Application of Nanomaterials
for Thermal Dissipation
S. Flórez, I. Garmendia, H. Vallejo, C. Jiménez,
E. Alberdi, R. Rodríguez
6th ESA Round Table on
Micro & Nano Technologies for Space Applications
ESA/ESTEC, Noordwijk
The Netherlands
11 October 2007
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Outline
•Introduction
•Objective
•Modelling. FEM analysis
•Experimental
•Influence of manufacturing process on final properties
•Conclusions
October of 2007
2 de 22
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Introduction
•
High temperatures in electronic components
•
Heat evacuated through conduction towards radiator(s)
•
Good conductivity needed all the way. Adhesive’s conductivity is critical
The aim of the THERDISS project (supported by ESA) is to conduct research in
nanocomposites to be used to dope adhesives for space conditions. Thus, it is
expected that the finally selected nanocomposite can multiply at least by a factor of
3 the thermal conductivity of a standard epoxy solution.
Objective
ELECTRONIC COMPONENT
ADHESIVE
K adhesive = 0 ,21
W
mK
NANOMATERIALS
ELECTRONIC BOARD
October of 2007
q
3 de 22
K objective = 6 ÷ 10
W
mK
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Methodology
•
MODELLING
How much nanomaterial is needed to reach Kobjective
•
EXPERIMENTAL
Real mix of nanomaterials and adhesive. Measurements.
9Commercial non conductive Hysol EA epoxy adhesive. K=0,2W/mk
•Commercial conductive epoxy adhesive. K=2W/mk
October of 2007
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Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Modelling. Finite Element Methods
1.
Mesh the model with commercial software
¾
Take into account the nano-material length
2.
Export the mesh topology to an ASCII file
3.
Add randomly the nanoparticles to the original mesh trough
THERDISS in house developed software
4.
¾
According to the weight percentage
¾
According to the properties of the nanomaterials
Establish the boundary conditions trough THERDISS
¾
5.
Solve the case with commercial software
¾
6.
Surface temperatures
The program calculates the heat flow q
Calculate the equivalent thermal conductivity by,
q = K eq ⋅
October of 2007
A
q d
⋅ ΔT → K eq =
⋅
d
ΔT A
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Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Materials
NANOMATERIALS
CNF
TYPE
Ø (m)
CNF
1.00E-07
MWNT
2.00E-08
SWNT
1.20E-09
BUCKYPAPER
1.50E-08
October of 2007
MWNT
L (m)
SWNT
BUCKYPAPER
ADHESIVE
K (W/mK)
ρ (kg/m3)
Th. (m)
1200
2100
-
MATERIAL
K (W/mK)
ρ (kg/m3)
3000
1350
-
HYSOL EA 9396
0.21
1150
1350
-
1.00E-04
5.00E-05
4.00E-05
5.00E-07
4.00E-05
1750 – 5800
5.00E-07
3775 (mean)
2.00E-05
5.00E-06
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1200
500
1.00E-4
5.00E-5
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Finite Element Models
FEM 01 and FEM 02
FEM 01
FEM 02
NANOMATERIAL
CNF
DIAMETER (m)
100.E-9
LENGTH (m)
100.E-6
50.E-6
0.1 ÷ 50
W. PERCENTAGE (%)
SCALED MODEL
NO
SCALE
-
FEM DIMENSIONS (mm)
2 x 2 x 0.1
FEM 03 and FEM 04
FEM 03
FEM 04
NANOMATERIAL
MWNT
DIAMETER (m)
20.E-9
LENGTH (m)
W. PERCENTAGE (%)
SCALED MODEL
SCALE
FEM DIMENSIONS (mm)
October of 2007
500.E-9
40.E-6
0.1 ÷ 50
NO
YES
-
1000 / 1
2 x 2 x 0.1
20 x 20 x 100
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Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Finite Element Models
FEM 05 and FEM 06
FEM 05
FEM 06
NANOMATERIAL
SWNT
DIAMETER (m)
1.2.E-9
LENGTH (m)
40.E-6
W. PERCENTAGE (%)
0.1 ÷ 50
NO
YES
-
1000 / 1
2 x 2 x 0.1
20 x 20 x 100
SCALED MODEL
SCALE
FEM DIMENSIONS (mm)
500.E-9
FEM 07 and FEM 08
FEM 07
NANOMATERIAL
BP
DIAMETER (m)
LENGTH (m)
15.E-9
20.E-6
W. PERCENTAGE (%)
SCALED MODEL
SCALE
FEM DIMENSIONS (mm)
October of 2007
FEM 08
5.E-6
19.79 ÷ 36.33
NO
YES
-
1000 / 1
2 x 2 x 0.1
200x200x100
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Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Results for fibrous shaped nanomaterials
FEM 01
FEM 02
FEM 03
FEM 04
FEM 05
FEM 06
15
14
13
THERMAL CONDUCTIVITY (W/mK)
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0,25
0,5
0,75
1
1,25
1,5
1,75
2
2,25
2,5
2,75
3
3,25
3,5
3,75
4
4,25
4,5
4,75
5
WEIGHT PERCENTAGE (%)
October of 2007
9 de 22
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Experimental
October of 2007
10 de 22
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Nanomaterials
CNF
Dispersion
SWNT <
MWNT <
CNF
Thermal properties
≈
≈
≈
Prize
SWNT>
MWNT>
CNF
Simulation: Ideal conditions
K adhesive = 0 ,21
October of 2007
W
mK
11 de 22
+ 2.5 wt% CNF
K objective = 6 ÷ 10
W
mK
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Hardener
mixing
Epoxy resin
Nanoparticles
Epoxy resin
Filler adition technology set up
casting
defoaming
Resin specimen
Hardener
DISPERSING
Curing
Mixing
under vaccum
casting
defoaming
Curing
NANOADHESIVE
Three roll mill
October of 2007
12 de 22
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Work Methodology
Manual Premix: CNF (2,5wt%) + Epoxy Part A
DEGBA
Dispersion device: Three roll mill
Control parameters: Gap and residence time
Degassing
Hardener Part B
H2N
N
N
N
NH2
Aliphatic Amine
Curing
NANOADHESIVE
October of 2007
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Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Nanoadhesive Morphology
CNF distribution into the polymeric matrix
October of 2007
14 de 22
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Thermal Conductivity Results
Guarded hot plate method
Termocouple method
T2
Cu
substrates
t
Nanoadhesive
Hot plate- T1
9 Conductivity
9 Mechanical test
Mechanical assembly
Results. Guarded Hot plate
K adhesive = 0 ,21
W
mK
K nanoadhesive = 0,5
October of 2007
15 de 22
W
mK
≠
K objective = 6 ÷ 10
W
mK
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
INFLUENCE OF LACK OF DISPERSION,
AIR PRESENCE AND NO CONTACT
October of 2007
16 de 22
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Influence of air presence on the thermal conductivity
K
(W/mK)
MODEL
FEM 02
FEM 04
WITHOUT AIR
5,15
4,75
1% AIR
5,10
-
-
4,24
10 % AIR
October of 2007
17 de 22
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Influence of lack of dispersion on the thermal conductivity
Nedge
Nnano
K
(W/mK)
FEM 02
FEM 04
5,15
4,75
1
5,5
FEM 02
5
FEM 04
2
4,93
4,02
3
4,66
3,29
4
4,39
2,66
5
4,09
2,12
7,5
3,59
1,20
10
3,13
0,77
15
2,61
0,47
20
2,19
0,37
30
1,48
0,30
40
1,14
0,27
50
0,98
0,26
60
0,82
0,25
75
0,71
0,24
90
0,59
0,23
100
0,52
0,23
October of 2007
Thermal Conductivity (W/mK)
4,5
4
3,5
3
2,5
2
1,5
1
0,5
0
0
10
20
30
40
50
60
70
80
90
100
Nedge/Nnano
NARIST
/ NNANO
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Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Influence of no contact on the thermal conductivity
NO CONTACT BETWEEN THE NANOELEMENTS AND THE ELECTRONIC COMPONENT
Adhesive
Doped Adhesive
Adhesive
d
(m)
K
(W/mK)
5,5
FEM 02
5
FEM 02
FEM 04
FEM 04
Thermal Conductivity (W/mK)
4,5
0,00E+00
5,15
4,75
1,00E-06
3,50
3,31
2,00E-06
2,65
2,55
3,00E-06
2,14
2,07
4,00E-06
1,79
1,74
5,00E-06
1,54
1,50
6,00E-06
1,35
1,32
7,00E-06
1,20
1,18
0,5
8,00E-06
1,08
1,07
0
9,00E-06
0,98
0,97
10,0E-06
0,90
0,89
October of 2007
4
3,5
3
2,5
2
1,5
1,0E-05
9,5E-06
9,0E-06
8,5E-06
8,0E-06
7,5E-06
7,0E-06
6,5E-06
6,0E-06
5,5E-06
5,0E-06
4,5E-06
4,0E-06
3,5E-06
3,0E-06
2,5E-06
2,0E-06
1,5E-06
1,0E-06
5,0E-07
0,0E+00
1
No Contact Length (m)
19 de 22
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Influence of the no contact on the thermal conductivity
NO CONTACT BETWEEN THE NANOELEMENTS
d
5,5
5
FEM 02
d
d
Thermal Conductivity (W/mK)
4,5
4
3,5
3
2,5
2
1,5
1
0,5
0
0
50
d
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100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950 1000
No Contact Length (nm)
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Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Strategies to improve thermal conductivity. Synergic effect
Boron nitride + fibrous nanomaterials (CNF)
K Boron nitride = 600
W
mK
EPOXY+BORON NITRIDE
October of 2007
21 de 22
EPOXY+CNF + BN
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Conclusions
1.
A methodology has been establish to predict K for doped adhesives and a FEM
program has been written.
2. In the fibrous shaped nanomaterials (CNF, MWNT and SWNT), the efficiency
depends mainly on the orientation of the nanoparticles, as well as the thermal
conductivity of the nanomaterials.
3. Good CNF dispersion into the polymeric matrix was achieved using the three roller mill
device.
4. Thermal conductivity increases to 0.5 W/mk using 2.5 wt% of CNF. This result is in
concordance with the simulation in which the main condition is that no contact between
the nanoelements takes place.
5. Adding boron nitride the contact among conductive elements was increased (SEM
images), therefore the thermal conductivity could be increased.
6. New and promising results are being obtained that assure succesful final for the
project
October of 2007
22 de 22
Application of Nanomaterials for Thermal Dissipation
6th ESA Round table on
micro&nanotechnologies for Space applications. 8-12 October 2007
Thanks for your attention!
October of 2007
23 de 22
Application of Nanomaterials for Thermal Dissipation