3. Assembly techniques

3.1 Issues

To create complex structures, it is often necessary to assemble two substrates of the same or different types. Examples include hermetic cavities (for absolute pressure sensors or acoustic gyrometers), capacitive structures (accelerometers, pressure sensors, microphones, etc.) where a moving electrode and a fixed electrode face each other, or the assembly of the sensor itself and a decoupling structure (intermediate encapsulation used by accelerometers and piezoresistive pressure sensors).

The assembly process must meet the following requirements:

• use materials with similar expansion coefficients ;

• can be achieved collectively;

• use operating...