Flip-chip light emitting diode device without sub-mount

• US 20070114557A1
• Filed: 01/16/2007
• Published: 05/24/2007
• Est. Priority Date: 03/05/2004
• Status: Abandoned Application

• Current Assignee: Gelcore (General Electric Company)
• Original Assignee: Gelcore (General Electric Company)
• Inventors: Arthur, Stephen, Eliashevich, Ivan, Venugopalan, Hari, Libon, Sebastien, LeBoeuf, Steven, Shelton, Bryan, Soules, Thomas, Weaver, Stanton, Chen, Chen-Lun
• Application Number:
  US11/654,165
• Publication Number:
  US 20070114557A1
• Time in Patent Office: Days
• US Class Current: 257/99
• CPC Class Codes: H01L 2224/0345 Physical vapour deposition [PVD], e.g. evaporation, or sputtering
• CPC Class Codes: H01L 2224/03462 Electroplating
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/04026 Bonding areas specifically adapted for layer connectors
• CPC Class Codes: H01L 2224/05005 Structure
• CPC Class Codes: H01L 2224/05023 the whole internal layer protruding from the surface
• CPC Class Codes: H01L 2224/05027 the internal layer extending out of an opening
• CPC Class Codes: H01L 2224/0508 being stacked
• CPC Class Codes: H01L 2224/05099 Material
• CPC Class Codes: H01L 2224/05139 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/05144 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/05155 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/05552 in top view
• CPC Class Codes: H01L 2224/05564 Only on the bonding interface of the bonding area
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/05611 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/13139 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/13144 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/13147 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/1357 : Single coating layer
• CPC Class Codes: H01L 2224/13599 : Material
• CPC Class Codes: H01L 2224/13639 : Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/13644 : Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/16 : of an individual bump connector
• CPC Class Codes: H01L 2224/16225 : the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16227 : the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/29099 : Material
• CPC Class Codes: H01L 2224/29599 : Material
• CPC Class Codes: H01L 2224/3003 : Layer connectors having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/73103 : Bump and layer connectors
• CPC Class Codes: H01L 2224/73203 : Bump and layer connectors
• CPC Class Codes: H01L 2224/83193 : wherein the layer connectors are disposed on both the semiconductor or solid-state body and another item or body to be connected to the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/83203 : Thermocompression bonding, e.g. diffusion bonding, pressure joining, thermocompression welding or solid-state welding
• CPC Class Codes: H01L 2224/83205 : Ultrasonic bonding
• CPC Class Codes: H01L 2224/8321 : using a reflow oven
• CPC Class Codes: H01L 2224/8323 : Polychromatic or infrared lamp heating
• CPC Class Codes: H01L 2224/83815 : Reflow soldering
• CPC Class Codes: H01L 24/81 : using a bump connector
• 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 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00013 : Fully indexed content
• 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 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 33/38 : with 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

A light emitting diode (10) has a backside and a front-side with at least one n-type electrode (14) and at least one p-type electrode (12) disposed thereon defining a minimum electrodes separation (d_electrodes). A bonding pad layer (50) includes at least one n-type bonding pad (64) and at least one p-type bonding pad (62) defining a minimum bonding pads separation (d_pads) that is larger than the minimum electrodes separation (d_electrodes). At least one fanning layer (30) interposed between the front-side of the light emitting diode (10) and the bonding pad layer (50) includes a plurality of electrically conductive paths passing through vias (34, 54) of a dielectric layer (32, 52) to provide electrical communication between the at least one n-type electrode (14) and the at least one n-type bonding pad (64) and between the at least one p-type electrode (12) and the at least one p-type bonding pad (62).

Claims

1. A light emitting device including:

a light emitting diode having a backside and a front-side with at least one n-type electrode and at least one p-type electrode disposed thereon defining a minimum electrodes separation;

a bonding pad layer including at least one n-type bonding pad and at least one p-type bonding pad defining a minimum bonding pads separation that is larger than the minimum electrodes separation; and

at least one fanning layer interposed between the front-side of the light emitting diode and the bonding pad layer, the at least one fanning layer including a plurality of electrically conductive paths passing through vias of a dielectric layer to provide electrical communication between the at least one n-type electrode and the at least one n-type bonding pad and between the at least one p-type electrode and the at least one p-type bonding pad.

2. The light emitting device as set forth in claim 1, further including:

a printed circuit board including electrical circuitry, at least one n-type bonding bump bonding connecting electrical circuitry and the at least one n-type bonding pad, and at least one p-type bonding bump connecting electrical circuitry and the at least one p-type bonding pad, there being no sub-mount disposed between the bonding bumps and the bonding pads.

3. The light emitting device as set forth in claim 1, wherein the at least one fanning layer includes:

a first fanning layer proximate to the front-side of the light emitting diode and distal from the bonding pad layer; and

a second fanning layer distal from the front-side of the light emitting diode and proximate to the bonding pad layer.

4. The light emitting device as set forth in claim 1, wherein the at least one fanning layer includes:

at least one n-type connecting pad arranged between the at least one n-type electrode and the at least one n-type bonding pad and in electrical communication with the at least one n-type electrode and with the at least one n-type bonding pad; and

at least one p-type connecting pad arranged between the at least one p-type electrode and the at least one p-type bonding pad and in electrical communication with the at least one p-type electrode and with the at least one p-type bonding pad.

5. The light emitting device as set forth in claim 4, wherein the at least one p-type connecting pad and the at least one n-type connecting pad define a minimum connecting pads separation therebetween that is smaller than the minimum bonding pads separation.

6. The light emitting device as set forth in claim 1, wherein the at least one fanning layer seals the n-type and p-type electrodes.

7. The light emitting device as set forth in claim 1, wherein the at least one fanning layer includes a plurality of fanning layers, each fanning layer further including:

n-type and p-type intermediate connecting pads disposed over a side of the fanning layer distal from the front-side of the light emitting diode, the n-type and p-type intermediate connecting pads electrically communicating with the n-type and p-type electrodes, respectively, the n-type and p-type connecting pads defining a minimum intermediate connecting pads separation;

wherein the bonding pads are formed on the intermediate connecting pads of the fanning layer adjacent the bonding pad layer.

8. The light emitting device as set forth in claim 1, wherein the at least one fanning layer includes a plurality of fanning layers, each fanning layer further including:

n-type and p-type intermediate connecting pads disposed over a side of the fanning layer distal from the front-side of the light emitting diode, the n-type and p-type intermediate connecting pads electrically communicating with the n-type and p-type electrodes, respectively, the n-type and p-type connecting pads defining a minimum intermediate connecting pads separation;

wherein the intermediate connecting pads of the fanning layer adjacent the bonding pad layer define the bonding pads.

9. The light emitting device as set forth in claim 1, wherein at least one of the n-type electrode and the p-type electrode includes a plurality of electrodes, and the corresponding at least one of the n-type bonding pad and the p-type bonding pad electrically connects the plurality of electrodes.

10. The light emitting device as set forth in claim 1, wherein the dielectric layer includes:

a polyamide dielectric layer having a thickness of at least 2 microns.

11. A method comprising:

providing a light emitting device including a light emitting diode having a backside and a front-side with at least one n-type electrode and at least one p-type electrode disposed thereon defining a minimum electrodes separation, a bonding pad layer including at least one n-type bonding pad and at least one p-type bonding pad defining a minimum bonding pads separation that is larger than the minimum electrodes separation, and at least one fanning layer interposed between the front-side of the light emitting diode and the bonding pad layer, the at least one fanning layer including a plurality of electrically conductive paths passing through vias of a dielectric layer to provide electrical communication between the at least one n-type electrode and the at least one n-type bonding pad and between the at least one p-type electrode and the at least one p-type bonding pad; and

flip-chip bonding the provided light emitting device to a support having electrical circuitry, the flip chip bonding electrically connecting the at least one n-type bonding pad and the at least one p-type bonding pad with the electrical circuitry of the support.

12. The method as set forth in claim 11, wherein the flip-chip bonding employs a flip chip bonding process having a lateral tolerance that is larger than the minimum electrodes separation and smaller than the minimum bonding pads separation.

13. The method as set forth in claim 11, wherein the flip-chip bonding employs a flip chip bonding process having a lateral tolerance that is greater than about 0.15 mm.

14. The method as set forth in claim 11, wherein the providing includes:

forming a dielectric layer having vias passing through the dielectric layer; and

forming the electrical bonding pads by (i) depositing a seed layer inside vias, and (ii) electroplating to fill the vias and to mushroom electroplated material over the dielectric layer to define the n-type and p-type bonding pads.

15. The method as set forth in claim 11, wherein the providing includes:

forming a first dielectric layer having vias passing through the first dielectric layer;

filling the vias with a first conductive material;

disposing a second dielectric layer over the first conductive material, the second dielectric layer having vias passing through the second dielectric layer for accessing the first conductive material; and

disposing the electrical bonding pads over the second dielectric layer, the electrical bonding pads electrically contacting the n-type and p-type electrodes through the first conductive material and the vias through the second dielectric layer.

16. The method as set forth in claim 15, wherein the providing further includes:

prior to the disposing of the electrical bonding pads, filling the vias through the second dielectric layer with a second conductive material and disposing a third dielectric layer having vias passing through the third dielectric layer over the second conductive material, the electrical bonding pads being disposed over the third dielectric layer and electrically contacting the n-type and p-type electrodes through the first conductive material, the second conductive material, and the vias through the third dielectric layer.

17. The method as set forth in claim 11, wherein the flip chip bonding includes one of conductive adhesive bonding and soldering.

18. The method as set forth in claim 11, wherein the flip chip bonding does not include interposing a sub-mount between the provided light emitting device and the support.

19. An apparatus including:

a light emitting diode having a frontside metallization including (i) n-type and p-type electrodes and (ii) n-type and p-type bonding pads spaced apart from the n-type and p-type electrodes by at least one dielectric layer, the n-type bonding pad electrically connected with the n-type electrode and the p-type bonding pad electrically connected with the p-type electrode; and

a support including printed circuitry, the light emitting diode being flip-chip bonded to the support without an intervening sub-mount such that the n-type and p-type bonding pads electrically connect with the printed circuitry of the support.

20. The apparatus as set forth in claim 19, wherein the n-type and p-type electrodes have a relatively more complex lateral configuration and the n-type and p-type bonding pads have a relatively simpler lateral configuration.