IP67 IP68 Waterproof Sealing for Electronics Guide

Understanding IP Ratings

IP Rating	What It Means	Typical Applications
IP54	Dust protected, splashing water from any direction	Outdoor sensors, workshop tools
IP65	Dust tight, protected against water jets	Outdoor lighting, marine electronics
IP67	Dust tight, immersion in water up to 1m for 30 min	Smartphones, wearables, outdoor sensors
IP68	Dust tight, continuous immersion beyond 1m (manufacturer-defined)	Smartwatches, underwater equipment, marine GPS

Key Seal Materials for Electronics

Material	IP Performance	Temp Range	Best For
LSR Silicone	IP68	−60 to +230°C	Smartwatches, wearable devices
EPDM (hardness 70A)	IP67-IP68	−45 to +150°C	Industrial enclosures, automotive ECUs
TPU (Thermoplastic PU)	IP65-IP67	−40 to +120°C	Budget electronics, cable glands
FKM (Viton®)	IP67	−26 to +205°C	High-temp electronics, oil-exposed enclosures

rubber sealing solutions Design Principles

1. Compression Seal (Static)

The most reliable method for electronics enclosures. A silicone or EPDM waterproof rubber gaskets is compressed between two housing halves using screws or clips. Key parameters:

Compression: 15-30% of gasket cross-section height
Gasket groove: Width = gasket diameter × 1.1 (to allow fillet)
Groove depth: Calculated to achieve target compression when assembled
Seal height: Should be 0.2-0.3mm above flush when uncompressed

2. Snap-Fit Seal

Elastomer overmolded or snap-in seal ring
Lower assembly cost — no screws needed
Less reliable at high pressure — suitable for IP67, not IP68

3. Lip Seal (Dynamic — for cables/buttons)

Radial lip seal for cable penetrations
Actuator button seal (silicon membrane with integral lips)
USB/connector port weatherproofing — silicone flap seal

Design Mistakes That Cause IP Failure

Insufficient compression: Gasket not compressed enough creates gaps — target 20% minimum
Stress concentration at corners: Gasket corner geometry must be radiused (R0.5mm minimum)
Sharp edges on housing: Will cut through the seal during assembly
Uneven compression: Screw preload variation causes local gaps
Thermal mismatch: Different housing materials expand at different rates — design tolerance accordingly

Testing IP Rating: What Manufacturers Must Do

IP67: Immersion in 1m water for 30 minutes — test at multiple orientations
IP68: Per manufacturer spec (often 2m for 1 hour or deeper)
Thermal cycling: −40°C to +85°C for consumer, (−40°C to +125°C for automotive)
Humidity test: 85% RH at 85°C for 1000 hours (accelerated aging)
Salt spray: For marine applications — minimum 96h per ASTM B117

LSR Overmolding for Electronics

LSR overmolding onto plastic or metal substrates is the premium approach for waterproof electronics. The silicone bonds directly to the housing during molding, eliminating any gap between seal and housing. Best for:

Smartwatches and fitness trackers (IP68 at depth)
Underwater cameras (IP68 for diving)
Industrial sensors in harsh environments
Automotive ECUs under-hood sealing

Anlintech offers LSR overmolding and compression-molded silicone seals for waterproof electronics. Contact us to discuss your IP rating requirements.

IP67/IP68 Waterproof Sealing for Electronics: Materials & Design Guide 2026