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Recent Progress for LED Device and Package for SSL

Presented by Carson Hsieh 01/11/2013

CONFIDENTIAL

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Outline

• Introduction

• Recent progress for LED Device

• New Package for SSL

• Summary

Ⓒ2013 Epistar Corporation. All Right Reserved.

LED Adoption : Key for Growth in the Lighting Industry 3

Source: Philips Lighting 2010, OSRAM 2012, LEDinside 2012

• PHILIPS predicts ~ 50% lighting revenue from LED by 2015 • LED light bulb show ~ 50% volume share in Japan

Ⓒ2013 Epistar Corporation. All Right Reserved.

Package Device for Backlighting Applications 4

• Total flux and power per package increases with time • Number of package decreased to reduce the cost

8.5 25

100

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Ⓒ2013 Epistar Corporation. All Right Reserved.

Mid Power Chip for A-Bulb – Low Cost Approach 5

Small/Medium power chips have better flexibility and broader applications. …… may results in a lower cost.

Choices

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Ⓒ2013 Epistar Corporation. All Right Reserved.

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Next: ~200 lm/W; 500 lm/$ vs. ~150 lm/W; 1,000 lm/$ @2015 ??

Same performance for cool white and warm white @2020 ??

LED Efficacy (lm/W) and Price ($/Klm) Roadmap

Ⓒ2013 Epistar Corporation. All Right Reserved.

How to Achieve 10x lm/$ Improvement… … 7

Performance up

Cost Down

Manufacturing improvement New package technologies

Efficacy improvement Package improvement Droop reduction

$

lm

2x

5x

Between 2010 and 2020 … …

Lm/$

$/mm2

W/mm2

lm/W

$/pkg

W/pkg

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Outline

• Introduction

• Recent progress for LED Device

• New Package for SSL

• Summary

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Low droop Lm/$, ..

PKG factor Lux/Lm, PKG efficiency

Cost 2”,4”,6”,… GaN/Si,…

Efficiency Vf, Po, Lm/W

Special Func. chip Binning POC,

Solid State Lighting

LED Chip for Solid State Lighting

LED Epitaxy Develop Trend V type

(horizontal)

F type (horizontal)

Active Layer n-pad

TCL

n-GaN

p-GaN

Buffer Layer

Al2O3 Substrate

p-pad

Backside metal (mirror)

Active Layer n-pad

TCL(ITO)

n-GaN

p-GaN

Buffer Layer

p-pad

Backside metal (mirror)

Al2O3 Substrate

Active Layer n-pad

TCL(NiAu)

n-GaN

p-GaN

Buffer Layer

p-pad

Backside metal (mirror)

Al2O3 Substrate

Next ? Next? Next ?? Next ???

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PSS type change

Patterned sapphire substrate (PSS) can effectively enhance light extraction efficiency from LED. Smaller and denser pattern structure is the trend of development.

Sapphire substrate with periodical microstructure formed by dry or wet etch provides a platform for GaN epitaxy and is now widely used for high-brightness LED.

Change in height & shape

Change in size &

pitch

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Advantages of nano-scale patterned sapphire substrate(NPSS): light extraction enhancement & higher epitaxy productivity due to thinner epitaxial layer required for coalescence.

PSS & NPSS

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Various substrate tech. PSS

GaN on Si

u-/n-GaN

Sapphire

LED

nRoS Nano-Porous

n-GaN

Sapphire

LED

u-GaN

u-/n-GaN

Si

LED

buffer layer

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• nRoS vs PSS : thinner epitaxial layer and shorter growth time make nRoS effective on cost reduction.

SEM – nRoS & PSS

15 Nano- porous (NP) LED process

Morphology of NP with different process time

16 Venus vs NP Venus

Sapphire

u-GaN

NP

n-GaN

Sapphire

n-GaN

u-GaN

Venus NP Venus

SEM

vs

P-GaN

NP

LED n-GaN

V45H V45H

Au-TO (s-site) w/o Glue 326 mW 334 mWAg-TO (N-site) w/o Glue 427 mW 428 mWAg-TO (N-site) w/ Glue 489 mW 502 mW

346 356

Type

MAP RS-Power

Venus NP Venus

Light extraction efficiency of InGaN LED can also be improved by nano-porous (NP) structure. Po of LED on NP is equivalent to that of LED on PSS.

NP

u-GaN

n-GaN

TEM

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Flat & PSS & NP (TEM)

Conclusion: performance of NP LED is equivalent to that of PSS LED. Higher dislocation density in NP LED can be reduced by optimizing NP density and size and also the growth parameters.

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GaN LED on Si Advantages of GaN LEDon Si: low substrate cost, large wafer size and hence low fabrication cost Challenges: large stress in epitaxial layer, epi crack, low epi quality wafer bowing, bad wavelength uniformity

Substrate revolution

6” Sapphire

2” Sapphire

4” Sapphire

6” Sapphire

??

LED Chip technology trend

thermal management !!!!!

Reduce the die thickness

Replace the substrate with high thermal conductivity material

Flip Chip

How to improve the thermal resistance

LED chip technology platform

V type (horizontal)

F type (horizontal)

SN type (vertical)

Active Layer n-pad

TCL

n-GaN

p-GaN

Buffer Layer

Al2O3 Substrate

p-pad

Backside metal (mirror)

Active layer P-GaN

Conductive substrate

Metal layer

Backside electrode

N-pad

N-GaN

Volume-emitter Surface-emitter

Active Layer n-pad

TCL

n-GaN

p-GaN

Buffer Layer

p-pad

Backside metal (mirror)

Al2O3 Substrate

LED chip technology platform

HV type (horizontal)

Flip Chip type (horizontal)

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Outline

• Introduction

• Recent progress for LED Device

• New Package for SSL

• Summary

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PKG trend

Rth

QFN

EMC

SMC

COB

EMC and SMC 26

The reflector requires a higher resistance for the high brightness light of an LED chip, so a silicone or epoxy compound replaces the injection PPA molding compound.

Ⓒ2013 Epistar Corporation. All Right Reserved.

LED Efficiency Improvement 27

LER (Lm/W)

10-20% increase in performance is real and achievable

28 Epistar Transparency LED Patent Application (Priority Date: Apr. 13, 2006)

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Transparent LED (Filed: Nov 15, 2007) CONFIDENTIAL

30 CONFIDENTIAL

FV60 + HA40

F). Chip connection: 2S2P

G). Operating current: 16mA (8mA per chip)

H). Power consumption: 68V x 0.016A = 1.09W

+ - P

P P

P N

N N

N

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Result -- package CONFIDENTIAL

HA40 Transparent encapsulating

FV60 NYAG encapsulating

Ⓒ2013 Epistar Corporation. All Right Reserved.

Candle Bulb with HV B & R LED Filament 32

+

Self heat dissipation

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HV FV60/HA40 HV filament 4pcs 2S2P Switching driver 6mA/filament Filament VF=58.5V @ 10mA ※ Filament 2串 VF≒114V AC110V input時 因壓差較大driver效率較差。

Epistar Reinvented the Edison Bulb

Reduced heat sink cost !

Filament solution

35 Frame Free Study LED Package Cost Structure

• Chip size reduction • Performance Improvement • Frame Free • Reduce encapsulation

Delete frame/ gold wire/ ……..

CSP: Chip scale package

Flip Chip

TSMC Flip chip approach

Toshiba CSP:GaN on Si

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CSP: Chip scale package

Philips Lumileds

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• The Co-Activation Service Model

• LED Lighting Ready

• Actualize LED Potential

Embedded LED Chip:直接貼片使用的Chip

2010 12 15

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Outline

• Introduction

• Recent progress for LED Device

• New Package for SSL

• Summary

40 Summary

• LED應用從背光移動到照明 • 為了提升磊晶效率及降低成本、磊晶基板有不同嘗試

• 為解決LED散熱等問題、晶片及封裝有不同解決方案

• 透明基板封裝有較好的封裝效率 • 新穎的趨勢：不只CSP、而且無支架

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Thank You!