1

Evolving Challenges In LED Manufacturing

Iain Black June 5, 2013

Wafer

LED DieLED PackageLED Product LED Array Was – Emerging products , Sub-con board level 1 Package type (DOC) 1 architecture 3” Sapphire Wafers mainly high power. 2 Phosphor technologies 1 die type 1970/80 Mfg Tech Many remote phosphor

Is – Plethora of products , Sub-con board level >5 Package type

3 architecture

6” Sapphire Wafers Hi, mid and low Power. In house integrated L2 up to 5 Phosphor tech each up to 4 types 1990’s Mfg Tech Direct white, some remote Some white plus solutions

Will Be – Plethora of products , Sub-con board level >5 Package type or more

3 architecture 6” Wafers – 8”’ Si?

Hi, mid and low Power. In house integrated L2 Consolidation of Phosphor each > 4 types 1990’s Mfg Tech Direct white, some remote Intelligence on L2 Alternate substrates ? Some white plus solutions Custom solutions SMART solutions

Incr

easi

ng v

alue

see

n in

Vert

ical

Inte

grat

ion

Bui

ldin

g B

lock

app

roac

hto

miti

gate

com

plex

ity

L2 p

rodu

cts

, pac

kage

free

die

for l

ower

cos

t

Con

trol

of d

istr

ibut

ions

and

com

mon

cos

ts

LED Applications

2

Control of Distributions/Costs

• Our approach was to start with Wafer Size Change : 3” GaN on Sapphire - > 150mm GaN on Sapphire

– Process Capability Improvements – enhanced tool capabilities – Process Productivity Improvements – efficiencies from GDPW – Process Yield Improvements – reduced defectivity, improved distributions Increase capacity (~4x more dies in single wafer) to meet volume ramp

≈ 3-inch

6-inch

Significant productivity gain from 3”inch to 6”inch conversion

> 3

Improved Process Capability - Annealing New equipment with advance capability for 150mm wafers allows process improvements and better process control.

Annealing Vertical furnace with Larger Flat Zone and Better Process Control

Vf_Mean (3 Inch WF) Vf_Mean (6inch WF)

LSL USL LSL USL

Sample Mean 3.06002 Sample N 13368 StDev (Within) 0.0659322 StDev (O v erall) 0.0755034

Process Data

C p 3.16 C PL 2.83 C PU 3.49 C pk 2.83

Potential (Within) C apability

S ample M ean 2.93325 S ample N 9422 S tDev (Within) 0.0230142 S tDev (O v erall) 0.0263232

P rocess D ata

C p 9.05 C P L 6.28 C P U 11.83 C pk 6.28

Potential (Within) C apability

4

Improved Process Capability & Productivity – Wafer Thinning

Thinning Consolidated single step machine

Diamond -> BC ->Polish Mounting process

3” WF 6” WF

Parameters Stdev Cpk Stdev Cpk

Thickness 7.91 0.97 2.35 2.06

5

Reduced 3 steps process into one single step

New equipment have full thickness control with In-situ thickness monitoring and single wafer processing hence achieve significant better Cpk.

Improved Process Productivity & Defect Density Dielectric Deposition (PECVD) Retrofit cassette station with robotic arm

palette tray

Cassette Loader

3” WF 6” WF

Parameters Average Stdev Average Stdev

Defect Density (count/cm2) 0.194 0.200 0.017 0.029

Defect Density for 150mm Wafer Processing An Order Of Magnitude Lower As A Result Of Reduced Manual Handling

6

The Benefit

Last 2 Quarters of 3” Mfg (mix) 150mm Mfg Only

Starting 2012

Last 2 Quarters of 3” Mfg (mix)

150mm Mfg Only Starting 2012

DL H/C – 3”or Equivalent

150mm LED wafer ~16kmm2

7

Control of Distributions/Costs - Future

• More of the Same – continuous improvement, through DfX programs. – Drive Yields? – Drive tighter product distributions ? – Low/Lower cost materials ?

• Move to 8” – Does this make sense ? : – In EPI ? On Sapphire ? On Silicon ? – In Wafer Fab ? Another 1.8x GDPW v substrate & tool cost/control ?

• Load the factories….embrace complexity – Resistance is FUTILE !

• Exploit Building Blocks & Common Processes

8

Building Blocks & Complexity

• Epi/Die Blocks that can be used – – As emitters – As part of emitters – In Modules & L2 (board products)

1. Single design → Upgrade Flexibility

2. Single design → Multiple SKUs

3. Single design → common Phosphor solutions

4. Single design → Manufacturing Simplicity

9

Manufacturing In the Future

• What will the Market demand ?

• Lower Costs/Higher Value ? • Enhanced performance.... • New form factor paradigms

• L1/L2 increasing levels of integration of technology

• Flexibility and expanded capability to include for Light engines a level of technology integration….electronics ?

• A supply chain of final product manufacturing using building blocks to allow final integration to vast arrays of SKUs, close to customers.

10

The Future – how can you change a 130yr old product….?

In 1873 - Alexander Graham Bell demonstrated the Telephone… In 1876 – Thomas Edison patented the electric light bulb…

Then later we got switchboards, direct dialing, digital, cordless…. Then later we got Fluorescent ,HID, Halogen etc….

But for 120 years, it was a box wired to a wall….and you could talk to folks who had another….. But now we have digital control of a solid state product….. What now ?

From the early 90’s till today……the Digital & WL revolution has put one in every pocket – it’s a computer, you type more messages than you call and you can talk to folk who don’t even have one….it is an essential lifestyle.

If the future of lighting is about more than the Light bulb….

Is the future of LED Manufacturing is more than Manufacturing LEDs ? 11