LTCCtechnology for Microsystem Applications

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LTCC-technology for Microsystem Applications
W. Smetana
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• Presentation outline
• LTCC-Technology
• Examples
• Sensors
• Microfluidic devices
• Aspects of LTCC-processing

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Ceramic-Technologies

• Two categories of Co-firing
• HTCC (High Temperature Co-fired Ceramic)
• Alumina Binder Process Temperature
  1600 C-1800 C
• Conductor Refractory metals (W, Mo, MoMn)
• LTCC (Low Temperature Co-fired Ceramic)
• Glass-Ceramic Binder Process
  Temperature lt 1000C Conductor Precious metals
  (Au, Ag Cu)

LTCC-Technology further development of Thick
Film Technology
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• LTCC-Technology (Low Temperature Cofired
  Ceramic)
• Conventional application
• multilayer circuits of high reliability

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LTCC-Technology (Low Temperature Cofired
Ceramic)LTCC Fabrication Process
1 Cutting
2 Laser micromachining
3 Vias filling screen printing
4 Collating and lamination
5 Firing800 900 C
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• LTCC-Technology
• tapes of different physical performance
• (e.g. low-k dielectric, high-k
  ferroelectric, ferritic tapes)
• tapes of different thickness (e.g. 120
  µm, 250 µm, 500 µm fired thickness)
• easily machinable e.g. by laser, embossing or
  stamping
• rapid prototyping

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• LTCC-Technology
• Unconventional application
• three-dimensional microsystems e.g.
• sensors transducers
• microfluidics
• device packaging

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Sensors

• Mechanical performance of LTCC-tapes
• mechanical sensors (force-, acceleration-,
  pressure- sensor etc)
• as well as suitability
• actuators (valves, switches, etc.)
• Cantilever, beam, membrane elements may be
  integrated in microsystems realized in
  LTCC-technology suitable for high temperature
  applications.

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Mechanical performance of LTCC-tapes
Samples for testing

• LTCC-stripes (dimensions 5 mm x 50 mm,
  thickness variable)
• LTCC-stripes metallization (Heraeus C4140 D) on
  both sides
• (thickness 22 µm)
• LTCC-stripes thick film piezoresistor (ESL
  3414, 2 mm x 1mm)

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Mechanical performance of LTCC-tapes
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Mechanical performance of LTCC-tapes
Samples with metallization(on both sides)
Samples without metallization
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Mechanical performance of LTCC-tapes
Samples with without metallization
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Mechanical performance of LTCC-tapes
Sample with piezoresistive sensor element e.g.
force-, position-sensor
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Mechanical performance of LTCC-tapes
Capacitive pressure sensor
Exploded view
Exploded view
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Mechanical performance of LTCC-tapes
Capacitive pressure sensor
Test set-up
Sensor characteristic
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Electrical thermal performance of LTCC-tapes
Capacitive temperature sensor
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Thermal performance of LTCC-tapes
Operating principle of humidity- gas-sensor
Tcap Tambient
lref
lmeass
Tref
Tmeas
Rref, measf(T)
lreff(T) lmeasf(T,X) X.... Mole fraction
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Thermal performance of LTCC-tapes

Calorimetric humidity/gas - sensor
Resistor size 2 mm x 1mm
Chamber 6 mm x 6 mm x 120 µm
holes
Total size 9 mm x 18 mm
Coductor path
subatrate
Cap
ambient chamber
reference chamber
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Thermal performance of LTCC-tapes
Calorimetric humidity/gas - sensor
Heater-Sensor-element
Cap
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LTCC-Microfluidic

Rotary pump
Schematic of pump
Components of pump
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Rotary pump
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LTCC-Microfluidic

Rotary pump
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Capillary electrophoresis (CE)separation
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LTCC-Microfluidic
CE-separation
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LTCC-Microfluidic Device packaging

• 3-D Monitoring module for biological
  applications

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LTCC-Microfluidic
3-D Monitoring module
Schematics of the monitoring module
reactor cell (1ml)
doping inlet ports 1..3 bio-fluid inlet
outlet sensor-ports A, B, C
spectroscopy-port
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Aspects of LTCC-processing

Optimization of Laser Machining Multiple Cutting
Cycles
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Aspects of LTCC-processing
Optimization of Laser Machining Multiple Cutting
Cycles

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Aspects of LTCC-processing

Optimization of Lamination Homogeneous
Densification by SVM (Sacrificial Volume
Materials) - Incorporation
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Aspects of LTCC-processing

Optimization of Lamination Homogeneous
Densification by SVM - Incorporation
Heraeus CT800 tape,240 µm 10 layers.
W 3.283 mm fired
SVM PMMA (Polymethylmethacrylate)
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Aspects of LTCC-processing
Optimization of Lamination Pressure Reduction
by Application of Adhesives

PMMA (Polymethylmethacrylate) PVA-S (special
polyvinyl acetate) HEC (Hydroxyethylcellulose)
Pressure reduction 300 bar (recom.) 60 bar
30 bar
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Aspects of LTCC-processing
Optimization of Firing TGA- optimized Profiles
Application of SVM

CT707 fired sample d 102 µm 9 layers
CT707 fired bridge w 312 µm 1 layer
W 3.226 mm fired
W 3.135 mm fired
Explosive burnout
Optimized burnout
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Aspects of LTCC-processing

Optimization of Firing TGA- optimized Profiles
Application of SVM Sacrifical Tapes
Ceramic Block (Biological Monitoring
Module) Vol. 172cm3Layers 135Weight 400
gSVM 30cm3
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Thank you for your attention!