IP67 Enclosure Design for Industrial IoT Devices
Industrial IoT devices — edge gateways, sensors, RTUs — often deploy outdoors or on factory floors where dust, washdown, and thermal cycling are daily realities. IP67 is a common target for sealed electronics housings. This guide covers mechanical design for reliable ingress protection without trapping heat or blocking maintenance.
What IP67 Actually Requires
IP67 means dust-tight (6) and protection against temporary immersion to 1 m for 30 minutes (7). It does not guarantee long-term submersion, condensing humidity management, or corrosion resistance — specify those separately.
Testing is performed on samples with defined cable entry states. Your design must include production cable glands, blanking plugs, and vent strategy in the test configuration.
Gaskets, Grooves, and Compression
Use a continuous gasket groove with consistent land width. Compression target typically 20–40% for silicone foam or solid silicone depending on shore hardness. Avoid gasket splice locations on corners without bonding quality control.
Groove design: Rectangular or dovetail grooves retain gasket during assembly. Provide positive stops (flanges) so screws cannot over-compress and crack plastic flanges.
For metal enclosures, watch paint/coating continuity under gasket land — bare metal or conductive finish where EMI continuity is required.
Cable Glands and Venting
Every penetration is a leak path. Use rated glands matched to cable OD with proper strain relief. Maintain bend radius clearance inside the box. Document spare gland plug torque for field installs.
Sealed boxes need breathable vent membranes (ePTFE) to equalize pressure from solar heating and altitude shipping — otherwise condensation forms inside. Place vents low in the convection path but protected from direct spray.
Thermal Management in Sealed Boxes
Without airflow, heat sinks must conduct to the enclosure wall or use heat pipes to external fins. Model worst-case ambient (55°C sun-loaded wall) with internal dissipation from modem + application processor.
Consider conformal coating and condensing humidity — IP67 does not eliminate corrosion from trapped moisture if venting is wrong.
Sheet Metal vs Cast/Injection for IoT
Sheet metal with folded gaskets scales well for gateways and small cells. Die-cast aluminum suits higher EMI shielding and heat spreading. Injection molded ABS/PC with ultrasonic welded seams fits high-volume sensor pods.
Ohmframe delivers IP-rated CAD, DFM for sheet metal and molding, and thermal simulation for sealed industrial products.