Aluminum
Nitride Manufacturing Guidelines
ALUMINUM NITRIDE is made by nitridation of aluminum or by conversion of alumina to aluminum nitride. It is a covalently bonded material and has a hexagonal crystal structure. Because of its resistance to sintering, an oxide forming additive such as Y2O3 is needed to form a substrate.
Aluminum Nitride AlN substrate
guidelines for tape casting.
For good quality Aluminum
Nitride substrates, it is essential to start with high purity AlN powders. Tape
cast thickness up to 1.5 mm can be obtained within one step with optimized slurry.
Typical Composition of
tape-casting Aluminum Nitride slurry
|
|
Weight (g) |
Volume % |
| 1-1.5
micron powder |
100 |
34.1 |
| Y203
|
3 |
0.7 |
| Mek
/ ETOH Azeotrope |
38.9 |
52.6 |
| Beycostat
C213 * |
0.5 |
0.5 |
| PVB
|
5.4 |
5.4 |
| PE
Glycol |
3.3 |
3.2 |
| DB
Phtalate |
3.3 |
3.5 |
| *Distributed
by CECA France |
| De-airing:
|
| |
0.15 atm, 30 minutes,
20°C. |
Doctor blade tape casting:
| |
Thickness: |
1.5 mm |
| |
Speed: |
1m/minute |
| |
Drying time: |
180 minutes in
air at 20°C |
| Dry tape characteristics:
|
| |
Thickness: |
0.94 mm
|
| |
Density: |
1.88 |
| Binder removal:
|
| |
Heating in air
between 150°C and 500°C. Above 650°C oxygen contamination will
occur. |
| Sintering:
|
|
|
Aluminum Nitride sintering
must be conducted in dry nitrogen atmosphere. Expected shrinkage approximately 18%.
NOTE: At
room temperature, thermal conductivity of Aluminum Nitride Ceramics is
independent of AlN grain size or number of grain-boundries, but, is controlled
by the internal structure of the grains, such as the degree of oxidation
(Oxygen contamination).
|
Recommended conditions:
|
Heating rate: |
300°C/hr |
|
Temperature: |
1820°C 1 to 3 hr |
|
Pressure: |
1 to 10 atm |
|
Holder: |
BN, BN coated alumina, or BN
coated graphite |
|
Cooling rate: |
100°C/hr to 1200°C
and then at 300°C/hr |
| This Aluminum
Nitride manufacturing procedure should yield products with: |
- High thermal conductivity
- High electrical resistivity
- Low dielectric loss
- High electrical breakdown
voltage
|
| Aluminum Nitride
applications include substrates which require good thermal conductivity
and heat sinks for semiconductor devices, power modules, mobile communications
and multichip modules. |
Aluminum Nitride technical related
Web sites:
www.aluminumnitride.com/alnplus.htm
Chemical analysis of Aluminum Nitride Ceramic substrates
www.aluminumnitride.com/beo-aln.htm
BeO and AlN Ceramic substrates
www.aluminumnitride.com/dicing.htm
Dicing Aluminum Nitride AlN wafers and substrates
www.aluminumnitride.com/links.htm
Aluminum Nitride related Web pages
www.aluminumnitride.com/polished.htm
Polished Aluminum Nitride AlN substrates and wafers
Return
to Home Page: Aluminum nitride substrates, aluminum nitride wafers
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