Complaint
Alumina ceramics are classified by alumina purity. Alumina purity of 99% is called corundum porcelain, and alumina purity of 99%, 95%, and 90% is called 99 porcelain, 95 porcelain, and 90 porcelain. Alumina purity of 85% is generally called high alumina ceramics.
The bulk density of 99.6% alumina ceramics is 3.95g/cm3, the flexural strength is more than 500MPa, the thermal expansion coefficient (CTE) is 7.9×10-6/ºC, the thermal conductivity is more than 29W/m·K, and the dielectric strength is more than 15KV/mm.
For material properties, please refer to the table below.
| Alumina Ceramic Substrate | |||
| Item | Unit | 99.6% Al2O3 | |
| Mechanical Properties | |||
| Color | / | / | Ivory |
| Density | Drainage Method | g/cm3 | ≥3.95 |
| Light Reflectivity | 400nm/1mm | % | 83 |
| Flexural Strength | Three Point Bending | MPa | >500 |
| Fracture Toughness | Indentation Method | MPa·m1/2 | 3.0 |
| Vickers Hardness | Load 4.9N | GPa | 16 |
| Young's Modulus | Stretching Method | GPa | 300 |
| Water Absorption | % | 0 | |
| Camber | / | Length‰ | ≤3‰ |
| Thermal Properties | |||
| Max. Service Temperature (Non-loading) | / | ºC | 1400 |
| CTE (Coefficient of Thermal Expansion) | 20-800ºC | 1×10-6/ºC | 7.9 |
| Thermal Conductivity | 25ºC | W/m·K | >29 |
| Thermal Shock Resistance | 800ºC | ≥10 Times | No Crack |
| Specific Heat | 25ºC | J/kg·k | 780 |
| Electrical Properties | |||
| Dielectric Constant | 25ºC, 1MHz | / | 9.8 |
| Dielectric Loss Angle | 25ºC, 1MHz | ×10-4 | ≤2 |
| Volume Resistivity | 25ºC | Ω·cm | ≥1014 |
| Dielectric Strength | DC | KV/mm | ≥15 |
Common ceramic substrate molding techniques mainly include dry pressing, isostatic pressing and tape casting.
1. Dry Pressing has high density and good substrate flatness, but low production efficiency and high cost, making it difficult to prepare ultra-thin substrates.
2. Isostatic Pressing has uniform distribution of compact density and low firing shrinkage, but it is difficult to precisely control the size and shape, and the productivity is low.
3. Tape Casting is easy to operate, efficient in production, capable of continuous operation and has a high level of automation. The density of the embryo body and the elasticity of the diaphragm are large. The processing technology is mature. The production specifications are controllable and products of various specifications can be produced. For these reasons, tape casting is widely used in the production of alumina ceramic substrates.
1. Our bare ceramic substrates have been widely used in LED's, laser and optical communications, aerospace, automotive electronics, microwave and other fields.
2. Customized sizes and shapes are available.
3. Lapping, polishing, laser scribing, laser cutting and other machining processes are also available.
| Alumina Ceramic Substrate | ||||
| Item | Substrate Thickness (mm) | Standard Tolerance (mm) | Best Tolerance (mm) | Laser Cutting Tolerance (mm) |
| Length and Width Tolerance | / | ±2 | ±0.15 | |
| Thickness Tolerance | T<0.3 | ±0.03 | ±0.01 | |
| 0.30-1.0 | ±0.05 | ±0.01 | ||
| T>1.0 | ±10% | ±0.01 | ||
