Is Polyimide Tapes Waterproof?
Aug 25, 2025
Polyimide tape (also known as Kapton tape) is a widely used high-performance material in electronics manufacturing and industrial applications.
Many customers often ask:
"Is polyimide tape waterproof?"
Waterproof and Moisture Resistance
Polyimide film itself has extremely low water absorption (typically <0.5%), and even in humid or high-humidity environments, it will not swell, deform, or lose performance.
Combined with a high-temperature silicone adhesive, the tape maintains stable adhesion even in high-temperature and humidity cycles.
Common Applications:
-Reliable protection of circuits in humid environments in PCB manufacturing
-Long-term insulation protection for motor and transformer windings
-Moisture-resistant protection for industrial equipment and outdoor electronics
In addition to moisture resistance, polyimide tape offers additional advantages.
1. Excellent high-temperature resistance: Long-term temperature resistance up to 260°C, short-term resistance up to 300°C. No adhesive residue or warping after reflow and wave soldering.
Solution: Avoids high-temperature damage or the increased cost of cleaning residual adhesive.
2. Strong electrical insulation: Dielectric strength ≥ 6kV. Effectively isolates circuits, preventing breakdown and short circuits.
Solution: Ensures long-term reliability of PCBs and electrical equipment.
3. Chemical resistance: Resistant to solvents, flux, cleaning agents, and oils.
Solution: No degradation during process cleaning or long-term use.
4. Excellent dimensional stability: No shrinkage or curling, ensuring stable adhesion over time.
Solution: Avoids shifting and waste during production.
5. Wide range of applications: PCB shielding and solder protection; Motor and transformer insulation; High-temperature protection by electroplating and spraying; Surface protection for 3D printing heated beds.
Solution: One material meets multiple application scenarios, reducing procurement costs.
Common Customer Pain Points
-Low-quality tape peels off when exposed to water or moisture
-Severe adhesive residue after high temperatures, making cleaning difficult
-Batch instability affects product consistency
-Slow delivery and unstable supply
Polyimide tape is a reliable solution to these problems.
