DMS Cover Glass Material Selection: Aluminosilicate vs Borosilicate Glass for In-Cabin Camera
When designing DMS (Driver Monitoring System) camera modules, selecting the correct optical cover glass substrate directly impacts system lifetime, imaging quality and compliance with automotive qualification standards. Aluminosilicate glass and borosilicate glass are two common options for in-cabin camera protective windows. This guide compares their key performance to help optical engineers make the right material choice.
Aluminosilicate Glass for DMS Cover Glass
Aluminosilicate glass is the most widely adopted substrate for modern automotive DMS cover windows.
- Advantages: High mechanical strength, excellent scratch resistance, outstanding thermal shock resistance. Good transmission at 850nm and 940nm NIR wavelengths. Can be chemically strengthened for higher impact resistance. Suitable for long-lifetime passenger vehicle applications.
- Limitations: Higher raw material cost than borosilicate glass.
Borosilicate Glass for DMS Cover Glass
Borosilicate glass is well known for low thermal expansion.
- Advantages: Very low thermal expansion coefficient, good thermal stability, lower material cost for some low-volume projects. Good optical uniformity.
- Limitations: Lower mechanical strength, cannot be chemically strengthened. Less ideal for environments with frequent scratching risk, not the first choice for mass-produced passenger vehicle DMS.
Comparison Summary
| Performance | Aluminosilicate Glass | Borosilicate Glass |
|---|---|---|
| Mechanical Strength | High (chemically strengthenable) | Medium |
| Thermal Shock Resistance | Excellent | Very good |
| NIR Transmittance (850/940nm) | High | High |
| Scratch Resistance | Superior | Fair |
| Main Use Case | Mass production NEV & passenger car DMS | Low-volume, low-abrasion industrial camera |
Recommendation
For mass-production automotive DMS and OMS camera projects for passenger new energy vehicles, aluminosilicate glass is the preferred material. Borosilicate glass can be considered only for special low-volume applications where mechanical impact risk is minimal.
Felix Glass fabricates custom DMS cover glass from both aluminosilicate and borosilicate substrates, with black shading printing and AR/AF coating services. Share your optical requirements and environment test standards, and our optical engineers will recommend the best substrate and coating combination for your camera module.
