HDC2010: How to waterproof HDC2010

Hello Vincent, 

What is the environment the HDC2010 is being used in and what are the average/expected humidity readings in this environment?

You would not be able to conformally coat an HDC2010, however, if you're looking for greater protection from water ingress I would recommend the HDC2022 as it has an IP67 filter on the device to protect it from water ingress. One thing to note is that while the functionality is the same, the pinout is different from the HDC2010.

Regards,

Harry

HI Harry

The humidity in the usage environment is very high, and condensation water is easily generated.   

Due to customer requirements, we can only use HDC2010.

We know that the humidity sensing part of HDC2010 is located on the bottom of the chip. We plan to open a hole with a diameter of 0.45mm on the PCB directly below the chip. The top of the chip is covered with conformally coat. Do you think this plan is effective?

Hello Vincent, 

I don't believe the proposed idea to conformally coat the part and add the hole under the PCB would solve the condensation problem. As the coating only really applies to the upper part of the sensor and not the sensing element. There would also be a risk of the conformal coat out-gassing and causes RH reading errors since the sensing element would be exposed due to the hole exposing the sensing element during the coating process.  

Additionally, have you tried running the heater in the part to try baking out the condensation on the sensor? You can find more information on it on page 9 of the datasheet. 

HI Harry

The purpose of waterproof coating is to prevent the pins of HDC2010 from being short circuited by condensed water, not to prevent the sensing element from getting wet.

I thought I applied waterproof paint on top of HDC2010 so that when condensation occurs, HDC2010 won't be short circuited. At the same time, a hole is opened directly below the chip so that the sensing element can come into contact with air and detect relative humidity normally. If there are no holes here, the sensing element will be isolated from the outside air.

Meanwhile, due to the limited space near the PCB holes, it is not easy to generate a large amount of condensation water.

If I don't apply conformally coat, when condensation occurs, HDC2010 will short-circuit and it won't work. The heater cannot be turned on.

Or Do you have other ways to make a judgment before condensation occurs, turn on the heater to prevent HDC2010 from short circuiting.

Regards,

Vincent Tang