BME280 coating insulation

[Eugene1215]

Hi, are there recommendation how to protect BME280's electrical connections from enviromental?

Our company uses BME280 as Temperature/Pressure/Relative Humidity sensor in outdoor ecology hardware. So the sensor PCB is working in conditions RH up to 100%, T=-40...+40, it is caused electrical connections problem (tracks/contact pad/etc not protected from the environment).

We want to protect electrical connections from the environment, without breaking "Handling, soldering & mounting instructions" (https://www.bosch-sensortec.com/media/boschsensortec/downloads/handling_soldering_mounting_instructi...

Do you have any recommendation what we can use as insulator?
Now we are using CRC Urethan 71 vernis isolant, but not sure it is good.

Thanks

[BSTRobin · Accepted solution]

Hi Eugene1215,

Please see below comment for reference,

1, As the description from BME280 HSMI document, we don't recommend total and partial covering the sensor.

• If you want to under fill the sensor with gel, should protect the air hole on the sensor surface and keep no gel into the sensor
• The performance of the sensor will be influenced with under fill gel

2, Based on the HSMI chapter5.1

• If you can use membrane to protect the sensor and pad
• If your equipment structure available, you can reference the design from chapter5.1