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Laser Based Selective Metallization of 3D Ceramic Substrates

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Laser Based Selective Metallization of 3D Ceramic
Substrates
Workshop
Visions to Products - MID and Beyond
Stuttgart, 07.10.2015
E. Ermantraut, F. Kern, A. Zimmermann
Outline
Motivation
Experimental Processing
Characterization Results
Conclusion
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 2
Motivation
Why using ceramics as substrate material?
High thermal stability
High thermal conductivity
Low CTE
High chemical resistance
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 3
Process Sequence
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 4
Process flow
Characteristics
Full additive process with short process chain
No special laser activatable additives
Substrate can be provided by e.g. CIM (ceramic
injection moulding)
Ceramic Injection Moulding (CIM)
Ceramic shaping
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 5
sharonoday.com flickr.com
Ceramic Injection Moulding (CIM)
We need plasticity !
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 6
sharonoday.com
Ceramic Injection Moulding (CIM)
Shaping: We need temperature, pressure and a mold
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 7
www.ytimg.com
140
°C
Injection Molding
Ceramic Injection Moulding (CIM)
Process scheme
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 8
Injection molding
Debinding
Ceramic powder
Sintering
Mixing and kneading
Shrinkage 20-30
vol.%
„Green part“
„Brown part“
Sintered body
Binder
Powder
particle
Binder and additives
Keramikspritzguss.eu
Feedstock Granulate
Finishing
Granulation by
extrusion
Extrusion
Final part
Injection molding
grinding
Sinterin
g
Debinding
75 - 88 wt. %
Ceramic Injection Moulding (CIM)
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 9
Felix Vuckovic Technische Keramik GmbH Rauschert GmbH
PIM International
Ceramic Injection Moulding (CIM)
Shaping process for net shape manufacturing of complex ceramic parts.
Good dimensional stability and high accuracy (ca. ± 0,02 mm 3 mm)
High surface quality (Ra < 0,5 µm „as fired“)
High reproducability of material properties and geometry
Complex shaped parts
Short process cyle times
Large quantities producable
High level of automation
High tool costs
Complex feedstock preparation
Relatively long overall process times
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 10
Kläger Spritzguss GmbH & Co. KG
Econimical process for complex parts
in large quantities
Exemplarily Influencing Factors for Laser
Activation and Electroless Plating
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 11
Laser activation
and electroless
plating
Laser
Ceramic
substrate
Copper
electrolyte
Ceramic
material
Grain
size
Surface
roughness/finish Wavelength
Pulse energy
Number of
passes
Type of
electrolyte
Activity
Laser pitch
Processing
Sintering
conditions
Puls duration
Grain Size Influence of Injection Moulded
Alumina Substrates
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 12
Improving metal deposition with decreasing grain size
Sintering parameter: T = 1675 °C, t = 3 hrs
Sintering parameter: T = 1650 °C, t = 3 hrs
All substrates activated with
similar laser parameters
Sintering parameter: T = 1625 °C, t = 3 hrs
Surface Roughness Influence of Injection
Moulded Alumina Substrates
Improving metal deposition with decreasing roughness
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 13
Blasted substrate: Rz = 40,28 µm
Untreated substrate: Rz = 4,17 µm
Polished substrate: Rz = 0,34 µm
Sintering parameter:
1600°C, 3hrs dwell
Oxygen Vacancies Influence of Injection
Moulded Alumina Substrates
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 14
Green Body
Sintering:
1625 °C, 3 hrs in
ambient air
Sintering:
1625 °C, 3 hrs in
hydrogen atmosphere
Laser activation
and metallization
Laser activation
and metallization
Optimized Parameter Set for Laser
Patterning and Metallization of Alumina
Sintering parameter:
1550 °C, 3 hrs in hydrogen atmosphere
No surface treatment
Laser system
λ = 532 nm
Puls duration = 10 ps
Spot diameter = 10 µm
Laser parameter
P = 2 W
Q = 10 µJ
Laserpitch = 7 µm
Number of passes = 2
Conductor path pitch: 300 µm
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 15
Characterization of Deposited Metal Lines
on Injection Moulded Substrates (1/3)
Electrical Characterization
Resistances and layer thickness comparable to those
obtained on standard LDS polymers
No short-circuits on test structures at 590 mm length
Smaller pitch feasible
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 16
0,0
2,0
4,0
6,0
8,0
10,0
12,0
Alumina LCP Vectra E840i LDS
Resistance in Ω
Mean of seven measurements with standard deviation
Characterization of Deposited Metal Lines
on Injection Moulded Substrates (2/3)
Roughness of metal layers
Roughness comparable to those obtained on
standard LDS polymers
First attempts show high potential for chip
assembly
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 17
Test structure for measuring
metal roughness
0,0
2,0
4,0
6,0
8,0
10,0
12,0
14,0
16,0
18,0
Alumina LCP Vectra 840i LDS
Roughness Rz in µm
Characterization of Deposited Metal Lines
on Injection Moulded Substrates (3/3)
Adhesion of metal layers
Measurement of the adhesion by Hot-Bump-Pull test
Samples preheated to approx. 90 °C
Soldering parameter: 210 °C, 9 s
Adhesion is higher than on standard LDS polymers
Promises good reliability of the deposited metal lines
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 18
Test structures for measuring
adhesion by pull test
0,0
5,0
10,0
15,0
20,0
25,0
30,0
35,0
40,0
Alumina LCP Vecrta E840i LDS
Adhesion σ in N/mm²
Characterization of Deposited Metal Lines
after Thermal Load (1/2)
Electrical Resistance
Several runs in reflow oven
(Tmax= 260 °C)
Measurement of the resistance after
every run
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 19
86,0
88,0
90,0
92,0
94,0
96,0
98,0
100,0
Sample 1
(Alumina) Sample 2
(Alumina) Sample 3
(Alumina) Reference
sample 1
(Vectra E840i
LDS)
Reference
sample 2
(Vectra E840i
LDS)
Resistance in % of resistance at unloaded state
Runs: 1
Runs: 2
Runs: 3
Runs: 4
Runs: 5
Results show no indications for
crack formation
Characterization of Deposited Metal Lines
after Thermal Load (2/2)
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 20
Adhesion
Several runs in reflow oven
(Tmax= 260 °C)
Measurement of the adhesion by Hot-Bump-
Pull test after five runs
No significant indications of reduced
adhesion due to thermal load
Puls energy: Sample 01: 10 µJ; Sample 02: 6 µJ
0
5
10
15
20
25
30
35
40
Before Thermal Load After Thermal Load
Adhesion in N/mm²
Sample 01
Sample 02
Mean of five measurements with standard deviation
Three-dimensional Technology
Demonstrator
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 21
Frustum of pyramid 35x35mm²
Different angles of the shell surfaces
(50°; 60°)
Conductor path pitch: 200 µm
Metal layer: Cu/Ni/Au
Conclusion
E. Ermantraut, F. Kern - 07.10.2015 - Visions to Products MID and Beyond 22
New injection moulding process for laser activatable ceramic substrates developed
(no additional additives required)
New process for laser patterning and selective full-additive metallization of injection
moulded ceramics developed
Both processes are 3D capable
Similar electrical properties and surface roughness of metal lines compared to LDS
MID
Significantly higher adhesion of the deposited metal layers compared to LDS MID
High potential of ceramic substrates with 3D metal lines for
versatile new applications
Thank you for your attention!
Dr. Frank Kern
Institut für Fertigungstechnologie keramischer
Bauteile (IFKB)
Universität Stuttgart
Allmandring 7B
D-70569 Stuttgart
frank.kern@ifkb.uni-stuttgart.de
+49-711-685-68233
The presented work was carried out in the IGF research project 488ZN accomplished by the Hahn-Schickard-Society (HSG). The authors
would like to thank the German Federal Ministry of Economics and Technology (BMWi) and the German Federation of Industrial Research
Associations (AiF).
M.Sc. Eugen Ermantraut
Institut für Mikrointegration
(IFM)
Universität Stuttgart
Allmandring 9B
D-70569 Stuttgart
ermantraut@ifm.uni-stuttgart.de
+49-711-685-83772
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