Ceramics

Alumina Substrates

Alumina Substrates

Features


Alumina Substrates

MARUWA has produced alumina (Al2O3) substrates for over 40 years under severe quality control with carefully selected high purity ceramic materials that ensures stable quality and excellent properties.

Our alumina substrate has well-balanced properties of insulation, thermal conductivity and breaking strength. Moreover, one of the unique properties is its surface roughness. We can provide the ceramic substrate which is excellent in adhesion with a thin film and thick film metalization due to fine particles.

  • Good smoothness / flatness with less porosity. Excellent in adhesion with thin film and thick film materials.

  • Less variance in outline, plate thickness, etc.

  • Minimal warpage, bending, and undulation.

  • Physical and chemical properties are stable even under a hot environment. Excellent in thermal shock resistance. High thermal conductivity and coefficient of thermal expansion similar to that of silicon.

  • Superior mechanical strength. Products with higher mechanical strength are also in our lineup.

  • Excellent resistance against oil and chemical.

  • Excellent in insulation properties, high dielectric breakdown voltage, high surface resistivity / volume resistivity, and small dielectric constant.

  • The high reflective substrate, especially suitable for optical applications such as LED, is also available.

Applications


LED packages, Power modules, FAX substrates for thermal printer head
*Various processing is available (thin film metalization, thick film metalization, glaze, etc.)

Characteristic Values


Condition Item Al203
AS970 HA-96-2 HBS HRA HA-996
Material - - 96.5% 96% 96.5% 96% 99.6%
Color - - White White White White White
Bulk density - g/㎤ 3.74 3.75 3.75 3.60 3.90
Surface roughness Ra - µm 0.4 0.4 0.3 0.3 0.1
Reflectivity 0.3-0.4mmt % 70 70 70 85 75
0.8-1.0mmt 80 80 80 95 85
Mechanical Bending strength 3-point method MPa 450 400 500 370 470
Modulus of elasticity - GPa 330 330 330 - 330
Vickers hardness - GPa 14 14 14 - 16
Fracture toughness IF method MPa・m1/2 3.0 3.0 - - -
Thermal Coefficient of thermal expansion 40-400°C 10-6/K 6.7 6.7 6.7 6.7 6.8
40-800°C 7.8 7.8 7.8 7.8 7.9
Thermal conductivity 25°C W/(m・K) 24 24 24 20 29
300°C 12 12 12 - 13
Specific heat 25°C J/(㎏・K) 750 750 750 750 780
Electrical Dielectric constant 1MHz - 9.8 9.8 9.8 - 9.9
Dielectric loss factor 1MHz 10-3 0.2 0.2 0.2 - 0.2
Volume resistivity 25°C Ω・㎝ >1014 >1014 >1014 >1014 >1014
Breakdown strength DC ㎸/㎜ >15 >15 >15 >15 >15

General Dimensional Tolerances


Item Unit Al203
AS970 HA-96-2 HBS HRA HA-996
Dimension inch(max) 4"×4" 4"×16" 5.5"×7.5" 5.5"×7.5" 4.5"×4.5"
Tolerance ±0.6% ±1.0% ±1.0% ±1.5% ±1.0%
Thickness 0.10~0.50 0.25~1.20 0.25~1.0 0.25~1.0 0.25~1.0
Tolerance ±10% ±10% ±10% ±10% ±10%
Through hole Φ0.14~0.80 Φ0.2~ Φ0.2~ Φ0.2~ Φ0.2~
Tolerance ±0.6% ±0.6% ±0.6% ±0.6% ±0.6%
Warpage 0.003/㎜ 0.003/㎜ 0.003/㎜ 0.003/㎜ 0.003/㎜

Processing


MARUWA can also offer additional processing to meet your requirements.
We have technologies and extensive knowledges about ceramic materials and that's why high reliability of processed substrates can be provided.

  • Glaze

  • Metalization

  • Polishing / Lapping

  • Mechanical Processing

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