TDK puts HDD-head manufacturing know-how to work in power components

HDD thin-film processes are being reused for AI data-center inductors

A hard disk drive stores information. Its head writes information to the magnetic disk and reads it back. TDK explains that the recording and reading elements are made by building up thin-film layers on a wafer, the substrate used in manufacturing (Glossary: Head for HDD).

A power inductor works in a power circuit or a DC-DC converter, which changes one direct-current voltage to another. It uses a coil’s ability to store magnetic energy and oppose changes in current. Recording information and working in a power circuit are different jobs (Power Supply Inductor, Choke Coil).

Thin-film manufacturing provides a connection between them. A thin-film inductor is made by forming a coil pattern on a wafer. TDK places inductors derived from its HDD-head thin-film process technology in the low-voltage, high-current part of its AI data-center power strategy (Glossary: Inductor, results briefing p.30).

HDD head

Read and write information

Works at the magnetic disk

Manufacturing

Layer recording and reading elements on a wafer

Apply HDD-head thin-film process know-how to inductors

→

Thin-film inductor

Oppose changes in current in a power circuit

Power circuits and DC-DC converters

Manufacturing

Form a coil pattern on a wafer

The arrow shows an application of manufacturing know-how, not reuse of finished heads or proof of identical equipment and every process step. Shapes and sizes are schematic.

Product roles: TDK GlossaryProcess application: April 2026 results briefing p.30

The application concerns know-how for making components with thin films. It does not mean finished HDD heads become inductors, or that the same equipment and every manufacturing step are used. Applying manufacturing knowledge to components with different functions gives TDK a role in both storage and power within data centers.

Alongside this application in inductors, HDD heads continue to serve their own storage function.

Magnetic heads now support data-center storage

Heads and inductors belong to a wider electronic-component portfolio. Across TDK as a whole, Energy Application Products, including rechargeable batteries, generate the largest share of sales.

Group sales are ¥2.505 trillion

Energy Application Products account for 54.7% of sales

Sales mix

Energy Application Products54.7%All other sales45.3%

The 45.3% “All other sales” is this site’s calculation of 100% minus TDK’s disclosed 54.7% Energy share. It combines every business outside Energy Application Products. Its scope differs from the company’s separate Other segment, which accounts for 2.1% (Corporate Outline p.5).

Passive Components, Sensors and Magnetic Applications each generate more than ¥200 billion in sales alongside Energy.

Passive Components, Sensors and Magnetic Applications each remain substantial

These components work inside ICT devices, automobiles and industrial equipment, where they can be less visible to consumers than a branded cassette. TDK’s sales and workforce span many countries.

Roughly 90% of sales are overseas

Applying manufacturing capabilities to another component also appears in TDK’s longer history. That history combines internal development with acquisitions that brought in other businesses.

The business-portfolio chart starts in 1935

Cassette tapes made the TDK name familiar to consumers during that expansion. The company presents the application of technologies and the broadening business portfolio in separate diagrams.

From cassettes into multilayer components and batteries

The diagram of applications in multilayer capacitors and inductors describes a different relationship from the chart of businesses added over time. They do not show one technology moving in a single straight line to produce every later product.

Magnetic tapes, heads, batteries and sensors became new branches

1935Establishment

CassetteRecording media

MultilayerElectronic components

Li-ionRechargeable batteries

Materials & process capabilitiesFerrite, multilayer and thin-film capabilities

1. Magnetic recordingFrom magnetic tape to HDD heads
2. Multilayer componentsCapacitors and inductors
3. Batteries & sensorsNew branches built internally and through M&A
4. AI componentsThin-film head processes reused for inductors

This is an editorial map of the article, not a reproduction of a company chart. Because acquisitions also shaped the portfolio, it should not be read as one linear technology genealogy.

It still says: “Evolve the Ferrite Tree”

The company’s image is of future businesses supported by roots such as technological capability, people and corporate culture. These foundations also appear in the Corporate Outline p.5 and the results briefing p.36.

THE VIEW AFTER THE NUMBERS

What the numbers suggest

At TDK, know-how for making a recording component also serves a component in a power circuit. HDD heads and thin-film inductors perform different jobs, connected by the application of thin-film process technology described by the company.

The earlier spread from cassettes into multilayer components and batteries also shows manufacturing capabilities finding other applications. Acquisitions helped broaden the portfolio into businesses including magnetic heads and sensors. TDK’s expansion becomes clearer when technology applications and acquired businesses are read together.