Protective Cover for Selected Humidity Sensors

Sensirion (Switzerland) now offers a protective cover for selected humidity sensors of the SHT3x series. The SHT3x protective cover is an optional polyimide foil directly attached to the top surface of the sensor. It covers the SHT3x’s complete sensing area and thus acts as a reliable shield against pollution during SMT assembly of the sensor and subsequent processes, such as conformal coating or potting. The protective cover is designed to withstand multiple reflow soldering cycles. To enable correct sensor operation, it must be removed after assembly.

A flap on the cover extends over the outer dimensions of the sensor package on one side and is designed to allow the cover to be peeled off easily with tweezers. After peeling off, the sensor will operate as specified in the datasheet. All typical conformal coating procedures, such as brushing, spraying or potting, can be used as long as the protective cover is attached. The cover will effectively protect the sensor opening from direct exposure to these coatings and other possible pollutants during the production process. More details on contamination and a list of suitable conformal coatings can be found in the document “Handling Instructions for Humidity Sensors”, downloadable from Sensirion's website.