The Patent Finder
US

Method for Etching a Tapered Bore in a Silicon Substrate, and a Semiconductor Wafer Comprising the Substrate

US 7,531,842 Term ended
OverviewFamilyAssignmentsSources & methods

Term ended Mar 29, 2025 · High confidence

Filed Oct 22, 2004 as application 10/971,849 · Granted May 12, 2009
Base term plus 158 days of patent term adjustment (USPTO delay)
Today
20 years from filing
Term ended Mar 29, 2025
2004 2026
Clock starts
Oct 22, 2004
Term ended
Mar 29, 2025
Granted
May 12, 2009
base term patent term adjustment after the term ends fee events Updated Nov 15, 2026 · includes USPTO assignment & status data published Nov 15, 2026 and grant & fee data published Nov 10, 2026 (weekly) · how we know
158
Days of term adjustment
Read from the USPTO patent term adjustment record, not recalculated here.
None
Terminal disclaimer
No disclaimer on this record.
3 of 3
Maintenance fees paid
Three maintenance fees fall due, at 3.5, 7.5 and 11.5 years from grant. This counts the ones the record shows paid.
33
Family applications on record here
Applications sharing this one's continuity chain whose file history this site holds. The family may have others.

This patent's term runs 158 days past its 20-year base term on prosecution delay. All three maintenance fees were paid, so no fee lapse ended it. Confidence: High. from the record

How we calculated this date

One row per rule, each showing its own input and what it did to the date. A step we could not verify says so instead of resolving itself.
StepInputDate after this stepConfidence
Base term, 20 years from filingClock starts Oct 22, 2004, when this application, 10/971,849, was filedOct 22, 2024High confidence
Continuity chainEvery parent in the chain resolvedno changeHigh confidence
Patent term adjustment+158 days, USPTO patent term adjustment recordMar 29, 2025High confidence
Terminal disclaimer capNone on recordno cap appliedHigh confidence
Patent term extensionNone on fileno changeHigh confidence
Fee events3 of 3 maintenance fees paidterm endedHigh confidence
Computed term endThe steps above, in orderMar 29, 2025High confidence

This family

US 7,531,842this patent
Mar 2025
Mar 2025
US 7,598,841In force
Apr 2027
Apr 2027
US 7,667,323Term ended
Apr 2026
Apr 2026
Application 11/353,359Abandoned
not computed
not computed
US 7,233,120Term ended
Feb 2026
Feb 2026
US 7,897,920In force
Nov 2026
Nov 2026
Application PCT/US2006/036666PCT application
no patent term
no patent term
Application 60/871,175Provisional application
no patent term
no patent term
8 of 33 applications in this family shown, earliest filings first. The applications whose file history this site holds. The family may have others.

Assignments

Assignment documents as recorded at the USPTO, oldest first, with the reel and frame each was recorded at. A recorded assignment is a filed document, not a statement of current ownership, and the absence of a later one is not evidence that the last one still stands.
RecordedAssignorAssigneeConveyance
Apr 6, 2009
Reel 22507, frame 504
Gormley, Colin StephenAnalog Devices, Inc.Assignment of Assignor's Interest

Sources

Google Patents · The patent document at USPTO · Assignment records at USPTO

USPTO account required: This application in Patent Center · USPTO's maintenance fee lookup

Maintenance fee events come from USPTO's own fee records. Its fee lookup asks for the patent number and the application number.

The Patent Finder CompaniesExpirationsCalculatorWatchlistPricing MethodologyCorrectionsLegalPrivacysupport@thepatentfinder.com Updated Nov 15, 2026 · includes USPTO assignment & status data published Nov 15, 2026 and grant & fee data published Nov 10, 2026 (weekly) Part of 137 Finder · © 2026 137 Finder LLC · Sources cited