Electromagnetic Shielding Patents: Leaders & Filing Trends 2026
- Filings have crested, not climbed. The year-on-year count peaked at 73 in 2023 and has since eased back toward single digits, with 2022's midpoint of 50 marking the point growth stopped compounding.
- One IPC subclass dominates the corpus. H05K (printed circuits and assemblies) sits behind 1,220 of the 1,283 families — almost every filer routes through circuit-level shielding rather than material science alone.
- China now outfiles the US at the office level. 354 China filings against 259 US and 209 Japan shows the center of prosecution activity has shifted east even as older US patents still anchor the most-cited list.
Filing growth compares 2021 (68 records) with 2024 (56) — 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 1,283 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Electromagnetic shielding materials patents cluster around a narrow engineering problem: keeping unwanted radio-frequency energy out of an enclosure while still letting heat, moisture or mechanical flex pass through. The search underlying this page pulls 1,283 patent families filed between 2015 and mid-2026 across conductive-filler composites, gasket assemblies, absorption-loss coatings and aperture-leakage control, indexed under H05K9, H01Q17 and C09D5.
Most of the corpus sits inside printed-circuit and enclosure-level claims rather than pure materials chemistry, which tells a filer where the crowded ground actually is before they draft.
Filing trend and technology composition
Two views of the same 1,283 families: how filing pace has moved year over year, and which IPC subclasses carry the claim density.
Filings rose then plateaued
Annual filings grew from 37 in 2017 to a peak of 73 in 2023, then declined toward 9 in the most recent (partial) year. Because publication lags filing by roughly 18 months, the last one to two years will backfill upward as pending applications publish — but the shape through 2023-2024 already shows the curve flattening rather than compounding.
H05K dominates; polymer and gasket classes trail
H05K (printed circuits and assemblies) covers 1,220 of 1,283 records, with C08K polymer additives (198), C08L polymer compositions (177), B32B laminates (170) and F16J seals/gaskets (76) forming a secondary tier. The gap between the lead subclass and everything else suggests circuit-level enclosure shielding is where claim space is most occupied, while gasket and coating classes carry comparatively lighter density.
Shares are the percentage of the 1,283 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Electromagnetic Shielding Materials with Eureka
This page is one run against one query. Ask Eureka your own question about electromagnetic shielding materials and every answer comes back with the patent numbers behind it.
Try EurekaRepresentative and most-cited filings
US5581048A — Corrosion resistant electromagnetic shielding gasket
A shielding gasket installed between a door panel and an enclosure that combines electromagnetic shielding effectiveness with corrosion resistance: a retaining medium bleeds a corrosion-inhibiting fluid onto the gasket's outer surface over time, protecting the interface between dissimilar metals. Variants include an elastomeric layer for a moisture-proof seal or a rigid metallic construction.Filed by OL Security Limited Liability Company, granted 1996-12-03.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5091823A | Inverter device | 237 |
| 2 | US20040020674A1 | Composite EMI shield | 225 |
| 3 | US5264992A | Modular computer system having self contained workslate unit detachably coupled to base unit including keyboa… | 202 |
| 4 | US4948922A | Electromagnetic shielding and absorptive materials | 186 |
| 5 | US4678699A | Stampable polymeric composite containing an EMI/RFI shielding layer | 175 |
| 6 | US4520562A | Method for manufacturing an elastic composite body with metal wires embedded therein | 164 |
| 7 | US5910524A | Corrosion-resistant, form-in-place EMI shielding gasket | 131 |
| 8 | US5366664A | Electromagnetic shielding materials | 129 |
| 9 | US5117066A | Retaining and locking electromagnetic gasket | 123 |
| 10 | US5164542A | Composite housing for a computer system | 121 |
Citation counts favour older filings simply because they have had longer to accumulate citations inside this searched set — read them as a signal of influence on the field, not as a measure of current commercial relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three signals worth reading before drafting into this space.
The growth phase is over
Annual filings climbed from 37 in 2017 to a peak of 73 in 2023, then fell sharply. Even allowing for publication lag understating the most recent year, the midpoint year of 2022 (50 filings) sitting below the 2023 peak confirms this is a plateau-then-decline curve, not a still-compounding one.
Enclosure-level claims dominate
H05K (printed circuits and assemblies) appears in the overwhelming majority of families, dwarfing polymer-additive (C08K, 198), laminate (B32B, 170) and gasket (F16J, 76) classes. Filers building a materials-only claim without an enclosure or circuit tie-in are working against a thinner prior-art base.
Prosecution activity has moved to China
China receives more filings in this dataset than the United States, with Japan (209) and EPO (157) close behind. WIPO/PCT (73) and the UK (47) round out a corpus that is genuinely multi-jurisdictional rather than concentrated in one office.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to electromagnetic shielding materials, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| KAHL HELMUT(DE) | TIBURTIUS BERND | 17 |
| BALSELLS PETER J | BALSELLS JOAN C | 15 |
| Pilkington plc | Pilkington Group Limited | 2 |
| Laird Technologies, Inc. (US) | WOOD DAVID B | 2 |
| Laird Technologies, Inc. (US) | NAKAUCHI EDWARD | 2 |
| Laird Technologies, Inc. (US) | CREASY LARRY DON JR | 2 |
| Laird Technologies, Inc. (US) | COOK KELLY G | 2 |
| Laird Technologies, Inc. (US) | BOYCE AMY L | 2 |
Only 10 co-assignee pairs appear across the corpus, and the strongest pairings (Kahl Helmut + Tiburtius Bernd at 17 shared filings; Balsells Peter J + Balsells Joan C at 15) are individual co-inventors rather than joint-venture assignees — evidence this is a field of solo corporate filers, not alliance-driven development.
Who is active, and where the field is still open
Recent-year momentum across the largest assignees is flat: several of the most prolific filers in this dataset show zero filings in the latest year, consistent with the overall plateau in filing pace rather than any single company pulling back.
Even the leaders paused this year
Pilkington, Kitagawa Industries, Parker Hannifin and Laird Technologies all show zero filings in the latest recorded year, and Nolato Silikonteknik shows a -100% year-on-year drop. That is consistent with the corpus-wide slowdown rather than a company-specific retreat, but it means recent activity should be read from pending applications, not granted counts.
A long tail beneath a modest lead
The assignee ranking spans the full 1,283-family corpus without a single filer approaching a dominant share of it — this is a fragmented field where specialist gasket, filler and laminate suppliers each hold pockets of claim space rather than one company controlling the category.
Collaboration is the exception
With only ten co-assignee pairs identified across 1,283 families, most patents here are filed by a single entity. The rare pairings that do exist are individual inventor teams, not corporate joint ventures, suggesting licensing or M&A due diligence should focus on single-owner portfolios.
| Assignee | Recent year | YoY |
|---|---|---|
| Pilkington plc | 0 | — |
| Kitagawa Industries Co., Ltd. | 0 | — |
| Parker Hannifin Corporation | 0 | — |
| Laird Technologies, Inc. (US) | 0 | — |
| BALSELLS PETER J | 0 | — |
| Nolato Silikonteknik AB | 0 | -100% |
| Ticona LLC | 0 | — |
| KAHL HELMUT(DE) | 0 | — |
Where to take this analysis
The dataset points to a mature, fragmented field with a specific geographic and technical shift underway. Three follow-ups worth running before committing a filing budget.
Model the white space directly
Gasket and coating classes carry a fraction of H05K's density — run a claim-level gap analysis on F16J and C09D before assuming the space is occupied.
Explore white space in EurekaTrack the China filing shift
With China now ahead of the US at the receiving-office level, monitor which assignees are filing there first versus filing in the US or EPO after a domestic priority.
Run a geography analysis in EurekaWatch for pending applications
Because publication lags filing by about 18 months, the apparent 2023-2026 decline will partly fill in. Re-run the trend query periodically rather than treating the latest year as final.
Set up a monitoring alert in EurekaCommon questions
The assignee ranking behind this dataset spans 1,283 patent families without a single company holding a dominant share — it is a fragmented field with a long tail of specialist filers in gaskets, conductive fillers and laminates. Several of the largest historical filers, including Pilkington, Kitagawa Industries, Parker Hannifin and Laird Technologies, show zero filings in the most recent year, which reflects the corpus-wide slowdown rather than any one firm exiting the space. Anyone doing freedom-to-operate work should check the full ranking table rather than relying on a short list, since ownership here is genuinely distributed.
No — annual filings rose from 37 in 2017 to a peak of 73 in 2023, then declined sharply toward 9 in the latest partial year. Publication lag of roughly 18 months means the most recent one to two years will revise upward as pending applications publish, but the plateau at the 2022-2023 midpoint already shows growth had stopped compounding before the visible drop-off. Treat the field as mature rather than expanding.
H05K, covering printed circuits and assemblies, appears in 1,220 of the 1,283 families in this corpus, making circuit-level enclosure shielding by far the most claim-dense area. Polymer additive and composition classes (C08K, C08L), laminates (B32B) and gaskets (F16J) form a secondary tier with meaningfully lower filing counts. A new entrant is more likely to find open claim space in gasket corrosion interfaces or absorption-loss coating formulations than in general circuit-level shielding.
China leads with 354 filings at the receiving-office level in this dataset, ahead of the United States at 259, Japan at 209, the European Patent Office at 157, WIPO/PCT filings at 73 and the United Kingdom at 47. The lead for China marks a shift in where prosecution activity is concentrated, even though several of the most-cited historical patents in the field originated in the US. Filing strategy should account for China as a primary jurisdiction, not a secondary one.
US5581048A claims a shielding gasket, installed between a door panel and an equipment enclosure, that combines electromagnetic shielding effectiveness with active corrosion protection — a retaining medium bleeds a corrosion-inhibiting fluid onto the gasket surface over time to protect the interface between dissimilar metals. It covers both elastomeric moisture-proof variants and rigid metallic constructions, assigned to OL Security Limited Liability Company and granted in December 1996. New designs that use passive corrosion resistance, different sealing mechanisms, or that do not rely on a fluid-bleeding retaining medium are more likely to sit outside its specific claim scope, but any door-panel gasket combining shielding with active corrosion inhibition should be checked against it directly.
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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.