A light emitting diode substrate assembly comprising:

a metal substrate having

a top surface; and

multiple reflecting recesses defined in the top surface of the substrate and each reflecting recess having

a top;

an opening defined in the top of the reflecting cup;

a bottom opposite to the opening,

an inner side wall to form as a reflecting surface; and

a diameter gradually increasing from the bottom to the opening;

a circuit board mounted on the top surface of the substrate and having

a top;

multiple through holes defined through the circuit board and mounted respectively around the reflecting recesses in the substrate; and

multiple current conducting lines formed on the top of the circuit board, wherein each adjacent two of the through holes has one of the current conducting lines mounted between the adjacent through holes and each through hole has at least two of the current conducting lines mounted adjacent to the through hole;

multiple chip strings mounted respectively in the reflecting recesses, wherein each reflecting recess has at least one of the chip strings mounted in the reflecting recess and each chip string comprises

at least one light emitting diode chip mounted on the bottom of a corresponding one of the reflecting recesses and connected electrically to two corresponding current conducting lines on the circuit board with bonding wires;

an annular wall mounted on the top of the circuit board around the through holes and having a holding space defined through the annular wall and enclosing the reflecting cups inside; and

an encapsulant with fluorescent powders mounted in the holding space in the annular wall and encapsulating the chip strings.

12. The light emitting diode substrate assembly as claimed in claim 11, wherein the reflecting recesses in the substrate are arranged in an array.

13. The light emitting diode substrate assembly as claimed in claim 11, wherein each chip string has multiple light emitting diode chips connected with each other in series.

14. The light emitting diode substrate assembly as claimed in claim 11, wherein each reflecting recess is truncated cylindrical cone in shape.

15. The light emitting diode substrate assembly as claimed in claim 11, wherein each reflecting recess is truncated cubic cone in shape.

16. The light emitting diode substrate assembly as claimed in claim 11, wherein the substrate has a bottom surface and multiple fins formed on and protruding from the bottom surface of the substrate.

17. The light emitting diode substrate assembly as claimed in claim 11, wherein the substrate has a flat bottom surface.

18. The light emitting diode substrate assembly as claimed in claim 11, wherein the substrate further has a cavity defined in the top surface of the substrate;

and

the circuit board is mounted in the cavity.

19. The light emitting diode substrate assembly as claimed in claim 11, wherein the reflecting surface is made of a metal having a high reflective index.

20. The light emitting diode substrate assembly as claimed in claim 19, wherein the metal is selected from nickel, aluminum and silver.

21. A light emitting diode substrate assembly comprising:

a metal substrate having a top surface;

a circuit board mounted on the top surface of the substrate and having

a top;

multiple through holes defined through the circuit board; and

multiple current conducting lines formed on the top of the circuit board, wherein each adjacent two of the through holes has one of the current conducting lines mounted between the adjacent through holes and each through hole has at least two of the current conducting lines mounted adjacent to the through hole;

multiple chip strings mounted on the top surface of the substrate and mounted respectively in the through holes in the circuit board, wherein each through hole has at least one of the chip strings mounted in the through hole and each chip string comprises

at least one light emitting diode chip mounted on the top surface of the substrate and connected electrically to two corresponding current conducting lines on the circuit board with bonding wires;

an annular wall mounted on the top of the circuit board around the through holes and having a holding space defined through the annular wall and enclosing the reflecting cups inside; and

an encapsulant with fluorescent powders mounted in the holding space in the annular wall and encapsulating the chip strings.

22. The light emitting diode substrate assembly as claimed in claim 21, wherein the reflecting recesses in the substrate are arranged in an array.

23. The light emitting diode substrate assembly as claimed in claim 21, wherein each chip string has multiple light emitting diode chips connected with each other in series.

24. The light emitting diode substrate assembly as claimed in claim 21, wherein each reflecting recess is truncated cylindrical cone in shape.

25. The light emitting diode substrate assembly as claimed in claim 21, wherein each reflecting recess is truncated cubic cone in shape.

26. The light emitting diode substrate assembly as claimed in claim 21, wherein the substrate has a bottom surface and multiple fins formed on and protruding from the bottom surface of the substrate.

27. The light emitting diode substrate assembly as claimed in claim 21, wherein the substrate has a flat bottom surface.

28. The light emitting diode substrate assembly as claimed in claim 21, wherein the substrate further has a cavity defined in the top surface of the substrate;

and

the circuit board is mounted in the cavity.