James E. Morris

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Nanopackaging Nanotechnologies in
Microelectronics Packaging

• James E. Morris
• Department of Electrical Computer Engineering,
• Portland State University, Portland, Oregon, USA
• j.e.morris_at_ieee.org

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(No Transcript)
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Nanopackaging

• Primary current issues in Microelectronics
  Packaging
• Embedded passives
• Thermal dissipation
• 3D integration
• Nanotechnologies in Microelectronics Packaging
• Nanoparticles
• Carbon nanotubes
• Nanoparticles CNTs in ECAs
• Nanowires, nanospring contacts

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Nanoparticle inclusion in epoxy AgNO3 Wong et
al, ECTC06 Jiang/Moon/Wong APM05
Pothukuchi/Li/Wong ECTC04
(hardener)
Surface treatments to avoid agglomeration
Nano-particles
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Nanoparticle Properties (High surface/volume
ratio?catalysts, etc)
Nanoparticles ? single grain, no defects (Mallik)
Criterion Fermi Level in Conduction
Band Aguilera-Granja Nanotechnology (2007)
(atoms)
DIFFUSION
Ostwald ripening
Sintering (thermally
activated) Coalescence Ohring (2002)
Melting Point Depression Normalized curves
independent of material Solder
0.05(273217) 24.5K TM ? 192.5C for
5nm i.e. 5 at 5nm Sambles, Proc. Royal Soc.
(1971) TEM observations
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(Hongjin Jiang et al, ECTC07)found by DSC
Melting Point Depression in Nanoparticle No-Pb
Solders
(Johan Liu et al, EPTC 2008)
Sn-3.0Ag-0.5Cu
SnAg
? 5 reduction (K) at 5nm
Sn-0.4Co-0.7Cu
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Embedded PWB passives (Das et al, ECTC 2009,
591-598)
BaTiO3 Nanoparticles
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High-k Ag nanocompositesAg nanoparticles from
AgNO3Coulomb blockade effect reduces
leakage/loss?
Lu/Moon/Xu/Wong, APM05
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Nanoparticle Charging the Coulomb Block (Morris)
Spherical nanoparticles, radius r, separation
s Electrostatic charging energy
Electrostatic charging energy
?
Field assistance
Net thermal barrier ?0 for qV?E
0.5nm 1nm 2nm 4nm
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Embedded Cermet Resistors Crx(SiO)1-x
(CrxSi1-x)1-yNy
Electromicrographs of (CrxSi1-x)1-yNy films (a)
x0.4, y0, (b) x4, y0.1.
(b)
(a)
Incr T Amb ? 77K
Nanoparticle film
Single nanoparticle
8020 SiOCr R(T) ve/-ve TCRs Balance
TCR?E lt0 and TCRmetal gt0
STM
Electrical characteristics typical of Coulomb
Blockade devices Coulomb effects wash out at
room temperature (thermal charging)
(Wu Morris)
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Printed Nanoparticle Interconnect Deposition
(Felba Schaeffer) e.g.
on flex
(Mei et al)
Ag nanoparticle paste Initially, and after
dipping in methanol for 180s, 600s, 3600s (Wakuda
et al)
Au line cured by 300mW laser (Bieri et al)
Nanoscale Ag on Si, before and after sintering at
280 (Bai et al)
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Nano-Silica Flip-Chip Underfill
Untreated Agglomerated Silane treated
CTE/modulus reduction with less settling
(Lall et al)
Sun Wong, ECTC04
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Metal Nanoparticles added to SnAg
Solder Intermetallic Compound (IMC) Growth
(Amagai)Impact resistance markedly improved by
the addition of Ni, Co, or Pt
One solder reflow Four solder reflows
Top Sn3.0Ag solder IMC growth Most no effect.
Bottom Sn3.0Ag0.03Ni limits IMC growth. Also Co,
Pt
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Carbon Nanotubes (CNTs)
Arc/laser deposition ? random spaghetti
Lee et al, ECTC05
High T CVD V-L-S process vertical growth,
uniform lengths
CNT classifications Single wall
SWNT Multi-wall MWNT Armchair, Zigzag,
Chiral Metallic Semiconducting SWNTs typ. ?
metallic, ? semicond Grow at
900C MWNTs Metallic Grow at 700C (?365C)
CTE 0 Thermal conductivity 6600
W/m.K Electrical (Metallic CNT) Imax CNT gt
109A/cm2 (1000 x Imax Ag/Cu) µCNT 70 x
µSi Ballistic resistance 12.5kO CNT
ropes 10-4 ?.cm
T Theoretical E Experimental
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EMC Shielding MWCNTs (Cheng et al)
Oh et al, Nanotechnology, 19 (2008) 495602
Shielding Improvement (Ionic Liquid) at low CNT
content (Jin-Chen Chiu, ECTC08)
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Open-ended CNTs for electrical interconnect Xiao
et al, ECTC 2009, 1811-1815
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CNT Interconnect (Naaemi, Huang, Meindl, ECTC
2007)(Banerjee, Li, Srivastava NANO 2008)
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CNTs in TSVs
?Xu et al, Appl Phys Lett (2007)
15nm MWNTs in 35nm vias Graham et al, Diamond
Related materials (2004)
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CNT inductors (Mousa, Kim, Flicker, Ready, ECTC
2009, 497-501)
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SWCNT Effects on 63Sn-37Pb Sn-3.8Ag-0.7Cu
Solders(Kumar et al)
CNTs in grain boundaries
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Mechanical Effects (Yamamoto, Nanotechweb.org)
Acid etch Aids dispersion Increased
interfacial friction Better than smooth CNTs
0.9 vol acid-etched CNTs 27 bending
strength 25 fracture toughness
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Electromigration (Yang Chai et al ECTC08)
CNTs inhibit void growth
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CNT Contact Bumps(Liu Wang)
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Placement of Aligned CNTs for Packaging
(Kyoung-Sik Moon, ECTC08 Zhu et al, ECTC06
Soga et al, ECTC08)
CNT Growth on Si Localized heating (Ting Xu et
al, ECTC08) ?T400C
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CNT Thermal Interface (Zhang et al, ECTC06)
(Mallik)
Aligned SWNTs?
Random SWNTs?
Random MWNTs?
?Graphite
Pradham et al, Nanotechnology, 20 (2009) 245705
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CNT Heat Sink(Liu Wang)
(Zhaonian Cheng, SMIT Center, Shanghai University)
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Nanoparticles in Isotropic Conductive Adhesives
(ICAs)
Percolation limits of different ICA filler
particles
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Ag nanoparticles added to Ag-flake ICAs
Fan/Su/Qu/Wong ECTC 2004 Wong et al, ECTC06

• 80 Ag nanoparticles no effect
• 70 Ag nanoparticles percolation threshold
• Ag more effective as flakes
• Until sintering!

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Nano-particle sintering Wong et al, ECTC 04
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Surfactants 5 diacids
Without surfactant ?
With surfactant ?
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ICA Microvia Fill (PWB)
Das Egitto
LMP
Cu
75C micro/nano Ag sintering
Ag
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Ag Nanowire Anisotropic Conductive Film (ACF) (Au
seed, Co alignment)Lin et al, ECTC05
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Ni Nanowire Contacts IEEE Trans CPT (2008)
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Microsprings(Ma et al)
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Nanosprings (Ma et al)
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Summary

• Nanopackaging materials (electrical, mechanical,
  thermal)
• Nanoparticle applications
• Carbon nanotube (CNT) applications
• Electrically conductive adhesives (ECAs)
• Nanowires, nanospring contacts
• Nanopackaging Nanotechnologies in Electronics
  Packaging, J.E. Morris (editor) Springer
  (August 2008)