Package array and package unit of flip chip LED

• US 20050199899A1
• Filed: 03/11/2004
• Published: 09/15/2005
• Est. Priority Date: 03/11/2004
• Status: Abandoned Application

• Current Assignee: Opto Tech Corporation (OptoTech Corp.)
• Original Assignee: Opto Tech Corporation (OptoTech Corp.)
• Inventors: Lin, Ming-Der, Lin, San-Bao
• Application Number:
  US10/797,191
• Publication Number:
  US 20050199899A1
• Time in Patent Office: Days
• US Class Current: 257/99
• CPC Class Codes: H01L 2224/13144 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/16245 the item being metallic
• CPC Class Codes: H01L 2224/451 with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/81805 involving forming a eutectic alloy at the bonding interface
• CPC Class Codes: H01L 24/13 of an individual bump connector
• CPC Class Codes: H01L 24/16 of an individual bump connector
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/81 using a bump connector
• 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 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/0105 Tin [Sn]
• 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 2924/12032 Schottky diode
• CPC Class Codes: H01L 2924/12036 : PN diode
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/1815 : Shape
• CPC Class Codes: H01L 2924/19107 : off-chip wires
• CPC Class Codes: H01L 33/641 : characterized by the materials

Abstract

A package array and its package unit of flip chip LED are proposed, wherein an LED chip is mounted on a ceramic material capable of enduing the eutectic temperature of the fabrication process for packaging. Next, metal wires are directly distributed on the ceramic material to finish an LED package unit, or a plurality of LEDs are serial/parallel connected with metal wires on the ceramic material to finish a high density package array. Because the ceramic material has a good thermal expansion match and a good thermal conductivity and the LED chip itself has a high reflective index match, the light emission characteristic and heat-radiating effect of the packaged LED can be effectively improved.

Claims

1. A flip chip LED package array comprising:

a ceramic substrate made of a material capable of enduring the eutectic temperature of the fabrication process;

a metal wire layer distributed on the surface of the ceramic substrate; and

one or more LED chips. mounted on the metal wire layer on the ceramic substrate, the LED chips being electrically connected together via the metal wire layer to form an electric circuit.

2. The flip chip LED package array as in claim 1, wherein one or more cavities are further formed in the ceramic substrate to accommodate at least one LED chip.

3. The flip chip LED package array as in claim 2, wherein a reflecting film is formed on the surface of each of the cavities.

4. The flip chip LED package array as in claim 1, wherein a reflecting cover is further annularly formed around each of the LED chips.

5. The flip chip LED package array as in claim 4, wherein the reflecting cover has one or more LED chips therein.

6. The flip chip LED package array as in claim 4, wherein a lens further covers the upper surface of the reflecting cover.

7. The flip chip LED package array as in claim 1, wherein the material of the ceramic substrate is selected from AlN, Al₂O₃, BeO, SiC, ZrO₂ and glass ceramic.

8. The flip chip LED package array as in claim 1, wherein the electric circuit is in one of the forms consisting of parallel, serial and serial/parallel connections.

9. The flip chip LED package array as in claim 1, wherein a. metal plate is further disposed on another surface of the ceramic substrate.

10. The flip chip LED package array as in claim 1, wherein the LEDs are mounted on the metal wire layer by using a eutectic substrate.

11. The flip chip LED package array as in claim 10, wherein the eutectic material is Au—

Sn or Au—

Si.

12. A flip chip LED package unit comprising:

a metal body;

a ceramic substrate mounted on the metal body, a conducting layer being distributed on the ceramic substrate;

an LED chip mounted on the surface of the conducting layer on the ceramic substrate to achieve electric connection, the ceramic substrate being made of a material having an coefficient of thermal expansion matched with the LED chip;

an external carrier substrate arranged on the metal body, the LED chip achieving electric connection with the external carrier substrate via the conducting layer as external conducting contacts, wherein the external carrier substrate is a printed circuit board or a metal leadframe; and

a lens covering said LED chip.

13. The flip chip LED package unit as in claim 12, wherein a reflecting cover is further annularly disposed on the external carrier substrate around the LED chip so that the lens can be mounted on the reflecting cover.

14. The flip chip LED package unit as in claim 13, wherein a reflecting film is formed on the inner surface of the reflecting cover.

15. The flip chip LED package unit as in claim 13, wherein the reflecting cover is mounted on the external carrier substrate by using a non-conducting attach.

16. The flip chip LED package unit as in claim 12, wherein the material of the ceramic substrate is selected from A1N, A1₂0₃, BeO, SiC, ZrO₂ and glass ceramic.

18. The flip chip LED package unit as in claim 12, wherein the metal leadframe can be mounted on the ceramic substrate by means of sintering.

19. The flip chip LED package unit as in claim 12, wherein the conducting layer on the ceramic substrate achieves electric connection with the external carrier substrate by using one or more metal wires.

20. The flip chip LED package unit as in claim 12, wherein the external carrier substrate is located at the lower surface of the ceramic substrate, and the external carrier substrate uses one or more conducting plugs to connect with the ceramic substrate.

21. The flip chip LED package unit as in claim 12, wherein a metal hear-radiating fin is further disposed on the lower surface of the ceramic substrate.

22. The flip chip LED package unit as in claim 12, wherein the LED chip is mounted on the conducting layer of the ceramic substrate by using a eutectic material.

23. The flip chip LED package unit as in claim 22, wherein the eutectic material is Au—

Sn or Au—

Si.

24. The flip chip LED package unit as in claim 12, wherein the ceramic substrate is mounted on the metal body by using a thermally conductive adhesive or solder.

25. The flip chip LED package unit as in claim 12, wherein the material of the metal body includes copper.

17. (canceled)

26. A flip chip LED package unit comprising:

a ceramic substrate made of a material capable of enduring the eutectic temperature of the fabrication process;

a metal wire layer distributed on the surface of the ceramic substrate;

at least an LED chip mounted on the conducting layer on the ceramic substrate to achieve electric connection.

27. The flip chip LED package unit as in claim 26, wherein one or more cavities are further formed in the ceramic substrate to accommodate the LED chip.

28. The flip chip LED package unit as in claim 27, wherein a reflecting film is formed on the surface of each of the cavities.

29. The flip chip LED package unit as in claim 26, wherein a reflecting cover is further annularly disposed around the LED chip.

30. The flip chip LED package unit as in claim 29, wherein a lens further covers the upper surface of the reflecting cover.

31. The flip chip LED package unit as in claim 26, wherein the material of the ceramic substrate is selected from AlN, Al₂O₃, BeO, SiC, ZrO₂ and glass ceramic.

32. The flip chip LED package unit as in claim 26, wherein a metal plate is further disposed on another surface of the ceramic substrate.

33. The flip chip LED package unit as in claim 26, wherein the LED chip is mounted on the metal wire layer by using a eutectic material.

34. The flip chip LED package unit as in claim 33, wherein the eutectic material is Au—

Sn or Au—

Si.