Technical Details of MEMpax®
High durability in extremely low thicknesses
Material properties
1. Optical properties
| Optical Properties | Value | 
|---|---|
| Refractive index* ng | 1.4803 | 
| Refractive index* nF' | 1.4768 | 
| Refractive index* nF | 1.4765 | 
| Refractive index* ne | 1.4732 | 
| Refractive index* nd | 1.4715 | 
| Refractive index* nD | 1.4714 | 
| Refractive index* nC' | 1.4696 | 
| Refractive index* nC | 1.4693 | 
| Abbe value νe | 65.4 | 
| Photoelastic constant in (nm/cm)/Mpa | 39.8 | 
* Refractive indices: Pretreatment of samples. 
Condition as supplied ["as drawn"] 
2. Thermal properties
| General thermal properties | Unit | Value | 
|---|---|---|
| CTE (Coefficient of thermal expansion) α | 10-6·K-1 (20 °C; 300 °C) | 3.26 | 
| Mean specific heat capacity cp | in J/(g·K)(20 °C; 100 °C) | 0.82 | 
| Transformation temperature Tg | in °C | 532 | 
| Viscosities | Viscosity lg ŋ in dPas | Temperature in °C | 
|---|---|---|
| Strain point | 14.5 | 528 | 
| Annealing point | 13.0 | 570 | 
| Softening point | 7.6 | 831 | 
3. Mechanical properties
| Mechanical Properties | Unit | Value | 
|---|---|---|
| Density ρ | in g/cm³ | 2.22 | 
| Young's modulus E | in kN/mm² | 62.7 | 
| Poisson's ratio µ | 0.196 | |
| Torsion modulus G | in kN/mm² | 26.2 | 
| Knoop hardness | HK 0.1/20 | 430 | 
| Vickers hardness | HV 0.2/25 | 510 | 
Chemical toughening (for thickness = 0.2 mm)
| Unit | Value | 
|---|---|
| Temperature ϑ in °C | 430 | 
| Time t in h | 4 | 
| Compressive stress (CS) in MPa | 120 | 
| Depth of layer (DoL) in µm | 8 | 
4. Chemical properties
| Hydrolytic resistance (acc. to DIN ISO 719) | Value | 
|---|---|
| Class | HGB 1 | 
| Equivalent of alkali per gram glass grains in µg/g | < 31 | 
| Acid resistance (acc. to DIN 12116) | Value | 
|---|---|
| Class | S 1 | 
| Half surface weight loss after 6 hours in mg/dm² | 0.16 | 
| Alkali resistance (acc. to DIN ISO 695) | Value | 
|---|---|
| Class | A 2 | 
| Surface weight loss after 3 hours in mg/dm² | 132 | 
5. Electrical properties
| Dielectric constant εr (at ϑ = 25 °C) | Value | 
|---|---|
| at 1 MHz | 4.8 | 
| at 1 GHz | 4.4 | 
| at 2 GHz | 4.5 | 
| at 5 GHz | 4.4 | 
| at 24 GHz | 4.4 | 
| at 77 GHz | 4.4 | 
| Dissipation factor tan δ (at ϑ = 25 °C) | Value | 
|---|---|
| at 1 MHz | 38 · 10-4 | 
| at 1 GHz | 58 · 10-4 | 
| at 2 GHz | 62 · 10-4 | 
| at 5 GHz | 73 · 10-4 | 
| at 24 GHz | 100 · 10-4 | 
| at 77 GHz | 150 · 10-4 | 
| Electric volume resistivity ρD in Ω·cm direct current | 
|---|
| 1.18 ·108 ( ϑ = 250 °C) | 
| 4.24 ·106 (ϑ = 350 °C) | 
6. Transmittance values
Spectral transmittance (250 - 3150 nm)

Spectral transmittance (250 - 500 nm)

| Wavelength in nm at thickness 0.2 mm: | τ (λ) in % | 
|---|---|
| 254 | 28 | 
| 380 | 92.4 | 
| 632.8 | 92.8 | 
| 1064 | 92.7 | 
| Edge wavelength λc (τ = 0.46) at thickness in mm | Wavelength in nm | 
|---|---|
| 0.2 | 269 | 
| 0.3 | 279 | 
| 0.5 | 283 | 
| 0.7 | 288 | 
| Luminous transmittance at thickness in mm | τvD65in % | 
|---|---|
| 0.2 | 92.8 | 
| 0.5 | 92.8 | 
MEMpax® products
SCHOTT MEMpax® is available as:
- Unpolished substrates and wafers
- FLEXINITY®
 
 
To find out more, please see the related products on the overview page.