A MEMS microphone patent typically claims the finished transducer — its diaphragm, backplate and acoustic response — and is classified under H04R, which covers 47 of the 49 families in this dataset. A MEMS fabrication patent claims the manufacturing steps themselves, such as surface micromachining or a specific etch sequence, and falls under B81B or B81C. In this corpus only 12 records carry the manufacturing-specific B81C classification, meaning most applicants fold their process steps into a transducer claim rather than filing on the process alone.

The dataset shows filings rising from a single family in 2017 to a peak of 7 in 2021, then falling back to 1 by the 2022 midpoint. This pattern is typical of a field where the core fabrication routes — backplate/diaphragm processing, surface micromachining, CMOS-MEMS integration — were staked out early, after which applicants shift to defending existing claims rather than filing new foundational ones. Note that 2025–2026 figures are understated because publication lags filing by roughly 18 months.

The most-cited records in this corpus trace to a single family of 2004–2005 filings on flexible MEMS transducers and their manufacturing method, cited well over 100 times by later filings. A separate 2013 family (US20150158722A1) on MEMS acoustic sensors and fabrication methods is also heavily cited. Any new backplate or diaphragm process claim should be checked against these families first, since they anchor the citation graph for the whole field.

Yes, based on the IPC composition: manufacturing-specific classifications (B81C, B81B) are present in fewer than half of the 49 tracked families, while audio-transducer classification (H04R) covers nearly all of them. That imbalance suggests process-only claims — on backplate perforation etching, wafer-level CMOS-MEMS bonding, sacrificial-layer release chemistry or diaphragm stress-relief structures — are less contested than transducer-level claims. Filing momentum has also gone flat across every major assignee in the latest tracked year, which can mean either that incumbents have paused or that a niche is open for a new entrant.

The tracked assignee set includes both Chinese manufacturers and international incumbents such as Knowles, Goertek, Samsung Electronics and Robert Bosch, alongside smaller specialist filers. Co-filing is uncommon — only 10 co-assignee pairs appear across the 49 families — and the strongest pairs link individual manufacturers to university research institutes rather than pointing to an industry-wide alliance. None of the named top assignees show a filing in the latest tracked year, so leadership in this dataset reflects historical portfolio size rather than current filing velocity.