Interested in advice on waterproofing a Bosch IMU, the BMI085

[pish]

We are considering waterproofing a small module that contains an IMU for a wearable application that must survive laundering, including extended and repeated full submersion in liquid. We are considering potting, or a conformal coating over the PCB inside a waterproof enclosure. The module has to survive storage at temperatures as low as -20C. Advice on handling the thermal stresses due to CTE mismatches between a potting compound or conformal coating and the IMU package mounted on a PCB, advice on application of the coatings to avoid damage to the chip, etc are most welcome. Are there any other suggestions on offer, other than the guidance to avoid only partially covering the IMU with resin?

[BSTRobin]

Hello pish,

1.For wearable application, the recommended part is BMI270.

2.In addition to "do not contact with any (epoxy resin) material, resulting in asymmetric stress distribution on the sensor assembly", you can: 1 use the coating of nano materials; 2. Or put a shell outside the IMU and make it waterproof.

[pish]

Thank you. Can you provide an example of a nanomaterials coating that might work?

[BSTRobin]

Hi pish,

Some of our customers used nano coating to make waterproof on watches.

[pish]

Can you point us in the direction of one or more commercial waterproofing nanomaterial vendors?