The photon delivery company
9th Annual MEMS Symposium, San Jose, CA
Thursday, May 19, 2011
Wafer-level micro-optics with
mechanical features
Dr. Jyrki Saarinen
Co-Founder and Senior Vice President
Copyright © 2011 Heptagon
JSa / 070207 v2.2 p.1
The photon delivery company
Outline
(1) Introduction to micro-optics
(2) Introduction to wafer-level micro-optics
(3) Company overview
(4) Wafer-level manufacturing
(5) Applications
(6) Summary
Copyright © 2011 Heptagon
JSa / 070207 v2.2 p.2
The photon delivery company
Outline
(1) Introduction to micro-optics
(2) Introduction to wafer-level micro-optics
(3) Company overview
(4) Wafer-level manufacturing
(5) Applications
(6) Summary
Copyright © 2011 Heptagon
JSa / 070207 v2.2 p.3
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Micro-optics
Micro-optics means
flat optical elements (refractive and diffractive) with features in the
sub-mm or sub-um range, which are fabricated mainly by state-of-theart lithographic methods
Refractive micro-optics
Analog to conventional optics, but smaller
and lighter
e.g. microlenses,
microlens arrays
Diffractive micro-optics
Enables functionality not possible with
conventional optics
e.g. pattern generators,
complex beam shaping
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Micro-optics (cont.)
Continuous transition from refractive to
diffractive optical function in many cases
e.g. Fresnel microlenses, where properties
can vary from refractive to diffractive
depending upon relief height
Refractive: low spectral dependence wellsuited for broad-band illumination
Diffractive: highly accurate focal length wellsuited for uniform microlens
arrays
Also integration/mixing refractive and
diffractive micro-optics together or side-byside
Copyright © 2011 Heptagon
JSa / 070207 v2.2 p.5
The photon delivery company
Outline
(1) Introduction to micro-optics
(2) Introduction to wafer-level micro-optics
(3) Company overview
(4) Wafer-level manufacturing
(5) Applications
(6) Summary
Copyright © 2011 Heptagon
JSa / 070207 v2.2 p.6
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Revolution of microelectronics
From transistor
To Integrated Circuit (IC)
• Invented in 1947
• # of transistors: one
• Invented in 1958
• # of transistors: >>1M per mm2
• Production in 300-mm diameter
wafer
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Why not in optics, too?
400 BC
Invention of lens
1950‘s
Injection-molded plastic lens
Mass production: few tens of lenses per shot
1980‘s
Molded glass lens
Robustness
Few thousand glass-like lenses per shot and waferlevel assembly for lens systems by stacking:
2006
Wafer-level (6“) UV replication for reflowable
singlet lenses at Heptagon Switzerland
2008
Wafer-level (8“) UV replication and stacking
for reflowable doublet lens systems at
Heptagon Singapore
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Wafer-level optics (WLO)
Silicon wafer
Heptagon‘s optics wafer
• Single or double sided
• Variety of substrates (e.g., fused silica,
borosilicate)
• Metal and thin-film coatings (e.g., IR-cutoff filter, anti-reflection coating)
• Stacking with spacer wafers
• Stand-off wafers / bottom spacers
• NEW: Mechanical features, alignment pins
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Value propositions
 Direct integration in SMT assembly
process, lead-free reflow, 3×260ºC
 Accelerated moisture resistance (>1000
hrs, 85ºC/85%, R.H.), Telcordia proven
Reflowable
&
Small
Parallel
Processing
 RoHS compliance
 Small XY footprint and low z-height
 1000’s of components per wafer, high
throughput, high quality and fidelity
Scalability
&
Innovation
Low
Cost
 8” wafer processing
 Wafer-level stacking and assembly
 Micro-optics enabling high performance
(efficiency and uniformity), flexibility for
beam shaping, and attractive cosmetic
appearance
 Platform for future technologies, e.g.,
computational imaging
Copyright © 2011 Heptagon
JSa / 070207 v2.2 p.10
The photon delivery company
Outline
(1) Introduction to micro-optics
(2) Introduction to wafer-level micro-optics
(3) Company overview
(4) Wafer-level manufacturing
(5) Applications
(6) Summary
Copyright © 2011 Heptagon
JSa / 070207 v2.2 p.11
The photon delivery company
Company overview
•
Pioneer and world-leader in designing and manufacturing wafer-level
optics: diffractive optics and micro-optics
•
Locations: Switzerland & Singapore & USA
•
First to industrialize wafer-level optics back in 2006
•
Key customers: mobile phone & data communication component
OEM’s
•
Shipped >200M optics components to date, reaching 500M in 2011
•
Highly yielding optics with a proven manufacturing capability
•
One-stop shop: from optical design to high volume manufacturing
R&D Facilities
Sales & Marketing
Sales & Marketing
Sales & Marketing
Manufacturing
Copyright © 2011 Heptagon
JSa / 070207 v2.2 p.12
The photon delivery company
Outline
(1) Introduction to micro-optics
(2) Introduction to wafer-level micro-optics
(3) Company overview
(4) Wafer-level manufacturing
(5) Applications
(6) Summary
Copyright © 2011 Heptagon
JSa / 070207 v2.2 p.13
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Production chain
Step-and-repeat wafer-level mastering
Mastering /
Wafer-level mastering
1st gen.
replication tool
Submasters
x,y,z
2nd gen.
replication tool
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Wafer-level UV replication
At room temperature!
No extra pressure applied!
Optional: coating
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JSa / 070207 v2.2 p.15
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Stacking and alignment in z
direction
• Separating single or double sided optical wafers from each other by
correct amount  optical systems, like lens doublets, triplets etc.
• Separating optics system from sensor or light source by correct
amount
• Heptagon developed replication technology for spacer wafers:
enables low-cost and robust glass-like polymer spacers
Cross-section
Glass wafers with
lenses
AB wafer
AB wafer
Spacer 1
CD wafer
Spacer 1
Spacer 2
CD wafer
Replicated spacer
wafers
Spacer 2
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Alignment in xy direction
Background:
WLO manufacturing technologies were developed first for optics,
extension to mechanical features recently explored with positive
results
Mechanical features (on both sides of a wafer) for passive alignment
in assembly
Option 1: Replicating the mechanical features in the same step and
materials as the micro-optics
Option 2: Combine WLO with SU-8 features, which are fabricated
using standard micro-electronic photolithography
equipment for a good positioning accuracy with respect to
the WLO and for good control of the geometry
Note: Depends on the specifications and materials.
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Examples of mechanical
features
12° slanted walls on a 150-um thick
alignment feature
100-um cylinder (top), 150-um
pitch, 12° angle, 150-um height
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Micro-optics with double sided
mechanical features
2×12 micro-lens array with 2-sided
alignment features
Diameter 700 um; thickness 300 um
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Precision dicing
•
Cutting stacked wafers into individual optical
systems by precision dicing
Copyright © 2011 Heptagon
JSa / 070207 v2.2 p.20
The photon delivery company
Outline
(1) Introduction to micro-optics
(2) Introduction to wafer-level micro-optics
(3) Company overview
(4) Wafer-level manufacturing
(5) Applications
(6) Summary
Copyright © 2011 Heptagon
JSa / 070207 v2.2 p.21
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Diffractive optics and micro-optics
by Heptagon since 1990‘s
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Reflowable lens module
Optical axis
Lens yard
Lens A
Cr A Aperture
IR filter
Glass 1
Lens B
Plastic spacer 1
Lens C
Glass 2
Cr C Aperture
Lens D
Plastic spacer 2
CMOS Sensor
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CIF+ lens modules (singlets)
Injection
molded barrel
& mount
(reflowable
LCP material)
MTF yield on
wafers >98%
TTL 2.7 mm
footprint:
1.7× 1.7 mm
2,000 lenses
per wafer
Sensor with
3.6-um pixel
Volume
production
since 2006
Copyright © 2011 Heptagon
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No-focus VGA lens modules
VGA doublet
• No-focus: no adjustment of focal length after
assembly (no barrel&mount needed)
• Includes IR cut-off filter, apertures, baffle and
stand-off for assembly without extra holder
TTL: 2.1 mm
footprint: 2.4 × 2.4 mm
VGA singlet
TTL: 1.7 mm
footprint: 2.4 × 2.4 mm
• Mechanical dimensions optimized for direct
mounting (semi-wafer-level assembly) on TSV
sensors
• Optical resolution meets typical specs for primary
and secondary VGA cameras (1/10” and 1/13”)
• Image quality at least on par with glass or
injection molded lens systems
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No-focus 2 MPix lens modules
• 2-wafer solution for entry level 2 MPix
cameras
• No-focus: no adjustment of focal length
after assembly (no barrel&mount needed)
• Includes IR cut-off filter, apertures, baffle
and stand-off for assembly without extra
holder
TTL: 3.3 mm
footprint: 4.2 × 4.2 mm
• Mechanical dimensions optimized for direct
mounting (semi-wafer level assembly) on
TSV sensors
• Image quality comparable to glass molded
lenses (2G)
• No AR coating on lenses required
Copyright © 2011 Heptagon
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LED flash lenses
Heptagon's LED flash lens based on micro-optics has
better visual appearance
higher efficiency at lower heights
higher uniformity and irradiance control
Heptagon Lens
Cosmetics
Fresnel Lens
2
-600
1.8
-400
y position [mm]
Performance
Normalized irradiance as a function of x and y position
1.6
1.4
-200
1.2
0
1
200
0.8
400
0.6
0.4
600
-500
0
x position [mm]
500
0.2
Copyright © 2011 Heptagon
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The photon delivery company
WLO for data communication
• Heptagon is changing the industry paradigm by offering replicated waferlevel micro-optics as a low-cost alternative to etched fused silica
components
• Possibility to fabricate refractive and diffractive micro-optics in a single
technology step
• Possibility to include high-reflection and anti-reflection coatings
• Telcordia compatible
Copyright © 2011 Heptagon
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The photon delivery company
Summary







WLO is cost-effective high-volume production method
Diffractive optics and refractive micro-optics enable
sophisticated, but miniaturized (flat/small height and small
footprint) control and modification of light
Easy pre and post processing (e.g., metal and thin-film
coatings) in wafer-level for miniature optics
Stacking wafers with spacer wafers allows manufacturing of
thousands of more complicated optical systems in parallel
Mechanical features, like alignment pins, enable accurate
passive alignment
Heptagon’s WLO is Telcordia proven, lead-free reflow
compatible, and RoHS compliant
Heptagon is already manufacturing tens of millions of optics
components in applications like, CMOS imaging, LED lighting,
and optical data communication
Copyright © 2011 Heptagon
JSa / 070207 v2.2 p.29
The photon
photondelivery
deliverycompany
company
www.heptagon.fi
Thank you!
Jyrki Saarinen
San Jose, CA
[email protected]
Tel. (415) 624-4343
Copyright © 2011 Heptagon
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