Humidity-related output shift on ADXL343 during tilt detection

Thank you for your previous detailed explanation. It was very insightful and helped us to better understand the potential causes for the ADXL343's output shift in high humidity.

Building on your last response, I've distinguished two potential types of influence for such sensor behavior:

Direct influence on the MEMS element itself: This would imply the MEMS material or structure directly reacts to humidity. If this were the case, the output trend might be more consistent and potentially amenable to compensation through software calibration.
Indirect influence via package deformation: The package absorbs moisture, leading to mechanical stress on the MEMS sensing die, causing shifts in the sensing elements. This scenario tends to be more complex and unpredictable, potentially making reliable compensation very difficult due to inconsistent or non-linear effects, as it often leads to "repeatability issues."
From your explanation, particularly the emphasis on "package absorbs the moisture, in a way that changes the mechanical force profile on the sensing die, which leads to shifts in position/orientation of the sensing elements," I interpret the ADXL343's issue as primarily falling into the second category (indirect influence via package deformation and stress propagation to the MEMS).

Given this understanding, you suggested using a coating material as a potential solution. My question is: aside from switching to hermetically sealed parts like the ADXL355/7B, is applying a coating the only viable countermeasure for this type of complex, indirect issue? We are open to exploring a wider range of solutions to address this and would be grateful for any other strategies or considerations that could be effective for the ADXL343, especially if switching to a different sensor family is challenging due to size or cost constraints.

Furthermore, I'd be very interested to hear from other engineers in this forum who have faced similar "repeatability issues" with plastic-packaged MEMS sensors in high-humidity environments. Please share any experiences, workaround solutions, or alternative ideas you might have. Your insights would be highly valuable.

Thank you for your continued support.

Thank you for your previous detailed explanation. It was very insightful and helped us to better understand the potential causes for the ADXL343's output shift in high humidity.

Building on your last response, I've distinguished two potential types of influence for such sensor behavior:

Direct influence on the MEMS element itself: This would imply the MEMS material or structure directly reacts to humidity. If this were the case, the output trend might be more consistent and potentially amenable to compensation through software calibration.
Indirect influence via package deformation: The package absorbs moisture, leading to mechanical stress on the MEMS sensing die, causing shifts in the sensing elements. This scenario tends to be more complex and unpredictable, potentially making reliable compensation very difficult due to inconsistent or non-linear effects, as it often leads to "repeatability issues."
From your explanation, particularly the emphasis on "package absorbs the moisture, in a way that changes the mechanical force profile on the sensing die, which leads to shifts in position/orientation of the sensing elements," I interpret the ADXL343's issue as primarily falling into the second category (indirect influence via package deformation and stress propagation to the MEMS).

Given this understanding, you suggested using a coating material as a potential solution. My question is: aside from switching to hermetically sealed parts like the ADXL355/7B, is applying a coating the only viable countermeasure for this type of complex, indirect issue? We are open to exploring a wider range of solutions to address this and would be grateful for any other strategies or considerations that could be effective for the ADXL343, especially if switching to a different sensor family is challenging due to size or cost constraints.

Furthermore, I'd be very interested to hear from other engineers in this forum who have faced similar "repeatability issues" with plastic-packaged MEMS sensors in high-humidity environments. Please share any experiences, workaround solutions, or alternative ideas you might have. Your insights would be highly valuable.

Thank you for your continued support.