Schreiner ProTech recently announced that it has designed a breathable, self-adhesive pad specifically for the requirements of a wireless humidity sensor. According to the company, the sensor-integrated die-cut part ensures optimal performance.

Produced by Disruptive Technologies using circuit boards embedded by Zollner Elektronik AG, the sensor measures ambient humidity and temperature in 15-min intervals. Afterward, it forwards the information to a cloud for storage.

Membranes in industrial applications work in ways comparable to those known in breathable functional clothing in the outdoor sector. They’re air-permeable toward the outside while protecting the interior against water ingress. The same principle applies to humidity sensors as well. The circuit board in the enclosure has to be protected against water ingress; to ensure such protection, the board must be positioned precisely above the hole in the housing.

Commissioned by Zollner Elektronik, Schreiner ProTech developed the steam-permeable adhesive pad located inside the sensor as a solution. Embedded in the adhesive pad is a membrane. The integrated, non-adhesive area enables fully automatic surface-mounted device (SMD) processing. In addition, the double-sided adhesive die-cut part creates the necessary connection between the sensor housing and the board.

“The adhesive pad provides optimum control because the embedded membrane enables moisture wicking toward the sensor while preventing water ingress,” said Michael Drollmann, business development manager, ETech bei Schreiner ProTech. “For this purpose, there’s a hole on both sides of the pad that ensures the necessary breathability.”

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