I’m looking for guidance on mechanical mounting sensitivity for a small IMU (accelerometer + gyro) in a compact application.
The sensor is used intermittently (typically <1 hour per session), and the system performs a fresh calibration at each power-up. We are primarily measuring relative motion/orientation changes over short durations, not long-term inertial navigation.
The IMU is mounted on a small PCB (~25 mm × 20 mm), with board thickness options of 0.8 mm or 1.6 mm. The current concept is to clamp the PCB around its edges within a plastic housing.
My questions:
Mounting Sensitivity:
Given the short operational duration and recalibration at startup, how critical is strict adherence to recommended PCB mounting guidelines (e.g., stiffness, isolation from stress)?
Specifically, is edge clamping likely to introduce meaningful drift or bias instability in this type of use case?PCB Thickness / Stiffness:
For a board of this size, is there a meaningful benefit in going from 0.8 mm to 1.6 mm thickness in terms of reducing mechanical coupling and signal error?Encapsulation / Potting:
We are considering fully encapsulating the PCB in a medical-grade silicone for environmental protection.
Are there known concerns with IMU performance (e.g., bias shift, thermal effects, damping) when using soft silicone encapsulants?
Any guidance on air-cure vs. heat-cure silicones for this type of application?
Real-World Experience:
Are there examples of similar use cases where IMUs are mounted on small PCBs with edge constraint and/or encapsulated, and what lessons were learned?
Any insights or practical experience would be appreciated.