Soft Magnetic Composite Patents: Leaders, Trends & White Space 2026
- Top 5 hold 50.4%. Five assignees account for 422 of the 838 records in scope, so half the field sits with a small group even before counting the long tail of single-filing entrants.
- Filing peaked in 2021. Activity hit 67 records that year and had fallen to 28 by 2024, a -58% move over that span — the clearest sign the initial land grab has passed its high point.
- Powder metallurgy claims run wide. B22F appears on 41.9% of the 838 records, second only to H01F at 65.4%, meaning most filings anchor on either the magnetic core class or the powder-processing route into it.
Filing growth compares 2021 (67 records) with 2024 (28) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 838 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This review covers 838 published records filed or published between 2015 and mid-2026 that combine soft magnetic composite or insulated iron powder terminology with process-level language such as core loss, compaction pressure, insulation coating, or annealing treatment. That pairing keeps the set focused on motor-core-relevant soft magnetic composite work rather than the broader powder metallurgy or magnetics literature.
Filing activity concentrates in a handful of receiving offices and a narrow set of IPC subclasses, which makes the technology composition and assignee concentration figures below more informative than the raw record count alone.
Filing trend and technology composition
Two views of the same 838 records: how filing volume has moved year over year, and which IPC subclasses the claims actually sit in.
Filing trend, 2017-2026
Filings rose from 27 in 2017 to a peak of 67 in 2021, then declined to 28 by 2024, a -58% move over that three-year span. 2025 and 2026 figures are still incomplete because publication typically lags filing by roughly 18 months, so the most recent two years understate actual activity and should not be read as a continuing decline on their own.
IPC subclass composition
H01F (magnets, inductors and transformers) appears on 65.4% of the 838 records, and B22F (powder metallurgy) on 41.9%, confirming that most soft magnetic composite work is claimed jointly across the magnetic-component class and the powder-processing route that produces it. H02K (electric motors and generators) reaches 26.7%, while C22C (alloys) and C23C (coatings) sit further down at 12.9% and 4.7%. Because records can carry multiple classes, these shares are read against the full 838-record base, not against each other.
Shares are the percentage of the 838 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Soft Magnetic Composites for Motor Cores with Eureka
This page is one run against one query. Ask Eureka your own question about soft magnetic composites for motor cores and every answer comes back with the patent numbers behind it.
Try EurekaRepresentative filing and most-cited prior art
Soft magnetic composite, method for preparing the same, and electronic components including the same as core material
The filing discloses a soft magnetic composite with an insulating layer formed along the inter-particle boundary of the soft magnetic core metal powder, together with a preparation method and electronic components using it as core material. The stated advantage is that forming the insulation along particle boundaries protects the coating film from damage during molding of the powder, which in turn minimises eddy current loss.Filed 2015-01-15 by Samsung Electro-Mechanics.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20040021437A1 | Adaptive electric motors and generators providing improved performance and efficiency | 233 |
| 2 | US4601765A | Powdered iron core magnetic devices | 194 |
| 3 | US4601753A | Powdered iron core magnetic devices | 128 |
| 4 | US20050184689A1 | Adaptive electric motors and generators providing improved performance and efficiency | 104 |
| 5 | US20060024181A1 | Reciprocating compressor and manufacturing method thereof | 73 |
| 6 | US20110024670A1 | Composite magnetic material and method of manufacturing the same | 58 |
| 7 | US20130292081A1 | System and method for making a structured magnetic material with integrated particle insulation | 55 |
| 8 | WO1996030144A1 | Soft magnetic anisotropic composite materials | 55 |
| 9 | US20180054094A1 | Motor Cooling System Utilizing Axial Cooling Channels | 53 |
| 10 | US20090102314A1 | Rotating electrical machinery | 52 |
Citation counts favour older filings simply because they have had longer to accumulate references; treat them as a signal of influence within this corpus, not as a ranking of current technical importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers mean for a filing decision
Three patterns stand out once the raw counts are set against each other: where claim density sits, how concentrated ownership is, and what the recent activity curve is actually telling you.
Ownership sits with a small group, not a single firm
The leading assignee holds 271 records on its own, but the next four combined still make up the bulk of the top-5 share; by tenth place the count has dropped to 13. That gap between first place and the rest of the ranked leaders suggests one filer set the pace early and others followed at a much lower rate, rather than several firms racing each other closely.
Two classes carry almost all the claim weight
H01F and B22F between them cover the great majority of records, which means new entrants are filing into already-dense claim space if they anchor on core structure or powder compaction alone. The classes with lower coverage — C23C coatings at 4.7%, B22D casting at 3.9%, H02P control electronics at 2.1% — carry far less prior art per the same denominator.
Peak filing has passed, but 2025-26 data is incomplete
The -58% move from the 2021 peak to 2024 is a real, complete-year comparison. It should not be read as a technology in decline so much as a first wave of claims settling into place; the 18-month publication lag means any read on 2025 or 2026 volumes is premature.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to soft magnetic composites for motor cores, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| Hoganas AB | YE ZHOU | 11 |
| Hoganas AB | SKARMAN BJORN | 10 |
| YE ZHOU | SKARMAN BJORN | 9 |
| Denso Corp | Hitachi Powdered Metals Co., Ltd. | 8 |
| YE ZHOU | STAFFANSSON HANNA | 5 |
| Hoganas AB | VIDARSSON HILMAR | 3 |
| Hoganas AB | JANSSON PATRICIA | 3 |
| Hoganas AB | HULTMAN LARS | 3 |
Ten co-assignee pairs appear in the dataset, with the strongest recurring pairing linked to 11 shared records and two others at 10 and 9 — a sign of a small number of stable joint-filing relationships rather than broad industry-wide collaboration.
Who holds the ranked positions, and where the gate sits for new entrants
The assignee ranking returned by the dataset covers 100 companies, counted by record — it is the full ranking the data endpoint returns, not a top-50 or top-100 cut chosen for the page.
One assignee sets the filing pace
The leading assignee's record count is more than five times the fifth-place figure of 25, and more than twenty times tenth place at 13. That gap is unusually wide for this kind of ranking and points to a single company treating soft magnetic composite claims as a core patenting programme rather than an occasional filing.
Even the leader's filing pace has cooled
The leading assignee filed only 1 record in the latest year, down 67% year over year, and several other named assignees in the momentum data show 0 records in the latest year. Read this alongside the publication lag rather than as a signal that these firms have stopped working the technology.
Filing spreads across US, China and Europe roughly in that order
The United States receives the largest single share of filings, with China and the EPO both drawing substantial volume and WIPO, Canada and India taking smaller but non-trivial shares. A filing strategy built only around one jurisdiction misses activity that is already visible in at least five others.
| Assignee | Recent year | YoY |
|---|---|---|
| Hoganas AB | 1 | -67% |
| Persimmon Technologies Corp | 0 | -100% |
| E V R Motors | 0 | — |
| Linear Labs | 0 | — |
| Romax Technology Limited | 0 | — |
| YE ZHOU | 0 | — |
| Denso Corp | 0 | — |
| MAXXWELL MOTORS INC | 0 | — |
Where to take this analysis
The figures above establish concentration and composition; the next step is usually to test a specific claim idea or a specific competitor against the full record set.
Check a draft claim against the cited prior art
The most-cited records in this dataset, including the two 1980s powdered-iron-core patents still drawing citations decades later, define the baseline any new insulation-coating or compaction claim has to clear.
Explore prior art in EurekaTrack the leading assignee's filing programme directly
With one assignee holding 271 of 838 records, understanding its recent filing pace and geographic spread matters more than the aggregate trend line.
Monitor assignee activity in EurekaTest the under-claimed branches for freedom to operate
Classes like H02P and B60L carry a fraction of the filing density of H01F and B22F, which is either white space or an early signal worth checking before committing R&D spend.
Run a white space search in EurekaCommon questions about this landscape
One assignee leads clearly with 271 of the 838 records in scope, well ahead of the fifth-ranked company at 25 and the tenth-ranked at 13. The top five assignees combined hold 50.4% of all records, so ownership is concentrated but not limited to a single company. Behind the ranked leaders sits a long tail of smaller filers, many with only one or two records, which is typical for a materials technology with both large manufacturers and academic or niche filers active in it.
Filing rose from 27 records in 2017 to a peak of 67 in 2021, then fell to 28 by 2024, a -58% change over that three-year span. That drop looks like a cooling-off after an initial wave of claims rather than the field disappearing, since the underlying motor-efficiency drivers behind soft magnetic composite research have not gone away. Figures for 2025 and 2026 are still incomplete because publication typically lags actual filing by around 18 months, so those two years should not be read as confirming a continued decline.
The two dominant classes are H01F, covering magnets, inductors and transformers, which appears on 65.4% of the 838 records, and B22F, covering powder metallurgy, on 41.9%. H02K, the electric motors and generators class, reaches 26.7%, reflecting how much of this work is claimed with an end application in mind. Coating-specific class C23C and casting class B22D sit much lower, at 4.7% and 3.9% respectively, which is one indicator of where claim space is less crowded.
The classes with the thinnest coverage relative to the 838-record base are H02P (motor and generator control, 2.1%), B60L (electric vehicle propulsion, 1.4%), B22D (casting-route fabrication, 3.9%) and C23C (coating and surface deposition, 4.7%). Low coverage in a class can mean either genuine white space or that the sub-area is simply harder to claim distinctly from the dominant H01F and B22F classes, so it is worth checking specific claim language before assuming an opening. Insulation coating chemistry tuned for high-temperature annealing and three-dimensional flux path core geometries are two areas where the coverage gap looks structural rather than coincidental.
The filing, assigned to Samsung Electro-Mechanics and dated 2015-01-15, covers a soft magnetic composite with an insulating layer formed along the inter-particle boundary of the core metal powder, plus the preparation method and resulting electronic components. Its stated technical effect is protecting the insulation coating from molding damage, which reduces eddy current loss. Anyone filing on insulation-layer placement at the particle boundary in a soft magnetic composite should read this claim closely, though the actual scope of blocking depends on the specific claim language, which a freedom-to-operate review needs to check against the granted claims rather than the abstract alone.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.