Publish Time: 2026-10-01 Origin: Site
A poorly insulated EV busbar can create exposed high-voltage surfaces, reduced creepage paths or greater vulnerability to heat and ejecta during a battery failure event.
Ceramic silicone composite tape can provide a flexible dielectric and fire-protection layer around selected busbar geometries when the construction is properly specified and validated.
The tape should not be treated as decoration or as a way to compensate for inadequate electrical spacing. Busbar geometry, voltage, fasteners, edges and thermal-runaway exposure must be reviewed together.
Leaving busbar surfaces insufficiently protected can increase electrical and thermal risk around adjacent conductive structures.
Use the tape where the design requires conformable electrical insulation combined with elevated-temperature or fire protection.
Saint-Gobain identifies an ultra-thin ceramifiable silicone/fiberglass composite specifically for busbar wrapping and EV battery thermal protection.[1]
Busbar Design Item | What to Check |
|---|---|
Voltage | Required solid insulation and spacing |
Busbar Edge | Tape conformity and puncture risk |
Bolt Hole | Electrical contact keep-out and tolerance |
Overlap | Finished thickness and gap control |
Thermal Exposure | Flame, hot gas and ejecta direction |
Covering an intentional electrical contact area or allowing insulation to lift around a sharp bend can interfere with assembly and create inconsistent insulation.
Define adhesive keep-out, contact footprint, hole geometry and overlap on the drawing. Bolt and washer interfaces that must remain conductive should not be accidentally insulated.
For difficult three-dimensional shapes, prototype wrapping is important because tape stretch, bend radius and adhesive behavior can change the final coverage.
Adding insulation tape does not automatically make an unsafe busbar spacing acceptable.
Treat tape as part of the solid-insulation system while maintaining the electrical-spacing strategy required by the product architecture.
IEC 60664-1:2020+A1:2025 provides principles for clearance, creepage distance and solid insulation for equipment up to 1,500 V DC, making it a useful reference when establishing insulation coordination.[2]
A tape that looks acceptable after assembly can still lift, tear or lose performance after thermal cycling and fire exposure.
Validate the finished busbar rather than testing only a flat material coupon. Check dielectric performance, adhesion, edge coverage, vibration, temperature cycling and application-specific fire exposure.
Where thermal-runaway protection is part of the requirement, material screening methods such as UL 2596 can help characterize severe thermal and mechanical exposure, although the final busbar system still requires application-level validation.[3]
Have a Busbar Drawing Ready?
Send Fuqiang the busbar CAD drawing, voltage, tape thickness target, bolt-hole geometry and required insulation area. We can review wrapping zones and prepare converted samples for fit and electrical validation.
Yes, if the tape and adhesive system are qualified for the required electrical, thermal and mechanical conditions.
Potentially, but surface condition, adhesive compatibility and the complete insulation design must be validated.
Not when that area is intended to create an electrical connection. The insulation keep-out zone should be defined on the engineering drawing.
No material tape prevents the initiating cell failure. Its role can include protecting circuitry and delaying damage from heat, flame or ejecta.
There is no universal thickness. Voltage, dielectric target, geometry, fire exposure, overlap and packaging determine the required construction.
A 15-Year Automotive Wire Harness and High-Voltage Perspective
After 15 years working with automotive electrical assemblies, I recommend designing busbar insulation from the contact zones, fasteners and edge geometry outward. The most reliable converted insulation parts are based on the actual drawing, not a generic tape width.
[1] Saint-Gobain — Ceramifiable Silicone/Fiberglass EV Composites
[2] IEC 60664-1:2020+A1:2025 — Insulation Coordination
[3] UL Solutions — Battery Enclosure Material Screening Under UL 2596