In this technical guide, Clayton Elliott, Design Engineering Manager at New England Wire Technologies, addresses one of the most pervasive misconceptions in high-frequency magnetics: the belief that Litz wire is difficult to terminate.
Litz wire is widely used in power conversion, electric vehicle chargers, switch-mode power supplies, and wireless charging systems because it suppresses high-frequency AC losses (skin and proximity effects), allowing magnetic components to be smaller and more efficient. Despite its performance advantages, some engineers avoid Litz constructions due to perceived termination complexity.
In reality, termination difficulty depends almost entirely on the enamel insulation type and the total strand count:
- The 94% (Direct Dip-Solderable): Over 94% of the Litz wire manufactured and sold by New England Wire is made with solderable magnet wire film (typically polyurethane-based enamels). Terminating these wires requires no mechanical scraping or chemical stripping. Operators simply slide back or strip the outer textile serve or jacket and immerse the bundle directly into a temperature-controlled solder pot. The molten solder burns away the thin enamel and tins all individual strands simultaneously in seconds—making termination as straightforward as standard bare or tinned copper wire.
- The 5% (Low Strand-Count Non-Solderable): Approximately 5% of constructions use high-temperature, non-solderable magnet wire enamels but have a low number of total ends. Because there are few conductors, they are easily prepped using abrasive techniques (such as fine sandpaper or mechanical wire strippers) or small salt pots before soldering.
- The 1% (High Strand-Count Non-Solderable): Only about 1% of Litz applications combine non-solderable, high-temperature films (such as polyimide) with hundreds or thousands of fine strands. These specialized cases require advance process planning, utilizing chemical stripping solutions, molten salt baths, or thermal wire fusion (welding).
Roughly 99% of all real-world Litz wire applications can be terminated quickly and cleanly using standard, accessible shop floor methods.
Key Technical Takeaways
- Solderable Enamels Dominate: 94% of custom Litz wire is produced with solderable magnet wire films that tin directly in a solder pot without mechanical pre-stripping.
- Dip-Soldering Simplicity: For solderable wire, removing the outer textile serve and dipping the bundle into a solder pot tins every conductor in a single operation.
- Low Strand-Count Prepping (~5%): Non-solderable cables with few conductors can be stripped mechanically, abraded with sandpaper, or dipped in a salt bath prior to soldering.
- Specialized Processes (~1%): High strand-count cables using non-solderable high-temperature enamels require controlled chemical baths, molten salt pots, or resistance/thermal fusion.
- The 99% Reality: The reputation of Litz wire being difficult to terminate is largely a myth; 99% of designs require only routine preparation and basic solder equipment.
Terminating Litz Wire Transcript
Introduction & High-Frequency Power Supplies
Good day. I’m here today to talk about terminating Litz wire.
I’m Clayton Elliott, Design Engineering Manager at New England Wire Technologies. I’ve been interested in power supplies and power conversion for quite some time. These are very important items that are behind the scenes in just about everything nowadays—on the internet, electric vehicles, even your cell phone. Power conversion and power conditioning is very important.
So I’m building a high-current power supply for fun. And that’s going to use high frequency and high currents in the magnetics. So those need to be carefully built.
Debunking the Myth: Is Litz Wire Hard to Terminate?
So I’ve decided to wind with Litz wire. This will make the components smaller and more efficient. But you often hear, or I’ve even read, “Litz wire is hard to terminate.” I believe this is a misnomer, though. I know we solder Litz wire and that works very well.
I wonder just how much of this type of wire that New England sells is solderable magnet wire?
The 94%: Direct Dip-Solderable Magnet Wire
As you can see by this chart, 94% of what New England Wire sells is solderable magnet wire—wire that takes no other process than dipping into a solder pot.
The solder process is pretty easy. You just remove outer coatings or serves such as this, and then you can dip it into the solder pot. So this takes care of 94% or more of the wire. As easy as connecting to tin or bare copper wires.
The 5%: Low Strand-Count Non-Solderable Wire
Another 5% of the wire is a low number of ends and non-solderable wire, such as this. There’s only a few ends here.
Now these ends are non-solderable, so you need to clean them beforehand. But there are techniques for this, such as a salt pot, or since there’s such a low number of ends, you can mechanically strip them, or you can use something like sandpaper even, and then you can solder. So this is still pretty easy. You just clean these off and then solder them.
The 1%: High Strand-Count Specialized Methods
For that last 1% of non-solderable, high number of ends of magnet wire, you’ll have to use something like a salts bath or chemicals to remove the enamel. Fusion does also work.
There are methods; just planning and research does have to be done for that 1% only.
So contact us at New England Wire for more information about electrically terminating Litz, or Litz wire questions in general. And remember, 99% of Litz wire is easy to terminate.
