Cleaning Method and Etching Method
US 6,939,409 Lapsed on the fee recordLapsed Sep 6, 2017 on the fee record · Medium confidence
20-year base term ended Dec 18, 2020
Why Medium: A terminal disclaimer is on file (approved) with no resolved reference, so the term may end earlier.
Third maintenance fee unpaid; grace period ended.
Dec 18, 2000
Sep 6, 2017
Sep 6, 2005
Dec 18, 2020
How we calculated this date
| Step | Input | Date after this step | Confidence |
|---|---|---|---|
| Base term, 20 years from filing | Clock starts Dec 18, 2000, when the earliest non-provisional application in its chain was filed (this one was filed Jul 23, 2003) | Dec 18, 2020 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | None on file | no change | High confidence |
| Terminal disclaimer cap | Disclaimer on file (approved), reference document not resolved | no cap applied, and none guessed | Medium confidence |
| Patent term extension | None on file | no change | High confidence |
| Fee events | 2 of 3 maintenance fees paid | lapsed Sep 6, 2017 | High confidence |
| Computed term end | The steps above, in order | Sep 6, 2017 | Medium confidence |
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.
Not on this page: the patent's family, its recorded assignments and its citation count. USPTO's assignment records, linked above, list every recorded assignment.
Every date shows its work: the base term, any term adjustment or extension, any disclaimer cap, and the maintenance fee record, each with a confidence tier. How this record was built
Computed patent terms end on the dates shown. Related patents and pending applications may cover overlapping subject matter.