Hermetic Sealing
Ceramic or metal pins are sealed into a sensor base using a specialized glass material to create a rugged and airtight electrical connection. This pyrex glass header bonding process provides the insulation needed to separate the signal wires from the sensor housing. It must withstand high pressures and extreme temperatures without leaking.
The glass acts as both a structural support and an electrical insulator.
Thermal Match
The coefficient of expansion for the glass must be closely matched to the metal pins and the header body. During pyrex glass header bonding, the assembly is heated until the glass flows and wets the surfaces. A poor match leads to stress cracks that compromise the hermetic seal.
Anodic Fusion
High voltage can be applied to create a chemical bond between the glass and a silicon substrate. This variation of pyrex glass header bonding is often used in the production of micro-machined sensors. It creates a permanent join at the atomic level that is resistant to mechanical shock.
Package Integrity
Helium leak testers verify the quality of the seal after the bonding process is complete. Any failure in the pyrex glass header bonding will allow moisture to enter the sensor and cause electrical drift. This integrity is vital for sensors used in subsea or aerospace environments.
