Assignment history — US Patent 6888181

Inventors

Wen-Shiang Liao: Employed by United Microelectronics Corp. at the time of filing.
Wei-Tsun Shiau: Employed by United Microelectronics Corp. at the time of filing.

Original assignee

The original assignee was United Microelectronics Corp. (UMC).
UMC is a global semiconductor foundry, manufacturing integrated circuits for various applications. They have historically developed and offered advanced process technologies, including FinFETs and strained silicon, making it highly probable they shipped products embodying the claims as part of their foundry services. UMC is currently an operating company.

Assignment timeline

2004-02-17 (executed) / recorded 2004-03-18 — Reel 014430/0719
- Conveyance: Assignment
- Assignor: Liao, Wen-Shiang and Shiau, Wei-Tsun
- Assignee: United Microelectronics Corp.
- Correspondent: Tseng, Hsin-Yi, 12F-1, No. 327, Sec. 2, Chung Shan N. Rd., Taipei, Taiwan.
- Context: Standard initial assignment from inventors to their employer.
2021-06-18 (executed) / recorded 2021-07-26 — Reel 056991/0292
- Conveyance: Assignment
- Assignor: United Microelectronics Corporation
- Assignee: Marlin Semiconductor Limited
- Correspondent: Sughrue Mion, PLLC, 2100 Pennsylvania Avenue, N.W., Washington, District of Columbia 20037-3213.
- Context: Transfer of patent ownership from an operating company to a patent asserting entity.

Timeline diagram

timeline
    title Ownership of US 6888181
    2004 : Assigned to United Microelectronics Corp
    2005 : Issued
    2021 : Assigned to Marlin Semiconductor Ltd
    2025 : IPR2025-01082 filed

NPE / troll-pattern signals

Shell-entity transfer: Present. The patent was transferred from United Microelectronics Corporation (an operating company and semiconductor foundry) to Marlin Semiconductor Limited. Marlin Semiconductor Limited is an entity that has been targeted by Unified Patents with an Inter Partes Review (IPR2025-01082) related to this patent, indicating its engagement in patent assertion rather than product manufacturing.
Known asserter in the chain: Present. Marlin Semiconductor Limited is a known patent asserting entity. Unified Patents, a defensive aggregator that targets NPE assertions, filed IPR2025-01082 against US6888181, naming Marlin Semiconductor Limited as the patent owner.
Repeat correspondent across the chain: Not present. The two assignments in this chain involved different correspondents: Tseng, Hsin-Yi for the initial assignment and Sughrue Mion, PLLC for the transfer to Marlin Semiconductor Limited.
Cascading transfers: Not present. There were only two assignments in the chain, spaced approximately 17 years apart, which does not indicate cascading transfers.
Pre-litigation transfer: Not present. The assignment to Marlin Semiconductor Limited was executed on June 18, 2021, and recorded on July 26, 2021 (Reel 056991/0292). The IPR case (IPR2025-01082) was filed in 2025, which is more than six months after the transfer.
Bankruptcy fire-sale: Not present. There is no information indicating that United Microelectronics Corporation filed for bankruptcy.
Privateering: Unclear. While the patent was transferred from an operating company to an NPE, there is no public information or explicit evidence to confirm that this transfer was part of a privateering strategy where UMC commissioned Marlin Semiconductor Limited to assert the patent on its behalf.
Defensive aggregator (anti-NPE): Not present. The current assignee is Marlin Semiconductor Limited, which is an asserting entity, not a defensive aggregator.

Verdict

NPE — high confidence
This verdict is based on two strong signals: the transfer of the patent from the operating company United Microelectronics Corp. to Marlin Semiconductor Limited constitutes a shell-entity transfer, and Marlin Semiconductor Limited is a known patent asserter, as evidenced by Unified Patents instituting an IPR against this patent with Marlin Semiconductor Limited as the patent owner.

(Verification link: https://assignmentcenter.uspto.gov/)