Method, apparatus and system for providing light source structures on a flexible substrate

• US 8,933,473 B1
• Filed: 06/01/2012
• Issued: 01/13/2015
• Est. Priority Date: 06/01/2012
• Status: Active Grant

• Current Assignee: Dubin, Valery
• Original Assignee: Dubin, Valery
• Inventors: Dubin, Valery
• Primary Examiner(s): Pham, Thanh V
• Application Number:
  US13/487,088
• Time in Patent Office: 956 Days
• Field of Search: 257/71, 257/98, 257/99
• US Class Current: 257/98
• CPC Class Codes: H01L 21/486 Via connections through the substrate with or without pins
• CPC Class Codes: H01L 21/67161 characterized by the layout of the process chambers
• CPC Class Codes: H01L 21/67173 in-line arrangement
• CPC Class Codes: H01L 21/6723 comprising at least one plating chamber electroless plating apparatuses C23C, electroplating apparatuses C25D
• CPC Class Codes: H01L 21/67236 the substrates being processed being not semiconductor wafers, e.g. leadframes or chips
• CPC Class Codes: H01L 21/67703 between different workstations
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• 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 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73267 Layer and HDI connectors
• CPC Class Codes: H01L 25/165 Containers
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• 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 2924/00014 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 2924/12041 LED
• CPC Class Codes: H01L 2924/15153 : the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: H01L 2933/0016 : relating to electrodes
• CPC Class Codes: H01L 2933/0033 : relating to semiconductor body packages
• CPC Class Codes: H01L 2933/005 : relating to encapsulations
• CPC Class Codes: H01L 2933/0066 : relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/40 : Materials therefor
• CPC Class Codes: H01L 33/486 : adapted for surface mounting
• CPC Class Codes: H01L 33/52 : Encapsulations
• CPC Class Codes: H01L 33/56 : Materials, e.g. epoxy or silicone resin
• 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
• CPC Class Codes: Y10T 29/53174 : Means to fasten electrical component to wiring board, base, or substrate

Abstract

Light emitting diode (LED) package structures employing large area substrates are described. Panel or reel-to-reel substrate processing is utilized in the manufacture of such LED package structures. In some embodiments, electrochemically deposited metal patterns and through substrate vias (TSuVs) are formed through glass substrates and/or interposers. In some embodiments, the metal deposited into the TSuVs offer high thermal conductivity a low coefficient of thermal expansion (CTE) that is to closely match the CTE of the glass. Singulated LED package structures including a plurality of LEDs arrayed for displays, such as, but not limited to, liquid crystal displays (LCDs) and LED displays or for general purpose LED light sources are described, as are LED package structures including active devices (e.g., ICs) and/or passive devices (e.g., capacitors, inductors, resistors, etc.) integrated with LEDs at the package level.

Claims

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

a flexible substrate including;

a layer of optically transparent dielectric material comprising a first side and a second side opposite the first side; and

a metal film disposed on the optically transparent dielectric material at the second side;

an LED affixed to the optically transparent dielectric material at the first side;

a pair of metal pads disposed on the first side of the optically transparent dielectric material and electrically coupled to terminals of the LED; and

an optically transparent cap disposed over the first side of the optically transparent dielectric material encapsulating the LED.

2. The LED package of claim 1, wherein the optically transparent dielectric material comprises a large area panel having a surface area of at least 3500 cm², wherein the LED is one of a plurality of LEDs arrayed over a first portion of the surface area on a first side of the panel;

and wherein the metal film is a continuous film covering a second portion of the surface area on a second side of the panel at least as large as the first portion.

3. The LED package of claim 1, wherein the optically transparent dielectric material comprises a non-alkali glass, soda lime glass, parylene, aluminum oxide having a thickness between 0.1 μ

m and 1000 μ

m.

4. The LED package of claim 1, wherein the metal pads comprise at least one of aluminum (Al), silver (Ag), gold (Au), nickel (Ni), copper (Cu), silver-tungsten alloy (AgW), copper-palladium alloy (CuPd), nickel-silver (Ni—

Ag), nickel-gold (Ni—

Au), nickel-copper (Ni—

Cu), copper-silver (Cu—

Ag) bi-layer, nickel-copper-tin (Ni—

Cu—

Sn) or nickel-copper-silver (Ni—

Cu—

Al) tri-layer.

5. The LED package of claim 1, further comprising:

a through substrate via (TSuV); and

a via metal disposed in the TSuV, wherein the via metal is selected from the group consisting of;

copper (Cu), nickel (Ni), cobalt (Co), tungsten (W), molybdenum (Mo), aluminum (Al), and their alloys.

6. The LED package of claim 5, wherein the via metal comprises a nickel-tungsten alloy (NiW), a nickel-molybdenum alloy (NiMo), a cobalt-tungsten (CoW), or cobalt-molybdenum (CoMo).

7. The LED of claim 5, wherein the metal film is selected from the group consisting of:

aluminum (Al), aluminum-silicon alloy (AlSi), aluminum-copper alloy (AlCu), aluminum-silicon-copper alloy (AlSiCu), silver (Ag), gold (Au), copper (Cu), chromium (Cr), a copper-silver (Cu—

Ag) bi-layer stack, or nickel-copper-silver (Ni—

Cu—

Ag) tri-layer stack.

8. The LED package of claim 6, wherein the TSuV has a longitudinal axis aligned with a center of the LED.

9. The LED package of claim 1, wherein the LED terminals are flip-chip bonded to the pair of metal pads, or wherein the LED is surface mounted to the optically transparent dielectric material with the terminals wire-bonded to the metal pads, and wherein the cap comprises a plastic lens.

10. The LED package of claim 9, wherein the transparent dielectric comprises at least one cavity with at least one LED or integrated circuit disposed in the cavity.

11. The LED package of claim 1, further comprising:

an interposer in contact with the metal film;

an interposer through substrate via (TSuV); and

a via metal disposed in the interposer TSuV, wherein the via metal is selected from the group consisting of;

copper (Cu), nickel (Ni), cobalt (Co), tungsten (W), molybdenum (Mo), aluminum (Al), and their alloys.

12. The LED package of claim 11, wherein the via metal comprises a nickel-tungsten alloy (NiW), or a nickel-molybdenum alloy (NiMo), a cobalt-tungsten alloy (CoW), or cobalt-molybdenum alloy (CoMo).

13. The LED package of claim 11, wherein the interposer comprises non-alkali glass, soda lime glass, parylene, amorphous silicon, polycrystalline silicon, aluminum nitride (AlN), boronitride (BN), aluminum-oxide (Al₂O₃) having a thickness between 1 μ

m and 1000 μ

m.

14. The LED package of claim 13, wherein the interposer TSuV does not extend beyond the metal film, wherein the interposer TSuV has a longitudinal axis aligned with a center of the LED, and wherein no interposer TSuV is disposed below the pair of metal pads.

15. The LED package of claim 14, further comprising an integrated circuit disposed on the interposer, and wherein the LED package further comprises:

a via extending through both the optically transparent dielectric material and the metal film, wherein a via metal disposed in the via is electrically isolated from the metal film and electrically contacting at least one of the pair of metal pads to an output pad of the integrated circuit.

16. The LED package of claim 15, wherein the integrated circuit comprises at least one of a controller or power supply.

17. The LED package of claim 14, further comprising an integrated circuit disposed on the first side of the optically transparent dielectric material, wherein the integrated circuit is surface mounted to the first side with wire bonds to at least one of the electrodes or the integrated circuit is flip-chip bonded to at least one of the pair of electrodes.

18. A light emitting diode (LED) display backlighting system, comprising:

the LED package of claim 1, further comprising a plurality of LEDs arrayed over the optically transparent dielectric material;

a metal chassis;

an interposer disposed between the LED package and the metal chassis;

a plurality of interposer through substrate vias (TSuVs) extending through the interposer, wherein each interposer TSuV has a longitudinal axis aligned with one of the plurality of LEDs; and

a via metal disposed in the interposer TSuVs, the via metal in direct contact with the metal chassis and the LED package to thermally couple each LED of the plurality to the metal chassis.

19. The LED display backlighting system of claim 18, wherein the via metal comprises a nickel-tungsten alloy (NiW), a nickel-molybdenum alloy (NiMo), a cobalt-tungsten alloy (CoW), or cobalt-molybdenum alloy (CoMo).

20. The LED display backlighting system of claim 18, wherein at least one of the dielectric layer and the interposer is a large area panel of non-alkali glass, soda lime glass, parylene, aluminum oxide, or amorphous or polycrystalline silicon, having a surface area of at least 3500 cm².

21. The LED display backlighting system of claim 18, further comprising a liquid crystal display panel disposed above the LED package.

22. The LED package of claim 1, wherein the optically transparent dielectric material is a portion of a flexible roll of dielectric film for reel to reel processing, wherein the LED is one of a plurality of LEDs arrayed over a first portion of the surface area on a first side of the dielectric film;

and wherein the metal film is a continuous film covering a second portion of the surface area on a second side of the dielectric film at least as large as the first portion.

23. A light emitting diode (LED) display, comprising:

the LED package of claim 1, further comprising a plurality of LED clusters arrayed over the optically transparent dielectric material, wherein each LED cluster includes at least three LEDs operable to emit at three different colors which, when combined, have a white point;

an interposer in contact with the metal film;

a plurality of interposer through substrate vias (TSuVs) extending through the interposer, wherein each interposer TSuV has a longitudinal axis aligned with one LED cluster or with one of the at least three LEDs in an LED cluster; and

a via metal disposed in the interposer TSuVs.

24. The LED display of claim 23, wherein the via metal comprises a nickel-tungsten alloy (NiW), a nickel-molybdenum alloy (NiMo), a cobalt-tungsten alloy (CoW), or cobalt-molybdenum alloy (CoMo).

25. The LED display of claim 23, wherein at least one of the transparent dielectric layer and the interposer is a large area panel of non-alkali glass, soda lime glass, amorphous or polycrystalline silicon, Al₂O₃ or AlN, having a surface area of at least 3500 cm².

26. The LED display of claim 23, further comprising a pixel controller integrated circuit surface mounted onto at least one of the optically transparent dielectric material and interposer, wherein the pixel controller integrated circuit is electrically coupled to at least one LED in one of the LED clusters.

27. A light emitting diode (LED) bulb, comprising:

the LED package of claim 1, further comprising a plurality of LEDs arrayed over the optically transparent dielectric material, wherein the plurality of LEDs is operable to emit at a white point;

an interposer in contact with the metal film;

a plurality of interposer through substrate vias (TSuVs) extending through the interposer, wherein each of interposer TSuVs has a longitudinal axis aligned with one of the LEDs or aligned with a center of the plurality of LEDs; and

a via metal disposed in the interposer TSuV.

28. The light emitting diode (LED) bulb of claim 27, further comprising an LED controller integrated circuit surface mounted or flip-chip connected to the optically transparent dielectric material or interposer, the LED controller integrated circuit electrically coupled to the plurality of LEDs and isolated from the LED by a dielectric material having a thermal conductivity no greater than that of silicon dioxide.

29. The light emitting diode (LED) bulb of claim 27, further comprising a heat sink coupled to the via metal, wherein the heat sink is of the same composition as the via metal.

30. A light emitting diode (LED) system, comprising:

a flexible substrate including;

a layer of optically transparent dielectric material comprising a first side and a second side opposite the first side; and

a metal film disposed on the optically transparent dielectric material at the second side;

an LED controller integrated circuit surface mounted or flip-chip connected to the optically transparent dielectric material or an interposer, the LED controller integrated circuit electrically coupled to a plurality of LEDs disposed on the first side of the optically transparent dielectric material; and

at least one of an RF and sensor circuit disposed on the optically transparent dielectric material or the interposer and electrically coupled with the LED controller integrated circuit.