Aluminum Electrolytic Capacitor Patents: Leaders & Trends 2026
- Filing has cooled since its 2021 peak. six records that year against zero at the 2022 midpoint and none yet in the most recent year, though publication lag means the last year understates real activity.
- The top 5 assignees already hold 63.4% of the field. 26 of the 41 records in scope sit with five companies, and the top 10 combined account for 87.8% — a short list of gatekeepers, not a fragmented market.
- Nearly all activity sits in one IPC subclass. every one of the 41 records carries H01G (capacitors), while implantable-device electrotherapy classes (A61N) and etching/corrosion classes (C25F, C23F) appear far less often.
A mature, concentrated field with a narrow technical core
Aluminum electrolytic capacitor patenting activity documented here runs from 2015 through mid-2026 and covers 41 published records tied to anode foil etching, ripple current rating, ESR at high frequency, electrolyte dry-out and lifetime-at-temperature claims. The search deliberately narrows on IPC classes H01G9, H01G4 and C25D11, so the corpus is small but technically focused rather than a broad sweep of every capacitor filing.
Within that scope, the field looks less like an open race and more like a settled hierarchy: a handful of assignees account for most of the record count, filing activity peaked in 2021 and has since gone flat, and the technology composition is dominated by one IPC subclass with only thin secondary activity in electrotherapy and etching-adjacent classes.
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Filing trend and technology composition
Two views of the same 41-record corpus: how filing volume has moved year over year, and which IPC subclasses the records actually sit in.
Filing trend, 2017-2026
Filings ran at 3 in 2017, rose to a peak of 6 in 2021, then dropped to 0 by the 2022 midpoint and have stayed flat since. The 2026 figure is partial and, like the last 18 months generally, understated by publication lag rather than a true drop in activity.
IPC subclass composition
H01G (capacitors) covers 100% of the 41 records, as expected given the search scope. A61N (electrotherapy) appears in 19.5%, C25F (electrolytic removal/cleaning) in 12.2%, C23F (corrosion/metal removal) in 9.8%, and C25D (electroplating) in just 2.4% — since records can carry multiple classes, these figures do not sum to 100%.
Shares are the percentage of the 41 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Aluminum Electrolytic Capacitors with Eureka
This page is one run against one query. Ask Eureka your own question about aluminum electrolytic capacitors and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited records in this corpus
Hybrid Polymer Aluminum Electrolytic Capacitor and Method of Manufacturing a Capacitor
A hybrid polymer aluminum electrolytic capacitor and a method for manufacturing a capacitor are disclosed. In an embodiment a hybrid polymer aluminum electrolytic capacitor includes a winding element having a diameter of more than 10 mm, at least two tabs electrically contacted with an anode foil and at least two tabs electrically contacted with a cathode foil.Filed by TDK Electronics, published 2019-10-10 as US20190311858A1.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20030056350A1 | Implantable medical device having flat electrolytic capacitor formed with nonthrough-etched and through-hole … | 23 |
| 2 | US20060215352A1 | Solid electrolytic capacitor and method of manufacturing solid electrolytic capacitor cathode material | 18 |
| 3 | CN101345137A | 电解电容器的阳极箔腐蚀工艺 | 16 |
| 4 | JP1991161918A | Long life type electrolytic capacitor | 11 |
| 5 | CN108183033A | 一种铝电解电容器用阳极箔腐蚀工艺 | 10 |
| 6 | US20190311858A1 | Hybrid Polymer Aluminum Electrolytic Capacitor and Method of Manufacturing a Capacitor | 10 |
| 7 | JP1991085714A | Electrolytic capacitor | 10 |
| 8 | US7221557B2 | Solid electrolytic capacitor and method of manufacturing solid electrolytic capacitor cathode material | 9 |
| 9 | US11158464B2 | Hybrid polymer aluminum electrolytic capacitor and method of manufacturing a capacitor | 7 |
| 10 | US3753051A | Electrolytic capacitor having low value inductance and equivalent series resistance | 7 |
Citation counts inside a searched corpus favour older filings that have had more time to accumulate citations — read them as a signal of influence, not of current technical relevance.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers say about where this field stands
Four read-outs from the filing trend, concentration figures and IPC composition — useful for deciding where further filing is likely to compete against dense prior art versus where it is not.
A short list controls most of the claim space
26 of the 41 records in scope belong to five assignees, and the top 10 combined reach 87.8%. That leaves a long tail of single- or double-filing entrants competing for the remainder — a pattern that rewards licensing or acquisition moves over greenfield filing at the core.
Filing has gone flat since its 2021 high
Six records published in 2021 mark the peak of this dataset; the count dropped to zero by the 2022 midpoint and has stayed there through the most recent year on record. Because publication typically lags filing by around 18 months, the last one to two years likely understate real filing activity rather than reflect a genuine stop.
Implantable-device use is a distinct secondary cluster
Nearly a fifth of the 41 records also carry an A61N electrotherapy classification, pointing to a real sub-market around implantable medical device capacitors that sits alongside the core H01G filings rather than replacing them.
Co-filing is rare and confined to two pairings
Only two co-assignee pairs appear across the corpus, each filing together twice. Most activity in this field is filed solo, which fits a market where a small number of established manufacturers each hold their own etching and foil-processing know-how rather than pooling it.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to aluminum electrolytic capacitors, with the prior art for and against each one.
Who is filing, and where the gaps sit
The ranked leaders in this dataset span Japanese, US and Chinese assignees, with the leader holding 9 of the 41 records and activity thinning quickly after fifth and tenth place.
One assignee holds more than a fifth of the corpus alone
The top-ranked assignee accounts for 9 of the 41 records in scope — well ahead of fifth place at 2 and tenth place also at 2, showing a steep drop-off rather than a gradual taper.
The middle of the ranking is flat
From fifth place down to tenth, filing counts sit at the same level, meaning there is no meaningfully differentiated 'second tier' — just a wide band of similarly sized filers below the leader.
No ranked leader has filed in the most recent year
Every one of the leading assignees tracked for recent-year momentum shows zero filings in the latest year on record. Given the roughly 18-month publication lag, this is at least partly an artefact of timing rather than firms having stopped work.
| Assignee | Recent year | YoY |
|---|---|---|
| TDK Electronics AG | 0 | — |
| Medtronic, Inc. | 0 | — |
| Resonac Holdings Corporation | 0 | — |
| Elna Co., Ltd. | 0 | — |
| Kasei Naoetsu Co., Ltd. | 0 | — |
| Hitachi Condenser, Ltd. | 0 | — |
| Ruyuan Yao Autonomous County Dongyangguang Formed Foil Co., Ltd. | 0 | — |
| Dongguan Dongyangguang Capacitor Co., Ltd. | 0 | — |
Turning this landscape into a filing or licensing decision
The figures above describe where the field stands; the next step is testing a specific claim or target against the full corpus rather than a summary of it.
Check claim novelty against the cited core
Before drafting around anode foil etching or electrolyte dry-out, run the specific claim language against the most-cited records in this set — several date back years but still shape what counts as novel.
Search prior art in EurekaWatch the flat mid-field for acquisition targets
Assignees sitting at similar filing counts below the leader are natural licensing or acquisition candidates if freedom-to-operate in the core H01G space is the goal.
Explore assignee profiles in EurekaRevisit under-claimed branches before the next filing cycle
C25D and C23F classes show thin coverage relative to the core — worth a fresh freedom-to-operate check before committing R&D budget there.
Run a white space analysis in EurekaCommon questions about aluminum electrolytic capacitor patents
Within this 41-record dataset, one assignee leads with 9 records, well ahead of the rest of the ranked field. The top 5 assignees combined hold 26 records, or 63.4% of all records in scope, and the top 10 extend that to 87.8%. This is a concentrated field rather than one with many similarly sized competitors, so freedom-to-operate work should start with the leading handful before looking further down the ranking.
No — filing peaked at 6 records in 2021 and had fallen to 0 by the 2022 midpoint, with the trend staying flat through the most recent year tracked. That said, publication typically lags actual filing by around 18 months, so the last one to two years of this trend understate real activity and should not be read as a hard stop in R&D investment. A clearer picture will emerge once filings from the last 18 months finish publishing.
Every record in this corpus carries an H01G capacitor classification, as expected given the search scope, but a meaningful secondary cluster — 19.5% of records — also carries an A61N electrotherapy classification, pointing to implantable medical device applications. Etching and corrosion-related classes (C25F, C23F) and electroplating (C25D) appear in smaller shares, suggesting most claim activity is general capacitor construction rather than niche foil-processing methods.
The classes with the thinnest representation relative to the core H01G volume are C25D (electroplating/electroforming, 2.4% of records) and C23F (corrosion and metal removal, 9.8%). These sit adjacent to the dominant anode foil etching claims but are not heavily claimed themselves, making them worth a closer look for a first-filer position — particularly around electroplating-based foil formation or corrosion-resistant treatments for high-temperature environments.
Yes, substantially. Nearly a fifth (19.5%) of the 41 records in this corpus carry both an H01G capacitor classification and an A61N electrotherapy classification, and one of the most-cited records in the set specifically covers an implantable medical device capacitor. Anyone filing in the implantable-device space should expect to run into both general capacitor prior art and medical-device-specific claims from the same small group of leading assignees.
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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.