The thermal expansion characteristics of SD2 are matched with those of silicon single crystal. Therefore, anodic bonding with little distortion can be performed over a wide temperature range.
- Matching thermal expansion characteristics with silicon single crystal
By carefully selecting the glass composition of aluminosilicate type (SiO2-Al2O3-Na2O type), the thermal expansion was matched with that of silicon single crystal over a wide temperature range.
- Easy anodic bonding
The volume resistivity is reduced by adding a small amount of Na. This results in a glass composition that can perform strong bonding even at temperatures of 400 °C or lower.
- Stable quality
The variation in the thermal expansion characteristics between production lots is very small and stable.
- Easy to process
SD2 can be etched with low concentration hydrofluoric acid aqueous solution, and the etched surface becomes a mirror like surface.
- Semiconductor pressure sensor substrate
- Acceleration sensor substrate
- Nozzle part of inkjet printer
- Glass for micro-machining bonding
|Coefficient of Thermal Expansion||x10-7/°C||32||30～300°C (thermal expansion meter)|
|x10-7/°C||33||30～350°C (thermal expansion meter)|
|x10-7/°C||34||30～400°C (thermal expansion meter)|
|x10-7/°C||35||30～450°C (thermal expansion meter)|
|x10-7/°C||36||30～500°C (thermal expansion meter)|
|Strain Point||°C||670||1014.5 poise|
|Sag Point (Ts)||°C||785|
|Modulus of Rigidity||GPa||35|
|Dielectric Loss||(tanδ)||0.010||20°C 1MHz|
|Dielectric Coefficient||6||20°C 1MHz|
|Volume Resistivity||x1012Ω・m||4.1||20°C DC500V 1 minute|
|x1012Ω・m||0.4||100°C DC500V 1 minute|
|x1012Ω・m||3.8||200°C DC500V 1 minute|
*1 Indicates weight reduction in mg/cm2 per unit area when polished glass sample of 43.7 mm diameter (30 cm2 on both sides) and 5 mm in thickness was immersed in well stirred 80 °C 30% HNO3 aqueous solution for 50 hours.
*2 Indicates weight reduction in mg/cm2 per unit area when polished glass sample of 43.7 mm diameter (30 cm2 on both sides) and 5 mm in thickness was immersed in well-stirred 80 °C. H2SO4: HNO3:H2O = 1:1:1 aqueous solution for 50 hours.
*3 Indicates weight reduction in mg/cm2 per unit area when polished glass sample of 43.7 mm diameter (30 cm2 on both sides) and 5 mm in thickness was immersed in well-stirred 50°C. 0.00N NaOH aqueous solution for 15 hours.