Taped Litz Wires


Taped high frequency litz wire constructions are mainly suitable for applications requiring high break down voltage. Taping improves the capability to withstand flexing and mechanical stress. Adhesive taped litz wire can be achieved by using thermally sealed or self adhesive tape. This ensures protection against re-opening during and after manufacturing processes and thus secures the compliance with defined creepage distance. 

Some tapes can be thermally sealed when used in conjunction with certain wire enamel types.

Excellent adhesion and bonding characteristics to the individual wires are possible. A wide range of thermally sealable tapes can be selected for special applications all promoting various degrees of flexibility and mechanical protection for the litz wire construction.

Features and benefits of taped litz wires

Variants Dielectric strength Flexibility Splicing Contacting
Standard high very good good very good
Thermally Sealed elevated medium very good very good
Self-Adhesive very high good very good good

Technical data sheet of different tapes

Taping materials PET PEN PI
Description Polyester Polyethylene Naphtalate Polyimide
Color transparent transparent brown
Standard PET PEN PI
Insulation class (UL) °C 105 (A) 180 (H) 200 (C)
Insulation class (VDE) °C 130 (B) - 200 (C)
Dielectric constant ℇr 3.3
(VDE 0345)
(JIS C 2318)
(ASTM D 150-92)
Flammability 400
(VDE 0345)
(UL 94)
(IEC 60695-11-10, UL 94)
UL-file no., tapes E53895 E206562 E39505
Processing fusible fusible mechanical stripping
Thermally Sealed
Insulation class (UL) °C 13 - 25 - 20
Insulation class (VDE) °C 9 - 0.2 - 0.5
Dielectric constant ℇr 3.25
(ASTM D 150-81)
- 3.4
(ASTM D 150-92)
Flammability n.a. - V-0
(IEC 60695-11-10, UL 94)
UL-file no., tapes E93687 - E39505
Processing fusible fusible mechanical stripping
Self Adhesive
Insulation class (UL) °C 130 (B) 180 (H) 180 (H)
Dielectric constant ℇr 3.2
(JIS C 2318)
(JIS C 2318)
(JIS C 2318)
Flammability - flame retardant
(internal test acc. UL 510)
flame retardant
(internal test acc. UL 510)
UL-file no., tapes E515235 E515235 E515235
Processing fusible fusible mechanical stripping
Custom materials can be arranged

Degree of overlapping

The degree of overlapping of two adjacent tape windings is defined by the gradient angle between tape and litz wire during the taping process. The overlapping determines the number of tape layers located on top of each other and thus the thickness of the insulation.


Diameter of single wires 0.040 - 0.700 mm
Outer diameter of litz wire 0.5 - 20.0 mm
Overlapping (typical) 50 or 67 %
Number of tapes (typical) 1 - 2


  • EV (Electric Vehicles)
  • OBC (Onboard charger)
  • DC/DC converter
  • Wireless charging
  • Charging piles
  • SMPS (Switch Mode Power Supplies)
  • HF transformers
  • HF transducers
  • HF chokes

Special constructions with VDE-approval for high voltage applications available:

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