Polyimide Film Patents: Who Leads, Where the Gaps Are 2026
- 44.3% concentration. The top 5 assignees combined hold 109 of the 246 records in scope (44.3%), with a long tail of single- and few-filing entrants behind them.
- Filing has flattened since its 2020 peak. Activity peaked at 19 records in 2020 and has since drifted down through the 2022 midpoint of 14, suggesting the core claim space is largely staked out.
- Condensation chemistry dominates. 71.1% of records sit in C08G (condensation polymers), far ahead of laminate (B32B, 41.5%) and printed-circuit (H05K, 41.5%) classes — the film chemistry itself, not its downstream integration, is where most claims are written.
What the polyimide film patent record shows
Polyimide film patenting sits at the intersection of polymer chemistry and electronics packaging: claims cluster around thermal stability and CTE control, dielectric constant and loss, adhesion in flexible copper-clad laminate, and transparency for display cover applications. The 246 records in scope span 2015 through the 2026 data cut-off, with United States, Japan and China as the dominant receiving offices — a spread that reflects both device-brand markets and materials-manufacturing bases.
Filing activity rose through the late 2010s, peaked in 2020, and has since flattened. Because publication lags filing by roughly 18 months, the most recent one or two years in any trend understate true filing activity — the apparent decline should be read cautiously for 2025-2026, but the plateau visible from 2021 onward is a real signal that the field's core claim space is well-occupied rather than newly opening.
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Filing trend and technology composition
Two views of the same 246-record dataset: filings by year, and the IPC subclasses those filings carry. Because a single record can carry several IPC classes, the composition shares add up to more than 100% of the record total — that is expected and is not a ranking error.
A 2020 peak, then a plateau
Filings rose from 3 in 2017 to a peak of 19 in 2020, held near that level through the 2022 midpoint of 14, and have since trended down. Read the final one to two years as understated given the typical 18-month publication lag rather than as a genuine collapse in R&D activity.
Condensation chemistry leads, laminate and circuit integration follow
C08G (condensation polymers) covers 71.1% of the 246 records, and C08J (polymer processing and solutions) covers 60.6% — together they confirm most claims are written on the film chemistry itself. B32B (laminates) and H05K (printed circuits) each cover 41.5%, showing substantial but secondary claim activity in how the film is integrated into flexible copper-clad laminate and circuit assemblies.
Shares are the percentage of the 246 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Polyimide Films with Eureka
This page is one run against one query. Ask Eureka your own question about polyimide films and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited prior art in this field
Highly heat-resistant and low-dielectric polyimide film and method for producing same
The film is obtained by imidizing a polyamic acid solution containing two or more dianhydride components — BTDA, BPDA and/or PMDA — with a diamine component including m-tolidine and PPD. It targets a glass transition temperature of 320°C or higher, moisture absorption of 0.4% or less, and a dielectric dissipation factor of 0.004 or less.Filed by PI Advanced Materials Co., Ltd., published 2022-12-15 as US20220396667A1.
View full record| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5582858A | Adhesive layer in multi-level packaging and organic material as a metal diffusion barrier | 114 |
| 2 | JP2001072781A | Polyimide film and substrate for electric and electronic apparatus using same | 81 |
| 3 | US6350844B1 | Polyimide film and electric/electronic equipment bases with the use thereof | 78 |
| 4 | JP1998036506A | New polyimide composition and polyimide film | 52 |
| 5 | JP1999054862A | Polyimide film for hard disk suspension wiring base material | 47 |
| 6 | JP2006124685A | Polyimide film for COF (chip-on-film), and laminate | 42 |
| 7 | US5326643A | Adhesive layer in multi-level packaging and organic material as a metal diffusion barrier | 41 |
| 8 | US20040053061A1 | Material for insulating substrate, printed board, laminate, copper foil with resin, copper-clad laminate, pol… | 37 |
| 9 | JP1985127523A | Base film for magnetic recording medium in high density | 35 |
| 10 | JP1999199668A | Polytmide composition, and tape for TAB and flexible printed circuit board therefrom | 34 |
Citation counts favour older records simply because they have had longer to accumulate citations inside a searched corpus — treat this table as a map of influential prior art, not of current commercial 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 in the dataset matter more than any single ranking: where citation weight sits, how concentrated ownership is, and how thin the co-filing network is.
Old packaging art still anchors the field
The most-cited record in scope is a 1990s multi-level packaging patent on adhesive layers and metal-diffusion barriers, followed closely by two Japanese base-film patents from the early 2000s. New filings on thermal and dielectric performance are being written against a prior-art base that is two to three decades old.
A handful of firms hold nearly half the field
The top 5 assignees combined account for 109 of the 246 records in scope, and the top 10 account for 146 (59.3%). The leader alone holds 52 records — well ahead of fifth place at 9 and tenth place at 6 — leaving a long tail of firms with only one or two filings each.
Co-filing is rare and shallow
Only 10 co-assignee pairs appear across the dataset, and the strongest pair links just 5 records. Most polyimide film patenting is done by single assignees working alone rather than through joint-development filings, which limits how much freedom-to-operate risk can be traced through partnership networks.
Filing follows both device brands and materials bases
The United States leads as a receiving office, ahead of Japan and China, with Europe, South Korea and the WIPO/PCT route trailing. That spread mirrors where flexible-electronics brands and materials manufacturers both sit, rather than concentrating in one jurisdiction.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to polyimide films, with the prior art for and against each one.
Who holds the claim space, and where it's thin
Ownership is concentrated at the top but the ranking runs 85 companies deep, with most holding only a handful of records. The gaps sit less in who files and more in which sub-claims remain open.
One assignee holds roughly a fifth of the field
The leading assignee's 52 records are more than five times fifth place's 9, making it the single most important filer to clear against before entering thermal-stability or dielectric-loss claim territory.
A tight cluster just behind the leader
Positions five through ten hold between 9 and 6 records each — close enough together that a small filing push could reshuffle mid-table rank, but far enough behind the leader that none individually controls a comparable share of the space.
Most filers hold only one or two records
Beyond the top 10, the ranking extends to 85 companies total, the great majority holding a handful of filings each. This long tail includes materials specialists, electronics OEMs and university-linked entities filing narrowly on specific formulations or applications.
| Assignee | Recent year | YoY |
|---|---|---|
| Kaneka Corporation | 0 | — |
| PI Advanced Materials Co., Ltd. | 0 | — |
| Resonac Corporation | 0 | — |
| Nitto Denko Corporation | 0 | — |
| Canon Inc. | 0 | — |
| Toray Industries, Inc. | 0 | — |
| Sekisui Chemical Co., Ltd. | 0 | — |
| Hitachi, Ltd. | 0 | — |
Where to take this analysis
The dataset points to a mature, concentrated field with specific technical openings rather than a wide-open one. These next steps narrow from landscape to action.
Map claims against the leader's portfolio
With one assignee holding 52 of 246 records, a claim-by-claim comparison against that portfolio is the fastest way to see whether a planned formulation or process falls inside occupied space.
Explore assignee portfolios in EurekaCheck the under-claimed sub-areas before drafting
Low-Df formulations, colorless PI for foldable covers and sub-0.4% moisture barriers show thinner claim density than the core condensation chemistry — worth confirming before committing to a filing strategy.
Run a white-space search in EurekaWatch the plateau, not just the peak
Filings have flattened since the 2020 peak of 19; because publication lags filing by about 18 months, the next 12-18 months of newly published records will clarify whether that plateau is a real slowdown or a reporting lag.
Track filing trends in EurekaCommon questions about polyimide film patents
Ownership is concentrated at the top: the leading assignee holds 52 of the 246 records in scope, and the top 5 assignees combined hold 109 records (44.3%). The ranking runs to 85 companies total, but positions drop off quickly after the top 10, which together hold 146 records (59.3%). Materials specialists and electronics manufacturers dominate the upper ranks, with a long tail of firms holding only one or two filings each.
Filings peaked at 19 records in 2020 and have trended down since, sitting at 14 by the 2022 midpoint. Part of this apparent decline is a publication-lag artefact: patent applications typically publish around 18 months after filing, so the most recent one to two years in any dataset understate true activity. The plateau visible from 2021 onward is still meaningful, though, and suggests the core chemistry claim space is well-occupied rather than newly attracting filers.
Most claims sit in condensation polymer chemistry (C08G, 71.1% of the 246 records) and polymer processing or solutions (C08J, 60.6%), meaning the film formulation itself is the most heavily claimed layer. Layered-product and laminate integration (B32B) and printed-circuit assembly (H05K) each cover 41.5% of records, showing substantial but secondary activity in how the film is built into flexible copper-clad laminate and circuit boards. Semiconductor-device integration (H01L) and adhesives (C09J) are smaller but present slices.
That filing, from PI Advanced Materials, covers a polyimide film imidized from a polyamic acid solution containing two or more dianhydride components (BTDA, BPDA and/or PMDA) with a diamine component including m-tolidine and PPD, targeting a glass transition temperature of 320°C or higher, moisture absorption of 0.4% or less, and a dielectric dissipation factor of 0.004 or less. It is a useful reference point for anyone targeting that specific combination of thermal and dielectric thresholds, but it does not cover every dianhydride or diamine chemistry route to similar performance — a design-around should focus on alternative monomer combinations that hit comparable Tg and Df targets.
The clearest openings sit in sub-areas that are technically specific but thinly claimed relative to the core chemistry: low-dielectric-loss formulations below 0.004 Df, colorless polyimide for foldable display cover windows, moisture-absorption barrier layers under 0.4%, and adhesion promoter chemistry for flexible copper-clad laminate. These sit adjacent to the densely claimed core condensation-polymer space rather than outside it, so a freedom-to-operate check against the leading assignees' portfolios is still advisable before filing.
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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.